997.1 GT3 - rear unsettled on heavy braking
#16
Racer
Make sure your shop installs those ramps correctly. Really easy to put them in backwards. As did the guy who put it in my car. Caused a failure. Then put entire Gard unit in. Make sure they speak with Gard about proper installation- just being experienced is no assurance it will be right
#17
Rennlist Member
^ This. Some times an effective diff will mask the problem. But always good to have both items sorted.
Diff parts, go with Guard, effective, good accessibility. Or PMNA, less accessibility for most, cost higher.
Diff parts, go with Guard, effective, good accessibility. Or PMNA, less accessibility for most, cost higher.
#18
Racer
Thread Starter
I'm waiting on the parts from Guard.. not sure if they will show up in time for install/racing.
I checked my alignment specs, running 3.0* toe in total at rear, how does this sound?
I checked my alignment specs, running 3.0* toe in total at rear, how does this sound?
#19
Rennlist Member
Most guys seem to run 1.5-2 per side in the rear.
#20
Racer
Thread Starter
#21
Rennlist Member
40/60 is most common for street cars
#23
I have a Guards diff in good condition and my back-end wiggles a little under braking from high speeds, I think it's just a 911 thing with the weight transfer honestly... I've spoken with a lot of others with 911s (including non GT) and they experience this too. The GT3 is my first 911 though, so no idea! I'm going to try adding more wing tho, right now mine's in the middle. gotta go full attack I guess
Also check the rear toe settings as was suggested. These tend to slip out of alignment after just a few days on track, especially if you're using R comps. I bought the locking toe plates from Tarett and now at least I know that's not a factor. It had popped out of alignment 2 or 3 times in the past for me - not super fun.
#24
Rennlist Member
On the locking plates... what's weird is I don't have them. Never have. And when I get a set down down the alignment/toe is completely in spec. Maybe my tech has popeye arms. lol. or i don't jump kerbs hard enough.
Sure, i get a little wiggle especially if the braking zone is kinda bumpy, but once I put the GT diff in it was literally night and day on braking AND acceleration. I had to get used to the exit traction I was ***** footing exit apex throttle and needed to drive the car harder to get it to rotate it had so much more traction.
Sure, i get a little wiggle especially if the braking zone is kinda bumpy, but once I put the GT diff in it was literally night and day on braking AND acceleration. I had to get used to the exit traction I was ***** footing exit apex throttle and needed to drive the car harder to get it to rotate it had so much more traction.
#25
Racer
Thread Starter
I did the Guard Transmission LSD internal upgrade last week, putting the car on the lift and grabbing one wheel, it was just open!
Here is how the install went.
Yup, metal!
You can see wear on the friction disc if look
Guard friction discs on top, OEM on bottom.
GT2 Ramps vs stock 997.1
All done
The install went smooth, and i opted for 40/60 as suggested here.
Aside from this fresh A050 Yokohama (soft compound) went on and I dialled more camber into the existing alignment, now running 3.5* all round.
I had the car out at Sydney Motorsport Park on Saturday for round one of our club super sprint, the car felt great, no wiggles and it was hooked up! Which gave moe confidence to push it, I bought my times down 6 seconds from last outing, frustratingly I did not quite break into the minute 40 zone, but managed a 1:50 lap time. A good time for this car would be about 1:45 at that track, so I am happy to closing in on that number, now I need a good seat, harness, roll bar and to just develop myself as a driver, with this car.
Cheers to all for the advice, very happy with this modification.
Here is how the install went.
Yup, metal!
You can see wear on the friction disc if look
Guard friction discs on top, OEM on bottom.
GT2 Ramps vs stock 997.1
All done
The install went smooth, and i opted for 40/60 as suggested here.
Aside from this fresh A050 Yokohama (soft compound) went on and I dialled more camber into the existing alignment, now running 3.5* all round.
I had the car out at Sydney Motorsport Park on Saturday for round one of our club super sprint, the car felt great, no wiggles and it was hooked up! Which gave moe confidence to push it, I bought my times down 6 seconds from last outing, frustratingly I did not quite break into the minute 40 zone, but managed a 1:50 lap time. A good time for this car would be about 1:45 at that track, so I am happy to closing in on that number, now I need a good seat, harness, roll bar and to just develop myself as a driver, with this car.
Cheers to all for the advice, very happy with this modification.
#26
Rennlist Member
Great!
#28
Racer
Thread Starter
I had the car at the local Porsche centre on Monday, I asked them to carry out a road worthy inspection (needed annually for our vehicle registration).
They found the RH track rod to have too much play in it, odd as I didn't feel this and it was at an alignment shop on the Friday prior.
So the question is, should I just replace with OEM or is this a great opportunity to upgrade?
Cheers
They found the RH track rod to have too much play in it, odd as I didn't feel this and it was at an alignment shop on the Friday prior.
So the question is, should I just replace with OEM or is this a great opportunity to upgrade?
Cheers
#29
Rennlist Member
Which specific component is it? There are a lot of rods/links on these cars.
That's a slippery slope question. I had a PASM damper go bad on mine and left the shop with Ohlins dampers and full monoball suspension. :-)
So, for example, if its the compression link or one of the rear dog bones I'd probably just leave it stock unless you are trying to do some more aggressive alignment things like change the roll center in the rear of the car. If its the rear toe steer or the inner links on the lower control arm I'd monoball those. If the sway drop links, definitely get adjustable links so you can corner balance the car.
Kinda priority list:
rear toe links
sway drop links f/r
a-arm inner links f/r
compression links + a-arm pucks f/r
front steer tie rods w/ bump steer
rotate front shock top mounts
monoball rear shock mounts
That's a slippery slope question. I had a PASM damper go bad on mine and left the shop with Ohlins dampers and full monoball suspension. :-)
So, for example, if its the compression link or one of the rear dog bones I'd probably just leave it stock unless you are trying to do some more aggressive alignment things like change the roll center in the rear of the car. If its the rear toe steer or the inner links on the lower control arm I'd monoball those. If the sway drop links, definitely get adjustable links so you can corner balance the car.
Kinda priority list:
rear toe links
sway drop links f/r
a-arm inner links f/r
compression links + a-arm pucks f/r
front steer tie rods w/ bump steer
rotate front shock top mounts
monoball rear shock mounts
#30
Racer
Thread Starter
Which specific component is it? There are a lot of rods/links on these cars.
That's a slippery slope question. I had a PASM damper go bad on mine and left the shop with Ohlins dampers and full monoball suspension. :-)
So, for example, if its the compression link or one of the rear dog bones I'd probably just leave it stock unless you are trying to do some more aggressive alignment things like change the roll center in the rear of the car. If its the rear toe steer or the inner links on the lower control arm I'd monoball those. If the sway drop links, definitely get adjustable links so you can corner balance the car.
Kinda priority list:
rear toe links
sway drop links f/r
a-arm inner links f/r
compression links + a-arm pucks f/r
front steer tie rods w/ bump steer
rotate front shock top mounts
monoball rear shock mounts
That's a slippery slope question. I had a PASM damper go bad on mine and left the shop with Ohlins dampers and full monoball suspension. :-)
So, for example, if its the compression link or one of the rear dog bones I'd probably just leave it stock unless you are trying to do some more aggressive alignment things like change the roll center in the rear of the car. If its the rear toe steer or the inner links on the lower control arm I'd monoball those. If the sway drop links, definitely get adjustable links so you can corner balance the car.
Kinda priority list:
rear toe links
sway drop links f/r
a-arm inner links f/r
compression links + a-arm pucks f/r
front steer tie rods w/ bump steer
rotate front shock top mounts
monoball rear shock mounts
Thanks again for your reply Spyerx