E34 rear suspension on E28? Rally-x tough suspension?

[95maxrider]

Hi guys,

I've had some trouble with my Bilsteins holding up to the abuse of rally-x, and need something stronger for next season. During one race, the circlip popped off the rear PS strut, leaving the car sitting on the ground. No, I don't do the hella-flush thing.



So after a month of waiting for Bilstein to ship us parts, we got everything reassembled and were able to finish off the season (I came in first place, woo hoo!!) However, that same strut now looks like this:



I'm pretty sure it's not supposed to sit all crooked like that.

In a perfect world where I have tons of money, I would just go get the $1600 GC coilover setup and rock and roll, but that's a bit out of the budget for right now, and I'm interested in other solutions. My main priority is getting rear struts that have a conventional spring perch, and aren't held in place with a wimpy little circlip. I could throw on some stock struts, but I don't think they will be firm enough for what I'm doing. In doing a bunch of searching, I thought I read about some Bilsteins that have a normal spring perch, but haven't found any like that for sale. Is it possible I was getting them confused with some old Koni product?

Someone mentioned I could use E34 rear suspension to raise the car up a bit, which I'm okay with, especially if it would give me more strut options. I did a search but didn't come up with anything. Can anyone shed light on what it would take to put in E34 rear shocks/springs?

Any help would be greatly appreciated, thanks!

[kronus]

could you spot weld the circlips in place?

[95maxrider]

could you spot weld the circlips in place?

It certainly could be done, and it was the first thing that came to mind, but it would mean we could no longer disassemble anything if the shock needs replacing, and the heat from the welding could possibly overheat/ruin the shock fluid.

[trevmmeister]

I just have to say, rallying an e28, that's just awesome. Hat is off to you, sir. Not sure if that is a common thing or not, but I find it very very cool. What kind of engine setup?

Also, I have something that may be of use. A link I came across which is exploding with helpful points pertaining to our cars.

http://www.m535i.org/officers/ra/articles.html#brakes

Rear E34 Shocks

The E34 rear shocks are a bolt-on modification for the E28. This is a good option to obtain the higher levels of damping required for stiffer suspension set-ups. However, the major ill-effect of this is that it raises the ride height of the E28 by about 1". This is true for Bilsteins and Konis. Both sets of rear E34 shocks (Bilstein Sports, PN B46-1486, and Koni Sport Yellows, PN 8240-1076Sport) will do this, and both sets do not have adjustable spring perches for the ride height. The Bilstein's spring perches are not welded, which could allow for custom spring perches to be manufactured and bring down the ride height. Koni's spring perches are welded in. Thus, you will need to rework the shock body in some manner that could void their warranty in order to fit them to the E28 and allow for correct ride height. Either way, there will need to be some customization or fabrication to allow them to fit correctly.

So I think if you were to pick up a set of e34 touring/hd billies or the koni equivalent, you'd get the desired results.

[95maxrider]

I just have to say, rallying an e28, that's just awesome. Hat is off to you, sir. Not sure if that is a common thing or not, but I find it very very cool. What kind of engine setup?

Also, I have something that may be of use. A link I came across which is exploding with helpful points pertaining to our cars.

http://www.m535i.org/officers/ra/articles.html#brakes

Rear E34 Shocks

The E34 rear shocks are a bolt-on modification for the E28. This is a good option to obtain the higher levels of damping required for stiffer suspension set-ups. However, the major ill-effect of this is that it raises the ride height of the E28 by about 1". This is true for Bilsteins and Konis. Both sets of rear E34 shocks (Bilstein Sports, PN B46-1486, and Koni Sport Yellows, PN 8240-1076Sport) will do this, and both sets do not have adjustable spring perches for the ride height. The Bilstein's spring perches are not welded, which could allow for custom spring perches to be manufactured and bring down the ride height. Koni's spring perches are welded in. Thus, you will need to rework the shock body in some manner that could void their warranty in order to fit them to the E28 and allow for correct ride height. Either way, there will need to be some customization or fabrication to allow them to fit correctly.

So I think if you were to pick up a set of e34 touring/hd billies or the koni equivalent, you'd get the desired results.

Hey, thanks! Yes, it is awesome! It is most certainly NOT common, and were I a smarter man, I would have just done an E30 like everyone else. There have been some difficult times where I wanted to get rid of the car, but after much tweaking, I'm quite happy with where the car is, and now I'm beating all the E30s (hell, all the other 2wd cars), so it worked out quite well. Check out my build thread for pics and videos! The car started with the 2.7 SETA motor, and we did the 885 2.5i head swap. It also has E36 17lb injectors, an Ebay chip, and a ghetto 3" exhaust that came with the car. It's not as fast as I would like, but it gets the job done.

Thank you for that link! The search for this site is really annoying.

Unfortunately, all the rear shocks I'm finding for the E34 are just like those for the E28- the only ones with a real spring perch are stock shocks.

Boge/stock
http://www.pelicanparts.com/catalog/Sup ... .htm#item5

Bilstein
http://www.pelicanparts.com/catalog/Sup ... HK_pg1.htm#

Koni
http://konimarket.com/collections/bmw/p ... -246646977

I don't even see a ring for a circlip on the Konis, does that mean they are inserts (into stock struts) for the rears?

[trevmmeister]

Yeah those all look like inserts. Well, the billies on pelican look like they have a ring a few inches from the top of the cylinder


(Billie Tourings)

While I am not 100% "with it" on how this kind of stuff sets up, what about these?


(Sachs)

[SPF2006]

I just have to say, rallying an e28, that's just awesome. Hat is off to you, sir. Not sure if that is a common thing or not, but I find it very very cool.

Agree - good stuff. Very much enjoying following this build.

[Jelmer538i]

I think E34 Koni's have a welded perch:

[95maxrider]

I think E34 Koni's have a welded perch:

Is that your own set or a pic you found? Mind if I ask where you got them from?

[athayer187]

Related to your rear spring perch issue - do your springs maintain tension when the wheel is off the ground, or do they rattle around? Reason I ask is if you're unweighting the spring, that's a bad thing for perch longevity.

[95maxrider]

Related to your rear spring perch issue - do your springs maintain tension when the wheel is off the ground, or do they rattle around? Reason I ask is if you're unweighting the spring, that's a bad thing for perch longevity.

Hmm, good question, and one I don't have a ready answer for. But I'm pretty sure they're tight when the car is up.

[Mike W.]

Related to your rear spring perch issue - do your springs maintain tension when the wheel is off the ground, or do they rattle around? Reason I ask is if you're unweighting the spring, that's a bad thing for perch longevity.

Either that or the coils are binding and the spring is no longer like a spring, but a solid.

[95maxrider]

Related to your rear spring perch issue - do your springs maintain tension when the wheel is off the ground, or do they rattle around? Reason I ask is if you're unweighting the spring, that's a bad thing for perch longevity.

Either that or the coils are binding and the spring is no longer like a spring, but a solid.

I don't follow, could you explain?

[95maxrider]

The Ireland Engineering coilover kit appears to be reasonably priced, and will work with my current Bilsteins. The kit is only for the rears for some reason, but that's all that needs fixing for the time being. Can anyone comment on its durability/quality?


http://www.iemotorsport.com/bmw/E28-E24 ... 29coR.html

And just for reference, here's the GC kit ($45)
http://www.ground-control-store.com/pro ... I=674/CA=2

And the full GC kit ($1600)
http://www.ground-control-store.com/pro ... 744/CA=282

Can anyone tell me what brand struts come with the $1600 kit?

[demetk]

Buy the coilover stuff separate from other sources and save money. IIRC, the rear cost me $160 for the kit, not including shocks.

[95maxrider]

Buy the coilover stuff separate from other sources and save money. IIRC, the rear cost me $160 for the kit, not including shocks.

Hmm, got any links and/or pics of what you did?

My co-owner doesn't really want to spend any more money on this car, and wanted me to look into the possibility of just welding on our existing spring perch to the Bilsteins. Can anyone comment on if that would ruin the fluid inside, or if there are other possible problems?

EDIT- After talking with a buddy who knows about this stuff, he says it's pretty common to tack weld the circlip/snap ring to the strut, and not the spring perch. I'm still a little concerned about the high heat, but it sure is a cheaper solution than anything else. What do you guys think?

[demetk]

Buy the coilover stuff separate from other sources and save money. IIRC, the rear cost me $160 for the kit, not including shocks.

Hmm, got any links and/or pics of what you did?

Sure.

2 1/2" kits I bought here: http://www.a1racing.com/coil_over_kits_suspension.aspx

Springs from here: http://www.jegs.com/p/QA1/QA1-Powdercoa ... 9/10002/-1 or http://www.summitracing.com/search/part ... =Ascending

No matter which way you go you will need to calculate what spring rates you will need for your application. That decision is a bit harder to figure out.

[95maxrider]

Buy the coilover stuff separate from other sources and save money. IIRC, the rear cost me $160 for the kit, not including shocks.

Hmm, got any links and/or pics of what you did?

Sure.

2 1/2" kits I bought here: http://www.a1racing.com/coil_over_kits_suspension.aspx

Springs from here: http://www.jegs.com/p/QA1/QA1-Powdercoa ... 9/10002/-1 or http://www.summitracing.com/search/part ... =Ascending

No matter which way you go you will need to calculate what spring rates you will need for your application. That decision is a bit harder to figure out.

You wouldn't happen to know the motion ratio of the rear on the E28, would you?

[dsmith]

You really don't want to weld straight to a gas charged struts. As you have found, stock shock setups don't hold up that well. You can make whatever you want and have more adjustability for less than off the shelf coilovers.

Here's what I did, since there weren't any options for the rally car I built. I used a Koni shock, made a sleeve to go over it with set screws and welded on pieces for the coilover perches to sit on. I then made a mount for the bottom. These were ebay cheapo $20 ebay coilovers and Southwest springs ($40 each). Modified 240Z adjustable camber plates on the front and appropriate hardware.

This setup made it through 6 Rally America events before needing rebuilt and cost about $250 per corner.

[95maxrider]

You really don't want to weld straight to a gas charged struts. As you have found, stock shock setups don't hold up that well. You can make whatever you want and have more adjustability for less than off the shelf coilovers.

Here's what I did, since there weren't any options for the rally car I built. I used a Koni shock, made a sleeve to go over it with set screws and welded on pieces for the coilover perches to sit on. I then made a mount for the bottom. These were ebay cheapo $20 ebay coilovers and Southwest springs ($40 each). Modified 240Z adjustable camber plates on the front and appropriate hardware.

This setup made it through 6 Rally America events before needing rebuilt and cost about $250 per corner.

Woah! Please tell me you have a build thread or something, I need to see this. Do you know exactly which Konis you went with? Mind sharing your suspension specs with me? I'm curious to know how high the springs rates should be on these cars. How high up are you?

[dsmith]

Sorry, no build thread. Just part of building 2 rally cars back in 2008. Mine was a 2000 lb car. They were Mitsubishi Mirage single adjustable strut inserts for the front and shocks for the rear. I think you want to go double adjustable for a comparable weight car about 3000 lbs.

I tried 350 front and 250 rear spring rates. That was too much and ultimately settled for 100 less on both. I would start with 450/350 on an e28 and adjust from there.

Building them took some research to match up OD/ID info to match it all up.
-shaft OD for top mounts and hardware-used Koni info sheets
-strut tube OD for sleeve tube ID- Koni info sheets
-sleeve tube OD for coilover sleeve ID
-cut off brake hose holders from stock struts to weld on

For the e28 rear, I might go with a strut insert, cut a stock bottom attachment point off of a stock shock and weld that to the bottom of the tube you make.

Anyway, just another idea that could work well. Very similar to what demetk posted with some fab work making strut tubes. Of course it's easier than what I did since you can use the stock front tubes.

[tsototh]

I would have to think that just doing some spot welds on your current shocks isn't going to damage the fluid. If you do one spot at a time, let it cool, do another, I can't imagine it causing any issues to the shock. Just don't get too much penetration on the weld and you should be ok in my mind...

[Mike W.]

Related to your rear spring perch issue - do your springs maintain tension when the wheel is off the ground, or do they rattle around? Reason I ask is if you're unweighting the spring, that's a bad thing for perch longevity.

Either that or the coils are binding and the spring is no longer like a spring, but a solid.

I don't follow, could you explain?

The pic isn't the best but if the coils are binding like the spring on the right it would do damage quickly.

I would have to think that just doing some spot welds on your current shocks isn't going to damage the fluid. If you do one spot at a time, let it cool, do another, I can't imagine it causing any issues to the shock. Just don't get too much penetration on the weld and you should be ok in my mind...

I'm pretty bold on welding, I've welded a few gas tanks in my time, empty of course but not steamcleaned or anything, but I wouldn't even do a gas shock, I wouldn't even think about it.

[95maxrider]

I'm pretty bold on welding, I've welded a few gas tanks in my time, empty of course but not steamcleaned or anything, but I wouldn't even do a gas shock, I wouldn't even think about it.

Yeah, the more people I talk to, the more I'm thinking it's "possible" at best, and potentially hazardous at worst. I'm on the lookout for some E34 rear Konis that come with the welded on spring perch, as opposed to the inserts. Can anyone enlighten my as to why there are apparently different versions of the Konis available?

[95maxrider]

Sorry, no build thread. Just part of building 2 rally cars back in 2008. Mine was a 2000 lb car. They were Mitsubishi Mirage single adjustable strut inserts for the front and shocks for the rear. I think you want to go double adjustable for a comparable weight car about 3000 lbs.

I tried 350 front and 250 rear spring rates. That was too much and ultimately settled for 100 less on both. I would start with 450/350 on an e28 and adjust from there.

Building them took some research to match up OD/ID info to match it all up.
-shaft OD for top mounts and hardware-used Koni info sheets
-strut tube OD for sleeve tube ID- Koni info sheets
-sleeve tube OD for coilover sleeve ID
-cut off brake hose holders from stock struts to weld on

For the e28 rear, I might go with a strut insert, cut a stock bottom attachment point off of a stock shock and weld that to the bottom of the tube you make.

Anyway, just another idea that could work well. Very similar to what demetk posted with some fab work making strut tubes. Of course it's easier than what I did since you can use the stock front tubes.

Wow, I have so many questions for you, I hope you don't mind!

So you didn't actually say if the car you built was an E28....was it? If so, how in the world did you get it down to 2000 pounds? What are your thoughts about running stiffer rear springs to eliminate the need for a RSB?