Race Slicks for 991 GT3 RS
03-22-2016, 03:45 PM
#31
Rennlist Member
Does anyone even know if there are slicks in the size that matches outside diameter or at least ratio front to rear VS OEM / 19" Hoosier R7?
It may not have been tested, but we can find out at least if the size and or ratio comes within 3% to at least know if it can be worth experimenting..
It may not have been tested, but we can find out at least if the size and or ratio comes within 3% to at least know if it can be worth experimenting..
03-22-2016, 04:48 PM
#32
Michelin PS GT S9 Hards in 28/68-19 & 31/71-19?
690 and 709 dia. > 2.75% but fronts likely need careful offset or addl. clrnc.
width 275/306 front & 316/343 rear
ps those widths are from 11" fr. and 13" rr. wheels
690 and 709 dia. > 2.75% but fronts likely need careful offset or addl. clrnc.
width 275/306 front & 316/343 rear
ps those widths are from 11" fr. and 13" rr. wheels
03-23-2016, 01:31 PM
#34
I tried nitrogen for my old cup given it had air jacks I needed it for. Tire pressure increase about the same as before but a bit more stable. Did not check tire temps but makes sense to no difference. Certainly not worth lugging a bottle around just for tires. Tools yes.
03-24-2016, 12:35 AM
#35
Three Wheelin'
03-24-2016, 09:54 AM
#36
Rennlist Member
Thanks guys for hijacking my thread. This isn't about PASM which by the way is SUSPENSION Management, nor PSM which is stability control. I was the CI of our region for 15 years, ex pro racer etc.
Driven properly the new RS overheats its Michelin Cup 2 tires in 4 laps. Like my previous RS it really wants race tires. The issue is whether 19 inch wheels will fit and if so whether 19 inch slicks will have the right rolling diameter to avoid causing the ABS to freak out. By now I hoped someone would have found a solution.
Regards,
Driven properly the new RS overheats its Michelin Cup 2 tires in 4 laps. Like my previous RS it really wants race tires. The issue is whether 19 inch wheels will fit and if so whether 19 inch slicks will have the right rolling diameter to avoid causing the ABS to freak out. By now I hoped someone would have found a solution.
Regards,
The MPSC are indeed amazing tires with excellent grip as long as you don not exceed 30psi hot.
Having said that, they are not as grippy as the R compound and don't last , but they are a good option for now...I have not yet seen anything that fits the car, unless you go to 19 all around and mount R6 on them.
03-24-2016, 10:59 AM
#37
Race Director
03-27-2016, 12:39 PM
#39
2nd Gear
Join Date: Nov 2009
Location: Québec city
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Slicks for RS
Does somebody hear about slicks for GT3RS in 20 and 21...for 2016?
I hear that Hoosier are working on R7 in that size...is it true???
With PCCB, we can't downsize to 19 anaway. Also, there is no interest to downsize discs diameter on a car like that...
I hear that Hoosier are working on R7 in that size...is it true???
With PCCB, we can't downsize to 19 anaway. Also, there is no interest to downsize discs diameter on a car like that...
03-27-2016, 02:06 PM
#40
Rennlist Member
Join Date: May 2012
Location: Mid-Atlantic (on land, not in the middle of the ocean)
Posts: 13,343
Received 4,526 Likes
on
2,576 Posts
My experience with the Cup 2 tires is similar to Bob's. Grip is quite good for several laps, then falls off as the tires get too hot. Changing the hot tire pressure doesn't make much difference, since the issue seems to be with the rubber getting too hot. The car is still drivable when the tires get too hot, and I usually finish my sessions, but lap time is 1-3 seconds worse and risk is probably a bit higher with greasy tires.
03-27-2016, 08:50 PM
#41
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Bob, as previously mentioned, GMG has run 19" wheels (replaced stock PCCB with Brembo small brake kit), with 19" Hoosier R7 (I realize not race slick) and had no issues with rolling diameter and ABS. Nannies off. Call James if you want more details on their experience.
Bob, we have indeed installed HRE 19" wheels on our of our TEST RS's with Hoosier R7's and the results were fantastic! On it's first outing, the car ran a 2:11 at Thermal on a fairly hot day and that's pretty damn quick if you know the full track layout and its relative lap times for different cars. A stock RS runs 2:15's on a good day with the same amount of prep on the car, so basically the difference was the tires and wheels.
We obviously had to adjust the suspension / ride height / etc for the new 19 setup but the client was over the moon with the results.....
Below are some pics of the car and wheels during the test at Thermal......
__________________
James F. Sofronas | President & Owner
Global Motorsports Group ™
E: james@gmgracing.com
P: +1 (714) 432-1582
F: +1 (714) 432-1590
A: 3210 South Shannon Street, Santa Ana, California 92704
W: gmgracing.com
James F. Sofronas | President & Owner
Global Motorsports Group ™
E: james@gmgracing.com
P: +1 (714) 432-1582
F: +1 (714) 432-1590
A: 3210 South Shannon Street, Santa Ana, California 92704
W: gmgracing.com
03-31-2016, 08:31 PM
#43
Still plays with cars.
Lifetime Rennlist
Member
Thread Starter
Many thanks James. I am partial to Forgeline wheels in part because we have local service for them. I will give this a try! Love the roll bar I got from you via my dealer Porsche Lauzon.
Best,
Bob
Best,
Bob
04-01-2016, 04:16 PM
#44
Rennlist Member
Join Date: Feb 2006
Location: Wishing I Was At The Track
Posts: 13,668
Received 1,899 Likes
on
978 Posts
R7's are a step up but doesn't answer the original question, which was race slicks.
Again, suggest you research the 991 Cup set up. It uses Michelin slicks in sizes 27/65-18 front and 31/71-18 rear, with diameters of 2025mm and 2131mm respectively. That translates to a 1.05 front to rear ratio, which happens to be virtually identical to the ratio of the stock RS tires (27.3" and 28.7").
More info available here: http://www.michelinmotorsport.com/Tyres/Circuit
Again, suggest you research the 991 Cup set up. It uses Michelin slicks in sizes 27/65-18 front and 31/71-18 rear, with diameters of 2025mm and 2131mm respectively. That translates to a 1.05 front to rear ratio, which happens to be virtually identical to the ratio of the stock RS tires (27.3" and 28.7").
More info available here: http://www.michelinmotorsport.com/Tyres/Circuit