Slakker

Can someone quantity for me the difference between R7s and Racing Slicks?

Veloce Raptor

Slicks = more grip

wanna911

1-3 seconds per lap, assuming Hoosier Slicks. Maybe more if Pirelli, Michelin, Dunlop.

R7 are more forgiving, but slower.

linzman

$$$$$

wanna911

Oh yeah and that too.

mark kibort

The main difference of a Slick vs a DOT is the construction of the tire.
often, the DOT slick and the racing slick can share a similar compound of softness. Slicks incorporate, very very stiff sidewalls, some times, and other times, a side wall that feels as thin as a balloon. They are not built for road safety and comfort, but for reduced weight and compliance. they are designed to give the maximum of grip at the lowest slip angles and percentages.


Not always... you see , there you go again.... more absolutes you critizise others from giving!
So, the answer is it depends (the grip part)
R7s have the same compound as the R100, which is a harder "slick"
its assumed that when someone compares a R7 to a "slick" they are talking about a DOT tire vs a racing slick.
But, both are slicks for the most part (no grooves)
And a R100 slick is not quite as fast as a R7.
slicks heat cycle out faster and lose more grip compared to DOT tires ive run

Again, it depends on the "slick". the DH pirelli (a harder compound and popular with WCGT racing, are about 1-2 seconds faster but only when new. after that, they are pretty close. the R100 slick from Hoosier is actually a little slower than the R7. but the R80 and softer compounds are much faster.

Slakker

Ok, that helps a lot. How many heat cycles on an R80 before it starts dropping a couple of seconds?

Veloce Raptor

And here we go again .

wanna911

Ill bet money that DH are more than 2 seconds faster on most tracks than R7's for the vast majority of drivers. And by the way, Hoosier is now on the S series slick.

Slakker

For how many heat cycles?

mark kibort

yeah.. here we go, fact vs your fiction and imagination! (aka... "feelings") hahaha!

thats a good question.

they were only 2 seconds faster than Toyo RA1s...as far as world challenge GT went. Ive heard that toyos are 1 second behind a R7 which is 1 second behind an A7... so, i wonder what you really have seen to compare the two tires.
many times some dont lean on the DOT tires as they can, and drive the slicks harder as they instill a lot of confidence. driver factor is big here too.

put it this way... if Randy Pobst ran 1:28 with the viper on street DOT race rubber (tread design), you would think that a R7 would be 1 second faster, and a A7 would be 1 second beyond that, and then the slick would be "more than 2 seconds faster"... do you reallly thnk that street monster ACR could run a 1:24 at laguna? just asking? (use this formula for any other car with historical , solid, results) something that was easy to see with world challenge, was that the toyo vs DH pirelli times went down about 2-3 seconds. so, my guess is that the pirelli is about 1 second faster than the hoosier A7 if i was to guess. if i could run 2-3 seconds faster with the pirelli DH, i would buy a set tomorrow...... and pay you if it worked. (Because your "money" would be on it working, right??? )

This i do know to be around 3 heat cycles before they act very similar to a new A7

Slakker

:Nono:

for not derailing the thread.

That is still mind boggling! I got to talk to Bob Bondurant about Randy Probst coming to their track to drive the ACR. He said he could push that car like nothing he's ever seen and that Randy was doing ride along instruction for Bob in it.

Ok, lots of great info and opinions so far. Keep it coming!

Veloce Raptor

The Viper OEM tire is ummmmm marked for street but is really a pure track tire. Super sticky and soft.

As for Hoosier slicks versus RA1 in World Challenge...mark you do know that WC hasn't used the RA1 since around 2007, right? The Hoosier slicks in 2016 (AKA right now) are vastly different and vastly faster than 8 years ago. Geez.

. And Dez is correct: DH is much quicker than R7. And will stay relatively good for maybe 10 cycles (not at peak but pretty close) if you don't over drive them.

Frank 993 C4S

It really depends what you are after - and that's why there are so many different answers.

The generic answer is that a slick tire will have more grip in cornering and braking once you get it up to temperature. A slick tire will also allow you to run higher slip angles so your driving style to go fast will likely be different. You will also run lower tire pressures on a slick tire so you will need to learn how to get temps into tires at very low cold pressures without damaging them.

There is a wide variation of slicks available for our cars and I have experimented with many of them and their characteristics are all different. It really depends on your goals, your driving style, your particular car, your set-up and track conditions. One is not automatically produce faster lap times than another. I typically run a set of slicks for up to 15 HCs but I will not use them to optimize a car set-up past 10 HCs. The only way to find out what the difference is for your car is to try a set. I used to run the R6/R7 and they came up to temp very predictably and I used to be able to run them for up,to 20 HCs before they chorded but they just didn't have the grip that a slick has.

Slakker

My first race is coming up soon with a local association. They use a loose version of SCCA classes (no windshield pin or fuel cell requirements) but my 996 is going to get classed as a GT2 with the cup cars. I'm going to get smoked, no way around it. But I should be able to hang with the GT3 class that will be on the track at the same time so maybe nobody will notice.

Anyway I was trying to figure out what tire makes the most sense to use. It sounds like the R7 may be the ticket at this point. Although I'm tempted to even use z214s and just focus on getting the wheel to wheel experience.