Gurus,

I put on a big wing (Aeromotions, 65" wing) on my 996 GT3. Alignment in the rear is set at -2.4 camber and .13' toe-in. Car is running 700/900 springs. Pressures are targeting at 36-38 hot. I didn't get pyrometer readings.

I am now consistently cording inside edges of rear tires. I had a set of Eagle RS tires that died (to the cords on the inside edge) and then put on a scrub set of R6s that also corded on the insided edge. This is happening on both sides simultaneously, although the loaded tire shows a bit more wear.

Question: do I need to take some camber out with the wing now? Adjust toe? Reduce springs? Change something else?

I dig the new wing, but it's a pretty pricey experiment changing one variable and then running through a set of rears. I figured I'd ask those in the know and save some time and heartache.

Thanks!

-td

 

It does sound like you're working the outside of the tires too much, but getting a pyrometer would be a much more cost effective way to diagnose tire usage than looking at what part of the tire is wearing out first. I suspect you'll find that the inside edge of the tire is significantly hotter than the outside - you'll want to reduce camber until you get the temps more even across the tire.

 

You SHOULD cord the inside edge before the outsides if your car is set up right. if you have well under half tread in the middle, I would leave it.

 

Agree with Mike...however, if tire life is essential, take a bit of rear camber out.

Also, don't forget with all that wing you will need to adjust front splitter to balance the car.

 

Here is my Set-Up.
Mainly run Nitto NT01

Alignment
Front
Camber - 3.2
Toe .2mm (OUT)

Rear
Camber - 2.8
Toe -2.5mm (IN)

Sways
Front 1 off full stiff
Rear 1 off full stiff

Moton Clubsports 14 way
Front - Spring Rate 685#
Rear - Spring Rate 913#

Also have RS Wing and Cup Splitter

 

This isn't an issue of cording the inside edge first. It's cording the edge after 2 sessions. I ran through 6 rears in 1 weekend - all corded on the inside edge. None of these were sticker tires.

-td

 

It could be that your rear toe is out of alignment. It might be a combination of camber and toe. If you floor it hard to induce wheelspin (like a dragster) you could be the source of your problem. Cording a new tire in 2 sessions is not normal. 315 wide MPS cups also used to do this because they are too wide for our stock wheels. 315 Hoosiers or other tires were not a problem. What brand, model and hot pressures are you running?

 

Yup, TD have your toe verified...

 

if you have stock toe arms in rear it is common for them to move under pressure, that`s why people get tarett arms.
http://www.tarett.com/items/996-997-...lnk-detail.htm

if you already have `em just re-check the toe settings.

 

Td, is your toe per side or total?

 

I ran a set of hooter 295s, eagle rs 315 and hooter 315. All corded inside edge rapidly. Although first set lasted 5 sessions.

Toe is .13' per side. I have tarret toe atms with locking plates. Will have aligent verified ASAP.


-td

 

You are not on a banked track are you? Daytona? Roval?

 

Inside wheel spin due to a weak diff?

 

I've been surprised before... but I would be very surprised if any kind of wing could produce a sudden and noticeable change in tire wear on a production-based car. Unless you're running for long, long stretches at 160 mph, the effect on the tires is probably comparable to driving with a passenger's additional weight or running a few extra laps per session.

I suspect your alignment settings have changed. Toe the most likely.

 

Will you be out at TWS this weekend for NASA or next for PCA ?
If so come find me and we can discuss this.