Track: Sway bar & tire wear (No suspension forum?)

[gofast182]

This is a question for a track car, my S2000. A couple years ago I changed to Koni Yellow shocks and S2000 CR springs, I'm also maxed out on negative camber in the front (-2.1), and I run Bridgestone Potenza RE-71R tires (which are insanely grippy). These changes allowed me to lap noticeably faster and lean on the car much harder in turns (I corner at 1.5-1.6g). Consequently I'm still wearing the outside edge of my front tires more than I'd like. I thought if I stiffen the front suspension so the wheel doesn't travel as far up the suspension arc I can keep a better contact patch, corner faster, while wearing my tires a little more slowly/evenly since the load is distributed on a bigger contact patch. My first thought was stiffer springs but I'm not sure what increment to increase by and, depending on the change, could require me to re-valve my shocks. Also a more invasive install. My second thought was a stiffer sway bar to keep roll (the travel of the suspension arc) in check. I've read conflicting opinions that sway bars can increase or decrease grip. I have a bar in mind that I don't think will be too stiff and my thought is increasing the contact patch will at least cancel out any negative effect of the bar. Anyone track their car and have experience with this? It would be nice to corner faster but my main concern is getting a bit more life out of the tires and at least not losing anything. Thanks! PS Why don't we have a suspension forum?

 

[CapriRacer]

I never got a chance to try it, but BBSS (Big Bar, Soft Springs) was what I thought would be the best set up. This was argued about oh ..... many years ago in Circle Track Magazine. I got out of racing before they finished arguing. But you're going after a different goal. Have you looked at your camber curve? Are your inside tires (relative to the turn) riding on the outside edge - hence the wear? What about your Ackermann (varied spelling)?

 

[qjohn]

A good track-oriented lowering spring will have a higher spring rate and also give more negative camber. But sway bars are a lot easier to install and cheaper, and if they are adjustable can be used to tune balance. Let us know your budget. Sorry to go off-topic: there is a lot of lap time to be gained by optimizing tire pressures, so get a good gauge and pyrometer if you do not already have those. Run with a roll bar, seat, harness, arm restraints in your convertible.

 

[Srt20]

Is this a double a-arm suspension? If so, you should have your geometry of the front arms so that you increase negative camber throughout the travel. Will have better contact patch. So a stiffer suspension would be working against you.

 

[OneEyeJack]

Can you stop with only front-end changes? If you put in stiffer springs and do nothing else will you like the increased understeer? And if you just do the sway bar will you like the turn-in changes? Have you contacted someone like Hotchkis to see what they think will help when installing one of their kits. They make good stuff and do a lot of track day research projects. I've put their sway-bar kits in my first generation xB and it's a lot of fun shooting on-ramps and back roads, now. It's a lot of fun sliding through a turn. The sway-bars, front and rear made a big difference along with some other Hotchkis stuff.

 

[gofast182]

Originally Posted By: Srt20

Is this a double a-arm suspension? If so, you should have your geometry of the front arms so that you increase negative camber throughout the travel. Will have better contact patch. So a stiffer suspension would be working against you.

It is. I'm already maxed out on neg. camber and I don't want to change major components of the suspension if I can help it.

 

[Srt20]

Originally Posted By: gofast182

Originally Posted By: Srt20

Is this a double a-arm suspension? If so, you should have your geometry of the front arms so that you increase negative camber throughout the travel. Will have better contact patch. So a stiffer suspension would be working against you.

It is. I'm already maxed out on neg. camber and I don't want to change major components of the suspension if I can help it.

You will be at you least amount of negative camber when your a arms are parallel to the ground. As your suspension compresses further, you will gain negative camber. Its not about changing anything but ride height.