jordanturbo

My rear toe is 0.06' on each side for a total of 0.12' total toe, front toe is at 0.10' both sides for a total of 0.20' total front toe. Front camber is at -0.40 each side rear is at -1.15 on each side. If you get your alignment redone I would ask them to not just do a "toe and go" alignment and properly adjust the camber as well, look at you left front wheel, you have almost double the camber of the right, both are within spec, but still different. I think with your original toe being so far out in the back is what gave you that solid feeling, so do it again just dont go beyond the maximum. I saw the audi logo on the alignment report so am guessing is is a Porsche Audi VW dealership where they will often give the apprentices alignments to do, and they are used to doing them on VW's and Audi's all day which is why the specs were always closer to the minimum.

My fronts are maxed out, but my rears are just beyond the half way point in the range recommended by Porsche, really even going all the way to 0.10 in the rears wouldn't be terrible. He had beyond the recommended toe in the rear on one side prior to his alignment and didn't suffer abnormal tire wear. in the big scheme of things 0.10' is not all that much and for the aggressive feel it offers, the way it seems to bite the road a little harder, and with the negative camber feels a little more like it is on rails and in reality the life of my tires is not much different from that of a way less aggressive alignment.

Having my own shop an seeing some of the vehicles people bring in, toe and camber has to be way out before you really notice rapid and uneven tire wear. I find that bad tire wear will be more apparent in vehicles with bad shocks, wheel bearings or tie rod ends.

perryinva

When you said maxed out earlier, you meant the top of the recommended MAX, not he actual maximum you can adjust them, I assume, then. You CAN adjust way past 0.10'. That will eat your tires faster than camber. -1.15 on the rears is mild, not aggressive, really. Aggressive starts at around -2.00, IMHO. Most I've read try to go -1.3 to -1.5 to balance aggressive and wear.

jordanturbo

Correct, I maxed them out at Porsches recommended maximum toe not beyond that to the maximum I can possibly go. I also mistyped on my number pad without noticing, I meant 1.45, not 1.15. Either way, my car does not have the most aggressive set up a porsche has ever seen, but it is certainly more aggressive than the alignment the OP has.

2001996c4

Now I have a choice, tweak the alignment to the slightly more aggressive, and or change the PSS back to the PS2's. The PS2's I had wore perfectly flat on the rear at the old settings, it was only the major wear on the inside of fronts that was a problem.

I'm leaning to switch PSS for PS2's and tweak the alignment towards the more aggressive.

Sneaky Pete

I have the PSS's. I love em. They have added track speed I have not experienced before. Have to say that I had mine replaced after a few track days because they wore the outside edges to a cord. It was under warranty where I paid a 1/3 for replacement cost. I think your specific alignment is the reason for the issue you have. I have mine set to X74 spec. I would give the tires another chance.

Jeff996

My PSS's have been excellent. Coming from many previous sets of PS2's I was surprised how much I like them. They have been great at the track also.

nick49

Your handling issues remind me of how my Turbo felt with PS2s on the front at 50% and new Sumis on the rear. The car hunted on the freeway and didn't want to go straight, a very small steering change would just about throw me in the next lane. The rear end slid big in a tight off ramp turn at the speed limit and PSM caught it. The car was just plain scary to drive even at the speed limit.

I consulted my alignment guy that said he could make it all work out, which I knew could. Instead I just ordered a set of front Sumis where the rolling diameters and rotations/mile are an exact match to the new rears. After doing this the car was transformed and has never handled so good. The HTR-Z lls actually feel and handle better on the street than the PS2s that at 50% came on the car. As an ex racer I can push the car pretty hard in the canyons and get a feel for what the tires are doing. I know the Sumis would grease up pretty quickly on the track but stick like velcro in town.

perryinva

HTR-Z IIs?? or IIIs? The IIs absolutely suck, in every department, except wear, on my 02 C2. In the wet the rear end was just plain all over the place. The full time 4wd must make a huge difference with those tires.

Dharn55

Keep the PSS and get the proper alignment. I ran PS2 for years and recently went to the PSS. Much better tires, quieter, more grip, better handling, better in the wet, supposed to last longer (and at the price we pay for Michelins that does count) and less expensive. Winners in all ways. Buying PS2 is buying older technology at a higher price.

2001996c4

Thanks Doug.

I wonder if I'm to blame for not being specific about my alignment needs or should the dealer have asked. Either way it's under $200.00 for another complete alignment, I just don't want to be too quick to assume responsibility for a very neutral alignment on what is intended to be a sharp handling car... thoughts?

2001996c4

I'm ready to be more specific about my alignment settings with the Dealer doing my alignment. Now that I'm setting the numbers I'd like to be sure I have a good bases for my requests.

Jordanturbo has offered some insights into his current alignment, but I'd like a little deeper pool to use as guidance, keep in mind I'm looking for the planted, sharp handling car I had before the alignment and tires not the neutral waffling thing I have now. My conclusion is my tires are fine, tried many different pressures and can't get it right with that alone.

Any insights to alignments of other 996 with upgrades to the suspension. I know this is highly personal, just need some insights to build a data set to provide the dealer.

Thanks!

perryinva

RE: MPSS vs MPS2, if you want to keep the rear at the desired 285/30-18, then there is no choice, as MPSS is still not available. I'm quite positive that the MPS2 is a better tire than I am a driver. According to everyone, the MPSS is a better tire, exactly as Dharn summarized, and I'm hoping that they will be avaialble in 3 years when my PS2s should be ready to be replaced. I'd still like to know what size all you installing MPSS are using in the rear.

Regarding alignment, there is a small point that is often missed, that is relevant here. When an "as found" alignment is done on new tires, it does not reflect the on road alignment that the driver experienced previously with his old worn tires. The road alignment with the old tires had far more camber, due to inner tire wear, so it would naturally feel far more planted. As an example, I did a simple trig measurement with a level with my old tires after I lowered the car with PSS9s. Previously, the rear fender to road was 26.5", and I ended up at just under 25.25". Putting a level against the wheel, and plumbing it, then measuring the gap to the same part of the wheel at the top, I found my new camber to be ~2°40', fairly aggressive. The tires were definitely worn more on the inside by 3/32", but I had a solid 4/32" left, so still 7/32" on the outside. Not a huge difference, it appeared. In addition, the cross sectional profile of the old Sumis was less than the new PS2s so I am aware the numbers will be skewed some, but nonetheless, the relative numbers are a good indication. Installing new PS2s, same size, the rear fender height is now 25.5" rear, and the same trig shows the rear camber is now only 1° 50", about spec for an X74 level996. Though the car feels great, as soon as I replace the tie rods this weekend, I will have it fully aligned. My front tires are currently ~10' positive camber on the pass side and about the same neg on the drivers side, so not ideal at all.

The point is, between the rather large toe out and what the actual camber the OP was driving with on his old PS2s, he likely DID have a more stable alignment and handling with his old tires and alignment. So while I certainly can't tell the OP what the definitive best alignment for his car is, I'd suggest with his lowered car, I'd agree with jordanturbos advice, and go with 10' toe on the fronts and 0 on the rears, and increase to camber to -45' front and -1°45' rear. The MPSS will last longer than the PS2s, and this is a mildly aggressive alignment, similar to what is speced for an X74 height car. The only thing that bothers me, is this does not seem like a significant difference over what he has now, relative to how he says the car handles. Could you possibly have the front ARBs set too stiff on the front? You should be on the softest setting, with those shocks and springs, based on feedback from others. I have M030 sways on mine, and find them excellent on the street, especially over the stock bars, so I didn't feel the need to go larger with Cup or GT sways.

2001996c4

To answer perryinva's question about tire sizes. The previous PS2's 245-40-18 front and 275-40-18 rear. I felt this 275-40 was a little too big and concerned me that I might be close to the 5% front to rear difference that can cause trouble with a c4, so went more towards stock keeping 245-40-18 front 275-35-18 on the rear. The difference in rear tire size is a change that until now I hadn't considered significant because all I changed was the side wall size, the 275 leaves the same amount of contact patch correct? perryinva, you say Jordanturbo said 0 on the rear, I think he said "My rear toe is 0.06' on each side for a total of 0.12' total toe".

Here's my some numbers I'm concluding to pass on the Dealer for the second go around:

Front Camber L: -40 R: -40
Front Toe L: .10 R: .10
Rear Camber L: -1.45 R: -1.45
Toe L: .06 R: .06

What do you all think and how does that compare to X74.

Again, H&R springs, Bilstiens, and Cup sway bars.

Thanks.

perryinva

Yes, I was going by memory, but really, 0 toe and 6' is at the splitting hair line. The tech would shoot for 0 or 10' and then if over or under, do another small adjustment to correct, and get it closer. Just rotating the wheel is likely to change a few seconds. I think the dealer might give you a strange look if you ask for 6' of toe on each side. It is unfortunately, not that easy to dial in that kind of accuracy. For instance, you have -38' camber on one side, IIRC, so the tech is not going to touch it to try for -40'. You can't adjust the strut plate bolts/nuts that little. Just tightening the nuts moves the strut a few seconds. The other side, he would bump in, and get closer because it is a decent amount off. Doesn't hurt to explain what you are trying to achieve, and get their suggestions, too, especially if they are a Porsche shop. And personally, I think front neg camber causes little wear compared to toe, especially for the turn in and corner stability benefit, so I think those are good numbers. I think you will find the "new" as found numbers will have changed a little since the as left. Make sure you have the tires inflated to where you think they are best handling, now. How many miles on the tires now? Also, and this is a long shot, you might have a defective tire. I had a new Michelin (a few years back, different car) with a separated belt, that was not easy to find, and the car was very squirrely until they figured out what it was. Only problem is that the way we found it was to rotate the tires front to back, one at a time, and pin point which tire it was, which we obviously can't do on the 996.

Is 245/40-18F and 275/35-18R standard for MKI C4? That just seems a lot larger F/R compared to my C2 where 18" standard is 225/40 and 285/30, as your fronts are 16mm taller and rears are 21.5mm taller than mine. Rough calcs show you went in the right direction for sure, as yours are less than .5% F/R difference where mine is 3.4% smaller circumference and has a 1% F/R differential. The previous tire son my car, the Sumi HRTZ-IIs had an even larger F/R difference.

2001996c4

Thanks perryinva,

So you'd recommend revising my rear toe to .10 L and .10 R. Should I go with a slightly more aggressive front camber, since is seems apparent with the old front toe being so far out why they wore so poorly? The tires currently have 180 miles on them. As stated before Tire Rack will take them back in the 30 day window. After my previous research and the followup from others on this forum, I'm feeling pretty confident the tires are good, just need to tweak the alignment.

As far as the stock tire sizes, I don't know what size is stock for the 01' C4, and what I meant to say is I've changed the rears "closer to stock", from where the previous owner had gone.

Thanks.