Ohlins - uneven ride height despite equal adjustment/install

I'm just wondering if anyone else has experienced this, and have any suggestions/solutions.

I waited a while to make a thread to make sure things were all correct, I really can't think of anything else.

So I installed Ohlins R&T recently on my stock E90, with dinan camber plates. I installed them the exact same way side to side. I got 6mm of preload on each spring/perch and the same distance between that perch botom and the top of the height adjustment collar sitting on hub/clamp.

Yet, the ride height is quite uneven. It's a good 5-6mm (almost 1/4") different (pass lower). I took multiple measurements on different surfaces. The rear comes out even.

I double, tripled checked everything. I even measured the amount of threads sticking out of teh top strut nut just to make sure one stack didn't have more into it than another (like a missing or extra washer. It's almost as if the passenger side doesn't have the 6mm thick dinan plate on the top mount, but it does ofc).

I'm just running out of ideas. I can adjust passenger side up the 6mm, but then the struts are not equal, dimensionally side to side and that bothers me.

I didn't do anything with the sway bar or links, no other parts used etc.

Thanks for any ideas or hopefully someone had something similar and a solution.

What's the history on your car? Ever been in any accidents?

I feel some variance is normal, just not sure if 6mm is a lot or not.

Also, did you get an alignment already?

Driver side being higher accounts for the driver weight.

You'll need to check height with the driver in the car, just like when you do an alignment, it should be done with the driver weight.

No accidents or anything. 1 owner, low mileage car. I think 6mm is a lot. I've experienced this on my e46, but it was very marginal like 2mm so I attributed it to variables.

This seems much bigger.

Alignment doesn't matter for something like this. I shoved the fixed camber plates all the way in, so camber is equal (estimated -2.6). As camber goes in, toe goes out, but, again, it is equal.

I'll need an alignment, I'm sure I have too much toe out, but things are pretty equal and car drives straight. I also did my last alignment while having the swift springs so the car was already almost this low (height also affects camber arc and toe).

Thanks

tdott wrote

Driver side being higher accounts for the driver weight.

You'll need to check height with the driver in the car, just like when you do an alignment, it should be done with the driver weight.

Yes, that's a well known thing from my e36/e46 days, but that's a small difference. Also, it'd be the front and rear together (driver SIDE like you say).

The rears are equal in setup and rear ride height is dead even. This is a major difference (6mm) and ONLY in the front.

Thanks

I think you're overthinking it. I've setup many cars, and very often the exact same setting on the coilover does not translate into the exact same ride height side to side. Almost always there is some discrepancy.

Yes, 6mm is a fairly large difference in this case, but it's nothing worth worrying about this much. Adjust the pass side up to match the height of the driver side and call it a day.

What exactly is your concern if they aren't on the exact same spot on the perch?

Variance is normal. Drive them 500 miles to let the springs settle and then re-adjust height on the perches to get the ride height you want. You can adjust preload and height using separate collars on the Ohlins so preload is not an issue.

tsk94 wrote

What exactly is your concern if they aren't on the exact same spot on the perch?

Thanks. The concern isn't specific, just the incongruity. As a very technical person, it bothers me. Like I said, I'd expect a small variance. I've never had one this large.

And the rear had no variance at all, so I'm just puzzled.

I had looked through many Ohlins install/impressions threads and no one seemed to mention anything about unequal adjustements or heights. Not that it's an Ohlins thing necessarily; could happen with any assembly.

TboneS54 wrote

Thanks. The concern isn't specific, just the incongruity. As a very technical person, it bothers me. Like I said, I'd expect a small variance. I've never had one this large.

And the rear had no variance at all, so I'm just puzzled.

I had looked through many Ohlins install/impressions threads and no one seemed to mention anything about unequal adjustements or heights. Not that it's an Ohlins thing necessarily; could happen with any assembly.

If it makes you feel better (it probably won't, lol), my current M3 when I installed my coilovers this past summer had about 5mm variance side to side up front. Rear was good and equal.
I've seen this enough that it's to the point where I've accepted it's just something that happens...

My OCD would like it not to be the case, but unfortunately it often is.

If it bugs you then get the car corner weighted. There will still be variance, but at least you can tell yourself it's for performance reasons lol

tsk94 wrote

If it makes you feel better (it probably won't, lol), my current M3 when I installed my coilovers this past summer had about 5mm variance side to side up front. Rear was good and equal.
I've seen this enough that it's to the point where I've accepted it's just something that happens...

My OCD would like it not to be the case, but unfortunately it often is.

It does make me feel better lol !

TboneS54 wrote

It does make me feel better lol !

Take tsk94 advice with a grain of salt though.

He’s only built a couple race cars entirely from the ground up…

All kidding aside, you’re getting sound feedback from both him and Redd. These cars generally arent as square as we’d believe. The aftermarket components will bring this into focus.

Still frustrated with you Tsk for removing your build threads.

DRLane wrote

Still frustrated with you Tsk for removing your build threads.

Then you need to him to set things straight:)

OP - manufacturing tolerances also result in different ride heights. Chassis repair manuals have tolerances of 0.xx” and 0.0x”.

DRLane wrote

Take tsk94 advice with a grain of salt though.

He’s only built a couple race cars entirely from the ground up…

All kidding aside, you’re getting sound feedback from both him and Redd. These cars generally arent as square as we’d believe. The aftermarket components will bring this into focus.

Still frustrated with you Tsk for removing your build threads.

Lol - sorry! In hindsight, I should have probably left it up. But, I'm sure it would've just gotten buried down the pages since it wouldn't have been updated in the last 4 years

If there was somewhere active to post my E36 build, I would, as that's an ongoing project.

My current E92 isn't very exciting, just some bolt-on goodies on non-stripped out track car...

M3SQRD wrote

OP - manufacturing tolerances also result in different ride heights. Chassis repair manuals have tolerances of 0.xx” and 0.0x”.

Exactly this. All these cars have tolerances when manufactured, so strut tower locations are in a 'range', be it a small range. This can result in the exact problem you're having of side to side ride heights not quite being the same.

Ok thanks chaps

tsk94 wrote

My current E92 isn't very exciting, just some bolt-on goodies on non-stripped out track car...

Hey, that's where I'm probably gonna end up so I'd love to see that!

Re: the OP's topic though - with the way my shop set up my Nitron R1, my rear left is slightly lower than my rear right, and my fronts are roughly even. So either this same thing struck or my shop messed up - likely the former though.

(not corner balanced but will probably do that the next time I get an alignment)

bipp wrote

Hey, that's where I'm probably gonna end up so I'd love to see that!

Re: the OP's topic though - with the way my shop set up my Nitron R1, my rear left is slightly lower than my rear right, and my fronts are roughly even. So either this same thing struck or my shop messed up - likely the former though.

(not corner balanced but will probably do that the next time I get an alignment)

Corner balanced cars will have different ride heights at opposite corners. I guess if someone has OCD, or is all about stance, then corner balancing is not for you.

I recently saw a video of a car with a stance setup that got stuck on a slightly raised manhole cover He had four friends jumping up and down on the front and rear (2 per each end of the car). It had zero compression travel so it stayed grounded on the manhole cover and the jumping up and down only caused damage to the hood and trunk lid

M3SQRD wrote

Corner balanced cars will have different ride heights at opposite corners. I guess if someone has OCD, or is all about stance, then corner balancing is not for you.

I recently saw a video of a car with a stance setup that got stuck on a slightly raised manhole cover He had four friends jumping up and down on the front and rear (2 per each end of the car). It had zero compression travel so it stayed grounded on the manhole cover and the jumping up and down only caused damage to the hood and trunk lid

I'm not too fixated on my ride height as long as it's "correct" - so it only bothers me now because I question what happened there :P I think corner balancing will help assuage that when I get around to it.

bipp wrote

I'm not too fixated on my ride height as long as it's "correct" - so it only bothers me now because I question what happened there :P I think corner balancing will help assuage that when I get around to it.

I wasn’t suggesting you had OCD and I know you’re not a stance guy because they all own BC suspension setups. BC is needed so they can lower their cars at least 4”.

I can’t recall your ride height story. You’ve probably told me or I’ve read it in a thread but don’t remember it. It sounds like it was a shop install story which won’t shock me.

I had a similar issue with uneven side to side measurements on another car of mine after coilover install - I did measure everything down the mm to make sure it was "even". It's just the nature of the beast. Driving it around and doing a slalom down the street helped it to settle closer together though.

t_win wrote

I had a similar issue with uneven side to side measurements on another car of mine after coilover install - I did measure everything down the mm to make sure it was "even". It's just the nature of the beast. Driving it around and doing a slalom down the street helped it to settle closer together though.

Just wanted to say, after many months, it does seem to have even out a tiny bit more. it's close enough now where I don't feel like there's a real "problem" perse, and can chalk it up to cars not being perfectly symmetrical I guess.