Suspension / Alignment problems
#46
Nordschleife Master
Are you referring to front or rear? In rear, it isn't to get more camber but rather to remove the movement under load (removing the rubber). The front is already a monoball piece.
#47
I was under the impression that upgrading from stock C2 to GT3 upper mounts, or aftermarket (Tarett) mounts allow additional camber in the front. From your comment, the more likely reason to upgrade is to "strengthen" the connection to prevent geometric changes during loading. Am I getting this?
-td
#48
Nordschleife Master
You got it!
However, the additional plus (if you need it) with the GT3 strut top mounts is they have an additional set of holes to allow rotation to get increased camber. The best is to rotate and use shims.
However, the additional plus (if you need it) with the GT3 strut top mounts is they have an additional set of holes to allow rotation to get increased camber. The best is to rotate and use shims.
#49
I was going to upgrade to Tarett monoball upper mounts to see if that will correct the noise. Maybe there's a bushing or washer or something that I can put between the mount and the spring to allow the spring to rotate rather than bind/release. Any thoughts on this? Or am I forever plagued with tapping noises...
-td
#51
Haven't given it any thought. I have helper springs, but I'm not sure of the spring rate. I'm a little concerned about what a change in helper springs would do - but I have no knowledge baseline to make an informed decision at this point.
I was actually going to put a nice plastic bushing around the upper mounting point, but wasn't sure if that would work. Did your GT3 front suspension make any noise after you did the upgrades? I would bet your Cab didn't, even after the ROW M030 as mine didn't. But for some reason, with the new suspension, I have a little noise. Handles wonderfully, but just a little noise.
-td
I was actually going to put a nice plastic bushing around the upper mounting point, but wasn't sure if that would work. Did your GT3 front suspension make any noise after you did the upgrades? I would bet your Cab didn't, even after the ROW M030 as mine didn't. But for some reason, with the new suspension, I have a little noise. Handles wonderfully, but just a little noise.
-td
#52
Nordschleife Master
Neither cars made any sounds after upgrade. The helper springs on the GT3 kept the spring in place on the coupler when not under load so there was no chance of shifting off (and then back on) which might be the clunk you hear.
#54
[
I was going to upgrade to Tarett monoball upper mounts to see if that will correct the noise. Maybe there's a bushing or washer or something that I can put between the mount and the spring to allow the spring to rotate rather than bind/release. Any thoughts on this? Or am I forever plagued with tapping noises...
-td[/QUOTE]
I have similar tapping noise with the PSS9 set up, TRG mount, TRG droplinks and GT3 ARBs. All bolts are tight!! The collar between the helper and coil springs has clearance from the shock. I suspected it hit the shock body and causing the tapping noise.
I also planning to install thrust bearing to ease spring movement.
http://www.daltonbearing.com/Torring...r-Bearings.asp
FYI
I was going to upgrade to Tarett monoball upper mounts to see if that will correct the noise. Maybe there's a bushing or washer or something that I can put between the mount and the spring to allow the spring to rotate rather than bind/release. Any thoughts on this? Or am I forever plagued with tapping noises...
-td[/QUOTE]
I have similar tapping noise with the PSS9 set up, TRG mount, TRG droplinks and GT3 ARBs. All bolts are tight!! The collar between the helper and coil springs has clearance from the shock. I suspected it hit the shock body and causing the tapping noise.
I also planning to install thrust bearing to ease spring movement.
http://www.daltonbearing.com/Torring...r-Bearings.asp
FYI
#55
Racer
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Front links are TRG, mount at the pinch bolt, rear links are from Arlan as well as the mounts to the shock. I'm not getting much credit here.
I suppose I could swap the links to the inside of the mount, rather than the outer side, in an attempt to get them more vertical. I know you guys are having fun here, but Occam's razor, IMO it's most likely the non GT3 bars or crappy tires. I'm not messing with the car till next week, have more pressing things to do.
BTW, my name is Dan.
Thanks again for everyone's help. Dell I may take you up on your offer sometime next week.
I suppose I could swap the links to the inside of the mount, rather than the outer side, in an attempt to get them more vertical. I know you guys are having fun here, but Occam's razor, IMO it's most likely the non GT3 bars or crappy tires. I'm not messing with the car till next week, have more pressing things to do.
BTW, my name is Dan.
Thanks again for everyone's help. Dell I may take you up on your offer sometime next week.
Last edited by Fissionx; 10-17-2008 at 02:31 PM.
#56
Front links are TRG, mount at the pinch bolt, rear links are from Arlan as well as the mounts to the shock. I'm not getting much credit here.
I suppose I could swap the links to the inside of the mount, rather than the outer side, in an attempt to get them more vertical. I know you guys are having fun here, but Occam's razor, IMO it's most likely the non GT3 bars or crappy tires. I'm not messing with the car till next week, have more pressing things to do.
BTW, my name is Dan.
Thanks again for everyone's help. Dell I may take you up on your offer sometime next week.
I suppose I could swap the links to the inside of the mount, rather than the outer side, in an attempt to get them more vertical. I know you guys are having fun here, but Occam's razor, IMO it's most likely the non GT3 bars or crappy tires. I'm not messing with the car till next week, have more pressing things to do.
BTW, my name is Dan.
Thanks again for everyone's help. Dell I may take you up on your offer sometime next week.
This leaves the ARB as the culprit. IMO, without the adjustalble ARBs, you have a situation that may not be correctable as-is. You have decreased ride height, upgraded springs/dampers, adjusted alignment, and a host of other things. However, one of the first things that is done to correct massive under/oversteer is to adjust the ARBs. Working on damper settings and adjusting tire pressure are fine tuning tools.
At this point I would suggest getting/borrowing at least a rear GT3 or aftermarket sway bar, stiffen it up, and see if that works. Alternately, you could put your old M030 rear sway on with your stock front sway. The 10% difference in front sway stiffness might just be the trick.
-td
#57
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One trick I've used at the track to help with set up is to disconnect both sway bars and drive the car. This will give you an idea as to what the suspension set up is on just the springs.
I would reccomend this, but you need to use your brain here. Don't go hot rodding around, the car will feel very different. If the problem mostly subsides, then you have your answer. Sway bars or drop links.
And for the record, I'm not fooling around. Just trying to help you out, Dan.
I would reccomend this, but you need to use your brain here. Don't go hot rodding around, the car will feel very different. If the problem mostly subsides, then you have your answer. Sway bars or drop links.
And for the record, I'm not fooling around. Just trying to help you out, Dan.
#58
Rennlist Member
Hey Y'all watch this!!!
Been reading this ENCYCLOPEDIC thread on alignment and understeer!!I don't know what I am talking about but I know that My 996 GT-3 loves to understeer out of the box .So I run it like this :More negative camber up front ALWAYS .Neutral Toe upfront ALWAYS .Full SOFT bar up front and full STIFF bar in rear ALWAYS .Most of the time a bit of toe out in the rear and lastly 2-3 pounds lower air pressure in the front .Seems to work for me !!CHEERS TVTH
#59
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Hi Tom,
I am friends w/ Ahmet, got a ride or two with you before at VIR. Will you be doing Chin after halloween? Not a while lot of useable info here, mainly trying to diagnose some of my specific problems.
Sooo... I put on the 235f 295r Michelin PS2s (HUGE thanks to deckman for selling me these!) and this made a NIGHT and DAY difference. The car has MUCH less understeer and IS FUN TO DRIVE again. The car is smoother and really cleaned up. This is the same exact set-up as above, just different tires. I have ordered GT3 ARBs which will arive this week and I will let you know how that affects the car.
I think the moral of this story is one change at a time...
I had the car on jackstands and put on new wheels (19s to 18s, different rim sizes and offset, different tire compound and tire size), new GT3 suspension, different ride height and susp geometry, and a new alignment. I had no clue what was causing my problems.
I am glad I did the tires first, so I will be able to tell a real difference in using the GT3 bars vs the C2 bars. Should be a substantial difference as well.
Oh yeah, Pirelli PZero Neros SUCK! At least mine did.
Thanks again Bill, Andy, Dell, and everyone else for their help.
I am friends w/ Ahmet, got a ride or two with you before at VIR. Will you be doing Chin after halloween? Not a while lot of useable info here, mainly trying to diagnose some of my specific problems.
Sooo... I put on the 235f 295r Michelin PS2s (HUGE thanks to deckman for selling me these!) and this made a NIGHT and DAY difference. The car has MUCH less understeer and IS FUN TO DRIVE again. The car is smoother and really cleaned up. This is the same exact set-up as above, just different tires. I have ordered GT3 ARBs which will arive this week and I will let you know how that affects the car.
I think the moral of this story is one change at a time...
I had the car on jackstands and put on new wheels (19s to 18s, different rim sizes and offset, different tire compound and tire size), new GT3 suspension, different ride height and susp geometry, and a new alignment. I had no clue what was causing my problems.
I am glad I did the tires first, so I will be able to tell a real difference in using the GT3 bars vs the C2 bars. Should be a substantial difference as well.
Oh yeah, Pirelli PZero Neros SUCK! At least mine did.
Thanks again Bill, Andy, Dell, and everyone else for their help.