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Lap Time Differences: 991 GT3 vs. 991 GT3 RS V GT3 Cups
Another great day and weekend with the Porsche Owner's Club at Auto Club Speedway in Fontana. A variety of cars, running in the red racer's group (cup cars) and street cars running in the Time Attack.
Before the event, I was curious as to what the time differences were between a totally stock 991 GT3 and other cars, namely cup cars. This weekend offered some data points. The data needs to be put into context for this past weekend under the conditions that existed then. Comparisons to other lap times in similar cars during different times of the year don't mean much..
Under the simplistic assumption that drivers are all similar in skill, here are the various lap time differences. (Cup car vehicle weights were per the Porsche General Competition Rules, and the street cars from Porsche materials.) All cup cars were running slicks.
For me in my 991 GT3, my lap time difference between Saturday and Sunday was mostly attributed to tire pressures - I was running Pirelli Trofeo Rs - and was running almost 6#s too little on Saturday on all four corners. There were numerous areas the car needed significant steering corrections, and I was late to power on those areas. At the correct pressure on Sunday (and with the sport suspension setting off vs on on Sunday), the car felt far more stable through the banking and in other areas.
Ambient and track temperatures seem to make a difference - Saturday's ambient temperate was 93 degrees; I ran Sunday am when it was in the low 80's. Times for all cars - cup and street - were slower than when the other big Porsche fest is there in April. I had previously ran my 7gen2 RS in Aril and where ambient temperatures were at least 20 degrees cooler. At that time, I was able to do 1.46s, so had big expectations for the 991 GT3.
My 991GT3 car is totally stock, and I believe the RS car was also stock. With a better driver, there is probably another few seconds in it, but the same assumption would probably hold true as to all the other times...
My crude spreadsheet is attached, but the summary is as follows:
Best times of the weekend
- 2014 991 GT3 Cup 1.39.466
- 2012 997 GT3 Cup 1.43.998
- 2008 997 GT3 Cup 1.43.711
- 2005 996 GT3 Cup 1.46.205
- 2004 996 GT3 Cup 1.45.735
- 2016 991 GT3 RS 1.49.960
- 2015 991 GT3 1.48.882
As someone said, "Figures don’t lie, but liars figure." (And no warranties as to the accuracy of my spreadsheet.... it definitely looks like crap)
The 997.2 Cup might've been able to shave up to a second-and-half if it had a different driver. In fact I suspect that both 997 Cups could've been faster.
That, and the 1RS on Cup2's is *definitely* faster than the 6 on any tire. The 1RS is IMO a foolproof Cup, with a much more powerful DFI engine and four wheel steering...
Unless the same guy was driving the 991 GT3 and RS the times don't really mean anything especially if one was on Trofeo R's and one was on SC2's or Dunlaps.
Also, it looks like the RS beat the GT3 most of the time on the time attack, but maybe the GT3 had a really clean lap. If I am reading the results right.
Also, it looks like the RS beat the GT3 most of the time on the time attack, but maybe the GT3 had a really clean lap. If I am reading the results right.
1RS didn't run on Sunday and morning run would have been faster. I think the 1RS would have been faster overall (2") than the GT3 as the segment time from the beginning of the oval to T3 is a very long segment, flat out for a large section of it. When I was following the 1RS, he was pulling me on the straights by a number of car lengths by the end of the straight. Better aero grip through the banking would also help.
Unless the same guy was driving the 991 GT3 and RS the times don't really mean anything especially if one was on Trofeo R's and one was on SC2's or Dunlaps.
Agree, most of the differences in time at ACS depends on how brave you are in turns 1 and 2. Infield needs to be be reasonably clean, but you can make up time on the oval. In the 3, I'm pretty slow thru 1 and 2 (115-120 mph), but have done 1:48.70. Those Cups with slicks will haul thru there 140-150!
I'm eager to see how the RS feels with the extra aerodynamic and mechanical grip, figuring 1-2 sec better? Will see soon. https://youtu.be/BlLMw_QFGxU
That GT3 RS time is actually mine. Was my first time at Auto Club in that car and have previously set a best lap time of 1:50.1 in my 997.2 GT3.
By Saturday afternoon I was getting a great feeling for the car and consistently getting my breaking points. Was excited to come back Sunday morning (when it wasn't 97 degrees) and put down something quick. Unfortunately when I was adjusting tire pressures prior to my first session I saw this on my rear right tire and realized Sunday wasn't going to happen for me
A few times I was able to go through 2 at 140-145. I believe that I could have easily dropped my time by 2-3 seconds. Saturday made me realize that l really need to get the suspension set up. Can't wait to go back with and see what I can do!
A few times I was able to go through 2 at 140-145. I believe that I could have easily dropped my time by 2-3 seconds. Saturday made me realize that l really need to get the suspension set up. Can't wait to go back with and see what I can do!
Awesome work Dan and pleasure to meet you! Your car is gorgeous - my biggest regret was that I didn't get a picture of my car with yours..... Blues brothers - lol!
Nice to meet you too! I would have loved that! After waking up at 6am on a Sunday, driving 90 minutes to the race track, sitting in a drivers meeting and then realizing that I couldn't take her out (while hearing everyone whizzing around on track) I left as quickly as I could haha.
Oh man that stinks. I'm getting my RS worked on today to take care of the rubbing and max out the camber. I was just going to have them do the spacers and rewire the RWS but NOT rolling the fenders (worried about the paint cracking, especially PTS). Based on your experience it looks like the fender rolling will be mandatory. What do you think?
09-12-2016, 12:48 PM
Lap Time Differences: 991 GT3 vs. 991 GT3 RS V GT3 Cups
