SCCA C Stock Discussion

[vroom4]

The car handles like a dream on the R1S. Its already easy to drive on the street tires...on the R-compounds you feel like a superstar.

Im about to head from work to do my course design for the weekend...AMPED! Last event of the CSR class

[7thgear]

Originally Posted by bimmer635csi

I thought the Hoosiers required major amounts of camber to be effective. That might hold the CSR cars back a bit.

no, they require camber to be optimal


simply having them is more than effective

[rx3]

Originally Posted by gconcept

Pax indicates CSR is a little bit faster (.834 vs .827). The top STX driver pax'ed 114 of 1157 which is fair enough. No one drove in CSR but the consensus is that the pax is pretty soft - or maybe that's just relative to CS.

I'd say I'm typically around 3% slower on street tires (treadwear 100) than the fastest guys running on racing slicks (same class of car) and I was wondering whether one would gain 3% just by switching to racing slicks alone.

All cars in the US appear to run on DOT-approved racing slicks - is this due to the rules applicable or because of tire availability?
(Avon is for instance a brand which is often applied around here and is also available in very soft compounds: http://www.avonmotorsport.com/resource-centre/compounds DOT-approved racing slicks on the other hand are not sold here.)

[vroom4]

Rules. Avons and other compounds of hoosier are run in higher classes such as prepared.

[qoncept]

Originally Posted by rx3

I'd say I'm typically around 3% slower on street tires (treadwear 100) than the fastest guys running on racing slicks (same class of car) and I was wondering whether one would gain 3% just by switching to racing slicks alone.

I'd say 3% is pretty close. Pax shows a difference of about 1.5% between the classes but as has been said, CSR has a soft pax and CS seems to be a little too high. I definitely think they gained me at least a second on a 60 second course. I was actually using the harder of the 2 Hankook Z214 compounds so I had some time to gain in CSR, too.

Originally Posted by vroom4

Rules. Avons and other compounds of hoosier are run in higher classes such as prepared.

I should just go look at the rulebook but aren't DOT tires required in prepared class too? Thought it was just modified that was open.

[vroom4]

Any tire (including recaps) meeting the Solo safety requirements and

the applicable portions of 3.3 is allowed.

[chkltcow]

Originally Posted by qoncept

I should just go look at the rulebook but aren't DOT tires required in prepared class too? Thought it was just modified that was open.

Nope. A friend runs the S2000 "Frankenstook" in FP class and is on Avons. He tested with the Goodyear bias ply, but they were crap. He went to Avon and hasn't looked back.

[rx3]

Originally Posted by qoncept

I'd say 3% is pretty close. Pax shows a difference of about 1.5% between the classes but as has been said, CSR has a soft pax and CS seems to be a little too high.

The comparison would be an STX (without power mods) with R-compound tires against an RTR/CS with street tires.
How much faster is STX compared to RTR?
(That plus the 1.5% may give the approx. total potential difference.)

[xwd]

I ran Hoosier A6s last year in 245/40/17 on stock sized rims. A few times some pretty good RX8 guys came out like Dennis Sparks and Jason Ruggles and I'd say a CS BRZ with A6s was about the same as a good STX car maybe a little faster. The top CS (race tire) cars from last year like the MX-5 MSR and Solstice were a bit faster than STX.

This is on not so grippy asphalt. Nationals is run on concrete which favors the race tires more that's why you usually do not see a lot of ST cars at the top PAX wise. You also see a lot more SP/P/M cars near the top of PAX than you would at an asphalt site.

[mla163]

Wrote my letter requesting the Z be moved out of CS. I'll play with apples to apples sports cars, but that orange has more power and tire.

[Kido1986]

Decisions have been mostly made from what I understand, we'll know October 20th.

Really hoping they moved the Z to BS and FiST to HS

[TrqlessWonder]

Originally Posted by rx3


How do C-Street on R-compound tires compare to
the STX-cars timewise?

Which class is typically faster or are they about
the same? (Do the mods allowed in STX make up for the tire disadvantage?)

Originally Posted by qoncept

Pax indicates CSR is a little bit faster (.834 vs .827). The top STX driver pax'ed 114 of 1157 which is fair enough. No one drove in CSR but the consensus is that the pax is pretty soft - or maybe that's just relative to CS.

In my own experience, my pax time in CSR was pretty comparable to a fully prepped RX8 with a good (as in better than me) driver at most local events.

Yeah, on index, it says we should be faster than STX, but against tour-trophy level STX guys, I never really got all that close. Some I could outdo on index, better drivers could get me on raw time.

I think it's more that CSR isn't soft, but CS (along with most of street) were given a tougher hill to climb relative to the other categories.

When you think about it, my car on hoosiers feels like it should be right about even with a proper STX car. One crap ton of grip versus lots of suspension trickery and significant help under the hood. But, the CS/CSR index isn't set at the twins level of performance necessarily, but rather is skewed a bit towards what a 370z is capable of (remember, PAX is an attempt to describe the statistical pointy end of the class, not the mean/median/mode of everybody). STX has no such animal to worry about as the new Z goes to STR and the 350 goes to STU.

As much as I hate to say it, I'm starting to buy into the idea of the 370 needs to be moved up. I would still like to actually run against one first to see it for myself, though.

[justint5387]

I think 370z should stay in CS.

[vroom4]

I will fight you sir.