Understeer .2RS
02-25-2019, 01:30 AM
#1
Rennlist Member
Thread Starter
Understeer .2RS
.2RS - totally stock - Dunlops. First half of sessions were ok- but 2nd half seemed to get worse. Tried lowering pressures to 28f 32r hot - and still did it.
Any ideas?
Any ideas?
02-25-2019, 07:17 AM
#3
Race Car
Work with someone who can adjust alignment and also the rear wing. The RS is fairly adjustable - you should be able to dial out some of the understeer.
02-25-2019, 08:45 AM
#5
You may also want to adjust the sway bar settings
02-25-2019, 09:53 AM
#6
Rennlist Member
Little bit more info is needed to help out with this. What track, what turns at the track did it understeer, and where in the turn did it understeer (turn-in, apex, track out)?
02-25-2019, 10:07 AM
#7
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They all come out of the factory with a ton of U/S.
A simple alignment will quickly solve the issue, we supply set up data with our shim kits.
JC
A simple alignment will quickly solve the issue, we supply set up data with our shim kits.
JC
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02-25-2019, 11:39 AM
#8
Nordschleife Master
Fwiw, I've found the RS out of the box to be really nicely balanced. Maybe a touch of corner exit oversteer, which is not necessarily bad. This is stock alignment and sway bar settings. However, despite what most people say, I run higher pressures. 33-34psi up front and 35-36psi in the rear when hot. 27 psi cold at first and then bleed once after first session to 33/35. After that, leave the pressures alone even if they go to 34/36 because I've found that if you don't mess with the pressures after that, they won't go any higher. Continue to bleed and the pressures will continue to climb
02-25-2019, 12:15 PM
#9
Burning Brakes
It comes pushy on slow corners on corner entry and corner exit. Corner exit understeer is normal with the 991s, but corner entry is annoying.
The .2 GT3 RS has a range of rear toe, set it to 0.15 degrees per corner, rather than 0.22 degrees (mine came at 0.22 in one corner 0.24 in the other). My .2 came with -1.7 degrees camber at all corners, and normally for my use (track mostly) my 3 other 991s (a Carrera S, a .1 TTS and a .1 GT3 RS) use anywhere from -0.5 to -0.8 more negative camber in the front axle compared to the rear axle, but this .2 GT3 RS is way different, and I don't think it requires more camber in the front compared to the rear (more about this below).
The rear sway bar comes at full stiff, leave it there. The front bar comes in the middle, move it to full soft.
On high speed tracks (VIR, WGI) I use the front bar in the middle, everywhere else the full soft front bar works for me.
The car has a lot of adjustment available, so you can dial understeer/oversteer easily. The stock alignment is fine for street use and mild track use. My stock MPSC2 are spot on wear at -2.5 camber in the rear. For the front, -2.2 (my 2nd alignment) was still producing higher temperatures on the 1/3 of the outer tread on the front tires, and at -3.0 (current alignment) it is too much camber for the MPSC2, so I would go -2.5 camber at all corners for MPSC2, leave the ride heights stock, 0 toe front and 0.15 degrees toe-in rear (per corner).
Sway bar adjustment is a matter of preference. You can also adjust just one corner of the front sway bar, so one side left stock in the middle (out of the 3 available holes), and the other side at full soft (hole at the end of the bar).
Tire pressures, the rear MPSC2 at 34psi is on the spot, so Porsche's recommended 33psi is about right. The front at 28-30 psi is fine too (Porsche recommends 29). Cold pressures will depend on weather, track, driver skills, my MPSC2 pick up 6psi on Florida Spring weather, but on my old .1 RS I was getting up to 10psi gain on MPSC2 at a local track in the Summer time.
The .2 GT3 RS has a range of rear toe, set it to 0.15 degrees per corner, rather than 0.22 degrees (mine came at 0.22 in one corner 0.24 in the other). My .2 came with -1.7 degrees camber at all corners, and normally for my use (track mostly) my 3 other 991s (a Carrera S, a .1 TTS and a .1 GT3 RS) use anywhere from -0.5 to -0.8 more negative camber in the front axle compared to the rear axle, but this .2 GT3 RS is way different, and I don't think it requires more camber in the front compared to the rear (more about this below).
The rear sway bar comes at full stiff, leave it there. The front bar comes in the middle, move it to full soft.
On high speed tracks (VIR, WGI) I use the front bar in the middle, everywhere else the full soft front bar works for me.
The car has a lot of adjustment available, so you can dial understeer/oversteer easily. The stock alignment is fine for street use and mild track use. My stock MPSC2 are spot on wear at -2.5 camber in the rear. For the front, -2.2 (my 2nd alignment) was still producing higher temperatures on the 1/3 of the outer tread on the front tires, and at -3.0 (current alignment) it is too much camber for the MPSC2, so I would go -2.5 camber at all corners for MPSC2, leave the ride heights stock, 0 toe front and 0.15 degrees toe-in rear (per corner).
Sway bar adjustment is a matter of preference. You can also adjust just one corner of the front sway bar, so one side left stock in the middle (out of the 3 available holes), and the other side at full soft (hole at the end of the bar).
Tire pressures, the rear MPSC2 at 34psi is on the spot, so Porsche's recommended 33psi is about right. The front at 28-30 psi is fine too (Porsche recommends 29). Cold pressures will depend on weather, track, driver skills, my MPSC2 pick up 6psi on Florida Spring weather, but on my old .1 RS I was getting up to 10psi gain on MPSC2 at a local track in the Summer time.
02-25-2019, 12:50 PM
#10
Rennlist Member
It is not the simple of using different holes on each side to get a middle setting for the sway bars. Doing this will affect the handling of the car differently for different turns. Right hand turns the car will act differently than left hand turns. Or vise versa depending on which side the shorter/longer arm is on. That is why most 3-hole bars are said to be either a 3-way adjustable bar and not a 5-way adjustable bar. This type setup might work well at a track like Lime Rock where this is only 1 left hand turn but it woun't work the same at VIR, Road Atlanta, etc since they have almost equal amounts of left vs. right hand turns. Another note is that a car with cockpit adjustable sways bars that has two levers to operate the front blade type bars does not function the same as a bar with an adjustment hole. The blade is more progressive in how it controls roll compared to a fixed location of a hole like our stock bars. So this is why the pro level cars with adjustable bars can have this type of adjustments in them.
02-25-2019, 12:53 PM
#11
Addict
Rennlist Member
Rennlist Member
It is not the simple of using different holes on each side to get a middle setting for the sway bars. Doing this will affect the handling of the car differently for different turns. Right hand turns the car will act differently than left hand turns. Or vise versa depending on which side the shorter/longer arm is on. That is why most 3-hole bars are said to be either a 3-way adjustable bar and not a 5-way adjustable bar. This type setup might work well at a track like Lime Rock where this is only 1 left hand turn but it woun't work the same at VIR, Road Atlanta, etc since they have almost equal amounts of left vs. right hand turns. Another note is that a car with cockpit adjustable sways bars that has two levers to operate the front blade type bars does not function the same as a bar with an adjustment hole. The blade is more progressive in how it controls roll compared to a fixed location of a hole like our stock bars. So this is why the pro level cars with adjustable bars can have this type of adjustments in them.
02-25-2019, 05:28 PM
#12
Rennlist Member
Thread Starter
Turn in and Apex seemed the worse portions
02-25-2019, 05:29 PM
#13
Rennlist Member
Thread Starter
02-25-2019, 05:30 PM
#14
Rennlist Member
Thread Starter
Fwiw, I've found the RS out of the box to be really nicely balanced. Maybe a touch of corner exit oversteer, which is not necessarily bad. This is stock alignment and sway bar settings. However, despite what most people say, I run higher pressures. 33-34psi up front and 35-36psi in the rear when hot. 27 psi cold at first and then bleed once after first session to 33/35. After that, leave the pressures alone even if they go to 34/36 because I've found that if you don't mess with the pressures after that, they won't go any higher. Continue to bleed and the pressures will continue to climb
02-25-2019, 05:42 PM
#15
Rennlist Member
Thread Starter
It comes pushy on slow corners on corner entry and corner exit. Corner exit understeer is normal with the 991s, but corner entry is annoying.
The .2 GT3 RS has a range of rear toe, set it to 0.15 degrees per corner, rather than 0.22 degrees (mine came at 0.22 in one corner 0.24 in the other). My .2 came with -1.7 degrees camber at all corners, and normally for my use (track mostly) my 3 other 991s (a Carrera S, a .1 TTS and a .1 GT3 RS) use anywhere from -0.5 to -0.8 more negative camber in the front axle compared to the rear axle, but this .2 GT3 RS is way different, and I don't think it requires more camber in the front compared to the rear (more about this below).
The rear sway bar comes at full stiff, leave it there. The front bar comes in the middle, move it to full soft.
On high speed tracks (VIR, WGI) I use the front bar in the middle, everywhere else the full soft front bar works for me.
The car has a lot of adjustment available, so you can dial understeer/oversteer easily. The stock alignment is fine for street use and mild track use. My stock MPSC2 are spot on wear at -2.5 camber in the rear. For the front, -2.2 (my 2nd alignment) was still producing higher temperatures on the 1/3 of the outer tread on the front tires, and at -3.0 (current alignment) it is too much camber for the MPSC2, so I would go -2.5 camber at all corners for MPSC2, leave the ride heights stock, 0 toe front and 0.15 degrees toe-in rear (per corner).
Sway bar adjustment is a matter of preference. You can also adjust just one corner of the front sway bar, so one side left stock in the middle (out of the 3 available holes), and the other side at full soft (hole at the end of the bar).
Tire pressures, the rear MPSC2 at 34psi is on the spot, so Porsche's recommended 33psi is about right. The front at 28-30 psi is fine too (Porsche recommends 29). Cold pressures will depend on weather, track, driver skills, my MPSC2 pick up 6psi on Florida Spring weather, but on my old .1 RS I was getting up to 10psi gain on MPSC2 at a local track in the Summer time.
The .2 GT3 RS has a range of rear toe, set it to 0.15 degrees per corner, rather than 0.22 degrees (mine came at 0.22 in one corner 0.24 in the other). My .2 came with -1.7 degrees camber at all corners, and normally for my use (track mostly) my 3 other 991s (a Carrera S, a .1 TTS and a .1 GT3 RS) use anywhere from -0.5 to -0.8 more negative camber in the front axle compared to the rear axle, but this .2 GT3 RS is way different, and I don't think it requires more camber in the front compared to the rear (more about this below).
The rear sway bar comes at full stiff, leave it there. The front bar comes in the middle, move it to full soft.
On high speed tracks (VIR, WGI) I use the front bar in the middle, everywhere else the full soft front bar works for me.
The car has a lot of adjustment available, so you can dial understeer/oversteer easily. The stock alignment is fine for street use and mild track use. My stock MPSC2 are spot on wear at -2.5 camber in the rear. For the front, -2.2 (my 2nd alignment) was still producing higher temperatures on the 1/3 of the outer tread on the front tires, and at -3.0 (current alignment) it is too much camber for the MPSC2, so I would go -2.5 camber at all corners for MPSC2, leave the ride heights stock, 0 toe front and 0.15 degrees toe-in rear (per corner).
Sway bar adjustment is a matter of preference. You can also adjust just one corner of the front sway bar, so one side left stock in the middle (out of the 3 available holes), and the other side at full soft (hole at the end of the bar).
Tire pressures, the rear MPSC2 at 34psi is on the spot, so Porsche's recommended 33psi is about right. The front at 28-30 psi is fine too (Porsche recommends 29). Cold pressures will depend on weather, track, driver skills, my MPSC2 pick up 6psi on Florida Spring weather, but on my old .1 RS I was getting up to 10psi gain on MPSC2 at a local track in the Summer time.
Lot of info here