991.2 GT3 RS batch '2' GPF?
Discussion
IREvans said:
Ah, I could talk people to sleep over ride and handling in relation to spring and damper rates....
You haven't met me yet 
Always interesting to talk about this kind of stuff for me with someone who actually knows what he's doing to satisfy my inner geek!IREvans said:
Regarding springs; as the primary purpose of the spring is to support the load of the car, and as the 991.2 GT3RS generates more downforce than the 991.1, then it needs stiffer springs to keep the car at the correct ride height at speed.
It's more a change of suspension philosophy than downforce driven though? the 991.1rs has (much) more downforce than the either gen 991 gt3 and yet has practically the same spring rates. iirc the .2 rs in max downforce mode at 186mph produces about 100kg more of downforce than the .1rs so that wouldn't be why the gen2 has 2x the front spring rate and 50% more rear I'd have thought given a 1500ish kg car. (the anti roll bars have been fairly significantly softened in return I believe).Interesting point is that the spring rates on the 991.2GT3 RS and GT2 RS varies considerably..I understand that as the latter has a more rearward bias complicating matters even further..Porsche struggled with the getting the damping/spring rates well balanced on the GT2 RS as it wanted it to be a usable compliant road car..Having a high downforce on a car also requires having higher tyre pressures to avoid having a dangerous blow out at Autobahn speeds. Manthey improved the GT2 RS hugely by concentrating more on Ring performance and less on practicality..They even remove the front lift as an example.
The collective 30Kg reduction in unsprung mass on a Mag/PCCB RS is pretty significant and IMO would greatly improve the ride..The CF ARBs which are 6Kg lighter would also help in this regard..
However a lot of US track drivers think the second gen RS is under damped which the DSC module has improved upon.
The collective 30Kg reduction in unsprung mass on a Mag/PCCB RS is pretty significant and IMO would greatly improve the ride..The CF ARBs which are 6Kg lighter would also help in this regard..
However a lot of US track drivers think the second gen RS is under damped which the DSC module has improved upon.
IREvans said:
Firstly, PCCBs and magnesium wheels will give a significant reduction in unsprung mass, and that will definitely have a positive benefit to the low and medium speed ride quality (I'd love to drive a car with steel brakes and standard alloys to compare). It's quite conceivable that the main contributor to improved low speed ride quality is the reduction in unsprung mass.
That should make a substantial difference - at least that's what I found driving 997s with steels and PCCBs back to back. Hence I am always going for PCCBs for my GT road carsTaffy66 said:
Interesting point is that the spring rates on the 991.2GT3 RS and GT2 RS varies considerably..I understand that as the latter has a more rearward bias complicating matters even further..Porsche struggled with the getting the damping/spring rates well balanced on the GT2 RS as it wanted it to be a usable compliant road car..Having a high downforce on a car also requires having higher tyre pressures to avoid having a dangerous blow out at Autobahn speeds. Manthey improved the GT2 RS hugely by concentrating more on Ring performance and less on practicality..They even remove the front lift as an example.
The collective 30Kg reduction in unsprung mass on a Mag/PCCB RS is pretty significant and IMO would greatly improve the ride..The CF ARBs which are 6Kg lighter would also help in this regard..
However a lot of US track drivers think the second gen RS is under damped which the DSC module has improved upon.
the GT2 weighs even more at the rear so hence people say not as well balanced but also has full monballs so I doubt they thought about road use with monoballs.The collective 30Kg reduction in unsprung mass on a Mag/PCCB RS is pretty significant and IMO would greatly improve the ride..The CF ARBs which are 6Kg lighter would also help in this regard..
However a lot of US track drivers think the second gen RS is under damped which the DSC module has improved upon.
the 3 RS and 2RS are track cars and they have gone solid bushings, in the past RS models were not track focused enough and now they have moved the game on and started rose jointing arms and links, where the gt3 is all rubber and is classed as the road going car.
with these extra G's on R spec tyres and down force it's no wonder , just odd it took so long.
I am full monoball in my Spyder and just done 1100 miles, it's not an issue if you want a car which tells you whats going on and brakes in a straight line.
1st thing I did on my GT4 was monoball the rear toe links as the rear just moved under brakes on track !!
I have the cup Monoball parts on my Gt3, some RS parts, some Manthey parts and soon to be BBS wheels, it's my Manual GT3 RS :-)
issue today is very few people swap parts out and just drive oem which is a shame as the cars can be greatly improved.
as for under damped, Manthey stated on their kit the 3 ways shocks on the .2 RS are only worth 5 seconds !! after 14 miles !!
so oem on the .2 seems pretty bloody good.
while the tyres are worth between 8 and 15 seconds.
the Manthey .1 tuned RS only did a 7.10 lap still with more down force and 3 way race shocks, that's only the same time as a .2 GT3 stock, on the same tyres , so these sub 7 laps from GT cars are ABOUT TYRES and once you get this grip you need a stable car and no rubber bush's to allow the driver to push the limits.
Porsche911R said:
the Manthey .1 tuned RS only did a 7.10 lap still with more down force and 3 way race shocks, that's only the same time as a .2 GT3 stock, on the same tyres ,
The manthey .1 rs did 7:10 per Sport Auto. That compares to 7:18 they got on the .2 gt3. That's not 'the same time as a stock .2gt3' as you are claiming. 
isaldiri said:
It's more a change of suspension philosophy than downforce driven though? the 991.1rs has (much) more downforce than the either gen 991 gt3 and yet has practically the same spring rates. iirc the .2 rs in max downforce mode at 186mph produces about 100kg more of downforce than the .1rs so that wouldn't be why the gen2 has 2x the front spring rate and 50% more rear I'd have thought given a 1500ish kg car. (the anti roll bars have been fairly significantly softened in return I believe).
Some more aero related geekery for you....The rear wing on a 991.1 GT3RS used to make a fairly audible buffeting sound at above ~60mph.On the 991.2RS, the buffeting sound is much quieter, and doesn’t begin until >85mph.
I’m guessing that as the latest spec rear wing creates more downforce and creates less buffeting, it’s managing the airflow more efficiently....or it could be that the rear window now being Gorilla glass instead of perspex offers more sound insulation...?
Porsche911R said:
430scuderia1 said:
why?
Customer might not have seen their own car yet.And then some one posts a car waiting for a pick up with reg plates in clear view etc.
I would not be happy if it were mine and I was picking it up tomorrow! But it was all over the net before I had seen it.
Dealer new PDI Process...
Edited by 430scuderia1 on Saturday 14th September 09:38
k it is then I’ll be very happy 
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