Front ride height after suspension work

[pretzel]

Hi there,

I only post occasionally but hope some more expert contributors can advise.

I have just had a new pair of struts, along with top mounts, gaiters, roll bar mounts etc. fitted by my OPC to my Cayman after the strut replacement was recommended following an inspection a few weeks back. All parts used are OE. When I arrived home I noticed that the front ride height looks very high.
Is this what I would expect to see, and it will settle after a few hundred miles? I have not yet queried this this with the OPC as it is the weekend. Note: the springs were not replaced.

Appreciate any comments.

Pete B.

 

[Motorhead]

Pete, I would expect the ride height to be dictated primarily by the spring length but it's possible that the increased stiction in the new damper seals and ARB bushes together with the replacement top mounts are making the suspension "stand-up". Give the car a good long run over the weekend to see if things settle down; take on a decent fuel load and/or try putting some additional weight in the front luggage compartment. If you're still concerned, I'd go back to the PC to get their comments. Unlikey, but it's possible that they've fitted some incorrect components. In its current state the car will be unbalanced, a situation which needs to be rectified. Good luck. Jeff

 

[pretzel]

Thanks for the comments Jeff. I do intend to give it a good run tomorrow and it will be with a full fuel load. Maybe I'll also deliberately subject it to some hard braking to load up the front end and see if that sorts it. According to the list of parts replaced I don't think any wrong parts were used and my OPC (Cardiff) have been faultless in all the years I have ben using them. I am hyper critical so maybe I'm being a little over sensitive to perceived differences. I'll report back how things go. Thanks again, Pete B.

 

[Motorhead]

Sounds like a plan Pete. Find some undulating roads to fully exercise the suspension - there should be plenty around in South Wales..! For reference, when I had my Cayman S geometry set up by Center Gravity a month ago they measured the front/rear ride heights as 368mm/390mm (wheel centre to wheel arch), though I'm running 19" wheels. Jeff

 

[Buddy]

Really the different wheel/tyre combinations will make a minimal difference to the ride height between the two cars from the ground and not at all from the wheel centres as described above Jeff it could well be the difference due to the old suspension sitting low before the new mounts and bushes. I'd suggest that the ride height be measured before the drive and then after, some settling may occur but it would show if it was too high, the spring mounts are in three thicknesses 3,0 5,0 and 8,0mm if they were changed from the old units to fit new spring collars then it is possible that the factory fitted 3,0mm and they have been replaced with thicker items this would raise the car 5,0mm of course it could be noticeable.

 

[Motorhead]

Yes of course Kevan, the wheel centre to wheel arch dimension will be independent of wheel diameter. Silly me..! Incidentally, I note that the PET shows only two "compensating plates" of 3mm and 6.5mm. Either way, whether the difference is 3.5mm or 5mm I wouldn't have thought it would account exclusively for the front end appearing to ride high, since you can see from the wheel centre to wheel arch dimensions I've given, the front should be about 20mm lower than the rear giving a slightly nose down appearance. I note that Pete's car is a late '08 model, so I wouldn't expect significant sag in the rear suspension unless it's very high mileage. Jeff

 

[pretzel]

Well, I measured the ride height yesterday morning at the front before my drive and got 2 quite different measurements when comparing nearside with offside. Nearside is near enough 368mm, offside is more like 388mm (both measurements taken as accurately as possible from wheel centre to wheelarch) I have 18" wheels but this is of course irrelevant. It was the look of the offside that made me question the ride height in the first place as it just looks ODD. I took my drive anyway as everything felt very secure (over 300 miles of varying road types). This morning I parked the car on a level surface and re-measured the front ride height. It is now 378mm each side and just looks better on the offside, so I guess there has been some settlement and evening up. Just out of curiosity is this near the factory spec? Are the factory ride height specs. published anywhere? I took a quick look around the 'net but could only find references to lowered suspension ride heights, and that was on Planet9. Thanks for your contributions so far. Pete B.

 

[Motorhead]

That sounds very strange Pete. As far as I'm aware, the dimensions I gave for my car (wheel centre to wheel arch) are within spec according to Center Gravity. Your figure of 368mm for the N/S front corresponds exactly with that for my Cayman which has covered only about 14k miles, so your O/S front figure of 388mm seems very high. I think that trip back to Cardiff PC is in order so that they can investigate the anomaly. Jeff

 

[pretzel]

Hi Jeff, have been editing my last post as I have been our re-measuring etc. on a level surface following my long drive yesterday. The car is much more even now, side to side at the front. 378mm each side. Am going to talk to the OPC tomorrow to discuss if what I have observed is what to expect after such work and will report back. I would still like to know what the factory spec. is, if anyone knows where to find that. Many thanks Pete B.

 

[Buddy]

When my Gen 1 was aligned last autumn I did ask Chris if it was possible to reduce the ride height and he told me of the shims, he found that I had the thinnest set and my ride height was 5mm below nominal, this is on original springs, shocks and mounts at around 65,000mls. I have just now roughly measured my ride height at the front and this figure is 363mm so 368 for a Gen 1 and quite probably a Gen 2 can be considered the "as factory" ride height. Interesting if the Gen 1 has 3 shim heights and the Gen 2 just two but understandable since rationalisation is common practise in engineering production. I often do over 100mls a day around the UK and the Cayman S at 77,000mls still pleases me on every trip. Impressive when in Germany I can press the pedal and 250kph comes up so easily and the car seems to hunker down as the speed gets up above 200kph. As your ride height seems to have altered it would be a good idea to check with the OPC stating your concerns that the geometry may have changed and ask if they will recheck due to settlement.

 

[Motorhead]

Pete, I'd forgotten that my Cayman has PASM fitted and I believe that the ride height is 10mm lower than standard, which means that your measurement of 378mm is probably about right. For reference, here are some ride height figures courtesy of P-9: http://www.planet-9.com/987-cayman-boxster-modifications/37793-please-post-your-ride-height.html Jeff

 

[pretzel]

Thanks again Jeff. That was the thread I read earlier but didn't see anything about standard ride heights, just mods. The P-9 site is down for maintenance at the moment so I'll check back again when it is back up. Thanks also for the note about PASM equipped vs. non-PASM. I've checked mine again and seems to be stable at around 378mm per side now so will see how it goes. I have been in touch with my OPC and awaiting comments about possible changes to geometry as a result of 'settling' and am waiting a response. I have a drive to Scotland and back coming up this weekend so will check the numbers again after the trip. Thanks once again to all for the comments. Pete B.