996 Suspension Set-Up Help
09-22-2014, 06:53 PM
#1
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996 Suspension Set-Up Help
Brand new to water-pumpers and had my first real outing with my 996 a couple weeks ago. Ran well, but had a tendency toward understeer (fairly significantly mid to late run). Thought I'd open it up to you guys and see what you've found to be the ideal setting on these cars; namely springs, tires and sways.
Few important points:
NOT a CUP. 2002 C4 tub with a 2010 Cup cage. Car is 2,690# off-track weight inc. driver
"All the right suspension stuff". Too much to list; assume standard
800/1,000 springs
2-Way adj. Motons
Full Aero (inc front cannards)
303bhp engine
sways set in the middle front and rear
Running the itty-bitty cup tires (240/280)
Couple Notes:
Regardless of the aforementioned, curious to hear what the peanut gallery has found as their favorite 996 set-up
Few important points:
NOT a CUP. 2002 C4 tub with a 2010 Cup cage. Car is 2,690# off-track weight inc. driver
"All the right suspension stuff". Too much to list; assume standard
800/1,000 springs
2-Way adj. Motons
Full Aero (inc front cannards)
303bhp engine
sways set in the middle front and rear
Running the itty-bitty cup tires (240/280)
Couple Notes:
- I switched to the GA rear tire (280/680) from the club Yoke (280/640) and the car ran way better deeper in a session. Made me think the car may be too highly sprung
- I managed to get the car pretty neutral in the 2-3 lap range, then progresses to a fairly profound push. Part of that is small front tires, but I have to imagine suspension setting is up there as well.
Regardless of the aforementioned, curious to hear what the peanut gallery has found as their favorite 996 set-up
09-23-2014, 10:01 PM
#4
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Jack I'm pretty sure I've said this before but you're over-sprung especially up front. I'd try 600/800 and see how that feels. I run 550f, 700 r, and have won a few races with that setup. My bars are almost always 1-off full stiff at both ends. I'd stiffen your rear bar 1 notch which should help with the understeer. Random thoughts:
Try the 250/650 front Yokes. I use the Clubsport 01 compound (soft) but others use the 02 medium compound. You can also match the IMSA fronts which are 250/640 (medium). Regardless, stay with the 280 rears until you dial out the understeer.
Take some bump out of the car especially up front. I run 2 clicks front bump and 5 clicks of rebound YMMV but play around...
Last thought: Do you have a new LSD and if so, have you changed the gear oil yet? That can make a difference in how/when it's locking up. If you coast a lot into turns like I do it can and will impact your turn-in. T9 at WSIR is a perfect example when you coast along the outside and then start to turn to the apex. Try using a little maintenance throttle to unlock the diff......
Try the 250/650 front Yokes. I use the Clubsport 01 compound (soft) but others use the 02 medium compound. You can also match the IMSA fronts which are 250/640 (medium). Regardless, stay with the 280 rears until you dial out the understeer.
Take some bump out of the car especially up front. I run 2 clicks front bump and 5 clicks of rebound YMMV but play around...
Last thought: Do you have a new LSD and if so, have you changed the gear oil yet? That can make a difference in how/when it's locking up. If you coast a lot into turns like I do it can and will impact your turn-in. T9 at WSIR is a perfect example when you coast along the outside and then start to turn to the apex. Try using a little maintenance throttle to unlock the diff......
09-24-2014, 10:27 AM
#6
Try carrying more entrt speed and waiting an extra instant before picking up the throttle at mid corner/exit.
You said you are new to the 996, assuming maybe you came from an older air cooled 911? The newer cars require a different style. When I first drove the 996 I struggled terribly with mid/exit push. Didnt change anything in the setup but focused on driving it differently and 98% of the push went away.
The newer cars have so much more grip than the trailing arm cars. The key is to carry tons of entry speed, let the mid corner scrub some of your speed amd be patient getting back on the gas. If you start picking up light throttle too soon mid corner the rear will not rotate and you'll have to feather the gas to manage the push. Wait just an instant until the rear rotates, then try to smoothly and relatively quickly add throttle in one continuous motion to 100%.
You said you are new to the 996, assuming maybe you came from an older air cooled 911? The newer cars require a different style. When I first drove the 996 I struggled terribly with mid/exit push. Didnt change anything in the setup but focused on driving it differently and 98% of the push went away.
The newer cars have so much more grip than the trailing arm cars. The key is to carry tons of entry speed, let the mid corner scrub some of your speed amd be patient getting back on the gas. If you start picking up light throttle too soon mid corner the rear will not rotate and you'll have to feather the gas to manage the push. Wait just an instant until the rear rotates, then try to smoothly and relatively quickly add throttle in one continuous motion to 100%.
09-24-2014, 11:21 AM
#7
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Mehoff, good advice above.
If you've come from an aircooled car... You cannot drive a Cup/996 like the aircooled car. You will get exactly the symptoms you've described.
-signed, Someone who tried, failed, and is still learning this too.
If you've come from an aircooled car... You cannot drive a Cup/996 like the aircooled car. You will get exactly the symptoms you've described.
-signed, Someone who tried, failed, and is still learning this too.
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09-24-2014, 12:19 PM
#8
Rennlist Member
Mehoff,
Once you think you are properly driving the car, the way to dial out exit understeer would be one or a combination of these :
Stiffen rear bar
Stiffen rear spring
Stiffen rear compression
Raise ride height
(make one adjustment at a time)
Mid corner is tricky but first I would work on the exit and see if it helps mid. Try the easy stuff first bar and or compression. Work in baby steps and always have your original set up written down so you can go back if needed.
I was having issues like you and would be leading the race by a straight away and then get an insane push. So bad that it would allow cars behind me to catch back up. My car was set up way to stiff and by just making changers to shocks and bars I dialed that mid race push out. In essence I was overheating the tires during the race with my old set up. Its amazing how long I can go now on a set of tires. 6-10 heat cycles and I am still within a second or less of stickers
Once you think you are properly driving the car, the way to dial out exit understeer would be one or a combination of these :
Stiffen rear bar
Stiffen rear spring
Stiffen rear compression
Raise ride height
(make one adjustment at a time)
Mid corner is tricky but first I would work on the exit and see if it helps mid. Try the easy stuff first bar and or compression. Work in baby steps and always have your original set up written down so you can go back if needed.
I was having issues like you and would be leading the race by a straight away and then get an insane push. So bad that it would allow cars behind me to catch back up. My car was set up way to stiff and by just making changers to shocks and bars I dialed that mid race push out. In essence I was overheating the tires during the race with my old set up. Its amazing how long I can go now on a set of tires. 6-10 heat cycles and I am still within a second or less of stickers
09-24-2014, 03:34 PM
#9
Rennlist Member
Mehoff,
Once you think you are properly driving the car, the way to dial out exit understeer would be one or a combination of these :
Stiffen rear bar
Stiffen rear spring
Stiffen rear compression
Raise ride height
(make one adjustment at a time)
Mid corner is tricky but first I would work on the exit and see if it helps mid. Try the easy stuff first bar and or compression. Work in baby steps and always have your original set up written down so you can go back if needed.
I was having issues like you and would be leading the race by a straight away and then get an insane push. So bad that it would allow cars behind me to catch back up. My car was set up way to stiff and by just making changers to shocks and bars I dialed that mid race push out. In essence I was overheating the tires during the race with my old set up. Its amazing how long I can go now on a set of tires. 6-10 heat cycles and I am still within a second or less of stickers
Once you think you are properly driving the car, the way to dial out exit understeer would be one or a combination of these :
Stiffen rear bar
Stiffen rear spring
Stiffen rear compression
Raise ride height
(make one adjustment at a time)
Mid corner is tricky but first I would work on the exit and see if it helps mid. Try the easy stuff first bar and or compression. Work in baby steps and always have your original set up written down so you can go back if needed.
I was having issues like you and would be leading the race by a straight away and then get an insane push. So bad that it would allow cars behind me to catch back up. My car was set up way to stiff and by just making changers to shocks and bars I dialed that mid race push out. In essence I was overheating the tires during the race with my old set up. Its amazing how long I can go now on a set of tires. 6-10 heat cycles and I am still within a second or less of stickers
What shocks are you running now?
Thanks,
JF
09-24-2014, 05:00 PM
#10
Rennlist Member
Thread Starter
Try carrying more entrt speed and waiting an extra instant before picking up the throttle at mid corner/exit.
You said you are new to the 996, assuming maybe you came from an older air cooled 911? The newer cars require a different style. When I first drove the 996 I struggled terribly with mid/exit push. Didnt change anything in the setup but focused on driving it differently and 98% of the push went away.
The newer cars have so much more grip than the trailing arm cars. The key is to carry tons of entry speed, let the mid corner scrub some of your speed amd be patient getting back on the gas. If you start picking up light throttle too soon mid corner the rear will not rotate and you'll have to feather the gas to manage the push. Wait just an instant until the rear rotates, then try to smoothly and relatively quickly add throttle in one continuous motion to 100%.
You said you are new to the 996, assuming maybe you came from an older air cooled 911? The newer cars require a different style. When I first drove the 996 I struggled terribly with mid/exit push. Didnt change anything in the setup but focused on driving it differently and 98% of the push went away.
The newer cars have so much more grip than the trailing arm cars. The key is to carry tons of entry speed, let the mid corner scrub some of your speed amd be patient getting back on the gas. If you start picking up light throttle too soon mid corner the rear will not rotate and you'll have to feather the gas to manage the push. Wait just an instant until the rear rotates, then try to smoothly and relatively quickly add throttle in one continuous motion to 100%.
I have had a hard time resetting my brain; braking zones are the hardest thus far. Going from a life long maintenance throttle to ABS is tough; my brain wants to modulate the braking pressure but that's just slow!
I learned to drive these cars with the throttle, and now the mechanical and aero grip necessitates rolling into corners with later throttle application....glad I'm not the only one struggling with it.
Gordon- I'm set up pretty similar to you but am WAY more stiffly sprung. I may need to try and dial it back a bit (though other shops have suggested I'm not stiff enough, go figure).
Sounds like seat time is where I need to start.
09-24-2014, 09:48 PM
#11
The cars can be made to work soft or stiff, it's a matter of personal preference.
For me, I had to overcome the instinct of "the rear is coming around - got to pick up the throttle now." There is still more rear grip there even once it feels like it's starting to rotate (contrary to my old trailing arm cars).
For me, I had to overcome the instinct of "the rear is coming around - got to pick up the throttle now." There is still more rear grip there even once it feels like it's starting to rotate (contrary to my old trailing arm cars).
09-25-2014, 07:38 PM
#14
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Softer springs will really help you speed up the learning curve. You can always change back to stiffer springs as I always intended to do but it's hard to argue with how well my car handles....
09-26-2014, 08:33 AM
#15
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I also swapped out my Cup car springs for softer ones, just as JRG did. The change was prompted by my move to FL and my proximity to Sebring, wish I did it sooner.
Absolutely use the 680 tire in the rear. But in making that change be sure to adjust ride height. Proper rake on this car is critical.
Absolutely use the 680 tire in the rear. But in making that change be sure to adjust ride height. Proper rake on this car is critical.