Suspension / Alignment problems

I just put on a gt3 suspension and aligned the car and it understeers a lot, much more than the ROW M030 I drove which was a perfect balance IMO. I can enter a turn off power and the car will still understeer. The second I get back on the gas i lose even more front end grip. I wanted to post my set-up and get some input as to what the problem might be... GT3 suspension, stock (C2) bars with adjustable links Stock GT3 ride height Front: -2.5degs camber 7.8degs caster 0.05degs toe in (i requested 0 but gave me a little in for even wear) Rear: -2.0degs camber 0.18degs toe in Tires are 225/285 Pirelli PZero nero N4 This understeers worse than my us spec suspension, although I had 245/295 tires.

What hole are you on the sways? That makes a difference. I went from a 245 fron to a 235 front and noticed understeer right away. You may have two factors that is contributing to your understeering problem. PM LVDell and he should be able to help you with the setup.

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The original post says "stock (C2) bars." Sounds like he is using stock sways, and not GT3 bars. I think if you upgraded the rear sway to a GT3 and ran it a bit stiffer, you could overcome the 225 front tires. -td

I assume the adjustable links mean you can alter the sway bar settings. What are they now? In any case to reduce understeer, soften the front bar, i.e. use a lower hole on the link (closer to the ground) and a higher hole on the rear bar. Ideally get yourself some GT3 sways and set the front in the middle and the rear one hole from full stiff. A little more caster will also help reduce understeer, you want about 8 degrees, maybe a little more like 8.2. Use shims in the lower A arm to increase the caster and readjust the camber to neg 2.5 In the rear you can use 2.4 degrees negative camber for the ideal set up. Best, best,

Def. wierd. Wonder if it's more tires than anything. You still got the old set you could mount back up to compare? Even with the stock bars you went from ~180F / 200 R springs to 228 F / 543 R springs which should have alone helped the car understeer less. Then add in the fact that you've got adequate camber at the front now and the car should be good to go. Question....is this all on the street or also observed at the track?

I just aligned the car yesterday, haven't put it on track yet. On the stock suspension (and larger front tire) the balance was pretty good, but I wanted faster weight transfer, less body roll, lower CG / better aero, and higher limits which is why I went with the GT3. I think the tires might have a fair amount to do with it, but wanted more input. GT3 sway bars will be my next upgrade, hopefully that will clear this up. Should I toe the car out in the front? This worked well on the M3 to dial out understeer. I am thinking maybe drop the camber by 0.5degs front and rear and add a bit of toe out? I may just leave the car as is, until I get gt3 bars and see where it's at then. My gt3 coilovers are using the 993.xxx front spring, which are said might be softer. Im wondering if the valving is too stiff for these softer springs. The understeer is more noticeable in slow corners, where there is faster weight transfer.

These are my settings as of 2 weeks ago. I have stock sways (well, widebody) but not as much understeer as there used to be. Although, I need more camber, but this is as good as it gets without going w/ other goodies.

Dan. You may want to try a little less camber for the street...and if you intend on tracking the car on street tires at first. Again our spring rates are different but I found -2.0 about right all around on street tires. I get more understeer than I'd like on my street setup because I know I'm running too much camber all the time due to me leaving the car setup for r-compounds and track use. It's a tradeoff I'm willing to accept.

Cool, I guess i'll go get a new alignment. -2.0front and -1.8rear camber Any input on what toe values to run? I would like to run a hair out on the front Andy, have you noticed bump steer issues with such a low ride height on stock wheel carriers? The front toe links had some angle to it, maybe 10-15 degs with the car on the ground. The toe link mounts higher on the C2 than the gt3, who all complain about bump steer. Also, the car feels rather twitchy, not nearly as smooth in transitions as my M3. I'm wondering if this is just bump steer or something else. Do people upgrade suspension bushings on these cars? The rear trailing arm bushings and front control arm bushings are pretty common to stiffen up on the M3.

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Yes. There's bumpsteer in my car...it's not horrible but it's there. I've got a set of bumpsteer adjustable toe arms for the rear that will go on this winter, still not sure if it's worth it to do the fronts yet or not. I run 0 toe in the front for the street. I had .10 degrees per side of toe OUT for the track this season and drove the car with that toe and -3.1 degrees of camber on the street for a few weeks and the car tramline'd (sp?) like crazy. It would follow every little variation in the pavement but the steering input was crazy quick. Just not the way I like it for the street. I actually just had my car re-alligned today as I'm done with the track for the rear and I"m running -2.5 degrees at the front with 0 toe and even that small change made a world of difference in the way the car drives. It actually sticks better at the front with that setup on the street tires. At my current height and with the GT3 monoballs rotated in the position they're in -2.5 is the minimum value I can get for camber. I didn't bother rotating them again because I was too lazy to take everything apart when I'm just going to go back to where they are in the spring. I run .25 degrees per side of toe in the rear. That combined with the stiff springs / bar keep the bump steer at the rear of the car to a minimum. Andy

Not sure why you haven't taken my advice on this yet as we have talked several times offline. To keep on guessing is just throwing money away and will NEVER get you what you are looking for. Why in the world do you have toe IN for the front? If anything it should be neutral. That right there will contribute to increased understeer. Think about what the direction of the wheel is at turn in??? And toe OUT is not the answer for street unless you want the car to be a handful of a nervous front end. Heck, I don't even run toe OUT up front on the track. It will do NOTHING for you other than INITIAL turn in which can easily be modulated through proper trailbraking. You need to decide if you want a street or track alignment and then you need to get a PROFESSIONAL that knows what they are doing to set it up properly. Are your springs matched to the shocks or did they just get "picked"? Also, you need to get adjustable ARB's if you are going to "adjust" your suspension. Having adj drop links does nothing more than allow you to correct the length of the drop length based on preload. What ride height did you settle on? If you went too low and didn't replace the toe arms with adj toe arms that allow for bump steer adjustment, you are not going to like the result (neither will your car for messing with the geometry). If you want a good setup guy I have already given you a recco in G'boro. It obvious that the shop in Durham (not sure if you ended up using them) doesn't know what they are doing based on our last conversation. Trust me, I have spent a TON of money on street and track setups and suspensions with years of experience to pass along. It's up to you if you want to take it or just keep guessing.

Dell, This is an OEM GT3 coilover setup with OEM springs and OEM dampers. I also went with factory ride height (118mm and 128mm front/rear) and factory gt3 alignment, save for maybe the camber. I requested 0 toe up front, but the shop owner suggest a bit in for tire wear Maybe it was wrong of me to agree to that. I was going for a street setup for a GT3 and will be running street tires on the track likely for the remainder of this year. Brad at Digital Chassis came highly recommended from friends of mine with 996 C2s and GT3s. I am moving to Petaluma, CA in 8 days, and the TRG shop is on the same street as my new home. I assume this will be an adequate track shop. Dell I do want your advice and value it highly. I don't recall (just looked through PMs) getting the name of your shop in Greensboro. What are adjustable ARBs? Also, how do the toe arms 'adjust' bump steer? Are they not just longer links to reduce the connection angle? I think GT3 wheel carriers are a better buy at this point since the mounting points will be lower. IMO this is a more ideal solution. Also, I just got back from driving my friend's GT3 with my car back to back. They behave very similarly, despite the obvious suspension (sways, geometry, etc) differences. It doesn't have as much understeer as my car, but the GT3 (on stock suspension) is definitely not as neutral as the ROW M030 I drove which had 225/265 PS2s.

TRG will definitely be able to hook you up. I don't understand why shops feel the need to do things to a car that you do NOT ask for. Toe in up front on the street is a recipe for disaster adn NOT something that is done primarily for tire wear. The best tire wear would be the result of all neutral settings. When you align a car you are trying to aid in direction change but also trying to have the car at neutral (or close to it) when under load. Toe in would actually accelerate tire wear. ARB=Anti-Roll Bars (which most called wrongly "sways"). The only way to adjust "some" of the bump steer is with the eccentric location. However the only way (proper) to truly bump steer a car is the have (a) adjustable toe arms; and (b) a shop that knows how to bump steer a car. And no they are not longer lengths. The length adjusts the toe angle (in vs out). The vertical adjustment on the outboard side allows for adjustment and spacers to correct the issue. Your understeer is more than likely attributable to the toe in up front and the inability to adjust ARB settings.

Once the bars are taken care of (or for that matter even now), I wonder if 225's are appropriate for this kind of setup. Maybe a 245/285 stagger might help?

He's just fine with the 225/285 setup but Mike, you are correct in that he can dial out some of that understeer with a wider front tire in front. However, the alignment isn't helping. To give a data point, I ran my fastest time at VIR on tires that were 230F 280R and with a proper alignment I had ZERO understeer issues so it's not always best to run a wider tire.

can i ask where you got your figures from for the alignment settings? gt3 street specs are as follows: Rear Axle: Camber: -1.50 degrees +/- .10 degrees Toe: +08' +/- 05' Total Toe: +16' +/- 10' axle angle: 0' +/- 10' Front Axle: Caster: +8 degrees +/- 3 degrees Camber: -1 Degree +/- .10 degrees Toe: +03' +/- 03' Total Toe: +05' +/1 05' this would have been the place to have started and then taken it from there depending on how you felt the car perform. making adjustments to setup from a known benchmark are always the best process.

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Kussmaul settings are pretty much a benchmark baseline for the GT3 guys as far as agressive allignments go. Dan's pretty close to those settings currently.

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My point on 245/285 isn't so much about the overall tire size as it is the ratio front to rear. With the -2.5/-2 camber he's running, I would not expect to have that much push. Granted the roll bars are probably not right, but I'm guessing (emphasis on the guess part, still learning this stuff) that the setup is overpowering the front tires. Going 245/285, or maybe dropping the rear tires to 275 might help balance the car some.

There should be no toe in on the front.. Toe should be zero (pretty sure I mentioned this in my pms). This is your biggest source of understeer. The only situation that you would want to go the other way and have toe out at the front would be in an autocross car setup. I still swear by zero toe at the front. Also, the C2 stock roll bars don't help things at all. The adjustable drop links that you bought are now the wrong length in the front to use with the GT3 roll bars that you need to upgrade to next.

I'm really unhappy with the car now. I am taking the car in tomorrow to adjust the alignment (0 toe front and less camber front and rear a bit). The car is unpredictable on entry, and as hard as I try, I feel like I can't be smooth with it. The car just does whatever it feels like on exit too. I knew the 911 was going to be much more challenging to drive than the M3, but damn. Also, I have this god awful crap box exhaust that is so damn obnoxiously loud. I still can't find some used OEM muffler cans. Oh yeah the tires suck too. AND I was pushed into an insulated light pole karting tonight and my chest and neck ache bad. Tomorrow is going to hurt. /vent

Fissionx, something is off here. 1) are the shocks new or did you buy them used? If used, you could have a dead shock. 2) The GT3 sways are designed to go with the GT3 shock set up, so you need the bars. 3) Sping rates. Sounds stupid, but did they F-up and put the wrong springs up front? Sillier things have happened to me. I noticed your post where you talked about 993 springs? sounds fishy. Start there. 4) Shock settings. Too stiff up front/too soft in rear will cause a push. (Same for sway bars.) 5) your alignment is not way off, but it could be better. 1 degree up front and 2 degrees out back for a compromise car. zero to slight toe in up front with some toe in out back. Remember, these cars toe out in the rear when they squat under acceleration. Just some ideas. I usually think opposite end 1st on changes (carry over from my karting days) but I'd need to know more. Pushing on corner entry under braking? Under throttle? How about mid phase and corner exit? Is the car darty or does it feel stable in a straight line?

1) used with 4k miles on them. It could, and that's what I thought at first, since the problem was much more noticible at low speeds, in turns with fast weight transfer. I don't know if it could also be poor valving from the factory, but the OEM gt3 I drove back to back with my car, felt more like my car than the ROW M030 I drove. 2) yeah i know, those are next 3) rear springs are right, the front 993.xxx spring is OEM, put on the gt3s in 2005. No one really knows why. Maybe the 996 spring was too stiff, or they ran out. 4) shocks not adjustable 5) Yeah, the difference in grip is huge when the car takes a set on exit, and feels like the rear 'steers' more, which I assume is toe change, not just weight change. But, I feel like this transition takes a while (too long) after i apply power, and it's not smooth. Ok so all this is from my experiences on street, so take it with a grain of salt. Car feels okay with trail breaking (ie has grip). Initially on throttle, the front end pushes a lot, i have to open up the wheel excessively to get it to bite. Car feels a bit darty, it has a lot of camber, but also toed out, which should help I guess. I'm hitting the bed now, post more tomorrow after alignment change. Do you have problems with bump steer in the front? When I had the car on the lift for alignment, the front toe links look like they had a 10-15degs upward angle. I have read the GT3 carriers use a lower mounting point. The car (GT3 height) is much lower than it was designed by porsche.

You should really use GT3 street control arms to go lower. Don't go too low on a Carrera, the suspension is not set up for it. **** binds and hits things -- bad. If your car is understeering that bad at street speeds, something is wayyyy wrong. I'd definitely suspect a shock or spring issue. Look there first. The darty feeling is from toe out up front. I don't like this. Zero toe is plenty darty for me. I like about zero to .03 toe in up front on each wheel. That is on a Hunter 4000 alignment machine. Rear is about .05 now, but we'll see what happens. I like the car to be "lively" at the track and change positions quickly, but this really makes the car a handfull on the street. You need to be on top of it, especially with the camber changes. Do you have aftermarket drop links? If so, make sure you did not dial in any "pre-load" to the drop links. In other words. set the drop links with the car level on the ground and they should each be movable with your hand. If they are bound --- fix it. I also like 1 degree greater camber up front than out back as a general rule. So -2.0 up front and -1.0 in back, and so on. PM me with any other questions. Sleep tight.

Bill, I have to absolutely disagree with you on the toe in up front recco. There is NO SITUATION you want toe in up front and these cars already push like a dump truck. Unless you are a hard core track junky and spend most of your time on track you need to have a street alignment and by all means have nothing other than ZERO (neutral) toe. My guess is that there are 2 things playing into his problems right now (and I doubt it is the springs or shocks)........ (1)Improper ARB's and drop links....(2) crappy alignment settings that keep getting "guessed". As far as ride height, he might have dropped the car TOO low and does NOT have adjustable toe arms in the rear to bump steer the car properly so his rear toe change is exponential under load. FISSION......can you take a picture of your car from the rear under the car so on a level surface we can see the orientation of the toe arms? These cars do NOT like half *** pieced together setups. You need to do it properly or leave it at is in STOCK form. Further, he could have a bad tire issue which is causing his woes. There are just TOO MANY variables that got thrown at it and now it's a fishing expedition. My recco is to get the alignment situated pronto! Very basic stuff but you need to make sure that is in fact what it is. Up front? ZERO toe and negative 1-1.5 camber Rear? 1-2mm toe IN to help with straight line stability. Camber (same as front but you can go up to 2.0). Check ARB's to make sure they are not loaded in a resting state. And if all else fails, swing on over to my place and let's go for a drive.

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+1 totally agree This is my guess as well. He has stock C2 ARBs with GT3 Shocks/springs. The closest parallel would be me running my gt3 front bar on soft and disconnecting the rear bar. And yes it would push like crazy! I really hope that it is not too low since I emailed Dan screen grabs of critical assembly and height measurement pages from my service manual.

The frustrating part of this is that his car is setup in such a way that makes it "un-fun" to drive. And nobody wants to see another Porsche brother not have anything other than "fun" when they drive. We will get this sorted out soon enough but the OP doesn't seem to be approaching this pragmatically. Rather his setup seems to be driven by anecdotal suggestion and personal desire for an outcome not supported by the current potpourri of parts and settings. Maybe the initial desire was based on published settings but that is obviously not where we are.

Dell, somewhat agreed. The difference between zero toe and .03 toe in is miniscule. For example, if a fan is blowing on the side of the car, you could see a .03 change. .03 is almost neutral, but compensates for when the car is depressed and will toe out. Next time your car is aligned, put tension on the wrench and see how easy it is to simply "lean" your way to a .03 change in toe or camber. Trying to diagnose things over the internet is a challenge, since there are just too many unknowns, but I think we all agree that you must first rule out a simple alignment issue or an improperly installed part, then go look at a part failure. If, at street speeds, 35-70mph his car is pushing this poorly, then something is very off. Usually these cars will "push like a dump truck" more towards the limit and at track speeds. I've never had my car push on the street. Anywhere. Now at the track, some push.

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True but he is nowhere near the high lateral G loads to induce a toe out condition up front. That is VERY rare and one I have NEVER experienced on track and that is with lateral G's approaching negative 2! There is absolutely NO REASON to create a toe in situation up front no matter how small. The fact is you still have INCREASED your propensity to understeer with each and every mm past neutral. The ONLY toe settings your car should have up front on a street car are neutral and neutral to slight toe out for the track. I have run both neutral and toe out on track and I much prefer neutral as the benefit of initial turn in is NOT worth instability on high speed straights.

[QUOTE=LVDell;5899011] As far as ride height, he might have dropped the car TOO low and does NOT have adjustable toe arms in the rear to bump steer the car properly so his rear toe change is exponential under load. FISSION......can you take a picture of your car from the rear under the car so on a level surface we can see the orientation of the toe arms? Check ARB's to make sure they are not loaded in a resting state. QUOTE] Excellent first step. It's doubtful that he's gone too low, but it's possible. For example, we've gone to almost cup car height and the car still drives fairly well. But, that is with very stiff springs (much stiffer than GT3 stock), so the car may not be bottoming out. If he went lower than GT3 stock, with anything softer than GT3 stock springs, the car will bottom out the rear suspension under power and the car will push.

Cup car height? I assume you have bump steer adjustable toe arms?

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Yes, but on a 996, you really can't get this low. I mean, you can, but you will wind up braking **** as you compress the suspension. I have cup rear toe links and lock them down with the Tarrett toe link bolt set up that removes the adjustment eccentric. Too many people leave the eccentric stock, but over time the blue gunk on the face of the eccentric wears away and the holding power of that bolt gets horrible. What was the final verdict on this problem?

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True, unless he has the proper suspension "package" of dampers and springs which we know is not present. BTW, the eccentric "lock" isn't needed if it is tightened down properly and checked after every event (which the entire car should anyway). My eccentric NEVER moved in over 2 years. The holding power getting horrible is (my best guess) due to over-tightening the bolt to an improper torque. As well, I'd like to know the final verdict. Hopefully he got all situated!

Here are some pics. When looking at the car on the shop lift, the only thing that looked 'off' to me was the front toe links, which again looked to have the most angle. I went to -2.0degs camber all around with zero toe front (didn't touch the rear) and the car still pushes, no better than before. So in my opinion a well set-up 911 will oversteer on turn-in if you you are not applying power correct? This is what I am looking for and is a characteristic of the ROW M030 C2s and stock C2s i've driven, however, not so as true for the GT3 I drove... I think the problem is in the following order 1) Tires 2) ARBs Ride height has dropped about 5mm or more since the first alignment. My plan is to get a set of 235/275 Michelin PS2s, reset ride height to factory GT3, and swap the strut mounts back to the original bolt locations. Install GT3 or H&R ARBs. I can't get any less than 2.0 camber now with the strut mount bolts swapped. The tires that came on my wheels have production dates varying from 01-04 and are generally a very hard, crappy tire anyways.

I purchased at set of 235/295 Michelin PS2s recently off a GT3 and wondering if these will work or if they will cause the same problem as my 225/285 tire setup, which is too much rear grip. I'm thinking I should buy a set of 275s for the rear. Rims are 8" front and 10" rear width. Thanks again for the help.

At this point I don't really think it's the tires. I suspect you have an issue with your ARB's. I do not like the orientation of the drop links in the rear either. Something doesn't look right. The tires (235/295) are a great combo but not really proper size for a 10" wheel. You can stuff it on there but it would prefer a 285. No big deal though. I don't think at all that this is a question of too much grip. These cars will oversteer when off the throttle and understeer when on it. The trick it to get the proper throttle application mid corner when you come off the break and increasing throttle to "track out" unwinding the wheel. If you are around today I am free and at home. I'd be happy to go for a spin and give you my thoughts. It's very tough to diagnose something without actually feeling it. For all we know, your car might be acting perfectly normal. My CAB has the RoWM030 on it so you can get a good idea how it rides and is setup very nicely. Tires are 225/285.

Dell, something looks off on those pics. Me thinks that those are not the right sway bars, or something? This may sound strange, but did they put the wrong sway bars on the wrong ends? Seriously, you have pre-load in them thar' bars. Those drop links should hang straight down.

Wait.....shoot a picture of the collar (ear) on the bottom of the shock where the drop link attaches to the shock. Something doesn't look right there.

Agreed. The drop links are not the same front to back and IIRC the "blue" ones are Agency Power which are total junk! Alot of reports here of broken links.....inferior materials. Also, the drop link perches at the base of th damper do not look stock. Maybe they are but hard to tell from the pic. Remember, he has stock ARB's from his C2 with GT3 suspension.

Here's mine:

Here's a couple shots from under my car to illustrate the connection b/t the ARB, drop link, and perch.

Yeah, Dell, that's what I mean. See how verticle yours are?

That is why I suspect he might have a ton of push. The rear might be binding.

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Although, too stiff in rear causes the rear to be loose. Anyway, sort out those drop links first, then we'll see. Basically, as the front suspension compresses under braking, the front bars might bind and cause push. Thoughts?

Correct, with a stiffer rear you will induce more push in low speed corners (but it depends on his front settings). My guess is that not only the rear is binding but the front as well. Hard to tell but it definitely looks like that in the pics. Here are some pics of my front......

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Related Q: When running GT3 lower control arms, what is the added benefit of running monoball upper strut mounts as well ? I'm getting enough camber with the lower control arms... Also, couldn't I simply rotate the stock C2 upper mounts rather than replacing them to get more camber? -td

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.

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Referring to the front. 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

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.

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Thanks! I have plenty of camber. And can still "swap sides" with the lower control arms to get more. The reason I was interested in the upper mounts is that, when driving on the street, the springs seem to be slightly bind and then release resulting in a "tapping" on the strut mount. At first I thought it was the drop link / sway bar connection, but it wasn't the culprit. [PSS9 FWIW] 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

Have you thought about using a zero rate helper spring?

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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

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.

So, did we fix the dude's car?

[ 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

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.

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From what I gather, it appears you have tinkered with all the components you can, and nothing has worked so far. 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

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.

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

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.

Nice....now get out there and enjoy the thing already.

Hey!Yes am doing Chin after the Goblin Run so did you switch to 18" wheels from 19"?I wouldn't think 19's would work too well on a 996 see you soon TVTH

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So yeah you are definitely right about that. I just put the GT3 sway bars on and the car pushes more than before. Not as bad as my previous **** tires, but a noticeable change. I am running rear bar full stiff, front bar 1 from full stiff. I do feel like the car has more grip with the sway bars, but it does understeer more. I also feel like I might be lifting my inside rear wheel just before I get on power (slow turns obviously); do these cars do that? I will change the front bar to setting 2 (1st from full soft) and go back to my previous alignment. I am also not sure if the front bar is binding. The bushings are really tight with the car in the air and the sway bar link geometry isn't perfect. Wondering if this may be a contributing factor. I think if someone want to run just the GT3 coilovers and C2 bars, that would be fine for the track.

Dan, should only look at the sway bar links when the car is on the ground and weighted. At that point, they should be somewhat loose and you should be able to wiggle them around with your hand. If you can't get under the car, drive it up on some boards, but make sure the car remains level. This should give you enough room to grab those drop links. For comparison, my C2 with GT3 bars, Tarrett drop links and Ohlins shocks has the drop links going straight down, not angled. I'm at second softest in the back and middle in the front, as per the GT3 manual.

Hey !I would go to full soft on the front bar it is pretty hard to get too much grip in the front ! Thanks TVTH also what alignment were you going to use ?

Hey guys, I'm back! This time, with sway bar questions!! So, I softened my front sway bar GT3 (1 hole) and the car feels like it understeers more **although I also made a SLIGHT alignment change, now running 2.4degs camber up front, 0 toe. I noticed the toe had moved around a bit since the last alignment.** The rear bar is set to full stiff, front bar is now at setting 3 (5=stiffest 1=softest) I am wondering if this is normal or can it be explained? Most porsche guys will say softer sway bars for more grip, and most 1st level suspension guides say this as well. On the M3 however, a stiffer sway bar up front resulted in MORE grip and that is generally accepted (then again some M3 track guys run no rear sway bar at all). I'm assuming there is some sort of bell curve, where you can have TOO LITTLE or TOO MUCH bar resulting in diminished grip. I am not looking for diagnosis as much as just an explanation how sway bars work with these suspensions. On my 1st order approach, a stiffer sway bar should result in less weight transfer and thus increased overall traction, grip, in the front. If someone could logically explain to me why the opposite is true, I would greatly appreciate it. I feel like this is more complex, and there are several competing, often opposing, schools of thought on the subject. Regards, -Dan

Dan,I think you have HOW the sway bars work fine .I think that you are in essence asking the front to work too hard and you need to balance that with help from the rear.I would stiffen the rear sway if you can (Can't remember if you have this adjustment ) if you can't then add more tire pressure to the rear tires .Then see what you have .let us know best Tom

Hummm...I'm always a fan of fixing the end that doesn't work first. And from my exerience the M3 oddball front bar stuff shouldn't apply...esp now that you'e got adequate nevtive camber in the front. Back to basics again. Slow speed or high speed corners. push on entry, exit, all the way through? trailbraking to set the front? My car with -2.5 on street tires pushes a good bit unless driven very near the limit. Even then it still understeers with the streets unless balanced mid turn with the throtle. I think the LSD in my car helps with that too. When I add the 30mm wider tires on each corner in the front at the track it's much better. Still I've never been able to full get the understeer out in the slow speed stuff that you'd typically find on the street. Another thing I found on the 996 that didin't apply in M3 world esp in a track setting is the front will actuall feel better after a couple of laps. There's soo little weight up front that it takes a little work to get heat in the front tires to where they work the best. Andy