Proturing or roadrace rear suspension

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60sMoparGuy

60sMoparGuy

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Not sure if this is the right forum for this but I'm going to toss it out for comment. What type of rear suspension works best for protouring or roadrace/autocross? Should I stick with the standard springs and use caltracks or should I consider a four link of some kind. I have also considered an independant rear suspension. There are a number of options on the market. I would have to do more work for an IRS but I can do the work. Any comments? Anyone with personal experience would be appreciated. :glasses7:
 
An IRS is great, as is a custom built to your application 3 link. Really not that hard to do, either.
 
Torque arms seem to be popular in autocross and road racing, that's what I'm building in my valiant. Its a LOT of fab work!
 
Here is how I did mine
9E69AAE1-8B3E-4FBE-873C-D2CBD8CE66AB_zpsfg9822oz.jpg

FCC0D7CE-FEFF-4C15-A329-5ACDDA51153B_zpsrd7wgmzp.jpg

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My RMS four link works awsome for both. Affordable and easy to install.
 
Just curious.....How is the torque arm tuneable?

Would not the reason to install a different suspension for ANY kind of racing is to be able to tune (for bite) the rear suspension for different tracks / varying conditions?

I am curious about the other brands also.....I see a lot of hardware...but no real ability to change much (other than ride height) if needed once it is installed.

Just want in to learn.....
 
HemiDenny said:
Just curious.....How is the torque arm tuneable?

Would not the reason to install a different suspension for ANY kind of racing is to be able to tune (for bite) the rear suspension for different tracks / varying conditions?

I am curious about the other brands also.....I see a lot of hardware...but no real ability to change much (other than ride height) if needed once it is installed.

Just want in to learn.....
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I agree.

For Those Interested, you need to check out Lateral G Forums. Auto x dedicate forums. One of the members, Ron Sutton, builds race suspensions, very knowledgable and pretty much provides a well written write up of suspensions and how to design them for whatever purpose you like.

I talked with him a lot, I decided on a parallel 4 link, fully adjustable rear suspension since it will handle and plant the power for drag racing and yet be able to adjust it for auto X and road racing.

If you're going to strictly road race it, a torque arm like above or a 3 link with panhard or Watts bar would be best.
 
I'm just going to do Hotchkis leafs and sway bars for the rear. Keep it simple. Tomwheels has been autocrossing his Valiant every weekend and has been very successful.
 
MuuMuu101 said:
I'm just going to do Hotchkis leafs and sway bars for the rear. Keep it simple. Tomwheels has been autocrossing his Valiant every weekend and has been very successful.
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that would be my bet....then as the car and YOU get faster....go to the next step if needed.

I see all kinds of different set-ups on cars where the owner has not the slightest idea how it functions......and I just ask myself....why?

I think Jo Diesel's torque arm is impressive.....just wonder how it works. I better read up.
 
I see all kinds of different set-ups on cars where the owner has not the slightest idea how it functions......and I just ask myself....why?

Who are these people you speak of? Never ran across any of them I guess? LOL.
 
Thank you all for your input! Jo you have done some great work. I was a R&D machinist for thirty plus years. You have feed me some chewing msterial for some time. I appreciate what each has contributed. I'm not afraid of the fabrication work. Having the tools at your disposal is great, but doing a job with the tools at hand, is sometimes another matter! I am going to read and explore these other avenues. Thanks for the links. I'm one of those guys that likes to know why something works the way it does. If you understand the principles behind why something works sometimes you can think of a way to do it better.....or not. Sometimes you can learn as much or more from a mistake than from your successes! You just keep on learning and doing. I have looked at the RMS setup. Nice, simple, efficent. I don't have the tools at home that I had at the shop.... but that will not keep me from building and driving what I build. Thanks guys, I'm always willing to learn something from someone else!:burnout:
 
HemiDenny said:
that would be my bet....then as the car and YOU get faster....go to the next step if needed.
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Yep.

The 68 Valiant that Lilcuda now owns was as fast at Portland International Raceway at C6 Z06 Corvette. It's got leaf spring and torsion bars.

The builder/owner (Tim Werner) would scoot down the straight at 160 mph. And the car still could have used some fine tuning and has since got added advancements now like better oil pan and adjustable splined front sway bar.

If I had that 68 Valiant, the car would be much more capable that my skills.
 
What IRS systems have you been looking at? Would love to do it some time, I don't think you can compare a straight axle with IRS when driving on a surface that isn't 100% flat.
 
Agree with AutoX, why reinvent the wheel?
Get some big T-bars, sway bars, good shocks and some chassis stiffening and see if you can hang on.
 
pauly v.100 said:
Agree with AutoX, why reinvent the wheel?
Get some big T-bars, sway bars, good shocks and some chassis stiffening and see if you can hang on.
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Don't forget the sticky, wide, low profile (go-cart) tires.

Add that to above and have at it.
 
autoxcuda said:
Yep.

The 68 Valiant that Lilcuda now owns was as fast at Portland International Raceway at C6 Z06 Corvette. It's got leaf spring and torsion bars.

The builder/owner (Tim Werner) would scoot down the straight at 160 mph. And the car still could have used some fine tuning and has since got added advancements now like better oil pan and adjustable splined front sway bar.

If I had that 68 Valiant, the car would be much more capable that my skills.
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Spot on......people SERIOUSLY underestimate the design of the torsion bar/leaf spring combo.
 
HemiDenny said:
Just curious.....How is the torque arm tuneable?

Would not the reason to install a different suspension for ANY kind of racing is to be able to tune (for bite) the rear suspension for different tracks / varying conditions?

I am curious about the other brands also.....I see a lot of hardware...but no real ability to change much (other than ride height) if needed once it is installed.

Just want in to learn.....
Click to expand...
I wondered the same thing, I know the old chevys with the "truck arm" rear suspension and the f bodys with that torque tube setup, seem to be difficult to get "fwd bite" But I am no suspension expert.
 
My hats off to you Jo diesel. Nice setup, its very similar to mine. The original question was what suspension works BEST for protouring or roadrace/autocross. The reason why I suggested a torque arm setup is because its what is favored in the roadrace and autocross world (not just mopar's). Google Mike Maier and whitness his mustang w/ his own torque arm suspension setup along with the stack of 1st place trophies spilling out his trunk. I believe its the best system, not saying that torsion and leafs dont preform well, but I don't believe they are the best.
 
A properly set up torsion bar system will be just as fast as a properly set up coilover conversion. Not a single doubt in my mind, the physics of the geometry says its true. Now, both torsion bars and coilovers have their advantages and disadvantages, and it depends on what you're doing and what your capabilities are. It's still easier to tune a coilover set up, although the options and parts for torsion bar set ups have improved a lot and continue to get better. But that's the front, and this is about the rear. ;)

The "best" set up for the rear is probably a 3 link, as long as your horsepower isn't obscene. Stupid simple, very tunable. More adjustable than a 4-link. But if you're putting down gobs of horsepower the 3 link won't handle it as well as a 4-link. And then you can argue triangulated 4-link vs straight, etc.

But really, if a '68 Valiant can hang with a Z06 while still equipped with torsion bars and leaf springs, what's "best" is just magazine racing.

I agree with what tomswheels said about his barracuda awhile back...

Here's the quote

tomswheels said:
Hey I know I'm a little late adding my 2 cents, but it really is all about what you want to spend. I'm sure a car with coil overs and a rack and pinion will be EASIER to drive quickly on an autocross, and if you have the money to do it, great. I don't have the money so my 69 Barracuda convertible runs torsion bars, leaf springs, $14.95 Gabriel gas shocks, a firm feel box, front sway bar, and subframe connectors. That's it. Less than $1000 in suspension/steering. At the last Goodguys Autocross in Del Mar it beat the $150k Camaro that just got invited to Optima (Alcala) and Steven Rupps "Bad Penny" Camaro. Just goes to show you torsion bars can still surprise the big-bucks guys....
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Which gets to what are you going to really use the car for? Any sort of motorsports competition is going to have rules. So you'll find people actually wheel to wheel racing, or even hillclimbs or FIA rally limited as much by tire rules as any thing else. But those who are just enjoying track time are generally pretty free to do what ever they want. And there's some places to play in between those two worlds.

If you like building things, then do whatever you want. If you're thinking about competing in anything, check the rules, go and observe what the other players are doing. Then spend the time on tuning and seat time. In competition, the biggest variable is the tires. Change them, and plan on making some adjustments to everything else.

I agree that leafs and t-bars will do fine for most purposes. For very fast, like 120+ adding a panhard can be worth the trouble. Daves got one on the Zebra Dart, one of the 70 T/A teams use one, and at least one of those cars is using one the last time I had a peek underneath.
 
You mean, this one? On the Gurney AAR.

GurneyAARrearsuspension-1.jpg


You can just about see the other end of that set up in this picture. Man I wish I had a higher res version of this one...

WC087160.jpg


Yes, absolutely the rules. If you're planning on actual competition, instead of just having fun, what's "best" is usually immaterial because it's probably against the rules too. :evil3:

And don't get me wrong, I have all kinds of stuff that I've done to my car that doesn't probably make it any faster. Not really anyway. Makes me feel better though. ;)
 
autoxcuda said:
Yep.

The 68 Valiant that Lilcuda now owns was as fast at Portland International Raceway at C6 Z06 Corvette. It's got leaf spring and torsion bars.

The builder/owner (Tim Werner) would scoot down the straight at 160 mph. And the car still could have used some fine tuning and has since got added advancements now like better oil pan and adjustable splined front sway bar.

If I had that 68 Valiant, the car would be much more capable that my skills.
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It's definitely much more capable than I am! The Valiant is scary fast and handles extremely well. I can't even come close to using half of it's potential on the street. Can't wait to get it on a track someday.

For those that don't know about the Valiant (aka The Red Brick), Google "track day 68 valiant".
 
72bluNblu said:
..................

And don't get me wrong, I have all kinds of stuff that I've done to my car that doesn't probably make it any faster. Not really anyway. Makes me feel better though. ;)
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this statement is one of the best (truthful) I have read.

Hey!!!!! you let the cat out of the bag. We are all guilty as charged.

:) back at ya'
 
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