205x45 17 or 225x45 17 for auto x

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Slow24
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Joined: Mon Nov 21, 2011 9:58 pm

205x45 17 or 225x45 17 for auto x

Post by Slow24 »

Hi Brian

I have two sets of wheels both with Hankook Ventus Evo V12 tires. The 205,s are on the stock wheels and the 225's are on RPF1 7.5's. Which combo would you suggest for auto x? I ran the 205's and the did well with 33psi cold. I did notice the I need to bump up the camber a little bit more. I am concern the the 225's would have too much roll over and my sharp steering might suffer. I have spoke with some and they told me that the 5sp is better for auto x. If that is so the 225x45 would give me taller gearing If you suggest the 225's what cold presure would you start with.
I used to road race in the W.C. Honda challange and it was much easier when you had to run a spec tire!

Thanks in advance.
Brian
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Re: 205x45 17 or 225x45 17 for auto x

Post by Brian »

Hmm, I would likely race the set with the most FRESH set of tires. The Hankooks are amazing new, and drop off quickly with age. Thus, if one set is half the age of the other....then I would expect it to be a few seconds faster.

You are certainly right that the 225 on the 7.5 will be slightly more sloppy to steer then the 205 on the 7 inch but it should still be slightly faster if the tires are equal freshness. The exception "may" be if totally stock suspension (depending on surface grip and other variables). If suspension totally stock then the 225 may lean the car so much that it lifts a tire and the car plows rather hopelessly. So, assuming at least front sway bar upgrade and set of KONI Sport shocks I would want to run the 7.5 wide and 225 combo.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
Slow24
Posts: 2
Joined: Mon Nov 21, 2011 9:58 pm

Re: 205x45 17 or 225x45 17 for auto x

Post by Slow24 »

Thanks for the quick reply. My suspension has been upgraded with HTS's and springs, F300 R180 and bigger bars on both ends. Right now the car is just pure neutral and has just enough throttle over steer to make it fun. Sounds like I will try the 225's at El Toro next weekend. Any suggestion on cold starting pressures??
Brian
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Re: 205x45 17 or 225x45 17 for auto x

Post by Brian »

I like less pressure than most, I would start 30 psi cold.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
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