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Question about running 275/40/18 square with T1 sway bars on C5

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Old 05-17-2019, 09:53 PM
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evolmotorsprt
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Default Question about running 275/40/18 square with T1 sway bars on C5

I'm currently working my way through NASA DE's and looking to get a stickier set of tires for the track. My plan is to run 18" wagon wheels with 275/40/18 RS4's all around. Right now I'm running Z51 springs, DRM Bilsteins, and T1 sways. For those of you that have gone to a square setup with T1 sways, how are you liking the balance and what setting is your rear bar? I like a little lift off rotation but I don't want to be having to fight the back end coming around constantly.
Old 05-18-2019, 11:29 AM
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SocalC5Z
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I'm running my C5Z with 275/35-18 Maxxis RC1's square on ZO6 10.5 X 18's, T1 bars and shocks, with an aggressive track alignment. The car is very well balanced and I have found that with enough rear camber, the back end sticks very well. I run the rear bar in the middle position and really use tire pressure to balance the handling at this point. I've run a larger tire (square) as well and that improves the rear stick to the point where I tighten up the rear bar on tight courses. Contrary to what you may read, the car is not a monster on smaller sized tires. Most people are so far from optimizing their alignment settings that many who run larger tires don't get the full benefit. .

Last edited by SocalC5Z; 05-18-2019 at 11:30 AM.
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Old 05-18-2019, 06:20 PM
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evolmotorsprt
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Originally Posted by DunlevysZ
I'm running my C5Z with 275/35-18 Maxxis RC1's square on ZO6 10.5 X 18's, T1 bars and shocks, with an aggressive track alignment. The car is very well balanced and I have found that with enough rear camber, the back end sticks very well. I run the rear bar in the middle position and really use tire pressure to balance the handling at this point. I've run a larger tire (square) as well and that improves the rear stick to the point where I tighten up the rear bar on tight courses. Contrary to what you may read, the car is not a monster on smaller sized tires. Most people are so far from optimizing their alignment settings that many who run larger tires don't get the full benefit. .
I hear you. I like the idea of the smaller tires for weight and cost. My plan for alignment is:

camber:
F: -2 R -1.5
toe:
F: 0 R: 1/8” total toe in

I figure I’ll start around 34psi hot all around with tire temp and adjust through the session. Also, I’ll try the rear bar in the center position. With my current staggered setup I run it full stiff.

If if you have any recommendations beyond that I’m all ears.
Old 05-19-2019, 11:21 AM
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SocalC5Z
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I think your numbers are a good place to start.My current alignment is F -2.2 Camber, +7.2 Caster, 0 toe. R-1.5 Camber, 1/8 toe in. As noted previously, these numbers are based on track tire temp, wear and vehicle balance. I did not start out with these numbers. With the Maxxis RC1's I end up with 35-36 hot tire pressures. I decided to try the Maxxi RC1's and the largest size is 275, so that's what I'm running at the moment.. I've run larger tires square with other R comps. If the Maxxis came in a wider size I would have gone larger..

Last edited by SocalC5Z; 05-20-2019 at 07:02 PM.
Old 05-20-2019, 06:51 PM
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davidfarmer
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I run square due to rules limitations. On my practice tires, and I have to be very careful, even with pretty aggressive wing the back end really wants to come around. However, when I put the good tires on the problem goes away. As with any setup, you can dial it in with camber, tire pressure etc. I'd probably run the rear bar full soft first time out, then stiffen as feedback allows
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