GT3 Watkins Glen/tire comparison
06-20-2004, 09:02 PM
#16
Racer
Join Date: Apr 2003
Location: Pa.
Posts: 364
Likes: 0
Received 0 Likes
on
0 Posts
Lynn,
I ran my GT3 at the DE just before your event and met Keith. We spoke about the Dunlops as the all around tire for the car. I ran mine on the Michilens that came on the car and could not get the confidence to turn fast laps. I am used to Hoosiers and my old 964 Cup car. I am planning a tire change but still want a tire I can drive to the track. Bottom line was Keith happy with his tire decision? I do not feel there may be much of a choice given the Sport Cups are not suitable if you should get stuck in the rain on the way to the track. What do you think? Thanks.
Best,
Don
I ran my GT3 at the DE just before your event and met Keith. We spoke about the Dunlops as the all around tire for the car. I ran mine on the Michilens that came on the car and could not get the confidence to turn fast laps. I am used to Hoosiers and my old 964 Cup car. I am planning a tire change but still want a tire I can drive to the track. Bottom line was Keith happy with his tire decision? I do not feel there may be much of a choice given the Sport Cups are not suitable if you should get stuck in the rain on the way to the track. What do you think? Thanks.
Best,
Don
06-20-2004, 09:27 PM
#17
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Join Date: Jun 2001
Location: CT
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
Don
I have never tested the Dunlop DOT 'supersport race' in the rain, but i would think that it might work reasonably well given the wear rating of 60 (MPSC is not quite as soft at 80), and the Dunlop's tread pattern. It is quite comfortable on the street and an excellent tire on the circuit with outstanding wear, progressive warnings at the limit of adhesion, proper sizes, and right price! The full Dunlop rain race tire is my favorite of all the full race rain selections and Dunlop is renound for their rain tires.
My experience with the MPSC in rain on the street has been challenging at best. On the way to Summit point club race last year, I was passed on the highway by another racer. He thought my car was sliding around so much that he was concerned I was on hoosiers by how it looked to him!
I have never tested the Dunlop DOT 'supersport race' in the rain, but i would think that it might work reasonably well given the wear rating of 60 (MPSC is not quite as soft at 80), and the Dunlop's tread pattern. It is quite comfortable on the street and an excellent tire on the circuit with outstanding wear, progressive warnings at the limit of adhesion, proper sizes, and right price! The full Dunlop rain race tire is my favorite of all the full race rain selections and Dunlop is renound for their rain tires.
My experience with the MPSC in rain on the street has been challenging at best. On the way to Summit point club race last year, I was passed on the highway by another racer. He thought my car was sliding around so much that he was concerned I was on hoosiers by how it looked to him!
06-21-2004, 12:39 PM
#18
Addict
Rennlist Member
Rennlist Member
Join Date: Jul 2001
Location: W. Palm Beach & Annapolis
Posts: 3,312
Likes: 0
Received 31 Likes
on
16 Posts
Lynn,
Did you practice/race on Dunlop slicks? 2:16 on DOT's sounds concervative for a GT3. Are the Hoosiers faster? I raced on 03 model Hoosiers 2700# 993 (fastest sunroof car on the grid ;>) 2:11/12 with a 2:09:9999999 qualify. Good to see some GT3's on the grid. I am thinking a GT3 may be my next car for club race and a little street use.
Did you practice/race on Dunlop slicks? 2:16 on DOT's sounds concervative for a GT3. Are the Hoosiers faster? I raced on 03 model Hoosiers 2700# 993 (fastest sunroof car on the grid ;>) 2:11/12 with a 2:09:9999999 qualify. Good to see some GT3's on the grid. I am thinking a GT3 may be my next car for club race and a little street use.
06-21-2004, 12:55 PM
#19
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Join Date: Jun 2001
Location: CT
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
Bill
The Dunlop SP Race DOT tire is the 2:16 lap time. The mpsc is a consistent 2:12-2:13 tire both with either me or Alexander driving. The 2:10 time is Dunlop slicks (235/285). We raced on the slicks just for fun to see exactly what the time differential was between the GT3 street as delivered and the Cup car.
If we would prep the car for racing (we only had the required safety modifications), the car would be much faster. First off, my car weighs 3150 with no gas and no driver. The rules allow it to be 2950 as I recall. The car needs a diff with much stiffer clutches. The ramps are fine and are the same as cup car. Most importantly, at proper weight, race ride height, full spring and shock set up, and light race wheels (ours were stock as delivered) would likely be 6 seconds per lap faster. The ride height and suspension would be most of this time. The lift involved in turn 2 is a very big lift and you must also lift a touch at the top of the hill. Because of the lift in turn 2, the lap is blown right there. In a cup car set up properly, there is no lift from departing the apex of 1 until the bus stop brake zone. Keep in mind we drove the cars bone stock at showroom ride height. We drove the cars to the track and then home following the race. If set up for aggressive race dedicated car, it could be lowered another inch, and I would use springs that approach cup car specification. The current springs are only minimally stiffer than regular 996. A good race set up would subtract 1-2 seconds just at turn 2. If set up correctly and at PCA weight, the main difference betweeen this car and a cup car is about 340 pounds(which is alot), and the gearing difference is more than substantial. The weight and gears will still leave a large amount of time on the table compared to the cup car.
So, I would think that if fully race prepped within PCA rules in B stock class, Keith and I would likely turn 2:06 with MPSC. Hoosiers would be perhaps a touch quicker, but there are problems with the larger size rears and we did not want to take a chance.
The Dunlop SP Race DOT tire is the 2:16 lap time. The mpsc is a consistent 2:12-2:13 tire both with either me or Alexander driving. The 2:10 time is Dunlop slicks (235/285). We raced on the slicks just for fun to see exactly what the time differential was between the GT3 street as delivered and the Cup car.
If we would prep the car for racing (we only had the required safety modifications), the car would be much faster. First off, my car weighs 3150 with no gas and no driver. The rules allow it to be 2950 as I recall. The car needs a diff with much stiffer clutches. The ramps are fine and are the same as cup car. Most importantly, at proper weight, race ride height, full spring and shock set up, and light race wheels (ours were stock as delivered) would likely be 6 seconds per lap faster. The ride height and suspension would be most of this time. The lift involved in turn 2 is a very big lift and you must also lift a touch at the top of the hill. Because of the lift in turn 2, the lap is blown right there. In a cup car set up properly, there is no lift from departing the apex of 1 until the bus stop brake zone. Keep in mind we drove the cars bone stock at showroom ride height. We drove the cars to the track and then home following the race. If set up for aggressive race dedicated car, it could be lowered another inch, and I would use springs that approach cup car specification. The current springs are only minimally stiffer than regular 996. A good race set up would subtract 1-2 seconds just at turn 2. If set up correctly and at PCA weight, the main difference betweeen this car and a cup car is about 340 pounds(which is alot), and the gearing difference is more than substantial. The weight and gears will still leave a large amount of time on the table compared to the cup car.
So, I would think that if fully race prepped within PCA rules in B stock class, Keith and I would likely turn 2:06 with MPSC. Hoosiers would be perhaps a touch quicker, but there are problems with the larger size rears and we did not want to take a chance.
Last edited by ldw; 06-21-2004 at 01:24 PM.
06-21-2004, 01:56 PM
#20
Addict
Rennlist Member
Rennlist Member
Join Date: Jul 2001
Location: W. Palm Beach & Annapolis
Posts: 3,312
Likes: 0
Received 31 Likes
on
16 Posts
Thanks for the info Lynn. One side of me says driving a pure stock car to the track and going racing would be fun. The other side says you will need the mods you outlined to compete so you need a cup car to race and a GT3 for the street. I better get to work $.
06-21-2004, 02:16 PM
#21
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Join Date: Jun 2001
Location: CT
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
Bill
Agreed!
Keith and I had pledged to race against each other with exactly identical cars in showroom stock trim with same tires and same alignment within stock range. Under these conditions, it was really fun. If I was out there against a group of prepared cars and was back of the pack, that would not be so enjoyable. The cost of running this car in races is much less than a cup car though, and Keith and I are planning to go head to head again at Summit and the LRP PCA races-so it will be good. He and I ran cup cars in the fun race in the torrential rain last year at Summit and our lap times were separated by 2/10 of a second and we ran nose to tail for 7 rain laps-so we are very close at many tracks. David Murry and I have already tested the car in stock trim at Summit with MPSC tires and the lap times are much closer to cup cars than WG both because of the shorter distance and the very long front straight.
Agreed!
Keith and I had pledged to race against each other with exactly identical cars in showroom stock trim with same tires and same alignment within stock range. Under these conditions, it was really fun. If I was out there against a group of prepared cars and was back of the pack, that would not be so enjoyable. The cost of running this car in races is much less than a cup car though, and Keith and I are planning to go head to head again at Summit and the LRP PCA races-so it will be good. He and I ran cup cars in the fun race in the torrential rain last year at Summit and our lap times were separated by 2/10 of a second and we ran nose to tail for 7 rain laps-so we are very close at many tracks. David Murry and I have already tested the car in stock trim at Summit with MPSC tires and the lap times are much closer to cup cars than WG both because of the shorter distance and the very long front straight.
06-21-2004, 02:26 PM
#22
Three Wheelin'
Join Date: Jan 2004
Location: LA, CA
Posts: 1,475
Likes: 0
Received 0 Likes
on
0 Posts
and same alignment within stock range.
Lynn, are you using the -2.5º camber that Michelin suggests for the Cups in these daily driver/track day tests?
I am about to do my third track day on the MPSC's, which will take the up to over 20 heat cycles, so I think it'll be their final day out. How often are you swapping out your tires, and how are you judging their demise, by feel on track, heat cycle counts, compound hardening or tread depth?
Lynn, are you using the -2.5º camber that Michelin suggests for the Cups in these daily driver/track day tests?
I am about to do my third track day on the MPSC's, which will take the up to over 20 heat cycles, so I think it'll be their final day out. How often are you swapping out your tires, and how are you judging their demise, by feel on track, heat cycle counts, compound hardening or tread depth?
06-21-2004, 02:41 PM
#23
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Join Date: Jun 2001
Location: CT
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
No, only 1.9 in front and 2.0 in rear since the car spends most of its time on the street. We are judging by feel when deciding to change to fresh tires. I would say that 5-6 track days with 20 mins each of 4 daily sessions is about right. This is with the assumption that wear appears reasonable and there is still some tread left. So, that comes out to about 20-25 heat cycles. They likely last longer though, it is just that the outer edges were looking pretty worn. Also, wear will depend on the track surface used, ambient temps, and who is driving.
06-21-2004, 04:16 PM
#24
Addict
Rennlist Member
Rennlist Member
Join Date: Jul 2001
Location: W. Palm Beach & Annapolis
Posts: 3,312
Likes: 0
Received 31 Likes
on
16 Posts
Lynn,
If you are interested in a low key tune up for Summit Point NASA has GTS sprint races July 10 & 11th. All PCA C stock or faster is grouped into SU so their is quite a mix but the few NASA races I did it was a small field. A few quick BMW GT cars to play with and a cup car or two.
The PCA fun race last year was a ball. I raced in my hand carved Hoosiers mounted on the wrong sides of the car. I could not imagine what was wrong with my car. Like driving on ice.
Why did you leave Hoosiers out of your tire test? Just curious.
If you are interested in a low key tune up for Summit Point NASA has GTS sprint races July 10 & 11th. All PCA C stock or faster is grouped into SU so their is quite a mix but the few NASA races I did it was a small field. A few quick BMW GT cars to play with and a cup car or two.
The PCA fun race last year was a ball. I raced in my hand carved Hoosiers mounted on the wrong sides of the car. I could not imagine what was wrong with my car. Like driving on ice.
Why did you leave Hoosiers out of your tire test? Just curious.
06-21-2004, 04:26 PM
#25
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Join Date: Jun 2001
Location: CT
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for the info. I am actually testing at Summit privately on July 26 and 27. See end of my second post above...... There have been issues with 18 inch Hoosiers......cording and failure in larger sizes on Porsches. Also, Rafael Lopiz, who also ran a GT3 in the race with me and Keith at WG, had both of his rears (S04) cord at Mid Ohio and they were new that weekend. He used the S03 at WG. I do not know his set up parameters.
09-09-2004, 10:24 AM
#26
Racer
Join Date: May 2004
Posts: 290
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by ldw
The stock speedometers are often out of calibration and are set up for the Michelin street stock tire as delivered. This is confirmed by the fact that KA and I often did not get into 5th gear which according to the gear charts should be happening at approx 141 mph with a tire of 25.0 inch diameter. The mph are provided for a comparison among the 3 tires in the same car, same driver. The Dunlop SP has a diameter of 25.0 inch, MPSC 25.2 inch, and Dunlop slick at 25.4 inch. Hence, the actual top speed for the slick is relatively higher (than that documented)compared to the other tires given it has the largest diameter.
09-11-2004, 03:33 AM
#27
Racer
Join Date: May 2003
Posts: 285
Likes: 0
Received 0 Likes
on
0 Posts
Can't wait to get out to Willow Springs with you guys. Moving back to Carlsbad around Dec/Jan and am anxious to get back to Willow. Last time I was there was about five years ago.
What organization are you guys running with out there?
What organization are you guys running with out there?
09-11-2004, 11:22 AM
#28
Three Wheelin'
Join Date: Jan 2004
Location: LA, CA
Posts: 1,475
Likes: 0
Received 0 Likes
on
0 Posts
What organization are you guys running with out there?
Anyone who'll have me!!!
Here are a couple of useful links to start you off, look forward to seeing you out here then!
http://www.cb-racing.com/track_schedule.htm
http://alltimeracing.homestead.com
http://www.tracquest.com/
Anyone who'll have me!!!
Here are a couple of useful links to start you off, look forward to seeing you out here then!
http://www.cb-racing.com/track_schedule.htm
http://alltimeracing.homestead.com
http://www.tracquest.com/
09-12-2004, 02:31 AM
#29
Racer
Join Date: May 2003
Posts: 285
Likes: 0
Received 0 Likes
on
0 Posts
Awesome. Thanks for the links. Looks like the usual suspects (clubs) are still there. One has disappeared. Can't remember what they were called, but I think they morphed into the LA chapter of NASA (at least V1, may be others running it now). It was something like IRRA... probably long gone.
Willow will become my second "home" track I guess starting in 2005.
Are there very many events open to street cars at Fontana?
I'm leaving the racecar here in AZ and will have it taken care of in an arrive and drive program. Mostly running enduros this year, and maybe the Grand Am Cup at PIR again. The $/fun ratio for Grand Am Cup is pretty weak though. You get like a total of 2 hours track time for around 10K. Not a good ratio! I used to spend that for an entire racing season of 12 double weekends with SCCA.
Any way, the GT3 will be a way to get track time in between maybe 5-6 race weekends in AZ this year (when it's not over 110).
Can you fit four race tires in the GT3? Maybe three in the passengers' compartment and one in the bonnet?
See you in early 2005.
Willow will become my second "home" track I guess starting in 2005.
Are there very many events open to street cars at Fontana?
I'm leaving the racecar here in AZ and will have it taken care of in an arrive and drive program. Mostly running enduros this year, and maybe the Grand Am Cup at PIR again. The $/fun ratio for Grand Am Cup is pretty weak though. You get like a total of 2 hours track time for around 10K. Not a good ratio! I used to spend that for an entire racing season of 12 double weekends with SCCA.
Any way, the GT3 will be a way to get track time in between maybe 5-6 race weekends in AZ this year (when it's not over 110).
Can you fit four race tires in the GT3? Maybe three in the passengers' compartment and one in the bonnet?
See you in early 2005.
09-12-2004, 01:33 PM
#30
Three Wheelin'
Join Date: Jan 2004
Location: LA, CA
Posts: 1,475
Likes: 0
Received 0 Likes
on
0 Posts
What is your race car?
and can I have a ride pleeeeeze!!!
You could always store your race wheels at Willow, there are some folks with big units up there who you a$k to house them. I think they are building some new garage units up there, so if you want to get a garage I'm sure a few folks will join in on one to keep Hoosiers at the track. Look forward to seeing you then.
PS; I think the only way to get your tires to Willow in a Porsche is like this......
You could always store your race wheels at Willow, there are some folks with big units up there who you a$k to house them. I think they are building some new garage units up there, so if you want to get a garage I'm sure a few folks will join in on one to keep Hoosiers at the track. Look forward to seeing you then.
PS; I think the only way to get your tires to Willow in a Porsche is like this......