[exE36M3]

[ updated 8/19 : rear spring settled after 75 mile drive. Numbers corrected below ]

Gentlemen:
I have been on/off this forum for about a year. I recently decided to drop my 435i M Sport RWD with a set of Eibach Prokit sport springs. Eibach claims a .8" drop in front and a .4" drop in the rear.

This spring kit, in my opinion wasn't engineered or designed for the 430/440. The same kit in the 335/340 gives a nice balanced drop (about 1" overall for the 3 series cars.) But that .8/.4 drop induces a rake/tilt in the profile of the 4-series cars.

After driving for a couple months with the Eibach Pro-kit, I started to notice that almost ALL 4-series kits have a pronounced rake... the rear of the car is higher than the front. I took photos off the internet and forced a horizontal guide in photoshop to confirm this theory. The 4 series stock has a slight rake, but with the springs, the rake is VERY pronounced and after driving with it, I noticed the front of the car and weight transfer during cornering are very front centric.

But what to do...

I recently won a logo design contest with the local BMW club and got a gift certificate. And I went shopping. I noticed Eibach also offered a Sportline kit that drops the 4-series car 1" up front and .8" in the rear. "Wait a minute," I thought "The Prokit is .8" in the front, what if I drop the rear .8" using the Sporting kit - rear?"

So there went that gift certificate and here's the result...

BEFORE


AFTER


Note the difference in rear ride height is ONLY 5/8"

But a fairly even drop line front and rear in the after.
Fenderwell to rim edge up front with the Prokit is 3.5" inches
Fenderwell to rim edge in the rear with Sportline is 3.75" inches (Prokit was 4.375", difference of 5/8").

Measurement with on my 2015 BMW 435i M Sport RWD with Adaptive Suspension.
Eibach PRO Kit number is E10-20-031-02-22 made for the 335/340 and 435/440 RWD cars. I used only the front spring in photo.
For the rear of the car, I used the Sportline kit E20-20-031-01-22 rear spring.

E39/E60 "Dinan" bump stops are also installed (PNs are 31331138814 and 33536762722). They are about 1" shorter than the stock ones.



Observed things:
1. Weight transfer when cornering and accelerating is definitely more middle of the car.
2. The Turner Monoball - which can be harsh... mellowed out. Guess is that they aren't carrying as much weight as before.
3. Definitely feel the rear more, but in that it feels more connected.
4. Front splitter isn't scraping as much.
5. Had to adjust my headlights DOWN. The rear came down, the front came up. Crazy how 5/8" in the back can change headlight tilt. (Edit, the adjuster arm may've flipped during the install! Correcting this :P)
6. Spring load? Eibach posts numbers of 1170 for the Prokit rear and 1160 for the Sportline rear. Not sure what that 10 represents (nanometers, foot pounds?), but it's 10 softer than the Pro-kit so not much drama there.

In short, it's a $582 suspension project (If you order both the Pro-kit AND the Sportline kit and just use the front and rear springs from each kit respectively) versus $291 of a single kit... if you need it NOW.
BUT if you have the pro-kit and just want the Sportline rear spring, the PN is...
21 20 031 01 HA


Eibach Europe will sell you individual springs for about $55-ish/pop... Hmmm... That's $220 for this set. That's cheaper than $291-$300. But wondering what shipping and VAT/Tax/Import would run.
https://eibachshop.com/index.php?p59...-bmw-3-4-coupe

Thanks to @Farkle! for his Eibach consulting!

[HybridAWD]

Im curious how this would play out with the xDrive.

[larrylam646]

Originally Posted by HybridAWD

Im curious how this would play out with the xDrive.

In my case, the Eibach Pro Kit lowered my vehicle evenly front and rear - https://f30.bimmerpost.com/forums/sh...32&postcount=5.

After reading Farkle!'s bump stop thread, I checked my setup and discovered my rear OEM bump stops were resting on the shocks at static height so I installed the M4 rear bump stops and to my surprise, the ride height dropped ~ 5mm. I have since raised the rear using Farkle!'s shim technique.

Larry

[exE36M3]

@larrylam646 - thank you! If you get bored, would you mind measuring your fender to rim space?

I seem to remember the ride height of the 435X-drive being different from the 435i.

[larrylam646]

Originally Posted by percychow

@larrylam646 - thank you! If you get bored, would you mind measuring your fender to rim space?

I seem to remember the ride height of the 435X-drive being different from the 435i.

Hi percychow,

Yes, the RWD sits 15mm lower than the xDrive.

Fender to rim measurements: 4" front, 3 5/8" rear.

Larry

[G80S58]

Originally Posted by larrylam646

In my case, the Eibach Pro Kit lowered my vehicle evenly front and rear - https://f30.bimmerpost.com/forums/sh...38;postcount=5.

After reading Farkle!'s bump stop thread, I checked my setup and discovered my rear OEM bump stops were resting on the shocks at static height so I installed the M4 rear bump stops and to my surprise, the ride height dropped ~ 5mm. I have since raised the rear using Farkle!'s shim technique.

Larry

what part number from Eibach did you get on the Prokit?

[exE36M3]

@larrylam646 - thank you. Looks like the 435/440 X cars got kit #E10-20-031-18-22.
I adjusted my post accordingly. Thanks for adding to this thread!

[larrylam646]

Correct, Pro Kit part number for 435i xDrive is E10-20-031-18-22.

[G80S58]

Originally Posted by larrylam646

Correct, Pro Kit part number for 435i xDrive is E10-20-031-18-22.

Thank you, I have the same kit with F80 bumpstops and my car looks higher than yours, I need to do measurements.

[larrylam646]

Originally Posted by CRAMAZIN

Thank you, I have the same kit with F80 bumpstops and my car looks higher than yours, I need to do measurements.

CRAMAZIN,

Just a reminder that I have installed oversized tires so the taller tire sidewalls reduce the fender gaps.

[G80S58]

Originally Posted by larrylam646

CRAMAZIN,

Just a reminder that I have installed oversized tires so the taller tire sidewalls reduce the fender gaps.

thats makes a lot of sense now, I'm running 255/35 and 265/35. Do you have any rubbing issues?
Only time I ever had an issue is when I go over a speed bump and come down straight I felt my fronts rubbing, so I have to come down on an angle.

[tr3flip]

Hey guys, Tony from Eibach North America here.

Are any of you local guys (LA/IE/OC area) interested in bringing your vehicle in so we can confirm our before and after ride height measurements? You'll get a free spring set, free installation and free alignment with the process. We'll just need the vehicle for an entire business day to get the work completed.

The Sportline kit we have for the F32 has only been confirmed for the 428i and 430i. We can test fit this as well on a 435i. If it works out, we can give whoever brings their car in the option to choose the Pro-Kit or Sportline. I just want to note that we will not mix and match our Pro-Kit and Sportline springs together like the OP has done.

Shoot me a DM if you're interested and we will work out further details.

-Tony

[exE36M3]

@tr3flip / Tony - well shoot, wish you guys were closer! Awesome to see Eibach wanting to look into this!

BTW - I'm not bashing Eibach. I've run Eibach Pro-kits on my 1991 BMW 318is, 1995 BMW M3, 1990 Miata, and now my 2015 435i. My post is pretty much solving a dilemma where I found the rear of my car a little higher than I wanted and gaining some unintended bonuses in handling (in my opinion).

Feel free to PM if you guys want any details.

[DeeM55]

I have the exact same issue with the H&R Sport Springs on my 2016 435i GC. The back sits higher than the front.

[exE36M3]

@DeeM55 - would you mind checking your part numbers against the 335/340 too?
Wonder if HR just used the same kit.

[tr3flip]

Originally Posted by percychow

@tr3flip / Tony - well shoot, wish you guys were closer! Awesome to see Eibach wanting to look into this!

BTW - I'm not bashing Eibach. I've run Eibach Pro-kits on my 1991 BMW 318is, 1995 BMW M3, 1990 Miata, and now my 2015 435i. My post is pretty much solving a dilemma where I found the rear of my car a little higher than I wanted and gaining some unintended bonuses in handling (in my opinion).

Feel free to PM if you guys want any details.

No worries! This just happens to be one of the kits we get from Eibach Germany since they get the jump on development before us. That said, we haven't test fitted these on any local US cars so there just might be some small installation discrepancies we can hopefully clear up.

[larrylam646]

Originally Posted by CRAMAZIN

Do you have any rubbing issues?

No rubbing issues on the rears and only very very slightly on the fronts (on the front inner fender liner where the cooling louvers are located) when backing up with the steering turned hard to the left/right.

[FaRKle!]

Originally Posted by DeeM55

I have the exact same issue with the H&R Sport Springs on my 2016 435i GC. The back sits higher than the front.

H&R has very few kits, and thus applies a single kit across a very wide range of models. It's pretty lazy.

Originally Posted by tr3flip

No worries! This just happens to be one of the kits we get from Eibach Germany since they get the jump on development before us. That said, we haven't test fitted these on any local US cars so there just might be some small installation discrepancies we can hopefully clear up.

Are you going to be taking a similar strategy as with rear springs 11-20-031-03-HA and 11-20-014-14-HA where they have the same spring rate, but different lengths to achieve the desired ride height?

I appreciate how Eibach releases their spring dimensions and rates. It makes it easy to do ride height and frequency calculations, and thus recommend their springs since you know what you're going to get.

[DeeM55]

Originally Posted by FaRKle!

H&R has very few kits, and thus applies a single kit across a very wide range of models. It's pretty lazy.

I agree. I'm already saving up for a set of coilovers.

[exE36M3]

Shoot if you live in the LA area and were interested in lowering your car FREE... sheesh guys, jump on this! Totally appreciate Eibach willing to contribute to the data and community here!

[DeeM55]

Originally Posted by percychow

Shoot if you live in the LA area and were interested in lowering your car FREE... sheesh guys, jump on this! Totally appreciate Eibach willing to contribute to the data and community here!

I know right! I DM'd Tony. I'm local too.

[exE36M3]

@DeeM55, if that works out for you that'd be pretty cool. Please post if you guys connect and how it goes.