FredC

How many 30 minute heat cycles can A6s last on a 2700# (all in) car? After how many heat cycles does performance advantage go back to R6s (same car)?

Thanks

bobt993

Fred what sizes? they don't last long. I have a set now for qualifying only and I plan to run two laps and come no matter how it went. In the cold 40degs they are great and would be optimal. Light rain same thing. Keep in mind my car is 2800 with driver and I have 275s up front and 315 rear.

FredC

225/45/15 front
275/35/15 rear

How about the SCCA guys who run them for entire races??????

Charles A. Toupin

I know of a 944 SP2 car using them for an entire race. He was starting from the back of the pack. He said it was a good thing to make up for that starting position. They were still good at the end of the race, for practice only.

c.

Greg Smith

Depends greatly on what kind of driver you are. I'd say between 6 and 30 HC's.

bobt993

Fred, Check with Dan Yonkers. He is running them in GT class on a light weight older 911. Ken Neilson ran them last year in his GT3 and would get a weekend out of them. It is going to depend on your driving style. I am just going to use them for qualifying, cold, damp tracks. No summer days. If your okay with using a set a weekend (race only) then your good to go.

FredC

don't know that - hard to say. How do they work for you?

Greg Smith

Never used the A compound, only R.

Bryan Watts

I find these discussions always depend on too many factors to give good advice to drivers I don't know well, but I can share that we got 4-5 heat cycles out of ours before they started to feel bad and change the balance of the car. I wouldn't call it going "back" to R6's, because tires don't tend to wear linearly at every corner, even with good rotation. Tires that start to heat cycle out tend to upset the overall balance of the car as they lose grip at different rates, at least in my experience.

Then again, some people will drive R6's for 30-40 heat cycles with little drop off in their laptimes. How hard and how close to the limit you drive is a huge factor.

FredC

Great info - thanks. Could a set of A6s with 3x30 min heat cycles then last for a 90 minute enduro? For reference, say a set of R6s last me 7 to 10 HCs before i notice the drop in performance that causes me to ditch them (they drop after 3 HCs but are still plenty good until 7 to 9).

bobt993

Bryan, what size rubber is on that car? I think the slicks I got from you way back were 240 fr, 280rr.

mark kibort

Ok Fred, ive studied this topic for some time now. Never used A6s before and heard the horror stories of how they would be dangerous for a road race. I remember following the cars with them for a few laps (noticed I said following) and waiting for their tires to explode in a 100 degree day! nope, no problems followed their progress over the entire season. these are good racers too, in very hot cars. (WCGT type times) So, when I had a chance to use some very new scrubs, i jumped at the chance. i got the pressure guidance, which was lower than my toyos, and much lower than hoosier advises, but heck these guys were flying, so I copied it all. my car weighed the same as them, and near the same as you Fred. so the advice was with the low pressures, they will take a lap or two to get into the "groove". true. when they get in the groove, hit them hard and they will last til the last 10mins of the 30min race, so just back off a second or so a lap and they will come back.

here is the thing. they have 6-800hp while I have 400hhp. i figure, if the are running 5 seconds a lap faster, im always in "back off " condition, right?
it was true. I hit the tires as hard as I can, they never went away, and im getting near 5 races out of them. (with qualifying.) this means since I get them with 4 heat cycles on them, im skinning them clean after about 12-14 heat cycles.

the sizes are 315, and recently started to use 315 and 335s in the rear. (since they are on small width rims, they are not fitting optimally, so there is no differnce in grip. just wasted extra size).

As Sofro's brother if my hoosiers are lacking grip after us going at it at laguna GTGP race. he was on slicks, I was on A series and actually did my best time ever in the last 3 laps of the hour long race!! They started out the 2 x 60 min race weekend, with 10 heat cycles in the rear and 6 on the front. the car was the best ever during the last laps of the race.

as a note, one of the WCGT guys was often running the As in Front and the Rs in the rear as he always had a big push in his turbo NSX . keep in mind, this guy did run a 1:29.xx at laguna on DOTs. and the tire sizes were 225 up front.

johnjohn

Quote:
Originally Posted by Greg Smith
Depends greatly on what kind of driver you are. I'd say between 6 and 30 HC's.

Greg is correct to point this out! from my experience with the A6 compared to the R6 is they come in much quicker so great for qualifying, for short races, and real advantage on cold days I.e. April or September to Nov.
I used them for a whole year and through enduros and had no noticeable issues, stayed consistent and even had a fastest lap on my 40th lap of a 44-45 lap race.


I did give a set to a friend that is as fast as me if not quicker on some weekend and I on other but we have different driving styles
and he chewed the front left at limerick in one sprint plus a 1 hour enduro, while this was happening he drop his times by almost1.8seconds and won both the sprint, enduro and fastest lap of the weekend in the sprint, and there lays the type of driver!!

I've been racing for4 years going on my 5th so this is my humble and personal experience and doesn't mean that is what will work for you but I do have add that sometimes just the perception of having an edge form the other makes you go faster so hey A6 it is again this year!!:
jJ

mark kibort

your right, it does depend on a lot of factors, primarily size of the tire, vs weight of the car and HP available. I think they are fantastic tires, but you can see the wear visably after each race, where with the toyos, that doesnt seem to happen. also, set up is critical. (and type of car) the 928 is really easy on tires , even wear wise. a 911 with 3 degrees of camber on a real fast track, might burn the inside edges and kill the tires after one day.

93 FireHawk 968

There's a few threads on this topic on the SCCA forum.