Wheel Alignment for Track Use

[MotherTucker]

After 3 two-day track events, I wore my left front tire's outside shoulder down to the cords. I was running Hoosier R6 DOT radial slicks. Hoosier has a great free phone service (if you are using their tires) where you can talk directly with an experienced technical guy about the trouble you are having. So I called them up and described the situation.

He asked which car I was using, which Hoosiers I was using, which tracks I run on, how long the tires lasted, etc. The problem I ran into was not enough negative camber on the front tires. When you go around a curve, the car leans, and if the tires were straight up and down before the turn, they are now tilting out towards the outside of the corner. What I needed to do was add negative camber, where the tires lean in on the top so that they straighten out to be more perfectly vertical when going thru turns (at racetrack speeds). The reason my left front outside should wore out is because the tracks I ran all go clockwise, so on average there are a lot more right turns than left turns.

The technician suggested -2 to -2.5 degrees of camber for the front tires, and -1 degree for the rears. He also suggested 1/8 inch of toe-in. These are ideal race settings. Of course, it will wear out your tires more quickly on the inside shoulder during normal driving, so it's somewhat of a tradeoff.

So I took it to a really good alignment shop (who charged $250 to do it since it was an "exotic", the scumbags...). The alignment from the factory was -1.1 degrees of camber on the front left, -.9 on the front right, and 1/3 inch of toe in on the front. That's a lot of toe-in. 1/3 inch of toe-in translates to .57 degrees.

The alignment shop dialed up as much front camber as the stock suspension allows, which is -1.5 degrees. We ended up with -1.5 on the front left, -1.2 on the front right, and a reduction in toe-in by .20 degrees front and back.

Here's what it looked like afterward:



What I really need is a camber kit to allow adjustment of the front negative camber beyond the -1.5 degree limit. I'm going to keep my eye out for that. Anyone know of where to get one?

I'll let you know if this setting helps at the track (other than decreasing the tire wear which I think it will, somewhat).

mt

[Teutonic_Tamer]

Interesting post, thanks.

So what were the actual manufacturers standard settings then (rather than what it was set at before your adjustments)? Because you have only increased the front camber by 0.3-0.4 degrees!

And have you run it on the track again? If so, does it change the handling?

[MotherTucker]

Anyone know offhand what the official alignment specs are?

Yes, I would have liked to have added a lot more negative camber to the front, but the stock adjustment mechanism there maxes out at -1.5. That's why I need a camber kit.

Haven't tried it on the track yet. Nov. 1 I will be going back to the same track I ran it on a few weeks ago before the adjustment (Barber Motorsports park in Birminham AL), so it will be a good comparison. I'll let you know if it seems any different.

mt

[desperado]

Here is a summary:

• Factory camber for the front axle is -1 +/- 1/6 degree, max difference left to right is 1/3 deg.
  
• Toe is 1/6 deg per wheel (1/3 deg total).
  
• Any time wheels are aligned, BOTH the front and rear must be checked.
  
• Wheels should not be aligned until after 1,000 - 2,000 km as it takes that long for the springs to settle.
  
• Caution: If the front axle settings are changed, the steering angle sensor must be recalibrated. (for ESP and ABS)

There is quite a bit more detail in the manual.

[MotherTucker]

Interesting - thanks Desperado, I think I'll talk to my dealer about that.

[desperado]

Interesting - thanks Desperado, I think I'll talk to my dealer about that.

Sorry to bump up an old thread however I'm curious what, if anything, your dealer might have said regarding the need for steering sensor recalibration after alignment.

[MotherTucker]

Ah, well I didn't ever ask the dealer about it, but I did take my R8 to the dealer for alignment, and all they did was align it.

I did look into it from other sources, and found that the steering angle sensor is used to detect when the front wheels are not turned, I.e. when they are pointed straight ahead, primarily for ABS purposes. The sensor needs to be recalibrated if you disconnect the steering mechanism or replace the steering wheel or other situations like that. Small symetric changes to alignment typically don't require it.

Here's some info I found on it, although this is not for an R8.:

"Calibration permanently stores the current steering whe
el position as the straight-ahead position in the steering angle sensor EEPROM. Therefore, the front wheels and the steering wheel must be set exactly to the straight-ahead position before calibration. In addition, the vehicle identification number is also read from the instrument cluster and stored permanently in the steering angle sensor EEPROM. On successful completion of calibration, the steering angle sensor fault memory is automatically cleared."

[musicom@yahoo.com]

I did the same thing last summer and maxed out the negative camber, etc. I was getting the exact same wear issues on my fronts. The race alignment definitely helps with performance and tire wear. However, we hit the same issue that MotherTruck identified: we couldn't get as much negative camber as we'd like.

If anyone knows of a good camber kit, there is interest here too.

[MotherTucker]

I heard PPI has one. I called Rich at OEMPlus, and he said he would check into it, but he never called back so I assume he didn't have any luck locating it.

mt

[desperado]

Here's the details on the PPI camber kit: Camber Adjustment: One for track regulars