Tire input....

[L98Terror]

Is there a weight penalty in ST2 for running a race slick vs a DOT A6/R6?....other than the penalty to the wallet and tire life!

 

My understanding is that they last longer so in the long run you maybe better off

[mrc24x]

Is there a weight penalty in ST2 for running a race slick vs a DOT A6/R6?....other than the penalty to the wallet and tire life!

 

 

Aaron,

 

Subtract .75 from your wt/pw ratio for slicks over 10.5" wide. (You would need to be @ 9.45)

 

0r run 10.5"-9.6" slicks to get +.4 back. (Putting you at 9.05 after the race to be legal)

 

Examples on the ST2 Classification form:

 

http://www.nasaproracing.com/rules/supertouringclassification.pdf" onclick="window.open(this.href);return false;

[Aaron B]

Thank You for the info guys

[philstireservice]

I don't think a true slick lasts longer than an R6......A6's and slicks are relatively close in length of useful life, R6's would be a few heat cycles longer.

 

Although a slick might edge out an A6 in useful longevity by a cycle or two

 

Of course this is always case (driver) specific....

[L98Terror]

I don't think a true slick lasts longer than an R6......A6's and slicks are relatively close in length of useful life, R6's would be a few heat cycles longer.

 

Although a slick might edge out an A6 in useful longevity by a cycle or two

 

Of course this is always case (driver) specific....

 

Than what would the point be? My testing has shown the slick to be no faster than a A6, although it was very limited testing

[jrgordonsenior]

I'm pretty much in agreement with Phil here....

 

My experience has been that while new A6's are as sticky as new slicks (Michelin, Yokes, or Hoosiers), they go away mid-race especially if you're driving the bleep out of the car. Michelin and Hoosier slicks handle the heat and stress better and stay hooked up longer when reasonably fresh like 1-4 HC's. The Yoko 'club' slicks go away faster depending on compound. The A6's are great for TT's and qualifying, but they simply won't hold during a race at least in my 2800 lb. 996. On a lighter car like a 2200 lb. RX7, they may well respond completely differently. I've also found R6's get slippery during a race regardless of HC's. I think they're about a 1/2 second off the pace of slicks or A6's, but they do last longer than any of them.

 

I can't understand how a reasonably heavy Corvette like Ken's, with tons of HP, can finish a race, much less be hugely successful, on A6's. Please explain.....

[kbrew8991]

weight to tire size ratio. Corvettes do very well here...

[L98Terror]

I can't understand how a reasonably heavy Corvette like Ken's, with tons of HP, can finish a race, much less be hugely successful, on A6's. Please explain.....

 

 

It's easy, you know how a little kid has no idea about physics and pain so they are able to do things us adults wouldn't even try because we understand the consequences. It's just like that, I had no idea an A6 wasn't supposed to last an entire race, same goes for my starts nobody told me that you need to take it easy in the first couple corners because your brakes and tires are not up to temp.

 

See at Miller (ST2 Championship Race) my fastest lap of the race was on lap 14 which was within a couple hundredths of my second fastest lap on lap 9. Now during the STR2 race my fast lap was #2 yet by laps 11 I was still within a few tenths of that time the later laps were slow but it was also starting to rain.

 

I just don't understand this thing about A6s falling off.

[ryan0]

Now during the STR2 race my fast lap was #2 yet by laps 11 I was still within a few tenths of that time the later laps

 

I just don't understand this thing about A6s falling off.

 

this is what we tend to find... golden lap is number two..

 

the falling off i think is a result of some people really slide cars around, and some are smoother.

 

i've had some races where im dodging traffic and busting ass to get to the front that the lap times fell off by 3-4 seconds. but if you hvae your pressures right... and focus on smooth and fast... i find the laps fall off by only a second.

 

i also find.. like ken did... if its a new track to you... you actually get faster during the race... they are a solid tire during the race... after a few heat cycles, its a different story.

[philstireservice]

 

but if you have your pressures right... and focus on smooth and fast

 

 

This is the point !!!

 

 

All tires benefit from the above quote, but the tires with more grip, i.e., A6's and slicks benefit more !!!

[L98Terror]

Now during the STR2 race my fast lap was #2 yet by laps 11 I was still within a few tenths of that time the later laps

 

I just don't understand this thing about A6s falling off.

 

this is what we tend to find... golden lap is number two..

 

the falling off i think is a result of some people really slide cars around, and some are smoother.

 

i've had some races where im dodging traffic and busting ass to get to the front that the lap times fell off by 3-4 seconds. but if you hvae your pressures right... and focus on smooth and fast... i find the laps fall off by only a second.

 

i also find.. like ken did... if its a new track to you... you actually get faster during the race... they are a solid tire during the race... after a few heat cycles, its a different story.

 

Actually it really depends on traffic, With NASA I almost never get a clean lap and I can only remember one race last year when I wasn't in 1st by corner #1 being in the lead helps to conserve tires. I really have been focused on driving smooth laps and only going as fast as I need to.

[Holster Maker]

265/630R17 Hoosier R80 $380

_________________

http://philstireservice.com" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Toyo Hoosier Yokohama Goodyear

949 Racing Enkei D-Force

Race Ramps

 

Phil, It appears this tire qualifies for the rule adjustment: tire size 10.5" (267 mm) to 9.6" (244 mm) if non DOT approved, add 0.4, being 10.1" ...Right?

Thanks, Mike

[Greg G.]

It qualifies because it is a 265mm (under 267mm), not because it is 10.1".

[philstireservice]

It qualifies because it is a 265mm (under 267mm), not because it is 10.1".

 

 

well there ya go !!

[Holster Maker]

Thanks guys.

I'm having trouble with the HP vs slick deal. Esp where this tire gives me back .4, so I guess the question is HP or slicks, seems most people have the power over the slicks.

Almost looks like 265 slicks have the advantage.

My 265 slick deal is 348 hp @3155 = 9.06 -.75 = 8.31 + .4 = 8.71

or

Tune motor to 380 hp @ 3155 = 8.30 + .4 = 8.70

 

So is 32 hp worth running DOT R tires?

 

(I have five 275/17 Kumo 710's bagged in storage)

[L98Terror]

Thanks guys.

I'm having trouble with the HP vs slick deal. Esp where this tire gives me back .4, so I guess the question is HP or slicks, seems most people have the power over the slicks.

Almost looks like 265 slicks have the advantage.

My 265 slick deal is 348 hp @3155 = 9.06 -.75 = 8.31 + .4 = 8.71

or

Tune motor to 380 hp @ 3155 = 8.30 + .4 = 8.70

 

So is 32 hp worth running DOT R tires?

 

(I have five 275/17 Kumo 710's bagged in storage)

 

Actually it's .75 for the slicks and .4 back for running 265s

 

8.7+.35= 9.05 which is where your at now

[kbrew8991]

So is 32 hp worth running DOT R tires?

 

depends on the car, track, driver, etc, etc, etc. Testing time

[horsewidower]

Mike: Our cars are typically under-tired already. For most Norcal tracks, getting off the corner at a higher speed is going to be more important than terminal speed at the end of the straight.

 

Wait a minute, we're going to be racing each other. No go for the HP,

[Holster Maker]

Bob, Yeah, I believe KB is right. Tracks, etc...T-hill and Miller I'll pick hp, Infineon slicks, but I can't afford both / testing / swapping around like that, so I'll pass you on the straights.......

 

I guess I don't even know how to figure the worksheet when I thought I was a mathematician. I guess I'll stay with dot's, the math looks easier.

 

I'm confused................ What's my hp max for 3155lbs w/275 dot?

I thought 380..........right?

[kbrew8991]

download the excel calculator I've got posted

[L98Terror]

Bob, Yeah, I believe KB is right. Tracks, etc...T-hill and Miller I'll pick hp, Infineon slicks, but I can't afford both / testing / swapping around like that, so I'll pass you on the straights.......

 

I guess I don't even know how to figure the worksheet when I thought I was a mathematician. I guess I'll stay with dot's, the math looks easier.

 

I'm confused................ What's my hp max for 3155lbs w/275 dot?

I thought 380..........right?

 

You had it right my reading sucks

[Holster Maker]

Thanks Ken.

I was ready to forget ST2 and the alien math.

[ST#97]

Bringing this back from the dead and posting more useful info...

 

ended up bolting on some 1.5 year old scrub R6's...ran personal best lap times that were 2 full seconds faster. ended up removing rear sway bar to balance car. Can't wait to see how the fresh set of R6's work in August.

[TexaST-1]

Welcome to the light!

 

If you really want to go faster try a fresh set of Hoosier A6's. Very, Very good grip cold. just have to manage them in the heat.

[ST#97]

Welcome to the light!

 

If you really want to go faster try a fresh set of Hoosier A6's. Very, Very good grip cold. just have to manage them in the heat.

 

May try that once I find me another 25hp that I am currently short on. I am going to weigh my doors soon and find out if glass door skins will get me some less weight and will also be searching for even more weight cutting measures in the off season.

 

Might have to move over to R100's if Farrah keeps upping the ante!