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      07-17-2013, 10:23 PM   #1
nilfinite
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Autocross Tires: Widest or Lightest?

Getting a set of autocross wheels & tires. 18x8 wheels to stay within SCCA stock guidelines while also getting a square setup.

I've read somewhere in the past that its best to fit the widest tires possible on the wheels for autocross. Is that true? Or is there a balance between tire size and tire weight?

Thanks!
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      07-23-2013, 02:40 PM   #2
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I am no expert but that's not true. It's all about stickiness of the tire. Also lighter tires will get more benefits than having light weight wheels.
Wider tires= heavy tires. Especially for autocross, you want ur car to be quick.
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      07-23-2013, 09:06 PM   #3
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Quote:
Originally Posted by Forgiven View Post
I am no expert but that's not true. It's all about stickiness of the tire. Also lighter tires will get more benefits than having light weight wheels.
Wider tires= heavy tires. Especially for autocross, you want ur car to be quick.
Definitely agree about the stickiness. Assuming the same tire, just wondering what would be best.

Based on a bunch of research, I looks the most people say you should get the widest tires you can fit (within reason).

http://farnorthracing.com/autocross_secrets4.html
http://drivefast.org/novice-tips/tire-tips/
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      07-23-2013, 09:43 PM   #4
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Quote:
Originally Posted by Forgiven View Post
Also lighter tires will get more benefits than having light weight wheels.
Not sure I agree with this since both the wheels and tires are unsprung weight. You want light wheels AND light tires if you can, but either or will help with handling over the stock boat anchors. Sticky rubber + light wheels = a World of difference in handling. I use Apex wheels (18.1 lbs ea) with Hankook Rs-3 rubber. I only use these for track events and autocrosses and every time I switch out my OE run flats and stock wheels to the "race" set up it feels like I bought a new car! Improved braking, turn-in, grip at the limit and greatly reduced understeer are all positive by-products of a light and sticky wheel/tire set-up.
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      07-23-2013, 11:43 PM   #5
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Originally Posted by Alpine F31 View Post
Not sure I agree with this since both the wheels and tires are unsprung weight. You want light wheels AND light tires if you can, but either or will help with handling
Of course wheel weights are important as tire but since tires are effecting rotational mass more than wheels. The tire weight does matter more than wheel weight... HOWEVER, tire grip matters more than small losses on weight. Losing wheel weight is an essentiall penalty free performance bonus... My main point here is sticky tires->then tire and wheel weights. Do not simply go wider tires and add more weights for no reasons.
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      07-23-2013, 11:47 PM   #6
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Quote:
Originally Posted by nilfinite View Post
Definitely agree about the stickiness. Assuming the same tire, just wondering what would be best.

Based on a bunch of research, I looks the most people say you should get the widest tires you can fit (within reason).

http://farnorthracing.com/autocross_secrets4.html
http://drivefast.org/novice-tips/tire-tips/
When I drove my AH3 as stock, I felt I didn't need to go with wider tires at all. Car handles just fine with very min. understeer. I am planning to go with 245/40/18 square.
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      08-05-2013, 12:51 AM   #7
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Arent stickier tires heavier?
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      08-05-2013, 01:26 AM   #8
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Yar with bigger sidewall n stuff, also we don't much choice like we do on wheels..:/
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      08-06-2013, 10:09 AM   #9
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I was just wondering about something similar to the OP's question... is it worth squeezing in a 9" wheel up front (for a little more tread width) when it's a couple pounds heavier than the 8.5"?
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      08-06-2013, 11:50 AM   #10
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For my wheels at least (403M), they're 8" up front and 8.5" in the back. So I'd say it's probably worth it.

Plus the 403Ms aren't lightweight wheels. If I wanted to reduce unsprung weight, I'd get rid of the RFTs first and then the wheels second.
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