mark kibort

A6s last as long as any other R compound tire. not quite as good as the harder slicks out there , that dont fall off as much.

the trick is ending pressures of about 30psi. the 600hp mustangs are using them for our near 20 lap races. no issues. they are pretty nice. and only slightly better than the Rs we had a lot of experience running same cars back to back on same days , same tracks with the R6s vs A6s, on slow and fast cars in the pack.

I told this story before, but whe these big powerful mustangs showed up with As, we were laughing thinking that they would explode after a few laps, but in the end, it was them who were laughing on the podium. (and me too, because thats when i started getting a bunch of their used scrubs! )

im trying some R100s this next weekend at sears. should be interesting

PS, that pressure i quoted is for the big 18" sizes. dont know what happens on the 17s or smaller 245 tires. however, Kip Olseon , in his monster NSX turbo with 600hp, ran them A6s on the fronts 225s and Rs in the rear.

Mk

ukrbmw

I don't mean for this to come off as arrogant but you might be overdriving them. It doesn't matter what kind of tire it is - it'll never be as good as new after 10-15 heat cycles. What I was trying to say is they were still very grippy and ran some extremely good lap times on 10+ heat cycled tires.

I understand there are no prizes, but we would be doing DEs and not racing if it didn't matter to everyone. Walk over and look at most ST2 cars - most are 3,000+ pounds, running A6s for 40 minute races and do pretty well (they are all putting down 350-400 hp range). These tires do last better than most give them credit for.

Ritter v4.0

Wait a second, classification and longevity aside, these (A6) are not faster than the equivalent Hoosier slick (say R80) are they? Or does the softer stickier compound make up for the contact patch delta?

J richard

yes I'm confused. who's actually run these new and compared them to R6 or hoosier slicks? was thinking about trying either the slicks or A6 on the boxster for GTS...

ProCoach

That's correct.

I have, on an F430C. Same day, same track, same driver. The A6's come up to temp quicker, ARE a little quicker, do appear to get greasy if overdriven and we're going fast enough so that no way do we get race winning performance for more than three cycles (on any tire). The R6's a better in VERY high ambient (90 degrees plus or 120+ track temps) and the slicks beat them all. YMMV.

racing916

This was a recommendation from a Hooiser race tire distributor...

"Tire Pressure Recommendations For Competition Traditionally, Hoosier tires have often required higher pressures than other brands. This has changed with the A6/R6. Roadrace/track applications

Vehicle size
Recommended Hot Pressure
Cold Pressure

1800-2200 lbs.
34-37+
26-31

2200-2600 lbs.
35-38+
27-32

2600-3000 lbs.
37-41+
27-32

over 3000 lbs.
38-43+
27-33

I think these pressures they suggest are a bit high. On my car with driver and gas about 2050 lbs. I usually start at 20 cold front and 21 cold back with the R6's and usually see a high of 29 to 30.

Steve

993PET

What pressures are you running hot on R6's? My 2950 lbs RS America (inc me and gas) is best at 34 all round hot, which is quite a bit lower than Hoosier recommends. This is after 3 seasons of fine tuning, any higher than 36 they get very greasy.

Regarding longevity R6, A6. I downgrade my R6's to practise after 12 heat cycles and scrap them at 20 heat cycles. From what I'm reading here the A6 is faster than the R6 but won't last as long either heat cycles or race distance and is more sensative to ambiant heat.

I'd love to run a set of A6's but adding yet another set of wheels and tires (I already have 3 including wets) is probably not going to happen.

JF

333pg333

To clarify. Some of the events we run down here are Sprint events. That is, a competition Time Trial. So you are on the track at the same time as people running the same speeds but not necessarily your competition class. While there is a bit of dicing occasionally, it is not strictly door to door stuff. This consists of one out laps and probably 3 hot laps, then a cooldown. Sort of like a qualifying session. So the tyre needs to come up to temp quickly and give you max grip for a short period. The car is a highly modified 951 currently at 400bhp / 2600lb wet no driver. It is being rebuilt with circa 600bhp and will lose approx 50lbs.

My experience with advice from Hoosier is questionable. I get the impression that their expertise seems to be still in a different format of racing.

mark kibort

no, R80s and even R100s are faster, come up to temp slower but more grip and dont go away at the end of a 30min sprint , even at hot ambient temps

our entire group has been running all three for a few years now. A6s are the best value, and no draw backs over a R6, other than probably a little faster wear. they dont seem to heat cycle out as badly

yep
dont listen to tire guys, they are usually the last to know and only have the info from someone that has the time to talk to them.

3000lbs and less , run the A6s at about 30psi hot for the big tires. and more like 32 hot for the smaller sizes. the real fast guys that run GT3 supercup times, (really fast) start out at near 22psi cold, where i start near 24 and 25psi to get the same ending pressures as the guys 4-5 seconds faster a lap and with the extra 200hp over my racer.

R6s are more in the 34 to 38 range hot for best performance.

onefastviking

^^^ Exactly !

The part about "race winning performance for more than three cycles (on any tire) " , is a key point and one that I think throws off, or causes a variance in what some peoples different opinions are regarding the amount of heat cycles available from a given tire. If you are driving at 90% of the tires potential then you CAN get more heat cycles out of them.

onefastviking

I've commented on this numerous times, but tire pressures can,AND SHOULD, vary from car to car, depending on what the car has modified, the drivers driving style and abilities, the track conditions, the race conditions (race time), the car set up, and many more variables. Probably the largest variance I see routinely is the difference between peoples air pressure gauges. If you ask me the pressure I use but my gauge reads 3lbs higher than your gauge, than you running my pressure numbers set with your gauge sure won't work the same will it.

Find what works for you and your particular car by taking tire temps and hot and cold pressures and ALWAYS use that same gauge, preferably having it calibrated from time to time or at least checked against another known accurate gauge. Also, if you don't understand how the tire temps and pressures can work to your advantage then hire a coach that understands it and can help you understand it for a weekend or even a day, it's well worth the expense.

333pg333

Ok, so how about this. How long does it take (on average) for heat up temps of the A6 vs R80 ? R spec tyres seem to come up to temp within a lap, sometimes seemingly less. Slicks, seems as if it's more in the 1-2.5 laps, yes/no?

onefastviking

Assuming say a 2 mile average track, then yes, A6's in half to 1 lap and you are good to go. R80/R100's and you better wait till lap 2 to really push them.

333pg333

So it's potentially line ball as to which might give the best result over such short events. I was considering trying Michellin slicks at some point but I've heard they take a little longer again vs the Hoosier slick.

ukrbmw

Patrick - I'd hesitate to run A6s with 600hp for anything more than 2-3 lap time trial session. Putting that much power through them will overheat them pretty quickly.