Shorter springs for Ohlins Road And Track Coilovers

[Obioban]

don’t swap them. You’re already going to have too much negative camber, just from the lowering.

[tnord]

I looked at this for a minute last night, and it appears that I have the struts on the wrong side once orientated with the little bit of slag below the tab in the opening of the clamshell. Which means the top mounts will have to be swapped also.

Is swapping mounts side to side still a thing, or has it been determined that's a bad idea for street cars because it results in too much camber?

[tnord]

oh shit. that'd do it.

I have it in there where the recessed portion sits inside the kingpin. that's like 3-4'' of ride height right there.

As I suspected, the simplest answer - that I'm an idiot - is the most likely. 😳

[Obioban]

You can see the tab in this picture:

[Obioban]

that strut looks not fully seated at the base.

IIRC the Ohlins have a welded on tab that should bottom out against the clamshell when fully seated.

[tnord]

It looks like the spring is compressing about an inch under load, it's a little tough to measure on the ground. from the setup manual, it's asking for 196mm spring length with preload, which is 7.7''. I'm measuring somewhere around a 6.5'' weighted length, and that's with the front of the car sitting about 1'' higher than the rear.

I also verified the stamped PN on the spring matches what's in the manual, so it should be the correct rate.

I was going to ask Barry, but I also figured the simplest answer is the most likely, which is that I did something wrong. This is really strange to admit, but even after over 20yrs of owning 7 BMWs, this is the first time I've messed with a spring/strut assembly.

[Obioban]

bumping this back to the top because I'm having trouble figuring out why my front ride height is so HIGH (14.75 LF, 14'' RF), and hoping someone has encountered this challenge before.

- off the shelf ohlins R&T from Barry at 3DM.
- no spacers
- OE top mounts and strut bearing in their original position, arrows pointed forward.

currently my adjusters are all the way at the bottom of the shaft with no preload, I confirmed the strut is seated all the way down in the kingpin, and the endlink is off the car. I did take the car for about a 5 mile drive, and didn't notice any major clunks, rattles, or noises that would indicate a significant problem. Some settling wouldn't surprise me, but from the way people talk about this setup is the challenge is not getting the car to ride too LOW, hence the spacers, and I'm having the opposite problem.

Barry's pretty great-- I'd hit him up for advice.

But, really, seems like it can only be...
strut not fully seated
height adjuster too high
spring too long/stiff
incorrect top hat assembly

Are the spring compressing at all when you lower the car to the ground? Or just staying at unloaded height?

[tnord]

bumping this back to the top because I'm having trouble figuring out why my front ride height is so HIGH (14.75 LF, 14'' RF), and hoping someone has encountered this challenge before.

- off the shelf ohlins R&T from Barry at 3DM.
- no spacers
- OE top mounts and strut bearing in their original position, arrows pointed forward.

currently my adjusters are all the way at the bottom of the shaft with no preload, I confirmed the strut is seated all the way down in the kingpin, and the endlink is off the car. I did take the car for about a 5 mile drive, and didn't notice any major clunks, rattles, or noises that would indicate a significant problem. Some settling wouldn't surprise me, but from the way people talk about this setup is the challenge is not getting the car to ride too LOW, hence the spacers, and I'm having the opposite problem.

[act9]

Are you using their stock yellow 8" springs?

Those are 400 and 8", I was able to get to ~13.3 with 375 and 7", so I think you can easily get to over 14 with the yellows. You can also get a bit higher is needed if you preload the springs a bit more.

You having tire rub issues, is that why you want to run 14"?

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No tire rub concern, only looking to maintain a minimum of 14” in front and 13.75” in rear.

Looking for:

-Ohlins quality damping.
-Moderate lowering from OEM (max 0.5”)
-Moderate spring rate increase from OEM (max 1.5x)
-Retain OEM top mounts

If Ohlins RT can reach hight requirement, the only downside is spring rates nearly 3x oem...

[mrgizmo04]

Can anyone confirm max ride height with Ohlins RT and OEM top mounts? Is 14" in front achievable?

Are you using their stock yellow 8" springs?

Those are 400 and 8", I was able to get to ~13.3 with 375 and 7", so I think you can easily get to over 14 with the yellows. You can also get a bit higher is needed if you preload the springs a bit more.

You having tire rub issues, is that why you want to run 14"?

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[act9]

Can anyone confirm max ride height with Ohlins RT and OEM top mounts? Is 14" in front achievable?

[mrgizmo04]

Gents,
Spacers from 3dm only change the attachment point at the bottom of the strut where the strut attaches to the knuckle via the pinch bolt. They do not change anything about the distance or suspension travel from the bottom spring perch to the top mount/camber plate. They don't change the attachment point of the strut shaft to the mount/camber plate.

So if these spacers let's say were a foot high (in reality they add only 3/4 inch), all that would change if you put them on the car would be that the ride height would he a foot higher. Again, they dont net you any travel, that is limited by the Ohlins piston shaft stroke itself.

What the spacer allows you to do is gain some ride height while unloading the spring preload. What that effectively allows you to do is "tune/adjust" how much of the piston stoke is going to be allocated to droop travel vs bump travel. Imagine a SUPER stiff spring so when the car is on the ground suspension does not compress at all and sits at full droop. You have 0 droop travel left, but all suspension travel is available for bump travel. If, on the other hand, you use a super soft spring, when you lower the car to the ground, you will compress the piston shaft and the spring and will basically be riding on bump stops because you won't have any suspension travel available for bump, but you will have plenty of droop.

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[jvit27]

Shortening the stack (less droop) creates LESS of a chance of the spring coming unloaded.

Sorry, you're right. Meant when using shorter spring

[Tbonem3]

Except it will also increase the likelihood of the damper topping out, and given how little droop travel the Ohlins already have the spring will become unseated under decompression, cause noise, etc.

Shortening the stack (less droop) creates LESS of a chance of the spring coming unloaded.

[Yeetus]

Except it will also increase the likelihood of the damper topping out, and given how little droop travel the Ohlins already have the spring will become unseated under decompression, cause noise, etc.



Tuning until it rubs is not how you set up a suspension... are you purposely trying to fuck it up?

Yes I’m purposely trying to fuck it up.


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