Texas RS

GeoJoe

Hoosier recommended that we run +4 psig at WGI vs typical pressures.

I started F/R 30/32 psig in my first session and ended 44/48 in a .2 GT3RS on R7s. By far the highest pressures I have ever experienced on an R7. I was getting a little extra rear end slip at the end of the run, but still manageable.

kfmcmahon

New PB at the Glen today 2:04 on Pirelli Scrubs

MarcD147

Scrubs?
Is that slicks?

kfmcmahon

yes, sorry...”take offs” I guess they call them - lightly used 19” 255f 305r from Ferrari Challenge series races.

as before, car has TPC toe links and street/track alignment and DSC V2

ShakeNBake

I ran a set of new Pirelli DH (I think medium) and set my fastest time at TWS in a .2 RS by 2 seconds over R7s. Slicks are a whole new level of drug that will help you keep your wallet on a diet. I would love to try a set on the GT4 - but kids need to go to college.

Texas RS

Pirelli DH slicks should be worth 3 sec/laps vs Hoosier R7s, so you will have to get to 2:01 to match the R7 lap record. If you really just want the fastest time, you need to get some Michelin slicks.

provoste

Maybe sticker P-Zero DH, not take offs. Yes P-Zero is faster than R7, but not treaded track tire to slick delta (3-5 seconds).

MarcD147

NJMP update 1:30.03 upgraded from sports button to pure Heel/Toe

Texas RS

DHs are 2-3 sec/lap faster than R7s at COTA and TWS when well driven. Some find it challenging to take advantage of all the extra grip when moving from an R comp to a slick.

GeoJoe

Wow that seems hot! Why the extra +4 there?

Ran my first set of Pirelli DH take-offs this past weekend... felt like a whole different car. Much higher level of trust. It'll be hard to go back to any street tire on the track.

If I can keep finding take-offs, then it's actually cheaper than a new set of RE71r or Trofeos by far, and much better experience.

.....but way lower PSI. Recommend 27 hot... and that worked for me for 3 secs better.

Texas RS

It was their experience from the Summer Nationals, I think they want the side support given high cornering loads at high speed. They recommend +6 at Daytona.

Yes, you definitely want to run much lower starting pressures on the slicks. Stay off the curbs for the first two laps until the pressures come up as the side walls can be easily damaged.

sportlife2012

:------

sportlife2012

I agree that Michelin's may initially help you with faster lap times because its a softer compound tire and as a result the number of heat cycles are significantly less than a Pirelli DH compound slick. My experience is that a Michelin slick drops off significantly with more than 5 heat cycles, whereas a Pirelli DH compound will be good for 12 and is a very consistent tire for HPDE up to 12 heat cycles. Pirelli make a DHA compound which matches the Michelin but in very limited sizes.

sportlife2012

Most race teams run their tires a cumulative maximum of 1 hour or 4 heat cycles whichever occurs first. There are some teams that will do more. If one assumes the practice sessions of 20 minutes = 3 heat cycles. Teams that run longer will put up to 5 heat cycles or maybe even more, so when buying takeoffs, obviously knowledge of the heat cycle count is important. I have run 12 heat cycles on a new sticker set and 10 heat cycles on a takeoff set that had 3 previous heat cycles. Go figure.....I Personally think the Pirelli DH compound is the best take-off tire for HPDE for the best value. I know guys that run 18 heat cycles but this is at at the risk of cording the tire (SAFETY CONCERN!!!!!) and significantly reduced lap times. Based on the price of the take-off, is it really worth the additional heat cycles above 12?

Veloce Raptor

Yes,
Full slicks will want a lot less hot pressures than DOT.
Joe, try 29 hot next time...