Lets talk rear suspension: specifically straight axle (Page 1 of 2)

Where do you propose we stick them?

doable. Do we keep the leafs and just add these?

I'm kinda newbish to this stuff, is there a good source to check out? I didnt find any good books at the bookstore, and web searches are hand to get any "real" info on.

If you can create or graft on a Watt's Linkage-style assembly to the pumpkin, it would work great. I've talked to some people running pickups and it seems that the rear leafs partially act in the same manner. I would just get some nice stiff shocks. The jury's out and dependant on the amount of rear sway the car gets, a ghetto anti-sway bar could be a big help.

The bottom line is that you want to limit or prevent undesired geometry changes back there. stuff like the axle sliding forward/back on it's perches or side-to-side movement. converting to coils may sound like an easy solution but may wind up being a bigger hassle than simply dialing in the leaf/live axle properly.

Good stuff! thanks guys. We were doing some digging, and apparently the new crown vics have a watts style link on top. We can snag one of those and try it out.

A panhard rod would be a good thing to add, but maybe you should drive the car first. It may not be really necessary. All depends on how much the rear end is moving around in the corners/

Springs, go get another set of the M2 rear springs. disassemble. Then you can add extra leafs to the existing packs on the M2 and if you want to lower it, flip one of the add on leafs.

This.

If it ain't broke, don't fix it.

Same thing for our firebird. We talked about all the possibilities to modify the rear with boxing things and reinforcing things. All the weight is iver the front. We are trying to get the front end from shredding tires so all the suspension focus is up there.. The rears weren't really a problem and the overall balance was decent.

I wish I could find the video I was watching a year or two ago. There was a ex-dirttrack Monte carlo at one of the houston events, and you could watch the two rear wheels bouncing around in the wheel well as the car came off a straight and into a turn.

A leaf spring will let the axle rap up, turning the spring into an 'S' on acceleration. I have done a lot of straight line drag junk, just never set anything RWD up to handle. I have watched high speed of a 2nd gen camaro on the drag strip wheel hopping, and it was not pretty how much the spring let the rear end jump, both up and down, back and forth, and side to side.

Is it currently set up as spring over, or under?  I'd do some quick hoon-testing to see if wheelhop is a problem on your particular vehicle before you end up re-engineering the rear suspension.  With a spring over setup, as long as there isn't much in the way of blocks, should be reasonable for wheelhop.

You can also get wheel hop with coils and a 3 or 4 link...

It's about priorities. Most races aren't won becuase of a Killer trick suspension. They are won because the car doesn't beak down!

If you have the absolute best rear suspension in the world.. as trick as there is.   You might save 3 seconds a day over what you have..
  Chances of you making anything that will massively increase reliability (which his how races are really won)  or speed is pretty slim..
  This isn't the cut and thrust of sprint racing like SCCA and Gymkana's have..
Get reasonably stiff shocks..
a wide wheel and tire and you have developed the rear end to 90% of it's full potential within the rules..
If the rest of your car is at 90% and you drive at 90% of the car's potential you will win every single event you enter..

Yes you are right, However anybody with the idea that a rear suspension update is critical doesn't realize how these events are won.. They are still in SCCA cut and thrust mode..  Simply not ready to believe the reality.