I need either a detailed drawing of an F-1 suspension or close up pictures. More specifically the linkage between the pushrod and the strut. I just cant figure out the mechanism they use to transfer the force into the springs. And the one i came up with is far too complicated to be practicle. Any help would be appreciated.

 

Current F1 stuff is very hard to get info on because the teams are so secret. However if you want to go back a few years, try this:

http://www.motolit.com/fefo1ipwr.html


Just curious: Why do you need F1 suspension info? There are a number of pushrod/pullrod suspensions that actually move more than a few cm. during use. Their linkages as more easily seen.

Are you looking at one-spring two-spring or three-spring front suspension?

 

I am designing an open wheeled race car. Its fairly primitive at the moment and would be way too heavy but it will be revised. What else uses a push/pull rod suspension? It would probably be 1 spring due to space constraints but if it ends up being too heavy i might have to use more. If you have a program that can open up cad drawings i can email you what i have so far.

 

If you're concerned with space, why not try a torsion bar front setup? (They're usually quite bouncy though, and can be a pain to tune).

Most open wheel cars use the push/pull type suspension.

 

If you don't have a good knowledge of suspension design, I would advise you study some good chassis design books in some depth. It doesn't matter whether it's an SAE vehicle or some form of SCCA open wheel race car, or a hillclimber, you need to keep the tires doing what's best for them.

Once you know what roll centers (or moment centers) you need, the amount of travel, roll, camber gain and a few other things, you can start determining the locations of all the pickup points.

If you are not using existing uprights (aka knuckles, spindles, etc), you need to design some based on your geometry, wheels, tires, brakes, etc. Somewhere along here you can package the springs/shocks pushrods and bellcranks if that's where you are going. I'd suggest a background of mechanical engineering design would be most useful. Stress analysis experience would also be helpful.

It might help to look closely at similar cars, especially if you are planning to race against them. Go where they race and take pictures. Better yet, buy a winning chasis, measure everything and plug it into a good suspension analysis program like Performance Trends' Suspension Analyzer.

Magazines like Racecar Engineering and RaceTech have excellent features on suspension, suspension design, and many folks who have done it before.

You might copy a design you know works. Suspension Analyzer has stuff like the C5 Corvette suspension stored in the program. The tire motions are pretty good and could be adapted to a smaller platform. Changing from a cross composite leaf to a pushrod/coilover wouldn't be difficult. The choice of springing medium is often a packaging concern, not how different springs act. It's much more difficult determining the correct (wheel) rate.

IMO, there are many times as many good engine designers as there are good suspension designers. My feeling is that good suspension engineering is one of the things that puts certain race teams ahead of their peers in closely contested, closely controlled race series. Nextel Cup comes to mind. It happened before, and I'd hazard a guess that it is happening again.

I can't tell from your posts, jerminator, how much understanding you have of chassis/suspension design. FWIW, I don't think trying to copy a F1 suspension has merit. Almost no other car has the downforce/vehicle weight ratio they have. That dictates a lot of their suspension design.

My $.02

 

Well i figured i would be hearing the most from you....I have read alot of your posts and am well aware of your seemingly endless technical knowledge on a multitude of subjects. I, however, am somewhat unlearned in such matters as chassis/suspension design. But before you or anyone else condemns my efforts i will say that this car will probably never be raced and certainly not against other drivers. My main goal is to make this a street legal, open-wheeled car (you know you'd want one). So the suspension doesnt necessarily have to work well enough to corner at 120....it just has to work.

I do appreciate the advice though, i would love to understand all of the work that goes into a finely tuned suspension. In the middle of typing this i had an epiphany and figured out the missing link in my double-wishbone set-up. I know that basics about transfering force, studying the wear and tear on parts is unnecessary as weight is not a really big issue and i tend to over-design for strength, but i do need to know more about the wheel travel and camber gains and such....where can i learn about this stuff???

Again i do appreciate your help and i promise i'm not just your typical dumb kid who is going to rush into something and waste alot of money for no good reason.

 

This may be cheaper.
http://www.arielmotor.co.uk/
The 300hp version is faster than almost all supercars. If you don't mind a Honda engine.

 

You are correct that would be cheaper....but i want a single seater and i want my LT1 sitting behind me!! (GM to the end, baby!)

 

I appreciate what you want to do. I've had the same "fantasy car" (one of MANY) in my mind. Seriously, log on to Performance Trends, and look at Suspension Analyzer. Buy it and copy the C5 Corvette geometry. It will do what you want, I am convinced. Your car will be lots lighter, so you can fabricate the control arms from DOM tubing, etc.

Just use pushrods attached where the springs attach to the lower control arms and work out the ratios. As I mentioned, RaceCar Engineering and Race Tech are invaluable mags.

Try a book called "Chassis Engineering" by Herb Adams. It's very readable. Herb is an old acquaintance, and one hell of a good engineer.

http://www.amazon.com/exec/obidos/tg...01559?v=glance

You can usually find it at Barnes & Noble if you are in a hurry.

Another great bok is "Tune toTo Win" by the late (and sorely missed) Carroll Smith. Worth it's weight in gold, at least.

http://www.amazon.com/exec/obidos/tg...01559?v=glance

Good luck, and thanks for the very kind words.

Jon

 

Thanks alot for the info, i'll definately get those books and that suspension program. I'm glad i'm not the only one who would want an open wheeled street car....heck, if i can build one cheap enough maybe there is a market for it? But thanks again.

Jeremy

 

yea, F1 suspension would not compare to what you want. They also use flexon wish bones (i believe that is what they are calling them these days)

like they said above, pick up a book on basic suspension design.. its all easy stuff to make "work" to make it work WELL is a WHOLLLLEEE 'nother thing!

 

I appreciate all of the advice...I have the basic design down now and have figured out the space issues i was having....now i just need to learn where to position the pieces on the chassis (namely the unequal length, converging A-arms)