volturbo

Hello all,

New member here but have been lurking for a few years.

I track a 2007 Z51 with Pfadt stage 1 suspension and have tried a few tires over the years with some success. I was convinced by friends to try the Pilot Super Sports but so far I am not impressed. The outside shoulders on the front are now showing the belts after 6 track days (the rears aren't much better). Even the cheaper BFG KDWs lasted a whole season with similar lap times. I've read several articles on this forum regarding excessive wear on the inside shoulders but those seem to be limited to street cars. Again this wear is on the outside shoulders, the rest of the tire is as expected.

I have our local Corvette "guru" set the front suspension up for me with the following specs:

Camber: -1.45 degrees
Caster: 7.5 degrees
Toe: 0.05 degrees

Even with the other tires (which lasted a whole season) there was definitely more wear on the outside edges but nothing like this. Does anybody have any better settings for the Super Sports? I can't believe the current settings are way off...

Any better tire suggestions? Just cut my losses and go for the cheap Asian brands like Kuhmo Ecsta XS?

Thanks

hklvette

Outside edges are worn off? Get more camber. Most use two degrees or more.

AU N EGL

Setting your car up to run on Mich PS may mean no more street use.

Mich PS need -2* to -3* camber, which is too much for street use.

volturbo

Thanks guys. I'll see how much more camber I can get. I know it will be tricky to drive on the road but the distances are minimal...

BEZ06

What tire pressure have you been running in them?

Bob

volturbo

I've been running about 33-34 psi hot. Any harder and they lost grip. Suggestions?

ttgangsta

Tire pressure is low, I find 38-40 necessary when you push them.

Not enough camber or castor. I run Mid Ohio so that affects my alignment some but these are my specs and I am not wearing out shoulders on tires:

Front -2.1 1.5
Rear 1.0 .8

Castor: 8.5-MAX

Toe: 3/32 out front, 1/16 in rear

The SS have a very soft side wall thus need lots of support. You can stiffen sways too to help deal with the body roll. I found I was loading the car so much in the turns 1.3-1.4g on super sports that adding some stiffness increased my lap times even though I sacrificed a little grip

A really great new tire that just came out recently is the BFG Rivals. It has a 200 wear rating but its a great track tire. You will notice it has A LOT OF MEAT on the shoulders!!! Plus the side walls are stiffer which will help in the vette. I am gonna run 315 fronts and 335s in the back eventually.

A great way to ever prevent this from happening again is to get a IR thermometer or pyrometer and get temp readings from the inside to outside of the tire to tell where the heat is. This will help you adjust pressure and determine camber angle. In the future if you see abnormal tire wear across the surface i.e. wear on outside increase the camber or vice versa for the inside. If you google this subject there is copious amounts of info about it.

PM me if you need some help with setup. I got plugged in with some smart guys that really helped me out.

volturbo

Great info Mr Gangsta . I have 2 new supersports on the way and will increase the camber to a little over -2 degrees. I talked to a Michelin rep who suggested switching the tires side to side every couple sessions due to the nature of our "abrasive" track. I'll also try more pressure.

It's funny how I never had to think of this stuff during my racing years. Somebody else did it for me lol.

Bad Karma

I've been running the PS2s with 38/36 psi hot and been very happy with their grip and wear on PFADTs street/track alignment specs (little wear on the outer edge as expected). I thought the Super Sports were suppose to be better for wear and at least as good for grip? I was about to buy some...

Would I be disappointed with the Super Sports then?

ttgangsta

Yeah switching side to side helps as well. Depending on the track you are running I would strongly consider asymmetrical alignment specs.

Hope someday I can have someone else fiddle with this stuff for me too

ttgangsta

Super sports are a great track/street tire you just need to account for the soft sidewall. As I mentioned also check into BGF Rival.

volturbo

I'm not able to comment on the PS2s as I've never used them. Before the Super Sports I was using the BFG KDW2s which for the money held up surprisingly well. The verdict is still out on the Super Sports, I'll try some different settings with my new fronts and see what happens. It doesn't help that I continually try to keep up with a pretty much full race Grandsport lol. A lot of over-driving I'm afraid...

Could you pass along Pfadt's alignment specs for me? Thanks in advance...

volturbo

It's a small track in eastern Canada called Atlantic Motorsport Park. It's claim to fame would be G. Villeneuve, B. Rahal and Keke Rosberg racing Formula Atlantics there in the 70s. It is quite technical and abrasive. I also run at Mt. Tremblant, Quebec occasionally.

BEZ06

I've only got two track days on mine, but I liked them a lot!!

I was running about 36-37psi hot all around.

As mentioned, the sidewall may need a little higher pressure to keep it from rolling over.

Here's a link to Pfadt's alignment specs.

Just be sure to pay attention to their note at the top that indicates "Negative toe measurements indicate toe-in", which is different than most all alignment machines measure toe.

Also, many of us actually run a very slight toe-out up front for a crisper turn-in.

http://www.pfadtracing.com/blog/wp-c...-9.12.2011.pdf


Have fun at the track!!

Bob

Bad Karma

Sure:
http://www.pfadtracing.com/blog/wp-c...-9.12.2011.pdf

I pretty much maxed out each range. But I will be bringing it back in to add some toe out to the front (currently at 0); and maybe a little more from negative camber if I have the range.

volturbo

Thanks for everyone's help!

MarkDFW

When I ran them a year ago, I shot for around 37 hot and that worked for me.

blkbrd69

Are you still on stock bushings? If so they may be going.

I like 36 hot. Using a pyrometer to check temps.