[Andy198712]

Hi,

Since installing eibach springs and b4 (m sport versions) on my e91 SE it’s lost all its small bump compliance.

On fast flat roads it’s good but 99% of driving it’s harsh and rattling the car apart, ruined the car for me.
It’s the poor roads in the U.K., lots of small bumps ect


Anyone got Sach shocks with the eibach springs? If so should I fit SE ones or M sport?


18inch pilot sport tyres.

Did the bushings at the same time. Poly bushings in the front control arms
Either this or I try 17inch wheels and bigger tyre

Thanks
Andy

[whyzee125]

The issue isn't the shocks but the springs. I'm guessing you're on stock bumpstops? Even though Eibach's aren't all that low, they'll have just about zero travel before the bumpstops begin to ramp up the spring rate significantly. Poly bushings will add some NVH too though that won't make a bone jarring ride. I'd recommend a better solution for lowering or going back to stock springs and I think you'll be very happy.

[michaelalex17]

I was on b4s and stock springs and now I’m on Koni yellows and eibach springs on my e91 and it’s definitely less crashy and jarring. I don’t like Bilstein’s. They are harsh. I used to have b8’s on my e92 and had the same issue.

[Brian86]

Originally Posted by whyzee125

The issue isn't the shocks but the springs.

This ^^^

Put stock springs back on. 16" non runflat wheels if you have the little brake rotors.

[aphael]

The eibach springs are trash, I got rid of them after a week. Stock msport springs are the best with the b4 sport shocks.

They lower the car a bit, but aren't any stiffer than oem, causing you to crash on the bump stops, making them bad on b6/b8/koni yellow shocks as well.

Swift Spec-R is what you should be looking at if you want a shock upgrade

[Suvorovo]

Non-runflats improved ride quality on bad roads quite significantly. I would try that first before spending bigger money on suspension. Running B4s + michellin pilot sports. So much more comfort, and probably better on the suspension components as well.

[Andy198712]

Originally Posted by Suvorovo

Non-runflats improved ride quality on bad roads quite significantly. I would try that first before spending bigger money on suspension. Running B4s + michellin pilot sports. So much more comfort, and probably better on the suspension components as well.

That’s what I currently run

[Andy198712]

Will see how much travel I have before the bump stops hits, there new bump stops for M sports models, they were febi/ bilstein if I recall

Frustrating as it was expensive to renew it all

[Andy198712]

Originally Posted by whyzee125

The issue isn't the shocks but the springs. I'm guessing you're on stock bumpstops? Even though Eibach's aren't all that low, they'll have just about zero travel before the bumpstops begin to ramp up the spring rate significantly. Poly bushings will add some NVH too though that won't make a bone jarring ride. I'd recommend a better solution for lowering or going back to stock springs and I think you'll be very happy.

So maybe buy some m sport springs? Or better yet SE springs but will they work okay with the M sport model B4’s I have?

[Andy198712]

Originally Posted by Brian86

This ^^^

Put stock springs back on. 16" non runflat wheels if you have the little brake rotors.

Have the bigger brakes on mine so guessing 17 minimum but keeping an eye out for after my pilot sports wear down (there fairly new)

[Andy198712]

Originally Posted by aphael

The eibach springs are trash, I got rid of them after a week. Stock msport springs are the best with the b4 sport shocks.

They lower the car a bit, but aren't any stiffer than oem, causing you to crash on the bump stops, making them bad on b6/b8/koni yellow shocks as well.

Swift Spec-R is what you should be looking at if you want a shock upgrade

Thanks!
Will try find some in the U.K. there appears to be a few options for the spring in the M sport flavour…

[whyzee125]

Originally Posted by Andy198712

So maybe buy some m sport springs? Or better yet SE springs but will they work okay with the M sport model B4’s I have?

Yup, any OEM springs will work just fine.

[Andy198712]

Originally Posted by whyzee125

Yup, any OEM springs will work just fine.

Will the SE ones with too or be over compressed with the bilstein shocks?

Thanks

[Andy198712]

The shocks I have the B4 OE replacements for sports suspenion
Part numbers
22-1350049
22-1350032

[Andy198712]

Seems like the SE springs are a bit longer then the Msport springs which makes sense, but loads of small variations within them, probably just stick with a known name like Sach or something instead of an off brand name?
Unless a spring is a spring…..

[Mike K]

e91 guy chiming in a bit late but I just carefully installed rear Bilstein B4s but left the stock springs in there. 108k miles. I also dumped the run flats for Bridgestone Potenza RE980 AS+ tires and I’m happy so far.

I’ve driven plenty in the UK so I know what your roads can be like. Chicago area roads are just as bad!

[Andy198712]

Was that the stock m sport yes or the SE?
Cheers, I think I located some stock m sport springs I can “simply” fit lol

[aphael]

The Sport springs came on earlier models, my 2007 had a sport package (no m package in that year). The m edition springs are marginally lower. Any of them should work with the Bilsteins b4 sport as these are OEM springs

[whyzee125]

Originally Posted by Andy198712

Will the SE ones with too or be over compressed with the bilstein shocks?

Thanks

No, M sport and sport springs are extremely similar. You wont even notice a difference.

[Andy198712]

Would the e30 top hats and spacers combo help me out here?
And Mini Cooper bump stops as per another harsh thread here?

[whyzee125]

Originally Posted by Andy198712

Would the e30 top hats and spacers combo help me out here?
And Mini Cooper bump stops as per another harsh thread here?

The e30 perches would give you more travel and ride heigh up front, likely putting it back about where you were stock. No need for shorter bump stops if you're back at stock height but the bump stops would help if you stay at your current Eibach height. In short I would do one or the other. Rear needs trimmed bump stops or the z4 ones if you keep it lowered.

[Andy198712]

Originally Posted by whyzee125

The e30 perches would give you more travel and ride heigh up front, likely putting it back about where you were stock. No need for shorter bump stops if you're back at stock height but the bump stops would help if you stay at your current Eibach height. In short I would do one or the other. Rear needs trimmed bump stops or the z4 ones if you keep it lowered.

Thanks

I’m wondering if I’m better doing that or switching out to some used m sport springs…..

I tried to get a look in there with the whee at full lock but there’s not much room in there. Might measure the wheel centre to the wing, take the wheel off then jack up the suspenion to that same measurement and see what shock travel I have left (if any)