What is best ride height setting for handling in 996 with PSS10?

Hi, What is the best ride height setting for a 996 C2 with PSS10 and 18 inch wheels 8J front/10.5J rear? The car also has GT3 sway bars and Michelin PSS. Does anyone has experience in setting up suspension height for best handling like rate of turn in with regarding to 996 weight distribution? I assume that our car has the same sweet spot like how certain type of sport bike with static sag and ride height. I�m willing to scarifice look for better handling. thanks,

I would guess that the factory settings on the GT3 are pretty close to the "sweet spot" you speak of, though many would argue there is no true "sweet spot" since so many factors are involved (weight of the car, where said weight is centered, tire size, driving style, spring rates, valving, etc.). A general rule of thumb is that the lower control arms should be parallel to the ground, but again, there are a lot of factors that can make that untrue. I guess the better answer would be that a properly corner balanced car is more important than a specific suspension height setting.

Set in the middle and experiment...

The PSS10's are not really meant for height adjustment, they are supposed to be set in a pretty narrow bank, 10MM in the rear and about 5MM in the rear,. It is more for corner balancing. I think lots of people make the mistake of going beyond these ranges. See the attached. bilstein install front.pdf bilstein install.pdf PSS10 rear.pdf PSS10 front.pdf

The PSS10's are not really designed to raise or lower the car much at all. They are supposed to be set in a narrow range, about 5MM in the front and 10mm in the rear. This is more for corner balancing. I think many people make the mistake of trying to raise and lower the cars beyond this range. See the attached.

PSS10s can be set at GT3 specs and are within Bilsteins range. Darin at Westend in Gardena did mine; GT3 specs lower, corner balance and alignment. Great adjustability with PSS10s.

The PSS10's are not really designed to raise/lower the car much at all from a very narrow range. 10mm on the front and 5mm on the rear. This is really meant more for corner balancing than raising or lowering the car. See the attached specs from Bilstein. I have additional specs and instructions, part number is a PDF format if you want them but they are pretty big files in a PDF format which I can't get to post on here.

Sorry I did not mean to post this information three times. It seemed to not be showing up on my computer after I tried to post it and so I tried three times and now it shows up three times. In any case, again, lots of people go out of the range specified by Bilstein and they are lower than the stock set up when they are installed within the specified range. But it is not just a matter of raising or lowering them however much you want.

Thanks everyone for the info. There is a lot for me to digest.

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Did you replace any other parts aside from the PSS10 kit + the supplied links to get the GT3 specs? Also just to throw in one more variable for the OP to think about... What has everyone set their front and rear damping out of 10 on?

I have a 2000 carerra with the PSS10 suspension (w/ M030 anti-roll bars) and it is set to factory GT3 specs. This is a good option, it handles well. No special parts were required. It is lower, but not a ton. It isn't a full race setup, it is a sporty street setup capable of light track work. The factory X74 (on my 2002) is quite a bit lower and stiffer.

Lowering a non GT car to GT spec height will not give you GT handling. A GT3 gets its lower ride height by a combination of lowered coilovers, subframe bushings, and different strut mounts. If you lower to the same height using just the coilovers it will put the control arms out of their optimal range of movement causing excessive roll due to actually raising the roll center. It will also increase bumpsteer.

I recommend lowering to carrera S spec, adding front GT3 lower control arms to get the camber you want and corner balance. From there play with sway bars, damper settings and alignment to get what you are looking for. When you have found what you like do one last corner balance check.

I'm sure you have reason to believe what you believe, but, in the real world, my c2 drives great with PSS10 suspension set to GT3 alignment specs. Nobody said I (or anyone else) was trying to make it into a GT3.

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while your C2 drives great at gt3 height I believe it would drive better slightly higher. I suspect your pss10's and any other mods are the reason for your improvement not ride height. OP asked how to make it better and was willing to sacrifice looks knowing there is an ideal range based on his motorcycle suspension analogy.

Racing cars and bikes for a better part of 45 years now a lowered car generally will handle better. Sure, alignment, suspension, stiffer sways all add up. And yes to get further alignment adjustments the slippery slope begins. A good start though is PSS10s, GT3 alignment and lower ride height you have a much improved package and all fit within the design parameters of the PSS10s on a 996. No, it wont handle like a GT3. The range of the PSS10s are great. Add stiffer sways next. Best bang for the buck for a street car with and the PSS10s after GT3 specs.

After all the replies, I gathered that my newly acquired 996 C2 suspension is not far from what I need. The car has PSS10 with 5/7 f/r setting, GT3 sway bars and lower control arms. The current ride height is 24.5in/25.8in f/r and running 18in light wheels 8J/10.5J with 235/40 and 285/35 Michelin Pilot Super Sport. The car�s weight is stock with a factory sunroof deletion option, backseats removal, Cargraphic mufflers and Magnaflow 444067 catalytic converters. It is aligned with front 2.2 neg camber and 0 toe, rear 1.8 neg camber and 3/32� toe in and corner balancing. The front caster settings are 8 degree on right and 7.5 on the left. The previous owner told me that it is because of the non-adjustable caster arms that don�t allow. The car handling is neutral with a very gradual slight oversteer when it is aggressively turn in and open throttle early. I like it like this very much, however because the ride height is too low I manage to scrape the mid section of the car when riding over small bump on freeway at speed above 90mph. I think that because it is too low from excessive pre-load on the springs (wrong static sag) that cause the ineffectiveness of the suspension travel for the street. I�m thinking raising the ride height by decreasing pre-load, and getting Elephant Racing adjustable caster arms to fix the unequal front caster settings. Elephant Racing claims that their caster arms also help to adjust the weight distribution which helps in front anti-dive and shifting weight in rear to advance the handling aspect. My question is will the adjustable caster arms be enhancing the handling with the current suspension components. Sorry for the long description, I just want to be clear for a good discussion.

Correction on the caster setting, 8 degree on left and 7.5 on right in the front. Car has X51 option.

Reviving thread... Just had PSS10s installed on a 2002 C4S by a shop. I see that the max permissible adjustment is (80-90MM) 10MM for front and (205-210MM) 5MM for rear. The shop lowered the car for me based on their judgement, but is there a way I can verify that the car is within the PSS10 specs? The instructions say measurement is from top edge of spring seat to center of mounting screw. But the exploded drawings do not call out those particular parts so not sure how to properly measure. TIA!

just absolutely dump it until the oil pan is on the ground then raise it up a little (for safety)

Ha re-reading this thread and the height specs are in the drawing on the right side for both the front and rear. Just doesn't use the same part names in the verbiage of the instructions but I assume the measuring points are those parts called out by the bracket in the drawing right side.

I found that at the bottom of the PSS10 range my C4S sat at GT2 specs. This is measured at the correct points that Porsche uses. Stock C4S, USA is 158mm (+-10) front, and 163mm (+-10) rear. GT2 specs are 118mm (+5) front, 133mm (+5) rear. With my front PSS10's at the bottom of the allowable range I was at 118mm, rear I had a little more adjustment, and I left it at 133mm. On a 4S I can see no way to get to GT3 specs which are much lower at something like 113mm front and 128mm rear if I remember correctly. If you search mainly in the Turbo forum you can find how to properly measure the heights. Hope this helps. Oh I forgot to mention the front shock specs are 80-90mm in there diagrams, I could not get to 80mm on the front. I contacted Bilstein and they said it was fine to use 85-95mm for the range.

Lowering the ride height will help but a set of good tires and a proper alignment will take you much further in terms of handling. That said, if you want the best height adjustability you really want a coilover that has independent spring preload and height adjustability. Billsteins, while a great coilover, do not provide that. As you lower the car you're also removing shock travel, which is very important. This is why they provide a safe range. This is one of the reasons why I went with Ohlins and also considered FortuneAuto and Feal coilovers as they offer this feature. With these you could lower the car as much or as little as you want and loose zero shock travel.

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I totally agree with tires and alignment. I had the car aligned to GT2 specs by what the guys were doing over in the Turbo forum. It is that limited range on the PSS10's that keeps the spring preload in check. I would have gone for the Ohlins but they went on backorder when they had the problems, they were only a few hundred more than the Bilseins. Well after they fixed the problems and re-released them they are now a great deal more expensive. I have never heard anyone complain about the Bilsteins. I ordered them because I was in there anyway doing front bearings, dif seals and cv boots, they shipped to me in two days. Feal coilovers were a 4-5 week wait. Honestly I do like putting German parts on the car when I can, call me crazy, no really.

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This helps a ton! I've been tinkering with the ride height (now on my 3rd time on the lift). I saw somewhere an ingenious method to measure from the ground to the various points underneath the car where you use a bolt and threaded spacer. Adjust the spacer on the bolt until the bolt/spacer assembly contacts the ground and point on the under carriage and then measure the length of the bolt/spacer itself. Seems much more accurate than bending a tape measure at 90 degrees while rolling around on the ground Current measurements are 110mm LF 115mm RF (doh) and 137mm both rears. Need to adjust the LF up on the 4th try. At this point Im positive the coilover perches are set to within the bilstein specs ranges. The rears are set to as low of a height that the range allows so I'm puzzled why it measures at 137mm. What occurred to me is that tire pressure (as well as gas tank fuel level) would affect these measurements, so I'm going to ensure pressures are set at half load spec for 18 inch tires (33f, 36r). Perhaps the rears are overinflated and it will bring that measurement down.

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It's so interesting how the same model car with the same model coilovers can be so different. I could have never been able to get to 110mm on the front. You are right, tire pressure and weight in the car will effect the measurement. I used "inside" measuring tools, like the picture below. They were pretty repeatable. I can tell you that the before and after alignment was a huge leap in drivability.

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Very interesting indeed. In fact, the front COs are set at ~90mm (so on the high end of the 80-90mm bilstein spec) so I think I can get even lower than the 110m measurement, possibly. I think the tire inflation and gas tank issues need to be calibrated. I get back on the lift tomorrow so will report back. Those are neat tools! I ended up just going to the hardware store to make a bolt/spacer measurer for a few bucks.

I found that I could not achieve 80mm with the rings all the way down. I contacted Bilstein and asked about this. I had also read in another post how someone else could not get to 80mm, they also contacted Bilstein and got the same answer I did, which is use 85-95mm range. So I guess I'm saying your good to go to 95mm if you need to.

@mikemessi was spot on with his comment about the geometry. You can't only pay attention to the shock range/values, there's other values at play. Admitedly, my knowledge of automotive suspension is pretty lacking...motorcycles on the other hand I can burn your ear off.... But the real answer to this question is "Find a suspension engineer at Porsche, or on the race team, and ask them." Whether that's the local dealer that has a race team or just generically speaking. It sounds ridiculous, but it's a viable solution. It's what I did with my BMW motorcycle despite having a reasonable amount of knowledge on the subject DESPITE the fact that I have an Ohlins enginneer that lives less than a mile from me. I reached out to a guy on Instagram that races for the BMW factory team. I asked him what his suspension settings were for various conditions with an Ohlins set-up and I got a TON of insight and a lot of disspelled "facts" and "so and so said this setting makes it better because..." that were SPECIFICALLY for the platform, aka that "sweet spot" you spoke of. Sure, I could have asked my buddy that's an engineer at Ohlins, but he's not familiar with my platform so it would have been limited information comparatively... You can't really go wrong with that approach. Worst case is the guy ignores you or is a total ******* and you move on to the next person on your list....but either way, you'll be better off than listening to a bunch of dudes on the internet with unknown credibility.

I may have missed it, do you have adjustable LCAs?

Well everything is dialed in now at 118M in the front and 132/134 in the rears (GT2 heights). Car sits at 25.5 from floor to fender in front and 25 and 3/4 in the rears (give or take 1/16) using 34 psi front and 36 psi rear with a full tank. I will say that when the shop originally delivered the car, it was slammed and it made both a "twang" spring binding noise at parking lot turning speed as well as a grumbling on the high side when entering sloped driveways at an angle which I guessed was the spring rattling around when there was no weight on one tire. After the adjustments back up to GT2 heights the twang is gone and there is only a slight spring rattle noise now. My guess is that raising the car added preload which fixed both these issues.