e82 subframe bushings

[elias 263]

Hello,

Ive put some coilovers in my e82 135i, and now it seems my spring rate is stiffer than the subframe bushings which makes for an interesting driving experience to say the least. Have seen 2 possible solutions to this, bussing inserts or replacing bushings with solid/poly/m3. Anybody done either of these?

Are the inserts any good or best to just go straight to new bushings?

Labour seems very very steep on the install been quoted about $1000 for labour. Was thinking of DIY, have done a fair bit of work on my car, including the coilover install obviously but not sure about dropping the whole subframe... if anyone here's done it would be interesting to hear how it went, getting the old bushes out and new ones in, photo of car for reference.

any advice, experiences etc is much appreciated!

 

Edited March 14, 2022 by elias
spelling

[M3AN 4016]

I put insets in my E87 with coilovers, to be honest I didn't notice much difference but then my suspension is pretty well sorted and designed for the vehicle. Many of the UK owners swear by them though and they're a lot less expensive than a full bushing kit and trivial to install whereas new bushings is a subframe out job so much more involved.

For the sake of ~$120 I'd go for the inserts, if they don't work you'll know soon enough and you could sell them as nearly new when you installed new bushings.

But I'm not sure you should be using bushings to compensate for unsuitable springs, can you exchange them?

[elias 263]

thanks for the reply, much appreciated, yes can change them, they're not true rear coil-overs spring sits next to the strut, was thinking of putting in some springs from bc coilovers, they recommend 12k for the rear, although I think mine right now might be 12k, not 100% sure will have to check. Just when I hit a bump sometimes it feels like the rear of the car sways Side to side a bit which is a weird feeling. Out of curiosity what suspension are you running? How was the install on the inserts, fairly straight forward?

[M3AN 4016]

Interesting, the swaying could of course be shot bushes and if that's the case inserts won't do much, I'd give them a visual inspection first and shove a screwdriver or other lever in them and give it a wiggle around.

My suspension is a JDM custom setup by Orange Wolf with Eibach springs (F: 8kg, R: 10kg), it's high quality and the ride is sublime.

Inserts are an easy DIY. Put a jack under the diff, loosen off the bolts but keep them all engaged and then, one-by-one, remove a bolt, lower the jack enough, install inserts, jack back up, insert bolt (keep it loose), move to next bolt, repeat x4. You may need a pry bar to lever the subframe down a little at each corner, it stiffens up as you go around so by the time you get the last one it could be tight. Do the front two, then the rear two IIRC for easiest access. Took me well under an hour (~40 mins) including getting the car up and down. I have Nolathane inserts but I think Super Pro are a smidgen cheaper and just as good.

Edited March 14, 2022 by M3AN

[Eagle 1679]

Dropping the subframe isn't that much work, same basic process on most BMW's. If you installing poly bushings you likely could heat up and knock or use a puller to remove the old ones out and press the new ones in by hand. Bushing can be done with or without dropping the frame.

[elias 263]

47 minutes ago, M3AN said:

Interesting, the swaying could of course be shot bushes and if that's the case inserts won't do much, I'd give them a visual inspection first and shove a screwdriver or other lever in them and give it a wiggle around.

My suspension is a JDM custom setup by Orange Wolf with Eibach springs (F: 8kg, R: 10kg), it's high quality and the ride is sublime.

Inserts are an easy DIY. Put a jack under the diff, loosen off the bolts but keep them all engaged and then, one-by-one, remove a bolt, lower the jack enough, install inserts, jack back up, insert bolt (keep it loose), move to next bolt, repeat x4. You may need a pry bar to lever the subframe down a little at each corner, it stiffens up as you go around so by the time you get the last one it could be tight. Do the front two, then the rear two IIRC for easiest access. Took me well under an hour (~40 mins) including getting the car up and down. I have Nolathane inserts but I think Super Pro are a smidgen cheaper and just as good.

right ok yeah maybe the bushings are just shot, I will check, car has done 130,000km. interesting that your setup seems to be much softer front springs than mine, Ive got a set of Aragosta coilovers, look quite similar to yours actually but a bit different, also JDM, with Rana springs(come with aragosta's) which I bought second hand after a guy removed them from a jap import car so it would pass compliance, if im not stupid, my front springs say 14k on them which seems insane compared to yours... and strange have front stiffer than rear, from what I can tell its 14k front 12k rear, might have to change front springs, I wonder how that would affect the damping though.

Might have to give those inserts a go then, fcp sells the whiteline ones for about 50usd$, about 120nzd by the time its here, might be worth a go.

Definitely strange about the spring rates, the fronts do feel very very stiff

[Jacko 2158]

My whole 130 is polybushed (superpro is what id recommend, they actually fit...)... I did it in my carport, build thread with pics on here. I dont mind the NVH at all. Its not a small job to do and seems less bandaidy than inserts. It sounds like your bushes are totally f**ked in saying that, so inserts probably not a good idea. 

 

 

Edited March 14, 2022 by Jacko

[elias 263]

that looks awesome man, would love to do all of that to my car, the difference in handling must be incredible, but bank account says otherwise... yeah im thinking my bushings in the subframe might be pretty shot so might be best off replacing them, do it once and do it right I guess. I see you are in auckland too, would you be able to install them, happy to pay you for your time obviously, and totally understand if you don't want to. That way I could watch and learn something rather than just giving my money to a shop and not learning anything.

Will have a look into the superpro bushings, saw you did an LSD too, that would be awesome, must grip a lot better coming out of corners! 

Will have another look into my spring rates too, to see if there's anything funny going on there.

[M3AN 4016]

Yep, @Jacko's is a pretty smart example, having driven it myself it's real tight and doesn't feel or sound untoward in any way, easily a comfortable daily. I can also vouch for Super Pro, that's what I've used in the M3.

With even my horsepower (~280) an LSD makes a huge difference, with your (potential) horsepower I'd say an LSD is essential, it will turn your car into another experience altogether. I have to be pretty silly with my right foot to induce any oversteer with a proper diff, whereas even gradual right turns from a red light in the modestly damp leans on the electronics without a LSD, and that's just robbing you of power. Expensive sure, but worth every penny.

As for the spring rates, give the guys at Raceline (Autolign) at call for some advice, they're some of the best in the business and know their stuff. 14k front seems like a lot to me for a RWD 1er with near 50:50 weight distribution, I don't have any unreasonable (nose) dive, even under extreme braking, with 8k but I'm no expert.

[elias 263]

5 minutes ago, M3AN said:

Yep, @Jacko's is a pretty smart example, having driven it myself it's real tight and doesn't feel or sound untoward in any way, easily a comfortable daily. I can also vouch for Super Pro, that's what I've used in the M3.

With even my horsepower (~280) an LSD makes a huge difference, with your (potential) horsepower I'd say an LSD is essential, it will turn your car into another experience altogether. I have to be pretty silly with my right foot to induce any oversteer with a proper diff, whereas even gradual right turns from a red light in the modestly damp leans on the electronics without a LSD, and that's just robbing you of power. Expensive sure, but worth every penny.

As for the spring rates, give the guys at Raceline (Autolign) at call for some advice, they're some of the best in the business and know their stuff. 14k front seems like a lot to me for a RWD 1er with near 50:50 weight distribution, I don't have any unreasonable (nose) dive, even under extreme braking, with 8k but I'm no expert.

yeah I haven't had my car on a dyno yet but at a guess id say its over 400 probably 430ish at the crank, MHD stage 2+, FBO+inlets, 98ron map definitely struggles to put the power down, which was the reason I got coilovers in the first place, was for the camber plates to fit wider front tires so I could run a wider rear tire and have a square setup. Will look into LSD in the near future but as a broke uni student I have to focus on one thing at a time...

I'll double check my spring rates and then ill call Racelign and see what they reckon, thanks for the recommendation! Yeah I was thinking 8k  12k might be a more balanced set up, maybe 10k fronts to account for the heavier n54 engine?