Are they not the rain compound with grooves cut into them?

 

Good info. Thanks for posting. Seems like the performance differential isn't that big for you.

Chris M: the records i am referring to were set in qualifying.

 

Bruce, I thought "autocross compound" tires were illegal in PCA Club Racing 3-4 years ago and then the ban was lifted 2-3 years ago... Sorry I guess I was wrong.

Fred, I would consider A6s IF I thought I could get a full weekend on one set (2 Sprints and an Enduro). Currently, I show up with a set of newer "race" tires and a set of "practice" tires. To enter A6s in the mix I would need another set of wheels because I can't imagine that A6s stay good during a 90 minute Enduro (hell, even my R6s struggle during an Enduro)... but again I could be wrong.

And Bryan's data (very helpful BTW) isn't sweetening the deal.

 

Anyone have some numbers or experience with Kumho V710's compared to A or R6's.

 

Yes, we were setup for R100's because that's what we normally run. We only ran A6/R6 in order to fit down into a lower power/weight class for that weekend.

I think the R100's are faster if you're talking a wide open track under testing conditions where you can get the tires up to temp and then hammer out a fast lap. But, on a weekend with lots of traffic, every lap is a little bit different and you are often catching traffic before the first lap is over due to staggered starts. It's entirely possible I could have gone faster on the A6's than the R100's had one of the laps worked out a little better...I don't buy the 2-5 second different that you'll read about from others. It's most often those who are running R-comps who pull these huge numbers out of the blue to help explain why they are 3-4 seconds slower than a similar car on slicks.

As for R80/R100, I've only run the R80's a couple times, but based on feel alone, the difference seems to be more about how they come up to temp than overall grip/laptimes. I'd need to do some back to back testing to really know much more.

 

The guys that ran between A6s and real slicks probalby more than anyone in the country, ran with us out west in SCCA. It seems their best times on the slicks were about 1 second faster. however, the car that did this most, was running some pretty small sizes up front. Anderson, in his lightning fast 928, usually runs about 2-3 seconds slower on DOTs. (toyos) and even JR was telling me his best DOT time (hoosier) was 138 at laguna, and now runs in the 1:35-6s on new slicks. I dont think its a streatch to class the slicks 1-2 seconds faster, and maybe 1 second between all the different types of R coupound tires. It was hard to tell the difference between the Rs and the As. but the main difference was how they came into temp faster (or got stick faster). when both were hot, they both were a lot better in grip than the toyos, and was about 1 second difference at the tracks I know well.

 

Mark it was a full 3 seconds faster with new Hoosier slicks versus new R6's. I actually raced that same set of slicks w/18 HC's Saturday at Spring Mountain. I was 4 seconds off my qual laps on stickers, but they worked well enough for the race....

Almost all the Corvettes and tube framed Mazda GT's I run against in NASA's ST2 class use the A series Hoosiers. It's my experience that they go away on them about 20 minutes into a race....

 

How much longer does it take to get the R100s up to heat vs say the A6s?
If you were running really short burst events such as a Time Trial or SuperSprint (often only 3 hot laps) would it be better to stick to the A6s?

Of course cars, tracks, temps, driving styles all add/subtract to the mix...but in general?

 

It takes like 2 laps for me (maybe I'm not aggressive enough with the warm up) stick to the A6s for TT

 

I raced on them recently in a 3 hour enduro at Road Atlanta in 70F ambients. Took about a full lap before they were really working. This is after an approximately 10 minute pit stop.

 

The R80/R100 combo that I've tried took much longer than the R6's I was previously using. I've never run A6's, but I'd assume they're similar to the R6's. I went hot on the second lap at Laguna and went 2-off at T6 with the Hoosier slicks. That would have never happened with R6's....

 

I think my toyo RA1s are much more confidence inspiring the first lap after warm up. but after the A6s get hot, they are very grippy! just feels like a lot more bite everywhere. I think you could get the A6s to grip in a TT to a greater degree, IF you really know how to warm them up on the warm up lap. Limerock might be tough, but laguna or longer tracks should be fine. if you are stuck behind a slow pace car, good luck . first lap will be a little dicey compared to toyos in any weather.
again, my opinion and experience.

 

This may or may not help since my exp is in a GT3 at 3200 pounds. I use A6s for time trials and I can pound them pretty hard on the warm up, by T1 they are like glue and stick pretty well. A6s are about 2 seconds faster on my car then NT01s and I'm guessing same would apply to RA1s. I actually bought a set of Hoosier slicks in R80/100 compound, but don't have another set of wide wheels to mount them on.

I also ran a nice 30 minute session on the As and they didn't drop off much towards the end. Was still lapping within a second of my average time.