Have i installed H&R Springs incorrectly?

[S.J.1981]

Hey guys,

Ever since i installed the H&R 29664-1 springs on my 1990 E30 325i three years ago, i have been experiencing an extremely harsh and crash ride on the front end. I matched those springs with Bilstein B8s, and the car came with M-Tech suspension from the factory (so thats with 20mm front sway bars and 14.5mm rears). The reason i went for this spring and shock combo, is because with 207,000 kms the car drove like a boat. The shocks were shot and the springs...well they were rusted and one could compress 20-30% of the coils by hand.

I recently swapped out the B8 suspension for B4 to get a softer ride, sadly that is not the case. The front end does not "crash" anymore, but it is still a very firm ride, combined with the horrible roads we have here, i was scratching my head wondering what the problem could be.

I was looking into springs and saw these images (a German online used market website).

Looking closely, the "progressive" part of the spring(s) are at the bottom of the strut housing. Those two springs are technically the same, but here in EU H&R renamed them and repainted them (for some unknown reason) but the technical data sheet is the same (same thickness of the coils, uncompressed height etc).

The springs i have, despite them being 100% technically the same, are basically "flipped over". Meaning the progressive part is at the top, when one comes to read the H&R markings. I installed them, in that order, meaning one could read the H&R markings and the progressive part on the top (not the bottom as shown in the pictures). Even the used H&R Group G springs i found, have the progressive part at the bottom (when one reads the H&R markings) as shown in the last picture.

My question is, since i had the progressive coils at the TOP, have i installed them incorrectly? should i "flip them around"? i can not find any concrete answers and please bear in mind, in EU we do NOT have H&R OE, Sport and Super Sport. We had the 19.01/19.03 springs that were renamed and replaced by the 29664-1.

[mike.bmw]

Having the springs installed in a flipped/upside down orientation shouldn't make a difference. I'm assuming that they fit into their spring pad slots correctly when you installed them? They will still compress the same and the spring rates will be the same.

Speaking of spring rates, I found this post that states the spring rate on the 29664's is about double the stock 325i springs for the front: https://www.r3vlimited.com/board/for...06#post6066606 . I had read a few reviews that the B8s are a bit harsh, but you've already swapped those out for the B4s, so that can't be causing the issue.

Here's a shot of the orientation of my 50404-55s installed:



Bottom line - as long as they in the lower spring pad pocket and upper retainer correctly, it shouldn't matter what direction the springs are installed.

[S.J.1981]

Having the springs installed in a flipped/upside down orientation shouldn't make a difference. I'm assuming that they fit into their spring pad slots correctly when you installed them? They will still compress the same and the spring rates will be the same.

Speaking of spring rates, I found this post that states the spring rate on the 29664's is about double the stock 325i springs for the front: https://www.r3vlimited.com/board/for...06#post6066606 . I had read a few reviews that the B8s are a bit harsh, but you've already swapped those out for the B4s, so that can't be causing the issue.

Here's a shot of the orientation of my 50404-55s installed:



Bottom line - as long as they in the lower spring pad pocket and upper retainer correctly, it shouldn't matter what direction the springs are installed.

Thank you Mike, but i am still on the fence regarding the orientation. Take a look at my springs.

The first picture shows, how the progression part (otherwise known as a "soft part) is facing up (just like yours) and one can read the H&R lettering.

The second picture shows when i flip it upside down (soft part down) and so is the lettering.

Comparing those with how the earlier pictures i uploaded are orientated, it is confusing. I have removed the front struts around 5-6 times, swapping springs and replacing top mounts (horrible play on brand new parts) and despite that, switching from B8s to B4s made very little drifference. It feels as if the front end is a go kart with bilsteins. Regardless, i always make sure, that the spring ends are snug up against both upper and lower spring pad shoulders.

Regarding spring rates, again it MAYBE a US thing, since H&R claimed to me that "we would never offer aftermarket springs with a significant higher spring rate than the factory springs, either the same or 10% stiffer). So it got me thinking, maybe i installed them upside down?

I am going for genuine BMW strut mounts this time around and new spring pads (i tried Sachs, Lemförder, Meyle, Febi and they all have play once installed and torqued down, only an aftermarket one did not have play, and i do not wish to gamble with aftermarket unknown brands with suspension).

[mike.bmw]

Yeah, that's interesting. For the front suspension, I wouldn't think the orientation matters as the spring is compressed in a linear fashion, so given a specific amount of compression, the spring rate would be the same regardless of right side up or upside down. But I'm not an expert, so maybe someone else can chime in to verify.

[S.J.1981]

Yeah, that's interesting. For the front suspension, I wouldn't think the orientation matters as the spring is compressed in a linear fashion, so given a specific amount of compression, the spring rate would be the same regardless of right side up or upside down. But I'm not an expert, so maybe someone else can chime in to verify.

Just ordered the parts from my BMW dealership, will be checking to see if the springs are indeed seated correctly when the "flip" of the springs are done.

[S.J.1981]

Mike,

I managed to install the springs, with the progressive side facing down (upside down lettering) along with new upper and lower spring pads and new mounts from BMW. I also threw in the M-Tech bump stops (again from BMW) and the car is a lot better like this.

It no longer "crashes" on every surface imperfection, it is still a very firm ride, only big road issues cause a "crash".

Sadly, the roads i drive on locally, and when i move to munich, are just falling apart. You are correct, these 29664-1 springs are just too firm for daily use, even with the B4s (and M-tech 20mm front/14.5mm rear sway bars). No doubt that, these springs would be great for track days, the front end feels like it is glued to the asphalt, full confidence and control, but my current roads and my regular driving, i need something softer.

I did some research into the Eibach springs, suprisingly there are two versions here in Germany available.

E2003-140 Pro Kit: These are basically the same ratings as stock, the rears are just a smidge higher than stock M Tech/Sport suspension.

E2019-140 Pro Kit: These are crazy, a smidge stiffer than the 29664-1 front springs, but the rears are a massive step up compared to the 29664-1, i would say 40-50% higher spring rate.

Both versions are claimed to lower the car by 30-40mm in the front and 30mm in the rear, same as the H&R ones.

The thing that i noticed, and you may find interesting, is the technical spec sheet, the one we require to give to the TÜV when renewing the registration.

Seems that the Eibach E2003-140 kit is around 10mm higher (uncompressed) than the H&R ones in the front, while the rears are the same.

Also the E2003-140 kit also recommends using the 75mm bump stop (the M-Tech one) and NOT the standard 85mm one.

I printed out the documents from Eibach and will drive by my TÜV and inquire, if by installing these Eibach springs, do i still get the Historic plates (it is some German thing they do here) or not. If i get the green light (which i should) i shall be swapping the springs.

My only concern is the front hight, since they are a bit higher than the H&R ones, i am wondering if i should get the E90 drop hats to "balance" it out or not.

Here is a shot of the eibach bumpstop mentioning in the tech sheet:

[mike.bmw]

I'm glad you saw improvement with the shorter bump stops and flipped spring orientation. I still don't understand how flipping the spring would make a difference in rate or travel, but I'm not an expert.

Here are a few things to think about regarding the Eibach E2003-140 kit:
- just because the uncompressed spring is 10mm taller than the stock spring, it doesn't mean that the ride height will be 10mm taller. The spring's coil thickness and wind pattern will also play a role here. The Eibach's may compress farther than the stock springs based on these factors, resulting in a similar or lower ride height than stock.
- the E90 drop hats will lower the ride height 10mm, regardless of the spring you choose (because it moves a static/fixed mounting point).
- There are various thicknesses of upper and lower front spring pads. It has been a while, but I *think* they come in 5mm, 7.5mm, and 10mm thicknesses. You can use these to make small changes in ride height, up to 10mm.

Good luck! All of the research you are doing will pay off! :-)

[S.J.1981]

I'm glad you saw improvement with the shorter bump stops and flipped spring orientation. I still don't understand how flipping the spring would make a difference in rate or travel, but I'm not an expert.

Here are a few things to think about regarding the Eibach E2003-140 kit:
- just because the uncompressed spring is 10mm taller than the stock spring, it doesn't mean that the ride height will be 10mm taller. The spring's coil thickness and wind pattern will also play a role here. The Eibach's may compress farther than the stock springs based on these factors, resulting in a similar or lower ride height than stock.
- the E90 drop hats will lower the ride height 10mm, regardless of the spring you choose (because it moves a static/fixed mounting point).
- There are various thicknesses of upper and lower front spring pads. It has been a while, but I *think* they come in 5mm, 7.5mm, and 10mm thicknesses. You can use these to make small changes in ride height, up to 10mm.

Good luck! All of the research you are doing will pay off! :-)

Thank you for reminding me about compressed and uncompressed spring lengths, you are right.

Most likely i shall get the E2003-140 kit, i do have the 3mm front spring pads (the 30 year old ones were also 3mm thick), i just renewed them.

I shall update this thread probably during the weekend.

[S.J.1981]

Just received the E2003-140 kit, and i am impressed by the black powder coating from Eibach, compared to H&R. It just seems like better quality (just a bit), and yes i am comparing new springs with new springs.

The H&R springs we get here in Germany, are definitely progressive (fronts only) , while the Eibach ones here are linear all round.

I am surprised how short the rear Eibachs are, look smaller and shorter than the H&R ones.

Since the car needs a service, including a new pan gasket and new front brakes (discs and pads) i am unsure how to tackle this. I am also changing the steering shaft, so i might just support the engine from the top and remove the entire front subframe, gives me a chance to tackle the oil pan, then tackle each front strut (for the springs) as well as the brakes and get that very annoying shaft replaced.

Coolant, brake fluid, plugs etc are about 1 year to 1.5 years old. Not sure if i should wait a couple of weeks and just give the car an inspection II service or not (new air and fuel filters, replace transmission and diff oils, coolant etc). It really does not need it, but would be nice to have everything tip top, can not decide.