NYC993

Probably a simple question but after a year of DEs (6 this year) I'm finally pushing the car hard enough to wear out the outside edge especially in the rear. What should I do to correct for that? Stiffer antiroll bars (i.e RS)? Stiffer springs? Pressures?
Allignement was just done and I have -1.9 camber in the back.
Car is lowered on H&Rs coilovers and everything else is stock.
Also looking to get NT01 next year. This year was spent on street tires.
I read Bill's posts and will probably refresh bushings/links with stock links plus tarrett toe links. I won't do more than 6 DEs a year and would like to keep it somewhat stock and long lasting.

OverBoosted28

For the most part, you can't have both. Either nice and compliant for the street, or tight, taut and crisp for the track. Hard to have both in one car. I choose to live with the punishment of poor roads (which I try to avoid), and enjoy great roads and the track.

JPS

Everything is a trade off.

You can play with pressures but that's just to make sure you have what you like for your style.

You can get more aggressive camber, but go too far and the car will feel very darty on any roads with a groove.

You can get more aggressive suspension, but real track suspension will never be super comfy on the road.

You can get stiffer bushings but you will feel that on the road.

Me: MCS suspension through Steve W who worked with them to valve it knowing its my family car and a track toy. Tarret toe, Walrod front bushings, RS sways, camber brought back a bit from spending a season having gone too far.

And the occasional Lotto ticket purchase to dream of a GT3RS or Cuo.

NYC993

Thanks guys, I get it, but I didn't say I want to keep it comfy, car is driven mostly for fun. I already have LWF, gt3 seats, and roll bar is going in.

For now, I just want to prolong tire life on the track and make sure my car will be able to handle more grip. I'll try to snap a pic of what my rear tire looks like.

How's your tire wear on the track? What tires do you run?

95_993

I think some of the mods you're planning this winter will definitely help. Reducing some of the "give" in the bushings with tarrett/ERP/Rennline toe links will help. M030 sways may compliment your springs better. As others have noted, "slightly" more camber will help as well, too much will make it "darty" as JPS noted. Your indy should have some idea what the right balance needs to be if he's doing a fair number of 993 alignments. I recently had EPE set my alignment and had a very similar conversation regarding striking a balance for tire wear and handling. Alignment feels just right in terms of balanced handling, etc.....too early to tell on tires wear as I only have about 1k miles on tires and no DE's yet.

Bill Verburg

Here's the recipe for an extremely nice and capable dual purpose 993
Elephant sport bushes on both ends of the front A-arms
RS rear A-arms, & KT arms
new stock camber links
Tarett or Rennline toe links
MCS shocks 600/800 springs
RS sways
8.5/10 x18 wheels 235 or 245 front 275 or 285 rear tires

If you are wearing the outer edge of the tires you need more neg camber as part of an aggressive street track alignment/corner balance,

lower the car as much as you are comfortable w/ if you get down ~RS height use RS wheel carriers and think about solid rear sidemounts

You can use mono-ball shock mounts w/o causing issues in street use, try to use sealed mono-ball bearings where possible

If LRP is visited a lot try to use non-directional tires so you can swap L/R tires

NYC993

Bill,
Thanks, that's pretty much the list I gathered from your other threads.

So do you think outer edge wear is due to alignment only?
Will RS sway bars make much difference esp. on nt01s?

I think RS a-arms and mcs with new springs will have to wait. My budget is not there, and neither is my driving.

NYC993

Here is one lap from last DE:
http://youtu.be/_0ohJbPQM40

k722070

the outside tire edge is wearing because you need more camber.
I'm not sure what you can get with stock eccentrics but whatever it is just max it out.
nitto says minimum camber for nt01 is -2.5, you need to get to -3 to get more even wear.
different sway bars won't fix the outside tire wear.

jscott82

What are your spring rates?

Bigger sway bar (RS/TRG/Etc) will help but stock springs are simply too soft. The problem will be compounded if you move to sticky tires.

Surprised you can get 1.9 deg in the rear with stock mounts. That is a fair amount of camber, I think I only run 2.5, but that is with 1000lb/in springs and heavy bars.

If budget is an issue, I would look at swapping out springs with something more akin to pss9/10 which I believe was something like 200/450. Raw springs are cheap, $50. Getting the right combination would be the challenge though.

NYC993

Ok thanks. Negative 1.9 was max positive they could get, so should be able to get another degree.

So as suspension compresses it doesn't lose camber? That's why I though stiffer bars might help, IF that was the case.

Bill Verburg

w/ RS rear adjusters I used to get a max of -2.5 rear camber, Now w/ Rennline and RSR links I get and -3 rear, There is and was no unusual wear. The extra camber has helped a lot w/ grip in the corners.

Almost no street use though, It was all turning and burning.

The more travel the suspension has and the softer the springs and the more speed carried thru the corners the more the camber pattern will roll onto the outer edges of the tires of the loaded tires.

In that sways add to spring rate in a corner, yes, they will help in a small way. You need to optimize the whole suspension for the intended purpose.

Bill Verburg

Pss10 will be a step in the right direction

RoW M030 springs are 246/457
993RS are 250/308f 375/508r

Bils PSS are 225/250f 400/685 rear
993 Cup 600/800

jscott82

It’s called camber gain, but you are right its really camber loss… As the suspension compresses it has negative camber gain (top of the wheel is tilted “IN” more relative to the chassis).

The other thing to consider: the more the suspension moves "UP" the faster the wheel tilts "IN". So at low static ride heights you get more camber gain for each inch of compression than you do at stock ride height.

All that being said: What matters is how the tread is presented to the road surface... So while the wheel is tilting into the chassis, the chassis leaning relative to the ground. The goal is to synchronize those two motions so the tread is presented flat or slightly cambered to the road surface.

Bars should be considered a tuning tool not the primary means of controlling chassis motion. What is the bar is actually doing is linking the inside and outside springs. So no matter how big the bar is, it can’t provide any more support than the inside spring.

jscott82

So pss10 is 250/685..... That is more aggressive than I thought... Those are good numbers..