[E90325ii]

My front springs gave up, and i wonder if M sport springs will fit my E90 325i (no M-sport)? Should i change the shocks too?

[vester86]

ideallly yes, change the shocks too. they are a bit shorter to accommodate the shorter springs

[Tambohamilton]

Have you seen how much the springs are compressed, even with the strut at full extension? The length of the strut doesn't matter. Likely the matching strut will be tuned better for the stiffer springs than a non-sport one though, so ideally you'd change them, but it really won't make a huge difference

[lowrydr310]

Originally Posted by Tambohamilton

Have you seen how much the springs are compressed, even with the strut at full extension? The length of the strut doesn't matter. Likely the matching strut will be tuned better for the stiffer springs than a non-sport one though, so ideally you'd change them, but it really won't make a huge difference

???

You want them to match. If you're installing sport springs, you want the sport shocks and struts to match. No point in mixing them up. If it didn't matter then there wouldn't be different parts specified.

I guess you could technically do it, sure it will fit, but why?

[Tambohamilton]

That's what I said. My point is that the length of the strut is of the least concern.

Anyhow, installing the matching strut is less important than installing the matching bump stops ('auxiliary springs').

[rothwem]

Dang, I didn't realize the front springs on these cars would break, I thought that was just a rear spring thing.

[vester86]

Originally Posted by Tambohamilton

Have you seen how much the springs are compressed, even with the strut at full extension? The length of the strut doesn't matter. Likely the matching strut will be tuned better for the stiffer springs than a non-sport one though, so ideally you'd change them, but it really won't make a huge difference

it's not about the springs, it's about the shock internals. you ideally want an equal stroke up & down from the "idle" position. with lowering springs you have less suspension travel in one direction. also you'll be riding on bump stops sooner.

[tcphoto]

I have always read that the strut/shock/spring need to be matched, if you install lowering springs on stock strut or shock, it will likely fail prematurely.

[Tambohamilton]

Well you'll need to have a word with the BMW engineers about the proportion of bump and droop travel available on these cars then. With either spring on either shock you'll have somewhere in the region of double the droop travel compared with bump. These cars are designed to ride on the bump stops - that's why BMW calls them "auxiliary springs". They're engaged at ride height, or very soon after (~5mm). Hence why I state that they're more important to change than the struts.

[E90325ii]

Originally Posted by lowrydr310

???

You want them to match. If you're installing sport springs, you want the sport shocks and struts to match. No point in mixing them up. If it didn't matter then there wouldn't be different parts specified.

I guess you could technically do it, sure it will fit, but why?

Mainly i want to lower the ride height, i talked to a bmw mechanic and he said that m sport springs wont influence the stock shocks that much. He told me that it most likely wont be a problem to have the old shocks. But he wasnt too sure if m-sport springs fit the stock struts, either way i ordered the springs and probably will buy the shocks aswell.

[mainbearing]

The standard shocks will be under damped with sports spring, especially with old shocks. +1 on matching ones.

[Tambohamilton]

Originally Posted by E90325ii

Mainly i want to lower the ride height, i talked to a bmw mechanic and he said that m sport springs wont influence the stock shocks that much. He told me that it most likely wont be a problem to have the old shocks. But he wasnt too sure if m-sport springs fit the stock struts, either way i ordered the springs and probably will buy the shocks aswell.

The only reason not to change the shocks and bump stops at the same time as the springs is if you can't afford it. Not judging, if that is the case! But if you can afford to change the lot at the same time, do it. Also consider refreshing other parts of the suspension at the same time, to save time/labour.

[E90325ii]

Originally Posted by Tambohamilton

The only reason not to change the shocks and bump stops at the same time as the springs is if you can't afford it. Not judging, if that is the case! But if you can afford to change the lot at the same time, do it. Also consider refreshing other parts of the suspension at the same time, to save time/labour.

Yeah, i ordered new shocks.

But lets say i didnt change the shocks for whatever reason. Would the m-sport spring fit the stock shocks? Would i even be able to put the new springs on there? (Trying to prove my friend that it is possible)
Thanks for the help

[vester86]

yes it's certainly possible to mount Msport springs on regular shocks (and visa versa).

[Tambohamilton]

Originally Posted by E90325ii

Yeah, i ordered new shocks.

But lets say i didnt change the shocks for whatever reason. Would the m-sport spring fit the stock shocks? Would i even be able to put the new springs on there? (Trying to prove my friend that it is possible)
Thanks for the help

Yes, no issues in fitment. It's just that the damping would be suboptimal.

Do also replace the bump stops with the m-sport ones while you're at it!