997 street class autocross tires?
11-21-2013, 08:35 PM
#31
Most m/t p-cars are good for 70+ MPH in 2nd.. depending on how fast your local events are, I'd go straight to 285/30-18 & pick the shortest od front to match.
Does the +/-1" rule apply at either end or require all 4 wheels to be equally up/down sized? a 235/40-17 on 17x8 would provide the desired stagger, ~9" wide contact patch, & allow overall CG reduction of ~3/4" when combined w/ the 285 rear..
Does the +/-1" rule apply at either end or require all 4 wheels to be equally up/down sized? a 235/40-17 on 17x8 would provide the desired stagger, ~9" wide contact patch, & allow overall CG reduction of ~3/4" when combined w/ the 285 rear..
11-21-2013, 09:09 PM
#32
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Most m/t p-cars are good for 70+ MPH in 2nd.. depending on how fast your local events are, I'd go straight to 285/30-18 & pick the shortest od front to match.
Does the +/-1" rule apply at either end or require all 4 wheels to be equally up/down sized? a 235/40-17 on 17x8 would provide the desired stagger, ~9" wide contact patch, & allow overall CG reduction of ~3/4" when combined w/ the 285 rear..
Does the +/-1" rule apply at either end or require all 4 wheels to be equally up/down sized? a 235/40-17 on 17x8 would provide the desired stagger, ~9" wide contact patch, & allow overall CG reduction of ~3/4" when combined w/ the 285 rear..
If you start with the 19" XRR option, however, then you can +/- 1" your way into an 18x8.5 / 18x10 combo, which will work much better with most 285/30-18 rear tires.
11-22-2013, 10:20 AM
#33
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Yes, you can mix-and-match which wheels you +/-1", but if you go this route, then you're limited to a 17x8 front wheel and an 18x9 rear wheel (+/- 1" from the OEM 18x8 / 18x9 combo,) which IMO is a bit narrow for most 285/30-18 street tires.
If you start with the 19" XRR option, however, then you can +/- 1" your way into an 18x8.5 / 18x10 combo, which will work much better with most 285/30-18 rear tires.
If you start with the 19" XRR option, however, then you can +/- 1" your way into an 18x8.5 / 18x10 combo, which will work much better with most 285/30-18 rear tires.
I believe that if I elect to run the 8.5 width up front (to fit a 255), I also have to run the 11.5 at the rear. My concern is I think the 11.5 is too wide for a 285 tire.
11-22-2013, 10:30 AM
#34
Burning Brakes
Correct you have to use the same wheel option front and rear before electing to go +/- 1" at either end.
Yes 285 on 11.5 is fine, actually quite ideal for a picky tire like the RS-3.
Example of a 285 on 11. Note Extreme Summer tires tend to measure wider than more others so your fitment might be similar:
https://rennlist.com/forums/10714404-post8.html
Yes 285 on 11.5 is fine, actually quite ideal for a picky tire like the RS-3.
Example of a 285 on 11. Note Extreme Summer tires tend to measure wider than more others so your fitment might be similar:
https://rennlist.com/forums/10714404-post8.html
11-22-2013, 10:45 AM
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11-23-2013, 10:03 PM
#36
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Upon reflection, when you wrote that you are planning to use an 18x8.5 front wheel, you were referring to applying the Street Class +/-1" diameter allowance to the option code XRR wheels, correct? If so, then ignore my comments above about the rarity of used 18x10 Champion wheels, as the most common 18" size I found when I was looking was 18x11.5, which is just fine for you, but much too wide for me.
11-23-2013, 10:57 PM
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11-23-2013, 11:43 PM
#38
I've been keeping my eyes open for the same sizes in offsets that would be acceptable on a 997 C2S. Agreed - not easy to find.
11-24-2013, 08:09 PM
#39
Burning Brakes
Have some Forgestars made, about $1400 or so depending on style/options but in your custom size/offest with about a 6 week lead time. I like mine, no affiliation.
11-25-2013, 01:23 PM
#41
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OZ makes a fairly light, inexpensive wheel in 18x8.5 & 18x11 but again no 11.5 width.
11-25-2013, 01:28 PM
#42
:goes back into 17" hiding:
11-25-2013, 02:33 PM
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11-25-2013, 03:13 PM
#44
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The base 997 came with 18" wheels. At least in the early 997 years. You had to pay to get the 19" lobsters that came on my car. Maybe later on, they changed that? Anyway, I think the base (non-S) version can theoretically run with 17" wheels next season. At least in my very limited (and hence possibly erroneous) understanding of the rules.
I say theoretically run with 17" wheels because I don't actually know if it would be possible to bolt 17" wheels on a 997. Clearing the brake calipers might be a problem--especially with the larger S calipers. I looked at my calipers on my non-S and *think* I could shoehorn a set on there. Not that I'm going to try.
I say theoretically run with 17" wheels because I don't actually know if it would be possible to bolt 17" wheels on a 997. Clearing the brake calipers might be a problem--especially with the larger S calipers. I looked at my calipers on my non-S and *think* I could shoehorn a set on there. Not that I'm going to try.
Last edited by Rotmilky; 11-25-2013 at 03:33 PM. Reason: Edited for clarity.
11-25-2013, 04:28 PM
#45
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The base 997 came with 18" wheels. At least in the early 997 years. You had to pay to get the 19" lobsters that came on my car. Maybe later on, they changed that? Anyway, I think the base (non-S) version can theoretically run with 17" wheels next season. At least in my very limited (and hence possibly erroneous) understanding of the rules.
I say theoretically run with 17" wheels because I don't actually know if it would be possible to bolt 17" wheels on a 997. Clearing the brake calipers might be a problem--especially with the larger S calipers. I looked at my calipers on my non-S and *think* I could shoehorn a set on there. Not that I'm going to try.
I say theoretically run with 17" wheels because I don't actually know if it would be possible to bolt 17" wheels on a 997. Clearing the brake calipers might be a problem--especially with the larger S calipers. I looked at my calipers on my non-S and *think* I could shoehorn a set on there. Not that I'm going to try.
My dilemma is I want to run the optional 8.5" width on the front, meaning I also have to run the 11.5" width at the rear, and that width in a 18" diameter is hard to find...