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CAE Tools for Car Performance Modifications? 223

Posted by Cliff from the you-think-that-rear-spoiler-is-cool dept.
RevHead asks: "Although after-market performance modification of cars is a discipline which claims a significant following all over the world, most of the information available on the topic tends to be more of anecdotal nature. To add to this and the plethora of conflicting information out there, most of the tips and techniques tend to be of 'do it and see if it works' type of experimentation. I am interested in the simulation approach prior to actual experimentation to get a decent picture of what to expect during the experimentation phase, which IMHO should be safer and more cost-effective. Has anyone resorted to this approach (successfully) when it comes to engine modification, suspension design, aerodynamic performance and emission control? If so what software is available for these tasks? Which are the most popular/most effective? Does anyone know of any public-domain automotive engine models available for CAE applications such as Catia and ADAMS?"
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CAE Tools for Car Performance Modifications? More

CAE Tools for Car Performance Modifications?

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  • speed prediction (Score:2, Interesting)

    by cybermint ( 255744 )
    The easiest way to validate these types of prediction mechanisms is to feed them only part of your data set and see how well it predicts your remaining dataset. For example, if you have an ocean temperature data set from 1920 to the present, you might start by feeding it 1920-1992 and seeing how well its predictions for then past ten years hold up to you actual data. You may think that the known data set it too small for accurate predictions, but there are some fascinating methods (like ice core sampling and tree growth sampling) that seem to allow pretty good deductions as to past climate conditions over a very long period of time.

  • Does GT3 count? (Score:4, Funny)

    by still_sick ( 585332 ) on Friday June 21, 2002 @07:56PM (#3747174)
    You learn important lessons. That if you ever get a dodge viper, putting in the most powerful NA Tune-up makes it pretty much undrivable. Remember that the next time you're modding your Viper in RL.

  • Rapid Line.... (Score:5, Informative)

    by MrWinkey ( 454317 ) on Friday June 21, 2002 @07:58PM (#3747185) Homepage
    These guys make a great one... Does nearly everything you could want I belive. I do not know if it does engine calibrations but it does most of your design work for you. It's great for engine and suspension building.

    http://www.rapidline.com/calc/

  • DIY EFI website (Score:2, Informative)

    by PsychoKiller ( 20824 )
    DIY EFI [diy-efi.org] is somewhat related, you will find tons of information on fuel-injection systems, with an emphasis on GM products. The mailing list archives go back about 5 years, with people posting from all different backgrounds, including Ford engineers.

  • Darwin awards, here we come... (Score:3, Funny)

    by stienman ( 51024 ) <adavis@@@ubasics...com> on Friday June 21, 2002 @07:58PM (#3747187) Homepage Journal
    Wait, don't tell me - let me guess:

    A friend has come across a few military HARM boosters, you live in the desert, there's an old mine nearby, and you wann see if you can make your big 'ol SUV go as fast as a sports car as quickly... Right?

    You don't need fancy-schmancy software. Just make sure your friend gets the first test ride. And double check the brakes, k?

    -Adam

  • I'm surprised there aren't more OBD-II interfaces (Score:3, Informative)

    by Chairboy ( 88841 ) on Friday June 21, 2002 @08:03PM (#3747206) Homepage
    Modern cars have, almost without exception, OBD-II interfaces. I'm surprised that more people have not made low cost adapters and software to use for doing telemetry and data-logging.

    If you want an adapter, you need to spend over $100, probably over $300. Software can cost the same.

    Where are all the sourceforge projects? Where are all the $20 in parts designs for hooking your laptop to your computer? C'mon!
    • I've wondered this as well. You can get a LOT of information from OBD II. There is a basic interface that all cars have to follow, but each make has it's own extensions that you would need to account for. And since OBD II has been a CARB/EPA requirement since 1996 in all cars sold in the USA, the specs for the basic operation and interface are freely available with a little digging.
      • Check out this link:

        http://www.ghg.net/dharrison/palm.htm

        This guy makes a universal reader for pretty much all makes and models of vehicles, for under $150. This link specifically mentions his version that runs on a Palmpilot - but he also has one for PCs running Windows. I use his "beta" version on a laptop in Windows with my Toyota Supra twin-turbo and it works quite well. Not only lets you see what those "check engine light" trouble codes really are, but lets you reset them, watch your O2 sensor and engine timing, and other nifty stuff.

        I used mine to determine that I had an O2 sensor starting to go bad.
    • It's actually not hard to read ECU ODB-II interfaces -- so easy that a little time spent googling can find howto's -- the big problem is that the code for re-programming the ECU is not available freely.

      If there was a good programmable ECU, like this one [aempower.com], available at less than $1200 that worked with 99% of all new cars, it would be worth buying. The problem with AEM's unit is that they have major difficulties keeping up with automatic transmissions on new cars, so if you own a 2002 auto, no joy for you. Oh, the other problem with them is that they aren't legal for on road use. heh.. but that's a minor setback, neither are half the aftermarket exaust systems that people have on their cars.

      I think I'm going to tell my next car dealer I want an open-source car. :(
      • There was such a thing!

        Software called Kalmaker (www.kalmaker.com.au [kalmaker.com.au]) was written that gives you access to nearly every function of GM Delco ECUs. This ecu was used on a wide variety of cars, from 2 litre 4 cylinders to 5 litre V8's.

        In Australia, where the software was written, the ECU was mostly used on the Buick 3.8 V6, from 1989 to 1997.

        Previously, it was available in a low cost home user version, but is now available only in workshop versions, for around US$600. ECU's themselves are also available, or can be had from wreckers. Many project cars of many and varied configurations have used the re-programmed ECU's to great effect.

        However - the original author never recovered more than a fraction of his time and effort, and the right to sell Kalmaker has passed through many hands and liquidation sales. Even at prices much less than programmable ECUs, there's apparently not a large enough market to sustain such a thing.

        Additionally, if you're interested in a more rational approach to car modifications, allow me to heartily recommend Autospeed [autospeed.com]. Well worth the very low cost, and there's a large number of free articles. A wider ranging Tech Journal, that should be of interest to Slashdot readers will be launched soon... I'm excited.
        • Actually, I drive an Acura RSX. The Fuel Injection system in that thing is @#$%@#$ restrictive as hell out of the factory. I've yet to see any software to edit the ECU in the Integra or RSX, replace the unit, yes, modify the existing, no. And replacing it is the part that violates Californian (CARB) laws here in the US.
      • id be very interested in knowing how the law does or should apply in this situation .. are car companies held responsible for bugs? hobbiests?

        this is one of the first situations that I know of where the result of bad programming on the party of a hobbiest could really fuck shit up physically ... and are you talking about using the car on tracks or my streets? :)
      • The AEM unit is ~1500 for the "plug n play" and projected ~1200 for the "race" version. The race version has the same ECU with just a different harness (generic/make your own) and no base fuel/timing map.

        Auto tuning is as much of a science as anything else. I know lots of people that figure out suspension changes (spring rates, sway bar thickness, etc) with their own spreadsheets. Fuel/timing programming is pretty straight forward. There are some basic rules that follow when making more power out of an internal combustion engine. The "try and see" is more for unknown new parts, modifications to stock parts, etc. This is mostly for pepole that don't otherwise have the "proper" equipment of a flow bench, dyno, wideband O2 sensor, fine control over fuel/timing maps and so on.

        BTW http://www.sema.org/ Look up the Magnusson-Moss act. Also... anything after the cat is fair game, fed laws don't cover anything past that.
    • Generally, the interfaces to the OBD-II computers are proprietary... thus forcing you to go to the dealer to get rid of that annoying "Check Engine Soon" light on post 1995 cars. Someone once told me the diagnostic "computer" for late model BMWs, which probably has all of the computational power of your average Palm Pilot, costs around $30,000 (note: could be totally wrong, this was a pretty old conversation I'm trying to recall).
      • Someone once told me the diagnostic "computer" for late model BMWs, which probably has all of the computational power of your average Palm Pilot, costs around $30,000

        Actually, by the time they fail you are probably looking at just a few thousand max, but bitch about that price, realize taht in addition to the computational power of a Palm Pilot, it is also designed to withstand extreame temperature conditions (Northern Alaska to the Middle of the Desert), dust, dirt, mud, rain, etc... Oh, yea it also is very tested to ensure that it won't fail even as the systems around it do...
    • The problem with OBD-II isn't the interface. There are $20 designs out on the net that work. The problem is that the protocol spec costs money. Any work that has been done on the software side was done via reverse engineering. The car companies are very tight lipped about their systems, and the automotive spec associations are paid lots of money to keep the information close to their vest. I don't believe you can buy the spec and just go posting it around, as that would violate the agreements you sign to get the information.

      You can get commercial All-in-one readers for $350, less for specific car models. These will read out data, error codes, and reset the service lights, etc.

      • Re:I'm surprised there aren't more OBD-II interfac (Score:1, Informative)

        by Anonymous Coward
        The ODB-II spec cost $85 from SAE and the shop manual for most cars has the rest of the information you need. Now shop manuals are a bit hard to find, but a little googling and you should be able to find one for your car.

        I have the SAE book and I have ordered the shop manual for my car (will be delivered in a week). I also have an order in for a DeltaDash unit (an excellent OBD-II interface and software which works with most any Subaru), but the dealer is out of stock.
    • Try http://www.obd-2.com/

      OBDII Automotive Scan Tool and Virtual Dashboard
      for '96 and newer cars, suvs, trucks, motorcycles

      Car Code OBD-II On Board Diagnostics Phase 2 Vehicle Communications

      * Why is your Check Engine Light on? Simply plug-in to OBD2 connector
      - Analyze trouble codes, performance and maintenance real time data logging.
      - Design your own virtual dashboard instruments.
      - Direct private, secure, fast digital connection from car to your personal computer.

      * Free Vehicle Explorer 1 software browser, data files and upgrades
      - Supports EPA ARB SAE ISO open source and code standards for automotive networks.
      - Can be used off line when not connected to your cars OBDII local area network.
      - Does not use phone, modems or Internet. No monthly connection fees, contracts or rebate coupons.
      - Does not violate warranty, emission regulations or modify performance. No decryption needed.

      * Browser Features
      - View up to 31 sites in your car, send and receive messages, down load data.
      - Analyze over 256 possible [data] variables from your car in real time or [freeze frames]
      - Check and reset over 200 [trouble codes], analyze [test] results, view [sensor] data.
      - Trouble code alarms and auto [monitoring] request timers.
      - [x] or [y]strip chart, [3-D]and bar graph with 10 power auto or manual zoom.
      - Report generator, real time [comments], data base and printouts.
      - 6 gauge designer[Dashboard] supports over 70 instruments including 16000 RPM tach.
      - Up to 13 years of continuous data storage and Play back flight recorder.
      - Used in EPA CARB OBD2 development since 1995. Vehicle certification available.

      $130 for kit (software + cable), slightly less if you want to make the cable yourself.
    • For your Audi or VW you can use the VAG-COM [ross-tech.com] software. You're able to read and write not only the OBD-II but also audi/vw specific stuff.

      There are actually a lot of people (GIAC [giacusa.com] for one) who are reprogramming ECUs to enhance performance. But it seems like most of them are manually tweaking various mappings.
      • Bet yer a Vortexer [vwvortex.com] too, eh? ;>
      • I spend enough of my life hitting refresh on Audiworld without running into that stuff here too! Slashdot is where I go when I have to stop thinking about the tradeoff between a house and K04's.

        Anyway, I did have a reason for replying. VAG-COM doesn't do OBD-II, it just identifies if the functions exist on the car. You need other OBD-II software, although the interface cable will work with them. You might be able to do something simple like clear codes, but I'm not sure you can even do that.

        Also, GIAC (via the engineers at AWE and PES), as well as companies like APR do a lot of extensive engineering well beyond simple remapping. Garret Lim is in a slightly different position of not actually doing any engineering himself -- he's purely a software guy, but he works very closely with the engineers via data logging to tune.

        Oh well, time to go hit refresh on Audiworld.
    • They're kind of slow aren't they? What's the sample rate on OBD-II interfaces? It seems like more professional data acquisition devices talk directly to the sensors rather than being mediated by the ECU or even the OBD-II port.
    • works great. I have the model for the earlier non odbII Mitsubishis but the odbII version is similar. $170 plus your Palm 3.0 os or better machine

      pocketlogger [pocketlogger.com]

      ---
      Tim
      '92 Gvr-4 #893/1000
      '91 Gvr-4 #?/2000
      If you have to ask, you dont need to know.

  • Computerized Car Mods (Score:3, Informative)

    by stevegee ( 587306 ) on Friday June 21, 2002 @08:07PM (#3747220)
    There's some software here:

    http://www.gmecca.com/byorc/

    though I doubt that it'll do what you're looking for. AFAIK, there's no one who's able to put together detailed enough models to truly simulate a production car.

    For example, if you wanted to see the result of changing spring rates, you'd need to know the exact suspension geometry and parts, materials information on the metals used in the arms, flex characteristics of all bushings, assumed frictions of all moving parts, and likely more stuff (I'm not an automotive engineer, I just play one on the weekends). And this likely would be one of the more simpler analyses.

    For example, I would guess that modelling properly something as commonplace as an exhaust replacement would be ridiculously complicated. Since you'd be optimizing flow through the engine, you'd need to understand flow details of all the components in the stream. I can't see any of the auto manufacturers releasing this information to the public, or any way for budget-limited hobbyists to obtain it.

    Finally, you could probably forget aerodynamic modelling without a 3-d CAE model. That's all black magic there. I have, however, considered putting the 1:18 scale model of my car into a 1:18 scale windtunnel...

    -sg
    • I guess one really needs to look at the problem and figure out if your really need all those and other variables in the model.
      There was a great example of this in economics, matmaticians spent years attempting to model market performance, so they could properly price options. The equation took everything in to account, and was pages long.
      Finally a few guys figured out that most of the variables effectively cancelled each other out, and came up with a five variable or su equation that could accurately plot market performance and stock option prices in real time at any resolution (continuous time).

      The auto manufacturers do use super computers to model the fluid dynamics through the intake, compustion and exaust systems, but starting with the basic functioning and building a rough model would probably allow an modder to determing if putting a larger turbo on would add any torque, or if a larger intake and exaust system would be necessary first.

      What I do find humourous many times is all these tweeked Toyotas with all the laughable stickersand emblems that smoke their tires off the line. They whole point of the engine mods is to get the powet to the pavement to move the car, or so I thought. Making pretty white smoke and noise I could do with a small windshield pump and brake fluid installed on the drive wheels of any vehicle.
  • There really isn't too much wrong with trial and error, unless you end up blowing your engine up!

    I know a guy who makes headers for Miata... his first design attempt at the making the header was based on past experiences with headers on rotaries. He went with the first design, after he tried 10-20 other pipe configurations, based on other educated guesses. None of which provided the overall better improvement in the torque curve and horsepower band that the 1st design, based on the long lasting design for the rotary header, provided.

    As for publically available CAE for engines... You'll never get designs directly out of the major automotive companies. most of the animations you see on the web now are based on taking an engine apart, measuring tollerances, and drawing them up in a CAD program.

  • try a new cpu (Score:3, Funny)

    by brer_rabbit ( 195413 ) on Friday June 21, 2002 @08:21PM (#3747278) Journal
    All cars these days have microprocessors of some sort inside of them. These control anti-lock brakes, cruise control, etc etc. Lots of these are processors are small 8 bit micros, like the Motorola 68HC11. These chips run at only a few megahertz, and are very slow by todays standards.

    One thing to try is overclocking the CPUs. But I doubt you'll get more than 8 or 10 MHz out of one of those things. What I'd suggest is reverse engineering the car's electronics. If you could drop in a new AMD processor in there and get a big performance enhancement.

    ok, I'm kidding. But you think hot rodding a '97 Honda Civic with a boat spoiler is any less a waste of time and money?
    • "If you could drop in a new AMD processor in there and get a big performance enhancement."

      Wouldn't that drastically dim my headlights?
      • You can go to your local car mega-stereo shop for alternator upgrades, so electricity shouldn't be a problem.

        I'd worry more about improving the car's cooling system to handle the heat...

  • Results are only as good as Input (Score:4, Informative)

    by grandpohbah ( 174190 ) on Friday June 21, 2002 @08:22PM (#3747280)
    As I'm sure you've figured out, predicting performance can be excruciatingly difficult on a system as complex as an automobile - this is why extensive testing still ensues all designs in the Automotive world, but that doesn't mean that the commercially available CAD/CAE tools available aren't useful, just that there are too many variables and too little available computing power to model up a whole car and know exactly how it will perform.

    Balpark numbers on subsystems can be had with some general purpose CAE design tools(Pro/Mechanica, Dynamic Desiner Motion, Visual Nastran, & Working Model are most common). If you are running on something less than a Cray, these will all require you to simplify your desings - thus the ballpark numbers. I'm looking forward to the day that I can open up a multithousand part assembly, run an FEA project, and have results in less than an hour - all on my desktop workstation. Right now something as simple as a MiniBaja vehicle or FormulaSAE chassis can easily take over 16hrs to run through a single FEA solution on a modern dual processor X86 system. BTW - if you are still in college, SAE Student competitions are a fantastic way to get some experience on how to make a car go.

    A great tool that is known to produce very accurate predictions for engines is Desktop Dyno (sorry URL not handy). But again, it wants simplified parameters (not physical geometry), so the program will only be as good as the numbers you feed it, on the plus side it has a good part database so aslong as you stick to COTSH you will get accurate results.

    MathCAD and Mathmatica are also very useful, but requrie strong engineering knowledge to be useful, again it all comes down to the results being only as good as the numbers you feed it.

    The two big ones you mentioned (Catia and ADAMS) are also fantastic tools, but are both expensive and complex enough that unless it's your job (and you get constant training), you probably won't ever become useful with them - The world of mechanical simulation isn't as well documented at the book store as even the most obscure programing methodologies.
    • Regarding Catia, it's not too difficult to learn. The same holds for Unigraphics and IDEAS. I've used them all during an internship one summer. If you are a techie, then you'll be able to pick up enough skills in ~3 months to out-design most designers (not engineers. I said designers).

      I found all three relatively easy to learn. The problem is having things to design with them. If it wasn't for a constant inflow of air-intake manifolds (which have very complicated geometries) that I needed to design, I wouldn't have learned the tools as fast.

      If I had one of those top 3 design packages installed on my home PC, then I never would have learned them since I didn't *have* to design complicated geomtric parts.

      As far as using these tools to test/design parts for your cars, I don't think it would be worth your time. If you could possibly get the files from Ford/GM/Whoever for what it looks like under the hood, then you might have some hope of testing out different variations of things. As far as things stand, under the hood is *extremely* cramped and you can never know the exact geometry of the cylinderheads in order to design/test an optimal air-intake system. Each air intake system is designed custom for each engine. It's hard to get better performance by altering the design *except*...

      ...many aftermarket parts mimic the design of the OEM part, but use better/lighter/stronger materials. For example, the inside of a Ford F150 sand-cast aluminum air intake manifold is rough, worse than sandpaper. By substituting this manifold for an aftermarket nylon-glassfiber-composite manifold, you will get a significant benefit. This isn't because the shape or design is anybetter, it's because the air flows easier through the plenum of the nylon manifold than it does in the rough-finished aluminum manifold.

      This is an advantage that you don't need CAE to *test*. You just know that ligher/stronger/smoother-surface = better performance.

      I'm done rambling for now.

  • Automotive engineering is science (Score:5, Informative)

    by Y2K is bogus ( 7647 ) on Friday June 21, 2002 @08:23PM (#3747284)
    You make a lot of assumptions.

    I know plenty of auto related companies, and I can tell you that it's far from "guesstimation". They don't just go off half assed and do something, there is a lot of engineering principle behind their products.

    You asked about aerodynamics, engines, and mechanicals. In each of these areas there is a lot of work.

    Aerodynamics is one of the most visible parts of design, and there is very little in the way of guessing (except, umm, for those tasteless wings and stuff that people put on their cars). A good source of information on Aerodynamics can be found via books. Specifically:

    Fiberglass & Composite Materials: An Enthusiast's Guide to High Performance Non-Metallic Materials for Automotive Racing and Marine Use
    by Forbes Aird

    Aerodynamics for Racing and Performance Cars
    by Forbes Aird

    Competition Car Downforce: A Practical Guide
    by Simon McBeath

    Race Car Aerodynamics: Designing for Speed
    by Joseph Katz

    I have the Aird books, and they're very good.

    Mechanical engineering is well understood and followed, especially by Cal Poly. The FSAE contests are a great proving grounds for designs.

    Books by Forbes Aird and Carroll Smith are really good points to start with. The Smith books are phenomenally thorough and put you in awe. That guys has FORGOTTEN more, than most people KNOW. The Aird book is more down to earth and easier to read than the Smith books, both authors are tremendously entertaining.

    Here are some books:

    Race Car Chassis: Design and Construction
    by Forbes Aird

    Tune to Win
    by Carroll Smith

    Carroll Smith's Nuts, Bolts and Fasteners and Plumbing Handbook
    by Carroll Smith

    Engineer to Win: The Essential Guide to Racing Car Materials Technology or How to Build Winners Which Don't Break
    by Carroll Smith

    How to Make Your Car Handle
    by Fred Puhn

    For engines and mechanical systems, I find that periodicals on the subject are very informative. I learned most of what I know about engines from reading Mustang magazines. There are books out there on rebuilding engines and performance.

    Here are some good books:

    Turbochargers
    by Hugh MacInnes

    Mustang Performance Handbook : Engine and Drivetrain Modifications for Street, Drag Strip or Road Racing Use. Covers All Models of the Ford Mustang, 1979 to present.
    by William R. Mathis

    Ford Fuel Injection & Electronic Engine Control : All Ford/Lincoln-Mercury Cars and Light Trucks 1988 to 1993
    by Charles O. Probst

    Fuel Injection: Installation, Performance Tuning, Modification
    by Jeff Hartman

    And finally, if you want to do engine simulation on the bench, err, computer, check out Desktop Dyno 2000. It's from Motion Software, costs $50 with the Cam-Disk CD (over 2000 cam profiles). It's a great program, however like all software, garbage in, garbage out. If you expect to get reasonable data from the program, you must supply it with reasonable data.
    • Race Car Aerodynamics: Designing for Speed
      by Joseph Katz

      Any relation to our famed Slashdot writer?

      Racing a car is difficult in today's society. Certain things need to be taken into account, for example, aerodynamics. What some people don't understand is that aerodynamics effect how the car reacts to large gusts of wind. But aerodynamics are not only significant when designing, but racing too.

    • You forgot one! (Score:4, Funny)

      by GuyMannDude ( 574364 ) on Friday June 21, 2002 @08:33PM (#3747316) Journal

      Race Car Aerodynamics: Designing for Speed
      by Joseph Katz

      Don't forget:

      21st Century Automotive Engineering: CAE In The Post-9/11, Post-Columbine Era
      by John Katz

      There goes some karma for sure... :)

      GMD

    • If you are at all serious about high performance automobiles, you HAVE to get all of the stuff by Carroll Smith. The absolute Bible, Talmud, Book of Saloman, Koran, whatever, of 4 wheel fastness! Read and put to use, and you will do better than 80 percent of those that do this for a living. Believe me!

  • sale modification (Score:2, Insightful)

    by alan_d_post ( 120619 )
    Instead of fixing up the car, modify your life by getting rid of it entirely. You will learn patience and calm as you wait for the bus. Seriously! You will also be able to read more. Less stress, more thought, all good! No simulation needed!
    • "Instead of fixing up the car, modify your life by getting rid of it entirely. "

      The problem with your logic is that you don't gain any new knowledge or experience by 'waiting for the bus'.

      You don't modify your car to get from Point A to point B faster, you modify your car to get the most out of it that you can.

      It's called a hobby. If you were to take up one or two of those, you might avoid making such embarrasing comments.
      • The problem with your logic is that you don't gain any new knowledge or experience by 'waiting for the bus'.

        I disagree completely, but have no idea how to convince you. Do you never read, or think?
        • "I disagree completely, but have no idea how to convince you. Do you never read, or think? "

          You could start by explaining why you completely disagree. It's easy to 'never read' what is 'never said'.

      • Re:sale modification (Score:2, Insightful)

        by xinu ( 64069 )
        "Instead of fixing up the car, modify your life by getting rid of it entirely. " The problem with your logic is that you don't gain any new knowledge or experience by 'waiting for the bus'. You don't modify your car to get from Point A to point B faster, you modify your car to get the most out of it that you can. It's called a hobby. If you were to take up one or two of those, you might avoid making such embarrasing comments.
        Ah but you do gain knowledge reading a book while waiting for a bus, opposed to concentrating on driving.

        "Getting the most out of your car" isn't going to be gas mileage, it's handling and speed.

        Embarrasing comments? I think he made a valid point. I'd reasses who made the silly comment.

        Nor do I see how having a hobby or multiple hobbies prevents one from saying stupid stuff...

        I can't believe you got modded up for such a troll.

        • Re:sale modification (Score:3, Interesting)

          by NanoGator ( 522640 )
          "Ah but you do gain knowledge reading a book while waiting for a bus, opposed to concentrating on driving."

          You can read all you want, you don't gain experience by reading. Just information. You can read a book about how cars can be modified all day, it's nowhere near as useful as actually doing it. If it were that good, you could get a good paying job straight out of college.

          "Getting the most out of your car" isn't going to be gas mileage, it's handling and speed." -- I didn't say mileage, I simply said the best. I didn't leave a word out. Some people tweak for mileage, some tweak for performance, some tweak just to figure out more about how it works.

          "Embarrasing comments? I think he made a valid point. I'd reasses who made the silly comment." -- No he really didn't. If this had been a thread like "what kind of car should I buy?", then yes he'd have had a valid point. In this case, he went into a thread and said "you'd be better off not pursuing your interest and learning to live without it." Sorry, I don't see that as a valid point. When I challenged him on it, his response was basically that he didn't feel like explaining it to me. I think it's funny that you think I'm the troll because I challenged him. You should really look at his post and think about what a car afficiando (sp?) would think of that remark.

          "Nor do I see how having a hobby or multiple hobbies prevents one from saying stupid stuff..." -- heh. Didn't take any time to brainstorm, didja?

          Well, I won't get into the insulting comments I could have made, but I'll keep it to the point: If you have a hobby, then you know what it's like for somebody else to be fascinated with something. For example, I don't get Linux. I tried it, didn't like it. But when a story like 'Linux can play Sorenson videos', I don't jump in and say something stupid like "I have a better solution for you guys, use Windows."

          That's basically what the parent poster did. He could have regained some respect from me if he had made a valid point. I don't think he had one, though. I think he just went karma whoring by saying the opposite of what other people were saying.

          Of course, if he had provided a reasonable response, my attitude about that could potentially be different.

          oh well. I have a tip for you though: A troll doesn't take the time to explain himself. Ponder that before you call me one again.

    • Getting rid of the car in your life - Good Idea.

      Taking a bus - Bad Idea.

      Public buses are dirty, uncomfortable, take too long, and are filled with people you don't want to be around.

      Tim
  • Call me a skeptic, but car mods come in two forms:

    Mass market canned solutions. Someone else does
    the engineering for you, and you bolt it on. I'd
    bet 75% of the mods fall into this catagory. Even
    for "complex" things like suspension or engine
    tuning, most people bolt on something with some
    (limited) adjustment.

    Fully custom solutions, built from the ground up.
    Believe it or not, some people still build their
    own engines / suspension / body, etc. In general
    these follow old positions, carburators insted of
    EFI and the like.

    So, your average home buyer can plunk down $$$'s
    for a prebuilt solution, complete with knowing
    what performance increase they can get. Or they
    can custom engineer something, which probably
    requires more knowledge than something simple
    a off the shelf program can come up with.

    In the end, I see little opportunity for what you
    suggest.

  • Not very practical... (Score:1, Interesting)

    by 8Complex ( 10701 )
    Being an engineer and also a big fan of vehicular modification in the mechanical sense (no big wings for me until I can do 180+mph) I can say that CAE is far too complicated for the average to even above average tuning facilities.

    Coming across 3d models of motors is quite impossible unless you work as an engineer or in IT at an automotive manufacturer's design facility. You don't give out your secrets, you know. :)

    The best method that most places come up with so far is to follow the simple principles of making power. Unfortunately you have to get deep into the understanding of all the principles around making power to really get these principles. Yeah, you can strap on a turbo or supercharger and gain big HP or big torque, but for that matter you could make the same horsepower by bumping the compression and/or using higher octane fuels, or even nitrous (FYI: NOS, or as my friend's and I call it, NAWWWSSSS!!, is a brand name, not an individual item).

    The trouble with all power adders is keeping the motor together mechanically. Some motor are built to handle it, others are not. If you have a motor which is not built to handle it, you have two options - 1. build up the motor so that it can handle it, or 2. switch to another type of motor. Building motors can be VERY costly, the most mild build, which would be a simple piston swap, costing $300-400 if you perform it yourself. The most expensive... well, just let your imagination wander since there are motors out there that cost $1M+ to build, like in CART and F1 race cars.

    Well, back onto topic :

    No, models are not available for CAD programs.
    Yes, it is possible, but extremely hard to account for all variables
    Sure, I could tell you how to make a 2.0L motor run 900 horsepower, but it'd cost you a fortune to build. :)

    - 8Complex
    • Actually, if you are dumb enough to just strap on a supercharger or turbocharger (they still make these for non-diesel? What's the point!) you will most likely blow a valve out the head, or shatter you cam or crank! you need certain things replaced in your engine before slamming 5-50x the airflow and fuel in! Besides, if you have money for a supercharger, why not go with a bigger cam, stronger rockers, flat top pistons (or domed pistons), better rings... porting and polishing the heads and a header exhaust system... Hell, you could bore and stroke it and get more than your "slap on a supercharger" and you'd have a stronger motor.
      As for changing to high octane gas, DON'T! The octane rating is trivial most of the time (low to midgrade is best for most cars); if you increase your compression of course, you'll want to go higher octane...

      As for the "least expensive" My Camaro started with a 305 G motor (High output). It's now a 327 stroker with 3" exhaust, I pull mid 12's in the quarter mile, and it's streatable. (about 370 HP). I used the stock block, replaced the cam crank, lifters, pistons, rings, bearings, intake and carb, timing setup, and HEI. The total cost (built it in my garage) was about $800 and that was because I went with alot of crome and forged parts (if all I had done was use forged pistons, clevite bearings, and molly rings, it woulda' cost about 250), and had everything temp treated so that, if in the futue I want to, the engine can handle a 300+ HP NOS boost.
      It took my dad and I about 40 man hours (one weekend, two twenty hour days with both of us working); that was from engine-out to backing outa' the driveway. (average engine swap time for us in the camaro is about 1 hour each way).

      And, 2.0 at 900? never seen that! Not even on the little foreign cars... what would the point of that be? you'd have to rebuild the tranny, replace ALL of the suspension parts, etc.

      It's actually easy and pretty cheap to build up a car to outperform a stock, or even most NASCAR cars. But, for 3d CAD, your SOL!
      • 900hp out of 2.0l has been done. You just get a REAL short time between overhauls. 900 isn't even pushing it that hard - As someone else said, look at the Mid 80's F1 cars (Before rule changes) - they were in the 1300hp range. It all depends on how fast you want to use up engines. If all you want is a couple of hours out of the engine before you throw it away, there are all SORTS of tricks

    • Building motors can be VERY costly, the most mild build, which would be a simple piston swap, costing $300-400 if you perform it yourself. The most expensive... well, just let your imagination wander since there are motors out there that cost $1M+ to build, like in CART and F1 race cars.


      Or the old saying "Speed is Money, how fast can you afford to go?"

      Back when the Ford Escort had the 1.9l engine, there was some VERY VERY interesting parts/plans available from Ford - we are talking multi hundred horses, instead of 85hp. There were a few problems of course - cost, legality, and worst of all, lifespan. They told you right off the top that some of these mods were going to get you into the = 500 mile before before overhaul range - aka real race engine class

  • Go work for an auto manufacturer (Score:4, Informative)

    by Anonymous Coward on Friday June 21, 2002 @09:04PM (#3747423)
    You sound way into it.. My suggestion: Go work at the big three.

    But first, hit the search engines. There's so much freakin' info out there now. Also, the SAE technical papers are an awesome resource. However, they are typically expensive. At the big 3, we had the complete set in our research library and I could check them out 50 at a time. What a library..

    Don't miss what is being done in the Formula SAE programs at universities around the country and world (FSAE). That is an incredible program and competition.

    I took a systems job at one of the big three. I'd always had a strong interest in cars, but it grew *way* out of control in that environment.

    I had a $60K workstation and access to all of the goodies - both the commercial stuff and the proprietary code. Today, your average PC has more than enough power to run these types of simulations.

    I used ADAMS Vehicle in those early days for my kinematic suspension modeling.

    Much more interesting to me were the proprietary engine simulation tools. Those were difficult to learn to use, but extremely powerful. Constructing an accurate model is a lot of work. Millions of dollars went into that company's engine sim development.

    I regularly used those tools to study my engine. Serious geek-fest. Most of my geek friends just did NOT get it.. Search for Navier-stokes.

    They had an 'optimizer' for the simulator that would 'wiggle' selected variables and find the best combinations for a particular goal. I found their optimizer somewhat cumbersome and ended up scripting my own (this all ran under UNIX). With this I could optimize valve event timing, and intake and exhaust dimensions. I also decided to develop my own graphing and reporting scripts for gnuplot. Of course all of this was on my own time and was done over a very long period.

    I had wanted to use the CFD tools to model the airflow through my cylinder head ports at a more detailed level, but didn't get around to it before I moved on.. It was just a lack of time (not tools) that prevented me. I had gotten as far as pulling silicone molds of my ports and had them laser CMM'd. Funny thing is, the company did not get around to doing port CFD for another year (had I not been out having fun or something, I might have been the first their).

    Eventually, I moved on :-(

    A year later, I ended up wanting to develop a traction control system for my race car. I decided to simulate it, knowing that such development would likely eat some pistons. I ended up writing an engine and chassis simulator in support of the project.

    This simulator used the torque curve from my engine simulations, dyno runs and data acquisition as input. I used Mitchell's book to develop a simple tire traction model, etc. It was Newton physics coming back to haunt me and probably the funnest program I've ever written. Pretty simple code.

    William Mitchell's _Race Car Vehicle Dynamics_ is considered a modern bible. It is *awesome*. Since the original publication Mitchell has released some of his software. I haven't checked the code out.

    Gordon P. Blair's _Design and Simulation of Four Stroke engines is also excellent. His two stroke book is also considered a bible. I believe he has released simulation code for both.

    Both are available via the SAE.

    Of the two, I consider engine simulation a far more challenging problem. Most of the commercial simulators are *toys* and fairly crude. However, they can still be very useful.

    Of those available, Ricardo's WAVE is reputed to be among the best (definitely not a toy) and is one of the few that would be used by a large manufacturer. Word on the street says it is a ripoff of an early version of a big-3 simulator, but that is just a rumor.

    RaceTech magazine has published some good info on suspension simulation and one of the authors, Mike McDermott is a strong proponent of open sourcing his tools. Here's a link to get you started: http://www.mgbv8.co.uk/frontsus.htm

    Along the way I learned to be a pretty good fabricator and welder. I have a pretty decent metal shop with a large 2 axis CNC mill and a Logan 12x48" lathe. The lathe is in the laundry room.

    I cannot tell you how much this car-hacking improved my skills and abilities as a system engineer and architect. I still believe that the most complex and challenging projects of my career have been on my own race car (and oh BTW, you die if you get it wrong). So I absolutely encourage you to dive in, hit the books, whatever floats your bowl.

    Today, I drive a Z06 Corvette and am Completely satisfied. I can build a car with better performance, but not with the *refinement* that car has. My quicker, faster, more nimble, louder and more violent road race car just isn't the same anymore, big slicks or not :-(

  • UMTRI's simulation efforts (Score:1, Informative)

    by Anonymous Coward
    The Unversity of Michigan Transportation Research Institute has some good tools you may want to look into.

    http://www.umich.edu/~driving/sim.html
  • There is an inexpensive solution to your problem. A CAE system is available that runs on commonplace hardware, and allows the user to simulate many different types of performance modifications. Not only do you get to simulate the effect of the modifications, but you can even test drive the car in virtual reality. As an added bonus, it has an excellent soundtrack while simulating the performance factors.

    Ladies (?!) and Gentlemen, I give you....

    Gran Turismo!

  • I work for a market leading virtual prototyping company (actually we were bought by a simulation software company recently) that has a huge presence in the automobile industry. A lot of production design work is done in the software, and I know the company race teams use the software to prototype concepts for their race machines, but I wouldn't want to spend the money to use it for myself.

    I also happen to drive a well modified Volkswagen GTI, and though I have entertained the thought of modeling my ride in AD^H^Hmy company's software, I prefer the 'do it and see if it works' approach. There is a lot of community out there, especially on the internet, and they can help you find what works, organize gatherings, and generally make the process more fun. Of course, if you want a sub-ten second car, and you have a large checkbook, and you want to learn a complex software system, then....

    But what the hell do I know... I am in IT. Oops. My bad.
  • The advent of computer simulations during the design phase means that car manufactures can design their machines to reach very high levels of performance "from the factory".

    While you used to be able to bolt on an exhaust and put on a cold air intake and expect to see a 20% increase in power, today, if you see 5% you are lucky. Look at the S2000 - 120 hp per liter!

    Most people will never see the 5%. Only if you are lucky enough to hit the track will it become evident.

    Even with regards to suspension, they are designed to match the vehicle's abilities so well now that to get any gains from, say a strut tower brace or larger sway bars, is very hard to achieve.

    I've found though, that "drivability" can in fact still be enhanced. While you are not going to see a big jump in peak horsepower (which doesn't really mean that much), you can get flatter torque curves. Does this make the car faster? Not much, but it makes it more drivable.

    And... a dyno sheet where you can "see" an improvement doesn't always equate to a drivable improvement. You need to test it on a track - straight or curved depending on your desires.

    But... the bottom line is that very few people ever experience they vehicles at even 80% of the "limit", and usually never on the street. So... as they say, YMMV. If you want to tinker, then ignore this reply. If you are looking for a faster car, please consider what I've typed as you might spend a lot of money for little gains.
  • I own a chassis dyno (in PA, Sosnin.com [sosnin.com] for Slashdot discount), and if you recognize my handle, you could guess I am in to cars.

    Several pieces of software exist for simulating car setups.
    However, if you are modding an existing car, your simulations are not going to work very well. You best bet is reading about how others have done with similar mods. Remember that something that "adds 10 hp" on a stock car is not going to add the same 10 hp to something that is already full of mods. Trying parts out on the dyno is your best bet.

    Cheers, Josh
  • You know, first it's "is it possible to build a computer from components" and now it's "how can I make my Sentra Type-R get an extra 10 bhp?"
    Sweet lord... Pretty soon there'll be an Icy Hot Stuntaz topic label. Well, time to subscribe to ArsTechnica.
  • I have seen a few articles in car related magazines quote results from a program called Quarter Pro [quarterjr.com]. At $265 a copy it's a little bit much for the occassional street racer, but for someone who runs every weekend, it could sure save them plenty of time/money/effort in the long run (pun intended).

    My brother, who will soon bring his '85 Cutlass to the track for the first time, may eventually purchase a copy, but until then I cannot give you any personal impressions or simulation vs. real-world results just yet. Unless of course someone would like to donate a copy for review. *wink* *wink*
  • It makes the experimentation so much fun taht you won't bother with a sim.

    Accel has a EFI system for Chevrolet V8 Engines (Wussymoble 4 cylinder drivers are out of luck) That is a blast to tune. You can hook a laptop up to the ECM and adjust it while it's being driven, and save the maps so you can load the map for the performance leveal you need for any given day.

    I Set up a Corvette with 400 cubes, a Paxton supercharger and the Accell EFI. That was a fun filled day. Beat the hell out of simulating it on a PC. The only bad part was returning the car to the owner at the end of the day.

  • What if I were not creating a NASCAR, what if an armature like myself would just like to find a handful of the cheapest ways to extend the horsepower of my stock automobile? For instance: how much horse power could you get by adding a cold air intake system to a 2002 Monte Carlo? I like car upgrade menu that comes with the game Grand Turismo 3, why can't software like that come with the car when you buy it? Or even offered by 3rd party for that make/model car?
  • is a software dyno simulator.(You can buy it at autozone.) If you are into big blocks or older stuff, this is a decent program to show you what a larger cam or bigger pistons would do for power. Be aware you need to know pretty much all the specifics of your engine for this to work for you though. If you are into ricers(as I am...) don't waste your money. The software isn't current enough for our engines. Just get yourself a big fsckin' turbo!

    Can't tell you much else, except that there are a lot of people out there with lots of experience in this stuff. Get on the message boards and ask the guys who are _really_ into this stuff.
  • &gt most of the tips and techniques tend to be of 'do it and see if it works' type of experimentation. I am interested in the simulation approach prior to actual experimentation to get a decent picture of what to expect during the experimentation phase, which IMHO should be safer and more cost effective.

    I'm going to have to disagree with you on this one. In the early stages of vehicle modification, there is such a thing as "paralysis by analysis". In other words, get the basics out of the way first. better flowing Cylinder Heads, Exhaust, Induction, etc. Why spend exorbanant amounts of time & money on software, training, and engineering classes when you could just put the money towards parts?

    On the other hand, let's say you're really hard core about this. You're already making....let's say 450 Horsepower in your "fast & the Furious" style Honda 4-banger. Adding 50 horsepower to a 450 horse engine is going to cost ya tons more than adding 50 horse to a 130 horse engine. Heck, a lot of the parts you buy can be right from a stock motor at a junkyard. Need a bigger throttle body? Grab one from a V6 motor. Need a bigger throttle body for your 450 horse motor? You're gonna have to shell out $300+ because you're not going to find one at the junkyard. My point here is, If you're hard-core, then it might be worth it to spend money on software. It can take years to become an expert on Finite Element Analysis, and even then, we still question our results. Finite Element analysis makes assumptions. Materials are assumed homogenous (same throughout), same grain structure (difficult to model forgings & some stampings), no casting flaws, bad welds, etc.

    If anybody is interested, I plan on doing some FEA work on my own project vehicle [kettering.edu] before my school finds out that I've already graduated and kick me off the system :-)

    I'm hoping to create a finite element model of a Ford Ranger frame to find out what I should do to strengthen the frame on my own vehicle. My '88 Ranger has been upgraded to 89 Mustang 5.0 power but unfortunately the frame has been twisting so much under load that the spot welds on the bed have been breaking. I'll plan on putting a link on my current webpage [kettering.edu] for those of you that would like to follow along. After July 1st, my username will change so check Here [kettering.edu]

  • I recently participated in a 450 member group purchase for the Megasquirt EFI. Two guys: Bruce Bowling and Al Grippo designed and built this programmable fuel injection computer, and provided all of the information for building the EFI: assembler source code, schematics, PC Configuration program, wiring & tuning diagrams, you name it.

    This system will allow you to replace the stock engine management system or fuel inject a carbureated vehicle. The obvious advantage over a the stock fuel injection system is that you can actually manipulate all aspects of the system: fuel curve, startup enrichments, accelerator enrichments, etc.

    Since the group purchase, people have been "megasquirting" everything: new cars, old cars, trucks, Rotary engines (Mazda Rx7), even motorcycles!

    Check out the website. Be sure to look at the PC configurator...

    Megasquirt Home page [bgsoflex.com]
    Yahoo discussion groups [yahoo.com]

    A lot of this information is very proprietary... They've performed a huge service for the community by developing this project. It inspired me to undertake a comparatively modest project of my own: the uSpark ignition controller [picasso.org]
  • One of the best programs out there:
    http://home.earthlink.net/~patglenn/ct.htm l

    It allows you to change hundreds of variables and run several different tests.

    The dos version is at the bottom of the page.
  • Since I have been building hot rods and drag racers since the early eighties, I am of the opinion that if it has to have a computer to run.....the engine is too small to begin with. If you want to go fast....and I mean really fast...get a big block V8 and do it the old fashioned way.

    • get a big block V8 and do it the old fashioned way.

      With you there 100%. Cars and computers shouldn't mix, other than maybe the mp3 player... :) I work on the car to get dirt under my nails and tinker with something non-abstract once in a while. (Currently building a 4.2L MGB ... gonna be one scary go-kart ... )

    • FI is good stuff, especially when you mix in a nice amount of displacement.

      Add some forced induction, and you've got a 700RWHP vehicle that you can still manage to drive on the street (or something along those lines).

      Never underestimate a 383 LT1 running 20psi of boost. :-)
  • A lot of responses to this thread refer to tools for vehicle dynamic simulation, like ADAMS. Many of the folks working in engine and emissions controls are using the Mathworks toolchain - MATLAB/Simulink/Stateflow and perhaps related autocode tools for prototyping. The cost of the toolchain represents a substantial barrier to entry, limiting really substantial modifications to engine manufacturers and well bank-rolled design houses. (e.g. racing teams) Most of the aftermarket fuel system tweaks have been boxes which live on the datalink between the ECU and fuel system control module if they're not integrated in one box. These typically fudge the fueling and timing commands a bit to boost the torque curve - design limits/warranty and tailpipe emissions be damned.

    Serious engine and emission control is pretty neat stuff. In fact, it's what I do for a living, but I'm not sure it's something for the casual tinkerer. It simply requires too much in the way of analysis, design, and test resources to do it properly.

  • The answer is largely "No"... (Score:1, Insightful)

    by Anonymous Coward
    I'm an aero engineer who also happens to be a car nut. It seems like you would like to apply engineering rigor and the computational capabilities commonly available today to get a grip on the real physics behind various car modifications.

    Unfortunately, the answer is that the availability of tools for these purposes to an engineering-minded enthusiast who is not directly affiliated with professional automotive engineering is fairly low. I think some people have posted links to various "desktop dyno" kinds of programs, and that is certainly a step in the right direction, but the fundamental problem is that fields such as aerodynamics are really hard to rigorously model, period.

    To support this assertion, I'm going to ramble for a good while about the aerodynamics aspect of the answer to your question.

    Even in the professional realm (i.e. Aerospace and Automotive Engineering Industries) you have tools such as CFD (Computational Fluid Dynamics), but very few good aerodynamicists in this world will trust CFD solutions on a magnitude-for-magnitude basis. There are a lot of specific cases or realms in which CFD folks can point to their solutions and say "for this aspect of the vehicle engineering, we trust the results of this CFD code" but CFD is never a substitute for wind tunnel or physical testing kind of work in conjunction with expertise & experience. You may say, "well duh, that's obvious, the same is true of computers, etc." and you'd be right, but that "phenonmenon" applies to a significantly higher degree to CFD. Moreover, low-speed, "low compressibility" kinds of flows (IOW "car aerodynamics") are some of the most difficult to model computationally.

    Setting aside all these kinds of "how much do you trust the results" questions, you should also realize that high-fidelity solutions require mighty close attention to the way you model (e.g. physical features -- small features can make a big difference in the flowfield or stress analysis) and "discretize" (grid) your geometry. To put it another way, it requires a *lot* of time and experience to get the most (or even worthwhile) results out of the tools we do have. There are people whose full-time job it is to generate *just the grids* for CFD cases for *one* part of an airplane or aircraft engine, etc.

    After all this, some will correctly point out the "analysis paralysis" problem, and that's definitely the case. If you want your model to capture the vast majority of the physical effects going on, then you'll have to (for the case of an engine for example) get down 'n dirty with seal/friction calculations (e.g. rings, crank seals), structural dynamics (e.g. crank torsion and vibration), reacting and non-reacting flows, and the list goes on... You can probably neglect a lot of these in order to get an answer to a specific topic or modifcation you're exploring, or to get "trends" as you change relevant variables, but if you want to conclusively prove in an engineering sense (via modeling) that some exhaust headers are going to be superior to another design, you'd better be prepared to spend a crapload of time with CFD, solid models, and actual engine hardware to measure the hell out of the relevant parts. Though parenthetically, it's still my personal plan to (once I get the right project car) design my own optimized turbo exhaust manifold with whatever CFD-type tools I can come up with or get access to. I predict the need to do a lot of straight-up control volume analysis in solving that problem as well.

    Or you take the approach that the vast majority of car modifiers do: use experience and intuition (the latter grows with the former) plus any sort of engineering/science background you do have to come up with candidate designs, and try them out. Unfortunately, the results from these kinds of tests frequently lead to theories created by people without the formal background to know whether or not what they postulate really makes sense. That leads to what you describe with conflicting, incomplete, vague, and sometimes logic-defying "conclusions" that are presented to the auto-modifying enthusiast crowd (see the persistent fallacy that you "need backpressure" for an engine to run or run well or "make torque"). Make no mistake, while the analytical/modeling tools we have today may have a hell of cost (in terms of time, money, knowledge) to use, these tools in conjunction with a good engineering understanding of the principles involved will get you a long way there. Which is obviously a part of how groups like automotive race teams with big money make significant advances in car performance.

    So unless you have: the appropriate engineering background, lots of time, access to the software tools and significant computational power, access to experts on the various "subtools", don't expect to have an enthusiast-level system of CAE-type modeling that can supplant large chunks of the "system" that we use today. However, you can get a huge leg up on the majority of people particpating in this society of car modification, by getting an appropriate engineering-level background in the aspect(s) you are interested in. Any good engineering degree+"hard" textbooks on the specific aspects of auto engineering (e.g. engine, suspension) you're interested in will be best complement to a great deal of testing-based experience and will get you very close to your goal of not just "trying stuff" but having a good idea of where the solution space lies and what its bounds are.

    If you get that far, you will (as I do) undoubtedly continue to wonder about the fate of the human race seeing the sheer number of ways the moron crowd with cut springs, egregious quantities of gaudy vinyl graphics, big, heavy-ass wheels, and aerodynamically "retarded" (for lack of a better word) "body kits" and "wings" violate good engineering judgment when it comes to anything that can affect objective metrics of automotive performance.
  • If your interested in a drag racing vehicles try the programs from RSA [quarterjr.com], 2 1/4 mile sims, 2 dyno sims, a 4 link suspension sim, and others.

    For 2 stroke applications there is TSR [216.239.51.100] (google cache, the site is not working)

    This site [auto-ware.com] offers several suspension programs.

    Here [pocketlogger.com] is a program/cable for a palm that's a data logger (works with OBD II and 90-95 DSM's).

    But the truth of the matter all the software in the world is not worth the value of plain ol' testing and experience. If the factory raced the model car that you have see if there is a factory racing manual for it out there. It might be all you need. Along with Carroll Smith's books (A must have for any type of racing IMHO)

  • Here's the biggest problem: (Score:3, Insightful)

    by UserChrisCanter4 ( 464072 ) on Saturday June 22, 2002 @03:26AM (#3748404)
    Simulation is nothing in the autmotive world, particularly the aftermarket. You have to test and test and re-test. Sure, I suppose a competent mechanical engineer could come up with some formulas to reasonably estimate what modification X might produce. In fact, a lot of drag guys will run simulations that reasonably calculate, based on their current weight, what kind of power they need to do a 1/4 mile at a certain time. That's a reasonably simple calculation.

    The catch is going to be getting the actual specs for a given car.

    Let's say I want to bolt on a simple turbocharger and intercooler setup. It's a reasonably good quality turbo with minimal lag. Now let's say I bolt the same turbocharger onto the following three cars:

    Older model Honda ('98) Honda Civic LX: My turbo and the accompanying modifications make, say, 400 hp at the wheels. My car is now close to undriveable because torque steer is ridiculous when the turbo starts to pull, and the necessary suspension mods will either make the car fast but unable to steer (too stiff a rear) or negate most of the power gain (rear is too soft and the front wheels hop).

    97' Camaro SS: My turbo add-in is basically worthless unless I do a lot of engine work. The higher compression pistons on the Camaro mean that unless I knock the boost down to about 6 PSI, I'm going to be knocking my engine apart with detonation. For the same $5,000, I could've stroked the engine, ported and milled the heads, and upgraded the intake and exhaust.

    '97 Toyota Supra: My intercooler is too big to work with the factory radiator, and thus, the car constantly overheats (not good). Either I need to get a bigger radiator or a smaller intercooler.

    Now, I could probably have predicted that the Honda would torque-steer like a mother, given a basic knowledge of its drivetrain. I would have selected a supercharger and been content to put 250 or 300 horsepower to the wheels and call it a day. Any reasonably well-written program would predict the same torque-steer. But it might not have been able to tell you about the suspension issues, as it would likely assume a purely physics approach to the suspension, while I would recognize that things like gravel on the road, short inclined exits from fast-food places, and crappy roads would mean that my car would lose traction all the time.

    As for the Camaro, any reasonably intelligent program could tell you that the compression ratio was too high too feed heavy boost to. It would likely recommend the same Natural Aspiration tuning.

    Now for the Supra, that would be the hardest to predict. Without a lot of raw data on engine bay heat buildup in various areas, I couldn't see any program reasonably predicting such an occurence. So, while the '97 Supra would've been the ideal recipient for such an upgrade, the computer would probably fail to recognize the terrible amounts of heat such an upgrade might generate.

    Blah Blah... let me shorten the long story: Tuning a car is not an easy process, and it certainly isn't like a lot of tuning mags will have you believe ("Joe had this and this and this done. He rolls on these type of tires and posts this timeslip. Joe hopes to add these modifications in order to acheive this lower time"). There's a reason professional shops charge about 3X what reasonable part and labor costs for a given complete upgrade might be. If you're running straight lines all day long and rebuilding at the end of the day (as in drag), a pick-a-part approach is somewhat suitable as long as you have a good idea of what you're doing. For turning a reliable, daily-driven car into a much faster, reliable, daily-driven car, it's a hell of a lot harder. Open source or no, there's a lot more that a computer needs to know beyond basic physics and math calculations in order to accurately predict what a given upgrade might do.
  • Making a fast car is a lot like a software engineering project. It has a long stage of planning and research, long before you cut any checks or turn any wrenches.

    First, you ask yourself what you want the car to excel at. Most fast cars will be faster than most in a straight line and around curves, but a car can only truly excel in one area. Ask yourself what your priorities are. Also decide on a budget, which will cover the cost of buying the car and the cost of the mods. Here is where you have to be really honest with yourself- you can only afford so much starting car and so many mods- lying to yourself about what you can accomplish with x dollars will only lead to dissapointment.

    Second, decide on a platform. The platform should be one that naturally supports your performance goals. For example, a miata for handling, a fox body mustang for drag racing and so on. You probably want to get as cheap a car as possible to save money for mods. Try and find a salvage title car with a straight frame or a car with a blown motor that can be rebuilt. You dont want something with car payments on it.

    Third, how much money do you have left? Prioritize and start researching each mod to find the cheapest way to do it. Getting a good spring and shock combo might give as 90% as good handling as a coilover kit selling for 4 times the price- talk to people that are doing what you are and ask them what their experiences were. Most people will be glad to meet another enthusiast who shares their hobby and even drives the same car as them.

    Now, where does simulation come into this? It doesnt. If you choose the right platform, it will almost certainly be one that other people are already modifying heavily, one with massive aftermarket support. If you choose the right mods, they will be the ones that are most readily available, with replacement parts for cheap. And the reason there is no need for simulation is because all the work has been done for you a million times.

    What if you want to do something extreme that hasnt been done before? People have been doing customizations, weird engine swaps and strange aerodynamic modifications for decades. There are companies that make all sorts of one-off parts like manifolds and braces etc. Electromotive makes a series of computers that can be used to controll nearly any type of engine in existance from a 4 cylinder methanol powered car to a mazda 3 rotor turbo. Once you decide what you want to do, there is assuredly someone who will help you with it for enough money.

    As for the guy who said that computers are useless and a sign that your engine is too small, I say thats BS. Any engine can benefit from fuel injection and computer controlled ignition and fuel. A lot of prostreet drag racers have begun to use big block turbos with electronic controls in place of nitrous. The cars are more consistently fast and dont break as often as the nitrous cars- and they run 5 second ETs in street trim.

  • First, you cut away all the dead weight, leave youtself with just a frame, then you put light weight fairings over the frame, then you tune the engine until it will rev to 18,000 rpm and finally get rid of the extraneous two wheels.

    It leaves you with something that looks approximately like this [clubdesmo.com]

    Pfft, "performance" and "car" used in the same sentence.

  • Who needs this fancy smancy CAE tools stuff! You guys should see how fast my Honda Civic HX goes now that I've added a triple spoiler, dual exhaust with headers, extra headlights, hood scoops, type-R and VTEC stickers, and cut the springs. I bet ground effects will give me another 5mph when I save up enough allowance!!!

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