Question: ZR1 Sway Bars

[jamison]

I just have a quick question. For the life of me I can not find any info on the stock size sway bars for a 1990 ZR1. I have a base model 1990 coupe and I was wondering if there is a size difference for the diameter compared to the ZR1. My front is a 26mm and my rear is a 22mm. Im considering buying some ZR1 sway bars I found online for better handling, I just want to be sure they are not the same size as I already have.

Thanks!

 

[Hib Halverson]

There would be no advantage in installing ZR-1 stabilizer bars on a base coupe.

Base bar sizes are 26mm front, 22mm rear
ZR-1 bar sizes are 26mm and 24mm.

You might be tempted to go to the Z51 bars but don't do it unless you change the springs, too. If you install the bars but not the springs, the car will understeer like crazy.

 

[jamison]

Alrighty! Thank you so much!

 

[Hib Halverson]

You're welcome.
Glad to be of service.

 

[ex-x-fire]

I wouldn't say it'll understeer like crazy, these cars have some pretty sticky tires.
I once had a 3rd gen base camaro, went from only a small front bar to thick irock bars front & rear. Stock springs, shocks, & struts,it drove very well. I'd be worried more about having a good alignment, not a "set the toe & let 'er go" alignment.

 

[Hib Halverson]

I'm sorry but...what you did to your 3G F-car is irrelevant to this discussion.

With a late C4, if go to the 30 mm solid bar from the 26 tubular, you add a "ton" of front roll stiffness because bar rate changes with the square of the diameter and for a given diameter, a sold bar has a higher rate that a tubular bar. When GM added the big front bar it also went up a bunch on rear spring rate.

If you add the big front bar and not the stiff rear spring, the car's roll stiffness goes way up in the front but not in the rear. Lots more front roll stiffness w/o a corresponding increase in rear roll stiffness makes for a car that understeers like crazy.