"Street" Tires and Wheel Width
#1
Safety Car
Thread Starter
"Street" Tires and Wheel Width
So what do you folks think about the new SCCA Street Classes and their relevance to wide street tires on narrow wheels?
I've heard of and saw (for example) S2000's running 275/40/17 Hoosiers on their narrow 7" wide front wheels. I suppose this works with Hoosiers, but I suspect that street tires will NOT work in such a fashion.
I suspect the widest anyone can make work is a 245 width or something like that.
For another example:
Lets take a C5 B Street car it can run +1 in the front so 18's all around are ok, but only 8.5" wide up front is allowed. Of the two street tires that actually work pretty good the only available sizes that "fit" (by the rim width range on Tirerack) is the 255/35/18 ditto with the stock 17's only 255/40/17 instead. Is that the widest that will "work" or will squeezing a 275/35/18 on the 18X8.5 be better?
Is there a point of diminishing returns?
I also think that car weight, gearing, HP, TQ, will factor in more now with the street tires. Case in point the lighter (compared to a C4) C5's have about 50 more HP and 35 more TQ. So adding rear tire would help as I suspect the C5's are going to have an issue with putting power down compared to a less HP and TQ and heavier C4. A C4 can wear the same size wheels and tires (bigger up front) thanks to the +1 rule. Where as with Hooiser's this is never an issue?
Thoughts/comments on my random Sunday night thoughts?
I've heard of and saw (for example) S2000's running 275/40/17 Hoosiers on their narrow 7" wide front wheels. I suppose this works with Hoosiers, but I suspect that street tires will NOT work in such a fashion.
I suspect the widest anyone can make work is a 245 width or something like that.
For another example:
Lets take a C5 B Street car it can run +1 in the front so 18's all around are ok, but only 8.5" wide up front is allowed. Of the two street tires that actually work pretty good the only available sizes that "fit" (by the rim width range on Tirerack) is the 255/35/18 ditto with the stock 17's only 255/40/17 instead. Is that the widest that will "work" or will squeezing a 275/35/18 on the 18X8.5 be better?
Is there a point of diminishing returns?
I also think that car weight, gearing, HP, TQ, will factor in more now with the street tires. Case in point the lighter (compared to a C4) C5's have about 50 more HP and 35 more TQ. So adding rear tire would help as I suspect the C5's are going to have an issue with putting power down compared to a less HP and TQ and heavier C4. A C4 can wear the same size wheels and tires (bigger up front) thanks to the +1 rule. Where as with Hooiser's this is never an issue?
Thoughts/comments on my random Sunday night thoughts?
#2
Burning Brakes
This is common on R comps but I've read it's less advantageous on street tires due to sidewall flex.
Seems like a 275 on an 8.5" wheel width should still work okay since it's only 1/2" narrower than the recommended minimum width.
Seems like a 275 on an 8.5" wheel width should still work okay since it's only 1/2" narrower than the recommended minimum width.
#3
Melting Slicks
Keep your eyes and ears open. Someone in sunnier clime's will test and figure it out pretty quickly. The folks in Cali run all year round and I am sure that there are folks testing as we speak. Network and find out what is working for them and then test yourself... If you can find several folks to get together with, split up the cost of three or four sets of tires and go out in the spring and burn them off.... Watch the SCCA forum and watch what wins on the west coast winter events. Ask what tires they were running and someone will know what tire and size is working.
It's pretty easy when someone wins, his car is in impound and everybody can see what he's running... No secrets out there after the first event..
It's pretty easy when someone wins, his car is in impound and everybody can see what he's running... No secrets out there after the first event..
Last edited by Solofast; 11-25-2013 at 11:35 AM.
#4
Safety Car
Thread Starter
Keep your eyes and ears open. Someone in sunnier clime's will test and figure it out pretty quickly. The folks in Cali run all year round and I am sure that there are folks testing as we speak. Network and find out what is working for them and then test yourself... If you can find several folks to get together with, split up the cost of three or four sets of tires and go out in the spring and burn them off.... Watch the SCCA forum and watch what wins on the west coast winter events. Ask what tires they were running and someone will know what tire and size is working.
It's pretty easy when someone wins, his car is in impound and everybody can see what he's running... No secrets out there after the first event..
It's pretty easy when someone wins, his car is in impound and everybody can see what he's running... No secrets out there after the first event..