Thinking about making a jump in tire size |
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Thinking about making a jump in tire size |
Woody |
Nov 6 2012, 06:06 PM
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#1
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Sandbox Rabblerouser and head toilet scrubber Group: Members Posts: 3,858 Joined: 28-December 10 From: San Antonio Texas Member No.: 12,530 Region Association: Southwest Region |
Im currently running the 205s and 225s Hankook Z214 AX tires. Even in the middle of the Texas summers they never overheated if I kept the pressures under 24 psi hot. Im wondering if running 225/45/15 front and 275/35/15 rear Hoosier A6s would be more of a detriment because the car is so light or should I just stick with the current size. I do have room for them under the fenders. The car is still an angry 2056 but will hopefully get a bump to 2270 or 2316 this winter. Thoughts?
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Woody |
Jan 27 2013, 06:00 PM
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#2
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Sandbox Rabblerouser and head toilet scrubber Group: Members Posts: 3,858 Joined: 28-December 10 From: San Antonio Texas Member No.: 12,530 Region Association: Southwest Region |
JP thanks for the advice. I intended to do some very similar bracing last weekend but life got in the way. It will be done before my next event. I like how you braced to the framerail instead of going to the firewall. The fronts are on 15x8s with a 20mm spacer and turn in was excellent, no noticeable understeer.
Randall the tires never got really warm. They were around 90 on the infrared but I was in the first run group and it was still a little cool out. The car is a completely different animal than last year. The Hoosiers are an inch and a half wider on each corner and blow last years Hankooks away. The setup with the Hankooks was spot on for the A6s. Didn't change a thing. I was very pleased with how it ran and nothing rubbed. This was my fastest run today. https://www.youtube.com/watch?v=xPTDnCa_KSw...be_gdata_player |
Randal |
Jan 29 2013, 02:45 PM
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#3
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Advanced Member Group: Members Posts: 4,446 Joined: 29-May 03 From: Los Altos, CA Member No.: 750 |
JP thanks for the advice. I intended to do some very similar bracing last weekend but life got in the way. It will be done before my next event. I like how you braced to the framerail instead of going to the firewall. The fronts are on 15x8s with a 20mm spacer and turn in was excellent, no noticeable understeer. Randall the tires never got really warm. They were around 90 on the infrared but I was in the first run group and it was still a little cool out. The car is a completely different animal than last year. The Hoosiers are an inch and a half wider on each corner and blow last years Hankooks away. The setup with the Hankooks was spot on for the A6s. Didn't change a thing. I was very pleased with how it ran and nothing rubbed. This was my fastest run today. https://www.youtube.com/watch?v=xPTDnCa_KSw...be_gdata_player That was what at 35 second run? Not much time to get heat in the tires. When you get a warmer day and PM run group, measure the tire temps (outside, middle and inside) on each tire and let us know what you find. Usually the backs are much hotter, by tens of degrees, than the front, so you'll we wondering how to get more heat into the fronts. (IMG:style_emoticons/default/biggrin.gif) Especially if you are experiencing understeer, i.e., the front washing out. One solution is to reduce the tire width in the front so that the heat secured is distributed over a smaller area all in the name of the most critical thing, i.e., figuring out at what operating temperature your tires get sticky and start providing more than just mechanical grip. If you are not to the "sticky" stage then you're not getting the most grip for your tires. That's why it's so much fun to run the Medford enduro. You are guaranteed to get a "sticky" tire as opposed to mechanical grip tire t some point over the +/- 3:50 minute course. When it happens you feel the grip and can increase your speed around corners. (IMG:style_emoticons/default/flag.gif) BTW, finding the understeer point in your car might take some pushing as you've set it up right, i.e., it's well balanced. IMHO the objective in autoxing is to get all tires to the sticky point so your grip is more than just mechanical. If you haven't been there, when it does happens it'll be an eye opener. (IMG:style_emoticons/default/w00t.gif) |
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