CAE Tools for Car Performance Modifications?

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?"

Comments

speed prediction

[cybermint]

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.

Not very practical...

[8Complex]

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

Re:Not very practical...

[the_brat_king]

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!

Megasquirt EFI -OpenSource Fuel Injection computer

[l8apex]

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
Yahoo discussion groups

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

Re:sale modification

[NanoGator]

"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.