[dregsz]

There is a thread on IRS vs Live axle on Camaroz28.com asking why the IRS Ccobras suck.
I thought they did well in AI but don't really remember.

Does anyone have info on the IRS Cobras vs solid axle?

http://web.camaross.com/forums/showthread....583#post4517583

Evan

[DanKeen]

Hey Evan - good to see you here, too.

Sorry if my tone is a little off on cz28 - I tend to get, um, pissed at members if I browse too much there. So don't take anything personal by it.

Last I heard (and, admittedly, it was a few years ago), the IRS Mustangs were doing very poorly on track, and most were swapping out the IRS for a solid rear.

Yes, an IRS can have many advantages. It's not just packaging reasons that cause people to use them. But a properly sorted IRS is much, much harder to accomplish than a properly sorted solid rear, so for most people its not worth the effort. A C4 IRS (going by your icon both here and there) has severe limitations in toe change during travel, etc - issues that a solid rear will not have. Camber control is better in a solid axle (modulo the fact that getting some camber requires bending tubes) - the tire does not go through a camber curve through suspension compression, but stays put. There are movements involved from the panhard rod, but with the length of rods we have in these cars, that's a minimal effect.

Yes, the LS1 Camaro brake hops like crazy - but that's not so much a function of the stock torque arm as it is a cycling issue with the ABS. Yes, a decoupled torque arm works better - but here again, we get a feature that an IRS can not have - insane levels of anti-dive and anti-squat at the same time!

Now I'm not crazy. I'd much rather have an IRS myself, and work around all the inherent limitations it has to get the benefits that only it can give. But considering that major manufacturers have a hard time designing a suspension that works better than a simple solid rear (C4, Mustang, BMW E30, etc)...