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Track wheel offset versus OEM

 
Old 10-24-2015, 05:51 PM
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ExMB
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Default Track wheel offset versus OEM

Looking at track wheels but it seems the offset on most is 50 which is bigger than the OEM offset of 61. So for test purposes I installed a 1/2" spacer on the OEM wheels for a comparison. I then took pics from the front and the rear.

Spacer - front view



Spacer - rear view



OEM - front view



OEM - rear view



My car at present has a 2.5 degree camber on the front. With the 50 offset I'm afraid that under a compression scenario the fender and tire would touch, possible good chance for damage. Looks like I have to go for wheels with a 55 offset on the front as a max to avoid touching. 3+ degree camber on the front is not an option for me since I plan on DD'ing the car a lot as well.

Hope this helps others going through the same process.
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Old 10-24-2015, 06:24 PM
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Rubbing? You got a baseball bat?

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Old 10-24-2015, 08:23 PM
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s2ktaxi
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jack up one of the right rear corner of that car so that you load the front and see how it goes.
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Old 10-24-2015, 11:59 PM
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Thanks for doing the test fit. I planned to do the same with a 5mm spacer, but now I can skip that. As you know TR has a relatively light weight, inexpensive 20" OZ with an 8.5" et 55 which should work for the front. The rear is not a problem (11" et 50). Unless something better comes along, that's my plan for track wheels.

Hope we see you April 22-24 for our advanced DE & PCA Club Race at Gateway.
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Old 10-25-2015, 11:52 AM
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Originally Posted by s2ktaxi View Post
jack up one of the right rear corner of that car so that you load the front and see how it goes.
Car has already been returned to std and spacers as well.

Your idea has merit, but keep in mind that your suggestion is for static forces and doesn't necessarily represent dynamic forces encountered during a track event. The thing to remember is that this test was done with the std 8.5" wide OEM wheel. If someone decides to go with a 9" wide wheel (GT3 size) you will also encounter a section width increase of the 245 tire of ~ 1/8" per side. Of course you can go with a smaller 235 tire but there are already some on here wanting to go with a wider one to help combat understeer.
The applicability of this test can be expanded to other than std wheel diameters for future reference once -1 or -2 sizes tires become available, ones that would maintain OEM OD in those configurations.
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Old 10-25-2015, 09:51 PM
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STLPCA,
Which OZ wheel do you see on TR with 50mm offset and 11" width? All I see by OZ for the GT4
are 10" rears. I have run 18"OZ Allegeritas on a 2010 CS and love them, but I don't see a 19x11
with the right offsets for the GT4.
CB
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Old 10-25-2015, 10:01 PM
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Originally Posted by ceebee View Post
STLPCA,
Which OZ wheel do you see on TR with 50mm offset and 11" width? All I see by OZ for the GT4 are 10" rears. I have run 18"OZ Allegeritas on a 2010 CS and love them, but I don't see a 19x11 with the right offsets for the GT4. CB
20" O.Z. Leggera HLT wheels in black or silver/grey. (change selection to 20x11)
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Old 10-25-2015, 10:13 PM
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Thanks, but I want 19s to mount Hoosiers for tracking.
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Old 10-25-2015, 10:16 PM
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Originally Posted by ceebee View Post
Thanks, but I want 19s to mount Hoosiers for tracking.
If you want to go with 19 you will need to select the MY '12 Carrera 4S to get 19 x 11 with an ET50. Don't forget to search on here in the other threads regarding fitment requirements of 19.
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Old 10-25-2015, 10:31 PM
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ExMB,
Thanks. I had been looking at the Carrera 2S. I believe those for the 4S can work.
CB
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Old 10-26-2015, 12:04 AM
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It seems like most, if not all, of the under steer can be dialed out through an alignment and sway bar settings, but it will be interesting to see if slightly wider front tires end up being the sweet spot.

If the MPSC2s end up getting terrible treadwear on the GT4s, I'd be tempted to get a second set of wheels and use MPSSs as my daily driver tire and swap the wheels out for the track. You can practically get a new set of OZs for the price of a set of MPSC2s.
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