Alrighty I was just wondering after seeing all these sway bars that are like 35mm solid in front and liek 25 solid in the rear if its overkill at some point or does it just keep getting better. I have BMR 32mm and 21mm both solid and hotchkis springs and mine feels prett freaking solid and doesnt roll much if any at all that I can tell. But I am thinking about upgrading some things and im looking at suspension too and just wondering if what ive got is good but can be improved or if it sucks or if theres no really noticable difference going any further. Im seeking to have htis thing as solid as possible, got bmr boxed subframes that conect in the center of the floor pan too, dunno if thats doubel diamond or not. Thanks

 

I installed a solid 35mm front swaybar 10 days ago. My observation is that initial turn in is very, very crisp on the street. I haven't had a chance to wring the car out yet (runnin' Lime Rock on Monday and we'll find out) but I have been told:

1) Initial turn in SHOULD be crisp
2) If you don't slow down enough on turn entry, you will induce severe understeer (I need to be mindful of this on the track)
3) Bite on corner exits should be improved. This should translate to higher straight away speeds.

This bar was installed specifically for autocrossing. I was willing to accept any downsides and haven't seen any on the street. Maybe I will on the track.

Finally, this is the only suspension modification from factory stock on the car right now (shocks are on order). I think that this assessment is accurate for the front bar. I don't know what effect the rear bar change would have in tandem with the front bar change (I can't change the rear bar in stock anyway).

 

My ESP autocross car used to have Hotchkiss springs and an LG 32mm front bar. Stock rear.

With 500's and a 35mm bar I get a better ride. Better compliance over bumps and less body roll than with the Hotchkiss springs and 32mm bar. I always hated those springs. They always seemed bi-linear as opposed to a true progressive spring. They seemed to be soft at turn in and then went from soft directly to very stiff.


The 24 or 25 mm bar will be to large for autocross use. It may work well on a track though.

 

To answer the very general question, no, bigger swaybars is not necessarily = better handling. It's a tuning balance. If you really wanted a completely flat handling car, you could just remove the springs and shocks and replace them with solid arms to keep your wheels from moving up and down, but folks don't do that because it would run slower around the track.

Dave

 

so whats the differece in an autocross setup compared to a road course setup and how would each respond on the street? Im basically looking for a solid ride that handles very very well and I may even take it autocrossing or even to the track whenever I get a chance some day.

 

The 35mm front bar will generally only be too much with very stiff front springs. If your front springs are 500 or less, "just do it".

On the other hand, it's very easy to get too much rear bar, which will make the rear very loose. I'm still running the stock 19mm rear bar, and probably the biggest rear bar that anyone needs for ANY handling application is 21mm.

The sole exception (for which handling is not a priority) is a pure, trailered drag car. For that case, the front bar is removed to reduce weight and increase front suspension travel, and a large rear bar is used to keep the driveshaft torque from tilting the axle. However, this is absolutely a straight-line only setup, and would be dangerous to drive on the street.

 

Eventually yes it becomes too much, the larger you go the more independance of the suspension you will lose.

 

Well I have the 21mm rear, 500 lb springs or more stay under 35, what about progressive just go by the max? Anywhere I can get some info on these sorts of suspension questions about the f-body besides the forum? Also what relation do the spring rates have to the sway bars?

 

"Anywhere I can get some info on these sorts of suspension questions about the f-body besides the forum?"

The intro is "Chassis Engineering" by Herb Adams. The intermediate book is "How to Make Your Car Handle" by Fred Puhn. "Tune to Win" by Carroll Smith is the Ph.D. course, but it's seriously tough.

"Also what relation do the spring rates have to the sway bars?"

The following is seriously oversimplified. They work in reverse. Overall, the more spring you have, the more antiroll the springs provide, and the less bar you need.

 

Thanks Ill check amazon for them.

 

Also "Performance Handling", by Don Alexander, which also gives some estimates/guidance for weight transfer through the bars vs how much through the springs.

If you're truly interested in chassis dynamics and lots of math doesn't scare you, there's always "Race Car Vehicle Dynamics", by William and Douglas Milliken (SAE, ~$90).

Norm