[rothwem]

Originally Posted by Soravia

Is the 2.5" ID spring able to mount without lower spring perch rubber on the OE non-M rear spring arm?

The Bimmer World Spring mount I bought goes on top and replaces the OE upper spring perch. I assume I will need 4 spring isolators for 2.5" ID springs.

I think you just need 2? One for each side. Not OEM BMW though, you need these: https://www.amazon.com/Energy-Suspen.../dp/B004ALKAKK

check the first review:

"I converted the rear lower camber arms of my e92 335i to e92 M3 and didn't want the 60mm springs to sit directly on metal. So I searched and found these. The inner diameter of these is slightly smaller than the outer diameter of the spring perch...but, not enough for them not to fit perfectly, which they do (to my surprise. The springs sit perfectly on these.

As for build quality, they seem built very well...hard, but soft enough to all the springs to gently sit on to"

Also, I see that the Bimmerworld spring perch is for 60mm (2.36") springs, not 2.5. I realized I linked you to a 2.5" spring on summit racing, sorry about that.

[Soravia]

Summit Eibach springs will come in today. I'll return them. Harrison Motorsports sells 60mm H&R springs at 250 mm (9.7"?) And 514 lb/in spec. I'll order a pair of those and use height adjust to get where I want it sit, about 1.5" fender gap.

I found this at another thread. They put it on non-M spring arm and had to shave a different part number Energy Suspension spring isolator.
If nothing fits, I was going to use 3M Poly window weld 😃

[rothwem]

Originally Posted by Soravia

Summit Eibach springs will come in today. I'll return them. Harrison Motorsports sells 60mm H&R springs at 250 mm (9.7"?) And 514 lb/in spec. I'll order a pair of those and use height adjust to get where I want it sit, about 1.5" fender gap.

I found this at another thread. They put it on non-M spring arm and had to shave

Exciting! As you can probably tell, I've researched this modification for a while but haven't pulled the trigger yet. I'm eagerly awaiting your experience to see how it goes.

[Soravia]

Won't be quick. Wife is back in school and I have to baby sit more. At least I'm off school.

Bimmer shop quoted $200+ labor to replace mid brake lines. But I'll see final quote after the car shows up there.

Will do suspension before that

[Soravia]

Got the Bimmer World rear top spring perch. Simple enough. Put in place and tighten bolt to expand top to stay in place. No isolators. I'll buy a thin pair of plastic from Turner for $1.20

https://www.turnermotorsport.com/p-2...ring-isolator/

[Soravia]

According to this thread X1 spring swap (marked H4 vs 328xi pre LCI stock C6 ) is the cheapest route to raise the rear of 328i xDrive. Slightly more coils? But there are X1 4 and 6 pot turbos with different weights, so better get H4 marked springs to be sure.
Mine are marked C8 as seen in pics. My 328i xDrive is LCI with panaromic sun roof and manual transmission. Not sure what the difference is from C6 springs.

https://www.e90post.com/forums/showthread.php?t=1413836

Quick look up on eBay VIN show springs marked H5 from 4 pot xDrive X1. WBAVL1C55FVY28029
H3 for 4 pot sDrive RWD X1.
WBAVM1C5XDVW42478

[Soravia]

X1 springs are 13.5" or so. I think OE Springs are actually at 12.5" to 13".

I'm changing order for H&R springs. I think I will get 250 mm (9.84") at 100 kg (570lb) and 300 mm (11.8") at 90 kg (514lb)

I'm also ordering a pair of H4 springs from X1 AWD (not sure 4 or 6 pot).
I'll try them all for best results

[rothwem]

Originally Posted by Soravia

X1 springs are 13.5" or so. I think OE Springs are actually at 12.5" to 13".

I'm changing order for H&R springs. I think I will get 250 mm (9.84") at 100 kg (570lb) and 300 mm (13.8") at 90 kg (514lb)

I'm also ordering a pair of H4 springs from X1 AWD (not sure 4 or 6 pot).
I'll try them all for best results

Either way, I'm interested in the results.

[Soravia]

I'm going with X1 E84 H4 springs or Bimmer World top perches (up to 1.5" increase), Energy Suspension bottom spacers (0.2"?), 250 mm (9.84") H&R springs (570 lb).
I think OE springs are 12.5" to 13.5" but at least 0.5" is free coils that stick out and sink to the lower arm. The top one is mated to top rubber.
And at least 1" of that is compressed as the arm is bolted to the sub frame.

My guess is flat spring 9.84" and top perch extended to full will prevent loose spring at full droop.

If it doesn't stay tight, I'll get helper springs.

As it sits, the rear tires go past the rear fender lip by at least half an inch. I think a lot of spring strength is needed just to recover the artificial rate lost from removing the bushing.

M3 E90 springs are 550 lb, and marked M3 as well as X3 according to eBay pics.

[rothwem]

Originally Posted by Soravia

I'm going with X1 E84 H4 springs or Bimmer World top perches (up to 1.5" increase), Energy Suspension bottom spacers (0.2"?), 250 mm (9.84") H&R springs (570 lb).
I think OE springs are 12.5" to 13.5" but at least 0.5" is free coils that stick out and sink to the lower arm. The top one is mated to top rubber.
And at least 1" of that is compressed as the arm is bolted to the sub frame.

My guess is flat spring 9.84" and top perch extended to full will prevent loose spring at full droop.

If it doesn't stay tight, I'll get helper springs.

As it sits, the rear tires go past the rear fender lip by at least half an inch. I think a lot of spring strength is needed just to recover the artificial rate lost from removing the bushing.

M3 E90 springs are 550 lb, and marked M3 as well as X3 according to eBay pics.

From an academic standpoint, the coilover+height adjuster is the right approach, since you lost RATE, not preload when you replaced the bushings with bearings. I doubt the X1 has a dramatically different spring rate, its probably just a longer spring to add lift, which means that your overall wheel rate will still be less than before.

As for the M3 Springs, maybe a set out of a convertible would work, since the E93 has an ass about as heavy as the E91, though I think the M3 has a lower ride height from the factory.

Then again, maybe none of this matters since you'll probably not be pushing this on the street hard enough to notice, but I'm a dorky engineer and it makes me happy for stuff to be "right".

[Soravia]

Yes, M3 springs are shorter and designed to sit low so even if I recovered the rate at 550 lbs, those will still sit low due to the shorter spring.
I'm hoping 10" 570 lb and extra 1.5" or so FIXED added length will solve the issue.
If not I'll have to get the same rate but 12" 300mm springs.

[Soravia]

I just ordered 12" 300mm 571lb 10kg 60mm ID Eibach springs from eBay seller Aristocrat Autosports.

I still haven't seen the order from Harrison Motorsports ship at all.

[Soravia]

I found correct used rear axles. Looked at the VINs on the eBay parts cars for PL/PM series and found a few that has correct shaft, inside and outside ends.
If you go just by shaft number you will get E93/93 parts , but they will NOT fit the sedan hubs, and do not have correct wider track. Looking only outside hub matching will not work with 335d xDrive, that has skinny shaft and bigger inside hub on the diff.

H&R springs ordered on 6 Jan finally coming in 23 Jan. I think they are shipped from H&R directly. So don't expect them in a hurry

[Soravia]

Got the 60mm 300mm 100 kg springs in (11.9" 574 lbs/inch) in! With the height adjuster at bottom it sits lower than the OE spring on the other side. The car and as rolled up and down a small bump from road to drive way to get them to settle.

The Bimmer World top mount rear 60 mm spring perch requires round pin spanner wrench made for MCS suspension kit.
https://www.bimmerworld.com/MCS-Spanner-Wrench.html

When all hardware are added, OE spring is significantly longer than H&R 300 mm springs. It was already an inch higher just springs vs springs.

So if X1 springs were put in place of OE spring with new rubber hardware, it will be a good solution for M3 control arm induced drop to recover back to standard xDrive heights, or closer to it. It will work for sedans for sure.
If anyone wants X1 springs, let me know.

I expect the H&R springs to get less compression when loaded compared to OE springs. I'll raise them up later on next week and load up with wheel, tires, and dumb bell weights in the back to find out.

Also replaced one of the Bilstein rear dampers.

If anyone wants a new Bilstein B6 HD and willing to rethread, let me know. Just pay shipping.

[Soravia]

Driver side spring in place. I'm raising the seat by 4 thread. You can see that hub is held up by bushing tension after 74 ft-lb torque on arms (M3 arm outboard is Bushings)

[rothwem]

Wow, damn man, doing work!

Hows it drive? How was the install of the rear spring setup? It looks like the spring will just fall off the perch at full droop, do you need tender springs?

[Soravia]

Originally Posted by rothwem

Wow, damn man, doing work!

Hows it drive? How was the install of the rear spring setup? It looks like the spring will just fall off the perch at full droop, do you need tender springs?

That's not full droop. The arm is disconnected from the hub. Full droop is limited by upper guide rod to subframe contact, even without bushing tension.

At full droop, the spring is under a lot of tension even with perch adding nothing to length. Even the 250 mm 9.8" spring will have tension at full drop with perch, and Energy Suspension spring pads on top and bottom, and the bushings torqued.

[Soravia]

Got the suspension exactly where I want it. All torqued and the perch is raised 4 threads and locked. this is after rolling up and down the drive way to street bump.

Because the way multilink articulate, you have to use a jack stands to hold up the hub spindle while you jack the spring arm into place to be able to push the bolt through. This applies to rear toe as well. You have to jack the arm up after the lower spring arm is connected to the hub. The hub will articulate for you to connect the rear toe arm properly, especially for non-adjustable stock arms.

[Soravia]

Bimmer World rear upper spring perch has round holes for adjustments and requires this wrench with round pin.
The usual ones on market are for slots and won't work.

The wrench is too long to work in the rear with the damper, body panels in the way so I cut the handle in half. This will work just enough to turn little by little.

[Soravia]

Rear now set to 14.5"L and 14.25"R from hub to fender.

You can see why the wrench had to be cut to half the handle length.

Bimmer World all aluminum spring perch was made by TCKline Racing model TCKE90RSA good for E90, E80, F30 series. It didn't need the tightening so much from the screw inside. There was enough friction to stay in place once the spring pressure was applied.

[Soravia]

Car now at shop. $680+ parts and labor to replace mid body hard brake lines that pass over the fuel tank.
The fittings won't seal back after rust damage.

[nsjames]

the rear fenders really make them look strange when you get it level and drop it.




it's probably a little more than yours. bear in mind the rear looks extra low because my winter tires are 26" diameter.
there's a bit more gap with stock sized rubber.