Gilhart 54

Just a little feedback from running Hoosiers R6 DOT tires at the "Sebring 48 Hour Event" on my GT1 930. The grip of these tires were incredible and allowed me to run very consistent laps throughout the race weekend. I have to believe that the difference in lap times between the DOT Hoosiers and slicks is getting smaller and smaller. Regarding wear, I was only able to get a weekend out of my slicks last year whereas the wear rate looks much better with the R6's.

I also made a change from 17" BBS to 18" Forgeline light-weight wheels. The wheel/tire combination worked great on the 930 with fitment being perfect.

I struggled through the fall/winter trying to decide whether to run slicks in GT1-R or run Hoosiers in GT1-S. When you throw $$$ into the equation it became a no brainer. Run almost as fast as the GT1-R cars at a cost savings.

I've not pin-pointed where the correct hot pressures should be and would be interested in hearing your opinions. I'm running 275's on the front and 335's on the rears.

A big thank you to the Florida Regions for hosting the Sebring event. Thanks also to PCA National Sponsors Hoosier Tire for making a great tire and Forgeline for making a great looking light-weight wheel.
http://www.Hoosiertire.com
http://www.Forgeline.com

To view the car click the link below...
http://www.Gilhartmotorsports.com

Rick Gilhart
#54 GT1-S

Larry Herman

Rick, that was here discussed late last year, and the general feeling was that on lighter cars hot pressures were around 34~37 lbs, and on the heavier cars 37~39. Of course it also depends on your tire profile, width and rim diameter.

Gilhart 54

Larry,

Thanks for the quick reply. In earlier practices I tried to end up at around 39/40. For qualifying and the race I had them end up in the 34 - 36 range and they felt much more consistent.

Has anybody else tried to go even lower with hot pressures, just curious?

Thanks,
Rick

Bull

On my heavy 993, I liked 37-38 on 245/295 x 18s. Having lost close to 600lbs with the new car, and running 235/275 x 17s, I'll be trying lower pressures when the season starts.

Larry Herman

Wow, your diet is really working great!










VR made me do that, honest. Let's go

Bull

Just as long as i don't think about the price per pound! And I know what a bad influence VR can be on all of us.....I suspect Mikey will be a bit sheepish when he gets back online.

Back to the R6s, I am finding that they last FAR longer than I expected from a Hoosier.

Larry Herman

I have sets with 12~15 sessions on them that look good. I still haven't worked up the nerve to run them to the cord, or there abouts.

bgiere

I've found that the R6 like lower than the Hoosier stated pressures....Mine felt best starting at 24-25 PSI cold on the cup car.

dave morris

I was on Hoosiers for the first time last weekend ... trying to figure out pressures ... ended up using 37/39 hot ... and will be going down 2 lbs next time out. But even at 37/39 they were so much better for me than the MPSCs I couldn't believe it.

analogmike

I have a set of R6s that I ran 5 SCCA and vintage races on last year, and they got frozen in the cold Northeast. Also had a brand new set of fresh R6s which I heat cycled Friday am at Sebring and put back on for qualifying. The old ones were a little faster, if there was any difference at all!

I run mid to upper 30s, they are fine at 30PSI when cold.

The new set were locked up going backwards from 85MPH to 0MPH in T1 in the sprint race. One rear has a half-dollar size melt mark, down to the core rubber. Two tires have some odd mottling (not much flat spot, might be useable) and one seems fine... these tires are pretty incredible.

Rick DeMan

Hey Rick,

Your car looked great in sebring...I was rooting for you in the sprint race..!!

I have found the R6 likes much lower pressures. I run them on my GT5 car and end up at 34 hot...they seem much better at the lower pressures. 3 other cars we have on hoosiers like the lower pressures. I would try a little testing to find the right spot. Keep a real good eye on the temp spreads across the tires while lowering the hot pressures in a test session. As soon as you see the tires loose the good spread, then the tire is not holding the proper shape, put back in a few pounds and that would be the optimum setting for your car and it's weight.

Also during that test session when you have gotten to the optimum hot pressures and the car feels good, let the set cool overnight then record each tires cold pressure for that track. You will see a few pound differences from corner to corner and then you can use those numbers for all your starting pressure set-ups.

Gilhart 54

Thanks for all the good info on the tire pressures, much appreciated. It sounds like Mike holds the record for trying to beat the heck out of his Hoosiers going backwards through T1.

Rick, good to see you at Sebring and sorry we fell a little short of P1 but all in all it was a fun race. The 930 handled fantastic but could not pull on the GT3RS on the back straight. Must be a combination of Aero, gearing, lag or something.

I remember talking to you about using Hoosiers vs. slicks last year at Rd. Atl. and have followed in your footsteps. Great bang for the buck and puts the emphasis on driving well to hang with or beat the "slick" guys. I'll try your setup advise at the next test day and see if we can make any progress.

One quick question regarding brakes. I'm running big reds in the front and 928 S4 front calipers in the rear. Front and rear pads are Pagid Orange. I was getting quite a bit of front lock-up as the race progressed, trying to dial it out but never really acheived dialing it all the way out. I've never used these pads or calipers however this is what came on the car. Any advice for improving the current situation?

Thanks,
Rick

Larry Herman

Rick you may want to try what some of the GT3 drivers are running. I run RS-19 yellows all around, and they are a far better pad than the oranges. Some are running the 19s in the front and RS-14 black pads in the back, to get more performance out of the rear brakes. Seems to work well for them.

esscape26

Much better at lower pressures, and I start mine low, which I had prior to this, felt was just me, on heavier or more stock car because it seemed to "work" tires more...

DeMan advice spot on, as to technical matters, as always!

In related idea, I was thinking about recommendations for making larger classes and less scattered entries. Hear complaints about the 1-4 cars in some. Thought that combining S versus R in GT might be good proposalt for next year. Run whatever tire you want. You have given me some good food for thought and future presentation to the powers that be (if you don't mind).

PM
#26