BMW E30 Strut Housing Shortening Tutorial + Ground Control Coilover Build
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- Опубліковано 7 лют 2025
- This is a video tutorial on how to properly shorten your E30 front strut housings to allow use of a shorter shock and how to assemble the Ground Control Coilover Conversion kit once the housings are shortened.
The work was performed on my 1991 BMW 318is and my setup is as follows:
Ground Control Coilover Conversion Kit - spring rates: 440f/650r
Bilstein HD front shock inserts for a 325ix model E30
82-02 Camaro KYB Gas-A-Just shock for the rear (not mentioned in video)
This video is just a general outline, your process may vary a bit depending on what tools, parts or coilover setup you use.
Work at your own risk. I am not responsible for any injuries or damaged parts/tools if you decide to follow my tutorial, I am simply providing some helpful tips.
Text from the video:
Step 1: Begin by removing both front strut assemblies (not every step is shown in this video)
Step 2: Once the strut assembly is out, remove the original top hats, springs and strut inserts. Use a spring compressor to perform this. Work at your own risk.
Step 3: Once everything is removed and the strut housing is bare, the next step is to remove the original spring perch. Use your own preferred method to do this. In my case, I used an angle grinder and cutoff wheel. Cut around the top of the weld where the spring perch is welded to the strut housing.
Step 4: Now it is time to cut the strut housing. Again, use your own preferred method to do so, just make sure the cut is straight and perfectly perpendicular to the strut tube to ensure that it doesn't have any slight bends or angles when everything is welded up. Otherwise, camber will be affected and the strut insert will not slide into the strut housing.
Step 5: Start your first cut just under the weld from the original spring perch. I used a band saw. I made sure everything was level and perpendicular and made my first cut.
Step 6: Now that the strut housing is cut into two pieces, it is time to make the second cut. This cut will determine how much you are shortening the strut housing by. Measure from where you just cut towards the top of the housing (threaded section). It is recommended to not cut any more than 2". Make sure you do not cut into the threaded section of the housing. I cut out 2". Note: The next clip shows what your strut housing should look like before and after making both cuts. I accidentally have the middle section flipped, which could cause confusion. This is the section that will be thrown away anyways.
Step 7: Now you are ready to weld. Prepare the end areas for welding and use welding magnets to keep everything perfectly positioned. Keep a small gap between the ends for the new metal to fill. The size of the gap should be the same size as the thickness of the metal of the strut housing.
Step 8: I would recommend MIG or TIG welding. When MIG welding, incorporate sheilding gas rather than using flux core wire. This will yeild much cleaner welds and better control. If you are ill-equipped or not comfortable with welding, have a professional weld everything up for you. Start off with a few tack welds and then weld the rest together all the way around.
Step 8: Once everything is welded up, grind the welds down so they are flush with the rest of the strut housing. I recommend using an angle grinder with flap disk.
Step 9: Now it is time to weld on the supplied adjuster perch. Use the threaded spring adjuster sleeve as a guide. Situate it so that the top of the adjuster sleeve is flush with the top of the strut housing as it sits on the perch. Make sure the flat area of the new perch is facing out towards the wheel. Start off by making a few tack welds and then weld the rest. Only weld on the bottom of the perch.
Step 10: This is how the strut housings should look once complete. Prep and paint to desired color. Do not leave any bare metal unpainted, it will rust over time.
Step 11: Once painted, you are ready to assemble the coilovers. Start off by putting two supplied O-ring's around the top of the strut housing to ensure a snug fit for the adjuster sleeve. Leave roughly a 1" gap between O-ring's. Install threaded adjuster sleeve.
Step 12: The next step depends on how much you shortened your housings by and your strut insert choice. You want to be able to tighten the insert down snugly with the collar nut. In my case, I had to make a 1.25" spacer out of metal tubing to achieve this.
Step 13: Once the strut insert is in place, install the collar nut and tighten it down. You will either need to buy or make a tool to tighten it.
Step 14: Install the spring adjuster followed by the spring itself.
Step 15: After the spring is in place, install the supplied top spring plate followed by the
original top hat (or whichever top hat you decide to run).
Step 16: Double check to make sure everything is tightened to spec. Now your new coilovers are complete and ready to install!
Hey, Thanks a lot for posting this video. There is no clear, easy to find directions on how to do this. It was made very well!
Amazing video, I just bought my kit and pictured this way almost exactly as how I would go about it. Your success video completely confirms my plans and now I'm even more excited to get started. Thanks for posting!
This is perfect for cars with little aftermarket support. I used these to fabricate air ride for my e12.
Very nice video!
If you end up using camber plates instead of top hats, you will achieve a lower ride height without losing an travel!
best coilovers instructional video out there. thanks so much
Nice video man, about to shorten my datsun shock housings. This most definitely helped me put things in prospective
Not exactly, the top of the tube is threaded on the inside to allow the collar nut to tighten down and hold the strut insert in place. If you just cut however much off, you wouldn't be able to install the collar nut. Watch the video again and it will make sense to you.
Wish i had this 2 years ago when i did mine with no idea! lol great informative video sir!
They are IX model Bilstein HD's, which are shorter than other model E30 inserts, thus allowing you to shorten the strut housing.
Most chilling E30 vid ever. I like to back again and again, just to watch, and listen your song again! :D
haha that's awesome, glad you like it!
Yes, they are 4x100 to 5x120 adapters. 18mm in the front and 20mm in the rear. I ordered them from 8380 Laboratories.
Great video and good job on the music aswell !
Super video!
Great tutorial, and nicely showing the steps involved (Y) Keep it up
Great video. Editing was pretty darn good. I personally wouldn't mess with e30 suspension though. It just rides too nice "as is". But, that's just my opinion.
You can run whatever you want.
Stock shocks will eventually blow and/or the ride will be bouncy since they can't compensate for the higher springs rates.
Thanks! The song is actually one I made a little over a year ago. I've been doing music production as a hobby since I was like 17, but have slowed down a lot. I'll get back into it again at some point. This song can be listened to and downloaded on SoundCloud. Search "Heebeejeebeats" and the song is called "Stinky's Box" (haha stupid name, I know). All my other songs are on there too.
Yes. All suspension components are the same on e30's except for 84 versions. (narrower strut tubes)
EXCELLENT VID MAN!! cant wait till I install mine!!
Yo,Awesome video my friend! thanks for that insight! my e30 will thank you when this is all done!
I'm quite a bit lower now than in the last clip, that was right after the install. It has since settled. However, my model E30 has the M42 engine, and the oil pan hangs very low. Going any lower for me would only make sense if I was on air suspension.
Awesome video!! Very helpful instructions! Cheers!
What a great tutorial!!
what shocks did you end up using im so thankfull someone mad a video of this. i have the tools and skills to do this and i didnt want to spend 1,200 bucks on coil overs when im just going to use them for ride height in my drift missle thanks alot
Great vid and awesome music!
this helps soo much.. but 1 question.. youve sorted out your mega lows on the front.. so how you get the back low to follow the front?!
Two Words that will CHANGE your life ! = the blue shirts youtube channel
Very good video!
Awesome video! Are those the adaptec wheel adaptors? How do you like them? Any problems?
I know nothing about BMWs (I own a Honda lol) but I know they make hybrid oil pans for VWs, so I was wondering if they made them for your specific engine. Might be something to look up. Just thought I'd mention that. Anywho, great video man. :)
Thank you and good luck on your e30! The song is actually one of my own productions from a while back. If you search "Heebeejeebeats" on soundcloud, you can hear all of my songs, the one in the video is named "Stinky's Box" haha stupid I know.
Great work. I like it
I'm curious how you managed to get a GC coilover conversion with the shorter shock inserts? On their website today you can only get the shorter inserts when you buy the full kit, which includes front and rear camber plates.
What you did is go for super low correct? Or is this how it's down normally? In other words if I chopped my spring perch and just welded the collar for the front adjuster this wouldn't go as low?
Very nice vid!
Hi, I have the GC conversion kit with the original off the shelf Bilstein Sport for Non-IX model and I was wondering what would be the best for the IX conversion between Koni Yellow and Bilstein?? :/ Does it worth the extra money to get Konis with adjustable damper?
Thanks a lot for the clip, it is very helpful!!!
good work
How come there's a metal disc-like piece on my performance struts where the strut piston/rod enters the chamber?.... it's preventing my sleeves from sliding down to the perch. Do I just cut that piece off?
Nice vid! Are those 15 or 16 inch BBSs?
Hello. Very informative video! Thanks but will this work on 89 325i sedans?
I have a few questions man. What size springs did you get for the rear? 5" spring or 6" spring? How low are you able to go? Do you like the spring rates you picked? I like a stiff DD and it seems you picked pretty stiff rates. The perch is provided by ground control correct? Thanks mate.
What kind of spacers are you using for your wheels. it looks like a 4*100 to 5*120 conversion adapter?
If you havent made this VID id never buy the kit :P
Now im going to test it out and finish it of with camber plates =)
How’s the ride quality?
I’m not a Daily driver but looking to add GC coilovers but unsure of springs rates. I’m in Toronto so roads are a bit shitty... looking for your thoughts. Thanks
I have a 1984 BMW 318i are there any coil over kits for my car that will lower it?
I did this once ,"another car " just want to know if every time when I lift the car will it have to adjust it to the top mount so it will ride nice again and not shave off the spring .?
Yes how do you do the rear? Nice video about to do mine. Luckily I stumbled upon this
rear is pretty straight forward, it's a separate spring and shock, so just replace as you wish
Got a question when u ordered the kit Wat all came wit it
nice video, i'm gonna start on my e30 soon :) i'll use your advise wisely :) extreme chill song btw, name? gtrz max
what type of front struts did u use? in your comments it says bilstein ix front shock inserts. ix bilsteins work with this?
can you have zero wheel gap if in the front even if you don't shorten the housings?
Is that a 4stud to 5stud conversion spacer on the disc? If so where did you get it from!?
What is the collar nut?
I just bought this kit and I can't seem to find it.
Hmmm.
did you make your own hub to go five stud?
found this on r3v. awesome vid! info on music?
How did that shock and strut setup work out? I am having a hell of a time figuring out what to get for my conversion kit. I have 550f and 700r spring rates. for front apparently the Koni 1198 sport for the VW corrado works well, but it might not be able to take my high spring rate. As for the rear I'm also not sure what could handle that high of a spring rate besides specially valved shocks from GC, but they don't like selling them individually.
Yes
a bro nice vid and how to they ride?
How stiff is your suspension the rates you picked seem pretty high
in your last picture of your car, were they adjusted all the way to the lowest setting?
what shocks are those? I have konis and they told me that they will bottom out and get destroyed if I shortened the housings... it looks like you are using konis as well but is it a different koni?
does the kit come with the springs or separate?
Were those bilstein sports ?
So the springs with gc are not tight off of the car ? What happened if you jacked the car up the spring would just jump around ?
nice track...
Hows the right quality?
What king of spacers are that, 4 to 5 lug nut? :)
Hey so is it absolutely necessary to shorten your strut housing when running the GC Adj Springs? I just ordered new kyb struts and I was about to buy the springs today but do I have to shorten the housing in order to use the spring?
From what car is the bottle refill?
Same concept on e30 verts?
does GC really work on stock struts? or its just bs
Does GC provide the adjuster perch to weld on?
The OEM strut bearing uses 3x washers. Two on the bottom (BMW parts 31336776760 & 31331110196) and one on the top (07119931021). The locking collar nut tool is available from Bilstein and costs aprox $5. Torque is a substantial 95ft/Lbs and I've seen several come loose because of improper tightening.
Nice video. Also whats the song's name, its catchy.
SEXY E 30 COUPE !!! NICE WORK
do ground controls drive smooth?
Does the smaller sleeve go on the front or back?
How long is the rear spring on the ground control kit? I have a 6'' spring with no adjuster now in the rear and I still have over 2" or wheel gap.
I am ordering a ground control set, can I just slap them on my stock struts?
If you want them to blow the following day, yeah sure. :D
depending on how low you want to go. If you are not looking to go much lower than stock, then you should be fine. Probably won't handle very well though. If you want to go low, you will blow the shocks out pretty quickly if you don't shorten the housings and run shorter inserts
great vid thnx
Did you revavle you bilsteins?
Do you have to do this if installing Bilstein Sport Shocks and H&R sports springs?
What Inserts are you using?
Would you build a set for a 95 Audi a6 quattro wagon, I can't find coilovers anywhere
Where can I get this kit?
Genious!!
hi man, what kind of wheels do you have? BBS Rc 15" ?
tire size please? thanks in advance
Amigo Que color pintaste suspension?.
How do you fix the spring on top ? It looks that it sits on air...
Absolutely not ideal. Some thin helper springs should be used to take up that gap so that the spring is never allowed to become detached from the hat.
enjoyed the video and I even don't own a BMW.
Is it necessary to remove it
shorten
What's this song called?
how to by suspenssion
How are the Billy's holding up to the spring rates?
On my set-up I ordered 600 front and 800 rear (wich was way to high!) and my bilstein sport (standard lenght) couldn't hold up with those rates... the car was bouncing around. If you want to use your bilstein sport you should order a rate around 400 front and 450 rear and use max half of the height adjusters. My 0.02$ :)
This morning I just ordered a new springs set from GC (525 and 750) with single way adjustable konis. The front cartbridge are shorter to keep the maximum travel. Cost me around 1000$ US shipped, wich cost me 1350$ CAN.
работа+музыка супер как называется?
Do you have any issues with the sleeves/springs spinning when you turn the wheel? I did the same set up and my sleeves twist when the steering wheel is moved left/right. I didn't use any O Rings before installing the sleeve but it never twisted or had play off of the car when I assembled it.
The Orings are there so the sleeves done spin when adjusting lol
проставки 4.100 на 5.120 такие есть где взять ?
please tell me which company you put the rack on BMW E30?
I made it myself, it's a custom piece.
Mikey Gaumann I realized that, I'm interested in the firm springs and struts and where to buy these items.
I am sorry for my english)) I'm from Russia
*People go low so they can get high! LOL*
I'm still way fuckin confused about the 45 mm struts vs the 51mm struts. I have a 85 318i, so what do I need to do to update my strut housing?
+carl shneebly a new strut housing. Everything newer than 88 should have the larger diameter strut.
kenny hultquist I wish they just made some for the 45 mm.
+carl shneebly sorry man :(. You can get used struts for pretty cheap, just gotta find a part out or hit up the pickn'pull.
Nice vid but the kit is stupid ... the spring has to be under at least a little bit of pressure, even when there is no load to the damper ... to prevent it from tilting/canting between the spring plates in case of air time or a holes in the street ...