Z3 Rear Sway Bar Fit?

[campione]

I have an "opportunity" to pick up an almost new 19mm 1.9 Z3 aftermarket rear sway bar reasonably cheap, with all the hardware. I just want to know-WOULD IT FIT WITHOUT MODDING THE EXISTING MOUNTING POINTS, ETC? Thanks for your response!

[jca]

A good question that I don't have the answer to. This is off thread, but what sort of ti did you finally end up with? I remember when you were in the market. Cheers, John

[spidertri]

Yes it fits. I ran one for a bit but ended up going back to stock.

[campione]

Spidertri-thank you! I may make the buy for and try it.

JCA-I recently bought another Hellrot '97. I wanted another colour but it was a local deal, has a perfect interor, needs a bit of detail and minor paint work but the price was irresistable. The engine and trans run beautifully and we've gone thru the rest of the drivetrain, brakes, etc. I'm gonna' use my old Racing Dynamics stuff in the warehouse on this one. Now I just need to find more room...

[zoner]

Originally Posted by spidertri

I ran one for a bit but ended up going back to stock.

Any particular reason why? I'm considering a 19mm rear myself.

[spidertri]

At autox it wouldn't let the rear rotate to my liking, it was more prone to oversteering. For the rear trailing arm suspension more spring rate is better than a bigger bar. It lets the trailing arms act individually rather than locking them together.

I will say that it made the rear end feel a lot tighter, less roll obviously, which felt nice on the highway.

[zoner]

OK, that's what I thought. I don't have plans to auto-x it and my goal is more oversteer/less body roll.

[campione]

Since I'm strickly a "highway" guy at this point in my life, that sounds perfect to me!

[jca]

Originally Posted by campione

Spidertri-thank you! I may make the buy for and try it.

JCA-I recently bought another Hellrot '97. I wanted another colour but it was a local deal, has a perfect interor, needs a bit of detail and minor paint work but the price was irresistable. The engine and trans run beautifully and we've gone thru the rest of the drivetrain, brakes, etc. I'm gonna' use my old Racing Dynamics stuff in the warehouse on this one. Now I just need to find more room...

Sounds nice...I remember that you did not want to travel a long distance to pick up a car.

[cooljess76]

Some Z3 guys disconnect their rear sways at auto x because they experience rear wheel lift.

[spidertri]

Yeah, I need to try that, but I don't think I have enough spring rate back there yet.

[3.2TI]

Would the X-brace be a better suspension upgrade than the rear sway?

[bullmand]

Originally Posted by 3.2TI

Would the X-brace be a better suspension upgrade than the rear sway?

Yes and no. It's not really a suspension upgrade as it doesn't touch any of the other suspension components at all. The effect you'll get from it is completely different than you'd get from a sway bar. But, it is definitely worth the effort and money. It really solidifies the car, even in straight line highway driving. It's a little hard to explain, but you can actually feel the difference between a car with one and without one. If you only have the money to do one or the other and your car's mostly a daily driver I'd go with the x-brace. Its function is constant vs. the relatively rare times on the street that you'd notice a difference in a sway bar.

[3.2TI]

I figured this would be more of a chassis upgrade than suspension. I am familiar with rear sway bar upgrade, as my r32 had night and day difference when driving even at slow speeds. What I would be concerned about is any negative results from the rear sway bar such as the ones mentioned above. Would this prevent any drifting from occurring?

[bullmand]

This is from the book "How To Make Your Car Handle". It's just an excerpt and there's much more relevant information in there and it's worth finding a copy.

Most anti-roll bars are used on the front suspension, except on front-wheel drive cars. It adds more roll stiffness to the front, which reduces rear suspension weight transfer in a turn. This delays or eliminates lifting one of the driving wheels , and may create an understeering tendency by increasing the loading on the outside front tire.
The steer characteristics resulting from a stiffer front anti-roll bar are unpredictable. On cars with similar front and rear suspension designs the tendency is for a stiffer front anti-roll bar to cause more understeer, due to increased weight transfer in the front.
If you install an anti-roll bar on the rear, or if you stiffen an existing one, the effect is to create oversteer. This is not a desirable modification unless the car understeers heavily under all conditions. (or if you want oversteer for drifting???)

So, there that is. Hope you find it useful.