Excellence Magazine's Review of 997 GT3
02-12-2007, 10:19 AM
#91
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Originally Posted by mitch236
I had PASM set to normal. I tried "sport" mode but really didn't like it. Remember, Sebring is very bumpy.
The real advantage to PCCB's is the reduction in unsprung mass which only track drivers will notice. I don't see any advantage to street driven cars having PCCB's
The real advantage to PCCB's is the reduction in unsprung mass which only track drivers will notice. I don't see any advantage to street driven cars having PCCB's
02-12-2007, 10:48 AM
#93
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Mitch,
Thanks for the report, how much faster per lap were you compared to "the olden days" ?. I'm currious to see how different the RS will be in the suspension setting, but I have to presume that it too will have to be set on "normal" for Sebring. I'm so pissed I missed the weekend, but I sold my car on Thursday with the promise that I would not track it this weekend, so I sat at home and did nothing !!. The first time in a long time that I missed the 48 hours. I'm just hoping that my car will be here by the end of the month so that I can try it around Moroso the first week of March.
Thanks for the report, how much faster per lap were you compared to "the olden days" ?. I'm currious to see how different the RS will be in the suspension setting, but I have to presume that it too will have to be set on "normal" for Sebring. I'm so pissed I missed the weekend, but I sold my car on Thursday with the promise that I would not track it this weekend, so I sat at home and did nothing !!. The first time in a long time that I missed the 48 hours. I'm just hoping that my car will be here by the end of the month so that I can try it around Moroso the first week of March.
02-12-2007, 11:14 AM
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Erik, I heard you had twins so I'm sure you weren't sitting around doing nothing! Congrats!!
I'm curious about the lap times too. I wasn't pushing all that hard because I am still getting used to it and didn't want to do something stupid during the car's maiden outing. I can tell you that I was able to take Art at will while driving well within my limits. I expect the car is cappable of low '20s.
I'm not sure I can make it to Moroso. Hope to see you soon though...
I'm curious about the lap times too. I wasn't pushing all that hard because I am still getting used to it and didn't want to do something stupid during the car's maiden outing. I can tell you that I was able to take Art at will while driving well within my limits. I expect the car is cappable of low '20s.
I'm not sure I can make it to Moroso. Hope to see you soon though...
02-12-2007, 12:20 PM
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Sorry I have not read through the whole thread but I just thought someone might benefit from our datalogging sessions and testing this last week end at the track with a 997GT3 RS.
The fastest times were recorded with 38 PSI hot front and rear the same. Driving style has a lot to do with it of course, however the results were pretty conclusive and the car was very neutral with those pressures, anything less than 36psi in the front was causing understeer with the rear wing set at the first lower setting and with factory suspension settings. The GT3RS was 3 seconds faster than the revised 996 GT3 MY.
The fastest times were recorded with 38 PSI hot front and rear the same. Driving style has a lot to do with it of course, however the results were pretty conclusive and the car was very neutral with those pressures, anything less than 36psi in the front was causing understeer with the rear wing set at the first lower setting and with factory suspension settings. The GT3RS was 3 seconds faster than the revised 996 GT3 MY.
02-12-2007, 02:15 PM
#97
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Mitch, low 20ties should be VERY do-able, if I can do 2:26's in the 996 GT3, and I'm far from the fastest driver out there. Shoot, I've done 2:24 on Hoosiers once. I figure just in Bishop Bend, there should be an extra second if you have the *****.
Jean, those pressures are very high, at least compared to what was mentioned by Porsche in Excellence Magazine. Maybe they were talking about cold tempuratures, because I remember reading 29/33 F/R or something very close to that. The 3 seconds difference of lap time is on how long of a total lap time ?. Of course eventually it will not matter since I'm probably going to 18", since there is just no choice in tires in the 19"s. Either way, I will use your results the first couple of times out, before the car has been completely turned into a track ***** :-)
Jean, those pressures are very high, at least compared to what was mentioned by Porsche in Excellence Magazine. Maybe they were talking about cold tempuratures, because I remember reading 29/33 F/R or something very close to that. The 3 seconds difference of lap time is on how long of a total lap time ?. Of course eventually it will not matter since I'm probably going to 18", since there is just no choice in tires in the 19"s. Either way, I will use your results the first couple of times out, before the car has been completely turned into a track ***** :-)
02-12-2007, 02:39 PM
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Erik, Buff and I were doing some testing on tire pressures but without the benefit of data aquision. We both agreed that anything much over 32/36 hot was too much. We went as high as 40.
I really can't wait until all you guys get your GT-3's. This is going to be a fun year, especially with SuperSolo doing so well and Daytona is becomming a reality!
I really can't wait until all you guys get your GT-3's. This is going to be a fun year, especially with SuperSolo doing so well and Daytona is becomming a reality!
02-12-2007, 02:53 PM
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Erik,
I use 34 psi hot on my 18" MPSCs (993TT) and find them to perform best but never really tested based on datalogging, Gs, times etc.. as we did last week end. On the GT3RS that is what we found out with the 19s, set on sport mode. The lap times were 2 minutes + or - 5 seconds. http://www.dubaiautodrome.com/autodr...thetracks.htm# and click on "Interactive map". There are two straights, up to about 160mph, a fast sweeper where you reach about 130mph with lateral 0.8Gs, and a few slower turns. Max lateral Gs of 1.4 and long Gs of about -1.2.
I use 34 psi hot on my 18" MPSCs (993TT) and find them to perform best but never really tested based on datalogging, Gs, times etc.. as we did last week end. On the GT3RS that is what we found out with the 19s, set on sport mode. The lap times were 2 minutes + or - 5 seconds. http://www.dubaiautodrome.com/autodr...thetracks.htm# and click on "Interactive map". There are two straights, up to about 160mph, a fast sweeper where you reach about 130mph with lateral 0.8Gs, and a few slower turns. Max lateral Gs of 1.4 and long Gs of about -1.2.
02-12-2007, 02:58 PM
#100
Originally Posted by Jean
Sorry I have not read through the whole thread but I just thought someone might benefit from our datalogging sessions and testing this last week end at the track with a 997GT3 RS.
The fastest times were recorded with 38 PSI hot front and rear the same. Driving style has a lot to do with it of course, however the results were pretty conclusive and the car was very neutral with those pressures, anything less than 36psi in the front was causing understeer with the rear wing set at the first lower setting and with factory suspension settings. The GT3RS was 3 seconds faster than the revised 996 GT3 MY.
The fastest times were recorded with 38 PSI hot front and rear the same. Driving style has a lot to do with it of course, however the results were pretty conclusive and the car was very neutral with those pressures, anything less than 36psi in the front was causing understeer with the rear wing set at the first lower setting and with factory suspension settings. The GT3RS was 3 seconds faster than the revised 996 GT3 MY.
02-12-2007, 03:06 PM
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Carrera GT
All the suspension settings were factory, I did not have any temps measured.The steel brakes performed flawlessly. It was the first time on the track so the in-depth test is taking place next week-end and I will be providing the data for a major UK magazine where it will be featured, I will also have my pyrometers. I have quite a bit of G data gathered already, also a 60-130mph run and a 175mph run among others.
All the suspension settings were factory, I did not have any temps measured.The steel brakes performed flawlessly. It was the first time on the track so the in-depth test is taking place next week-end and I will be providing the data for a major UK magazine where it will be featured, I will also have my pyrometers. I have quite a bit of G data gathered already, also a 60-130mph run and a 175mph run among others.
02-12-2007, 03:06 PM
#102
Originally Posted by mitch236
Well, I am going to try to give my first impression of the weekend with the GT-3. Luckily, a good friend and great driver also has a new GT-3 so we compared notes.
1. The MPSC's supplied with the car are about 1 second slower than the "real" MPSC's.
2. PASM wasn't a problem at all.
3. TC did come on but the system lets you get very loose, I was fishtailing coming out of the safety pin and TC didn't chime in at all. It did come in if I intentionally caused power on oversteer.
4. Another driver mentioned that the springs seemed too soft and I have to agree. The car is slow to set in transition. It also has too much wallow and tends to nose dive quite a bit under braking.
5. The engine spools up extremely quickly making downshifting very fast.
6. The car tends towards understeer although I still have to get the setup dialed in so it may be a function of how I set the car up. The amount of understeer is not great and most drivers like a little of understeer anyway.
7. This car is as close as you can get to a cup car while being street legal, although it needs a diet badly. I can't understand where all the weight is. It weighed 3230 with the driver's seat replaced with a Recaro. My goal is to get under 3000. I'm sure it's possible but Porsche should have that as a goal as well.
8. The brakes are great. I can't see a need for PCCB's as I never experienced fade. The effort and brake force are completely consistent. I'm sure there are advantages to PCCB's but until there is a couple of years of positive history with them, I will hold out.
9. TPC. It's good and bad. Well not really ever bad but annoying. It's great to be able to see hot pressures on the fly. I found the pressures to be low by one pound according to my Longacre guage. The problem with the system is that you can't program what pressures you think are optimal and so at track pressures you constantly get warnings about low pressures. Also having the sensors mounted in the wheel makes it very difficult to convince local tire shops to mount tires. The sensors are expensive and nobody want to damage one. I will take mine out most likely.
All in all, I had a great time because driving this car is easy. It is very forgiving. It doesn't seem to be plagued by unsavable oversteer issues as older models and I think even average drivers will give good drivers in 996 GT-3's a run. I will post some pictures.
1. The MPSC's supplied with the car are about 1 second slower than the "real" MPSC's.
2. PASM wasn't a problem at all.
3. TC did come on but the system lets you get very loose, I was fishtailing coming out of the safety pin and TC didn't chime in at all. It did come in if I intentionally caused power on oversteer.
4. Another driver mentioned that the springs seemed too soft and I have to agree. The car is slow to set in transition. It also has too much wallow and tends to nose dive quite a bit under braking.
5. The engine spools up extremely quickly making downshifting very fast.
6. The car tends towards understeer although I still have to get the setup dialed in so it may be a function of how I set the car up. The amount of understeer is not great and most drivers like a little of understeer anyway.
7. This car is as close as you can get to a cup car while being street legal, although it needs a diet badly. I can't understand where all the weight is. It weighed 3230 with the driver's seat replaced with a Recaro. My goal is to get under 3000. I'm sure it's possible but Porsche should have that as a goal as well.
8. The brakes are great. I can't see a need for PCCB's as I never experienced fade. The effort and brake force are completely consistent. I'm sure there are advantages to PCCB's but until there is a couple of years of positive history with them, I will hold out.
9. TPC. It's good and bad. Well not really ever bad but annoying. It's great to be able to see hot pressures on the fly. I found the pressures to be low by one pound according to my Longacre guage. The problem with the system is that you can't program what pressures you think are optimal and so at track pressures you constantly get warnings about low pressures. Also having the sensors mounted in the wheel makes it very difficult to convince local tire shops to mount tires. The sensors are expensive and nobody want to damage one. I will take mine out most likely.
All in all, I had a great time because driving this car is easy. It is very forgiving. It doesn't seem to be plagued by unsavable oversteer issues as older models and I think even average drivers will give good drivers in 996 GT-3's a run. I will post some pictures.
Excellent pic getting up on three, marvelous photog.
I think you have to try PCCBs back to back with good conventional brakes to appreciate (whether or not you prefer or value) the difference. Aside from unsprung and rotating mass, the feel and consistency and simply later braking points does account for something. Assuming I ever figure out the high temps in the rears ... otherwise, I think a good two-piece steel rotor is better for peace of mind.
I saw TPMS sensor prices somewhere, maybe a couple of hundred for a set? Not really "expensive" compared to the risk of scratching a wheel or destroying a $500 tire.
It sounds like PASM was a problem insofar as the car is clearly nose-diving and there's excessive roll. And you could get PASM into "Sport" -- which I find is a sort of acquired taste -- you put up with some skating and jiggling in return for less dive and more roll stiffness. PASM clearly knows about braking, but perhaps lets more weight transfer occur in Normal mode. Early days.
I agree with your comments on weight.
As for understeer, I've had mixed results. I think more tire up front and operating at the right temperature and pressure will make the car more "911."
Thanks again.
02-12-2007, 03:56 PM
#103
Three Wheelin'
hey mitch,
whose that guy on your tail there?
whose that guy on your tail there?
02-12-2007, 04:31 PM
#104
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awesome thread... the depth of knowledge among people on here for hardcore track driving is second to none... 
i track my 997GT3 a lot, though am hardly a fast driver. clearly a case of driver running out of talent long before the car does.
having said that, i still want to find optimal settings for my car... with that in mind, can anyone comment on the following?
1) will using the "circuit settings" make a huge difference to tire wear on the street?
i'm assuming the answer is yes, given the much more aggressive camber would wear the inside edges very quickly. the car isn't driven much other than on trackdays, but the track is over 90 mins drive from home...
given what people have said on here, it seems that the circuit setting would be overkill on the standard OEM MPSC's, since the tires aren't grippy enough to maximize the camber?
2) what's the consensus-- if any-- on good starting point for pressures?
i'm a bit confused what settings to go with. the thread seemed to start with Excellence's 28/31 as one way to go, but others on here have said 25/28 would be better.
i realize there are going to be different views on this... for what its worth, the track i go to is a relatively slow track, without much high speed corners. my last few times on-track with the car, i seemed to be getting some mild understeer, though hardly serious. the biggest issue was at the circuit's lone long-ish right hand sweeper, there's a mid-corner bump that unsettles the rear. its so bad that i'm faster in my Evo and M3 thru that section, because those cars' suspensions soak up the bump no problem.
3) i usually fill the tires with nitrogen. how would this change the recommended "cold" pressures for me then, since the gas obviously won't expand/heat up as much as normal air. again, for track.
apologies for the newbie questions... and thanks in advance!
i track my 997GT3 a lot, though am hardly a fast driver. clearly a case of driver running out of talent long before the car does.
having said that, i still want to find optimal settings for my car... with that in mind, can anyone comment on the following?
1) will using the "circuit settings" make a huge difference to tire wear on the street?
i'm assuming the answer is yes, given the much more aggressive camber would wear the inside edges very quickly. the car isn't driven much other than on trackdays, but the track is over 90 mins drive from home...
given what people have said on here, it seems that the circuit setting would be overkill on the standard OEM MPSC's, since the tires aren't grippy enough to maximize the camber?
2) what's the consensus-- if any-- on good starting point for pressures?
i'm a bit confused what settings to go with. the thread seemed to start with Excellence's 28/31 as one way to go, but others on here have said 25/28 would be better.
i realize there are going to be different views on this... for what its worth, the track i go to is a relatively slow track, without much high speed corners. my last few times on-track with the car, i seemed to be getting some mild understeer, though hardly serious. the biggest issue was at the circuit's lone long-ish right hand sweeper, there's a mid-corner bump that unsettles the rear. its so bad that i'm faster in my Evo and M3 thru that section, because those cars' suspensions soak up the bump no problem.
3) i usually fill the tires with nitrogen. how would this change the recommended "cold" pressures for me then, since the gas obviously won't expand/heat up as much as normal air. again, for track.
apologies for the newbie questions... and thanks in advance!
02-12-2007, 05:05 PM
#105
The "race circuit" alignment will be too much camber in the rears for the street and it sounds like too much for the track for you too.
You'll have to find your own best temps, but you could start at 29/34 cold and work up and down from there. Someone just suggested 38/38 hot works well -- I will be trying equal pressures just to see how things change.
Good idea to go to the big N. Just start about 4psi above normal air temps -- as long as you have N at the track, otherwise, start at your desired hot temps and be careful to air down conservatively of course.
You'll have to find your own best temps, but you could start at 29/34 cold and work up and down from there. Someone just suggested 38/38 hot works well -- I will be trying equal pressures just to see how things change.
Good idea to go to the big N. Just start about 4psi above normal air temps -- as long as you have N at the track, otherwise, start at your desired hot temps and be careful to air down conservatively of course.