zero roll rear suspensions

[gbmetcalf]

What existing zero roll suspension designs are the best?

[Doug FST 5]

Brian - I think folks aren't jumping on this one because it usually becomes an "active thread"! Here's my two cents:

There are two major types - leading arm and trailing arm. In the trailing arm style the arm attaches to the chassis ahead of the axle. That is, the axle trails the attachment point. In the leading arm style the attachment point is behind the axle.

There are MANY points of view here - all meaningful design choices in a race car involve a huge group of tradeoffs. IMHO the major points go like this:

Trailing arm suspensions will exhibit roll steer but that is controllable through design. The weight of the system is towards the center of gravity of the car.

Leading arm suspensions can have less, or about zero, roll steer. They add weight to the very back of the car.

We've been pretty successfull through the years running a trailing arm set up.

Good luck!

Doug FST 5

[rgu]

If you are designing everything from scratch (it looks like that) you need to consider what road to take as Doug has sketched out. But if you just want an off-the-shelf zero roll system then others can advise you. Larry Campbell, who builds the FST Evolution, at one time sold a very nice zero roll conversion for the Lynx. This featured a very compact cradle and used the relatively inexpensive Carrera shock. I’d bet this turned at least a 100 z-bar Lynx’s into zero rolls. I had a friend, Dave (now deceased) who built twelve of these on company time and since his company had the best stuff, they were fabulous. Some of these are still around. Butch Deer will certainly know more than me—ask him.

Other sources. Our last five cars used Bill Vallis’s units. There are very compact so they don’t have the best rocker motions, but their simplicity and general fine performance makes them winners. (PM me for contact). Jim Nash from Mission Race Cars also uses this unit on his brilliant design. Jim is also making extra parts and shortly will be selling many rear suspension (especially trailing arms and pickups) parts.

So the stuff is out there –somewhere -it won’t be a long hard search.

[lawyerbob]

[quote=rgu;288785 Our last five cars used Bill Vallis’s units. There are very compact so they don’t have the best rocker motions, but their simplicity and general fine performance makes them winners..[/quote]

As soon as the snow clears and I can get the racecar shed, Patch Adams is getting that same set-up. My car is a leading arm set-up so I'm hoping the "Vallis" system will work well with that too. Of course, ANYTHING will be better than last year so . . . . .

[gbmetcalf]

This helps a lot! My chassis can be either leading (chassis with side pods) or trailing (chassis without pods). So the only thing I need to look at is examples of both. Anyone have photos of their setup including the mounting?

G.

[Diamond Level Motorsports]

Here is a picture of the zero roll setup from my Mysterian M5. It is basically the same as the Mysterian M2. Feel free to snoop around in my photobucket account as I have hundreds of construction pictures from cars that I have either built or rebuilt.

BTW, I prefer the trailing arm rear suspension design and I also run a rear sway bar so my cars technically are not zero roll.

http://s138.photobucket.com/albums/q254/samiam520/

[Bill Bonow]

Here is a couple of photos from various cars

[provamo]

Bill Bonow:

thanks for posting those images.......just when i thought i had seen about everything.............man i got to get out of the house more often!

[Jim Nash]

Since the BRD set up has been mentioned I thought I would post a photo of it as used on the MRC-09.

Jim

[gbmetcalf]

Thank you guys! This helps a ton. I now have a few options on how to design mine.

G.