Solid subframe bushes has always been something I want to avoid due to the increase in ride harshness and noise. Recently I've become interested in subframe risers, modified solid subframe bushes which push the subframe up closer to the body and slightly correct bad roll centers on lowered cars. Unfortunately, I'm yet to come across rubber or urethane ones. I imagine their impact on ride quality/noise would be identical to solid subframe bushes. Who has accounts of the latter installed in their Z32? -A
I have solid subframe bushes with energy rubber diff bushes and it doesn't give you the harsh /noise you think . .but adding the solid diff as well will submit more noise vibration .(vibration /noise comes from drivechain) its only when I added the BDE engine mounts and nismo gearbox mount that I noticed a difference in vibration at 2200rpm ,then its smooth as .
That's interesting -the Nismo mount is fairly soft (as aftermarket mounts go), much more forgiving than the urethane one that UAS make.
Most is coming from the BDE but the nismo is firmer than stock ,also raises the box about 10-15mm (maybe stock was sagged)
I noticed no difference when going from oem to nismo box mount. I also noticed no difference going from stock to urethane subframe bushes. I'd be more worried about cracking the subframe with solids in (check previous threads about it).
I have solid ams subframe mounts in mine, its only noisy after I installed the steel one piece tailshaft but only after initial acceleration
Collars go either side of the bush -usually used to "pre load" saggy bushes but can also be used to adjust the angle of the diff for better traction
Thanks Rob ive got some spl collars ill be installing...now to just find some replacement bushes or go solid but dont like the risk of the subframe cracking as mentioned by Ryan & mungyz Abraham
Oh ok, well is there any other option other than solid bushes? If there isnt, then i might just use the collars. Abraham
**** the solid bushes. Rubber are your best bet if you can get your hands on some suitable Nismo items (I don't know if they make them or not, you'd need to do some homework on that) otherwise just fit urethane bushes.
Nismo don't make rubber subframe bushes for a 300zx. I've got some nismo subframe bushes out of another car on the way that I'm going to test fit though.
Ryan from what i searched, Nismo used to make them but have been discontinued & i cant seem to find any for sale anywhere Would the 240sx or skyline bushes fit? As most of the suspension is the same Abraham
I used the collars & they made quite a difference, no more axle tramp & reduced squat, piece of piss to install too
Thank you for the feedback people. I did some research into this yesterday and unfortunately a non solid subframe riser isn't really feasible. OEM design subframe bushes leave about 10mm tops between the subframe and the unibody. At best, replacement urethane bushes could be trimmed 5mm to allow for the subframe to be positioned higher while still maintaining enough of a buffer to have some room to flex/vibrate. Obviously 5mm is nothing to write home about... something to do when replacing the bushes, but not something to go to the trouble for for a "mod". These ads I've been reading about solid subframe risers allowing the subframe to be positioned 25mm higher are complete baloney. At best, they'd gain 5mm more than trimmed rubber/urethane ones. Hardly worth it don't you think? Collars, at least placed between the frame and body would only space the subframe further away from the unibody. they make roll center and suspension travel even worse! although admittedly, only slightly. If collars are only used to squish back together sloppy bushes as is my understanding, owners would be much better off not being slack and replacing the bushes properly. fitting up trimmed replacement bushes while you're there, as opposed to inserting collars, would result in the subframe being 10mm higher compared to collar use (based on a 5mm thick collar).
