[Estoril6rod]

Has anyone here gone all-out with solid sub frame bushings and solid rear diff mounts? Turner has some really good kits on their website for our cars and I would love to get some feedback on them!

Current mods relevant to suspension behavior on my car include increased TQ output via tune, Dinan springs and wider wheels and tires (18x8.5/9.5 225/40 255/35). Car is x-drive with EDC, stock sway bars. Thanks!!

[NISFAN]

Originally Posted by Estoril6rod

Has anyone here gone all-out with solid sub frame bushings and solid rear diff mounts? Turner has some really good kits on their website for our cars and I would love to get some feedback on them!

Current mods relevant to suspension behavior on my car include increased TQ output via tune, Dinan springs and wider wheels and tires (18x8.5/9.5 225/40 255/35). Car is x-drive with EDC, stock sway bars. Thanks!!

My 2 cents, if you are still running stock EDC dampers, then no point in going solid mount. Solid subframe will add a lot of NVH, possibly even ruining DD duties. So for me at least, would be the last mod after all the other parts are upgraded to a high level.

Not even m235i Racing comes with solid subframe mounts, but it does use stiffer ones.

[Lancelot]

Originally Posted by NISFAN

My 2 cents, if you are still running stock EDC dampers, then no point in going solid mount. Solid subframe will add a lot of NVH, possibly even ruining DD duties. So for me at least, would be the last mod after all the other parts are upgraded to a high level.

Not even m235i Racing comes with solid subframe mounts, but it does use stiffer ones.

I have put powerflex black subframe bushings inserts on my f30 and the increase in NVH is barely noticeable; plus they can be installed and removed if you don't like the result.

Hasn't made a crazy difference in handling but it definitely feels tighter, i haven't had the opportunity for real spirited driving since yet though

[Estoril6rod]

Originally Posted by Lancelot

I have put powerflex black subframe bushings inserts on my f30 and the increase in NVH is barely noticeable; plus they can be installed and removed if you don't like the result.

Hasn't made a crazy difference in handling but it definitely feels tighter, i haven't had the opportunity for real spirited driving since yet though

Thank you both for the input! It seems that the middle ground between stock and full metal is a polyurethane bushing. I haven't found a full poly replacement only the inserts Lancelot described so I'll be giving those a try and see how it goes.

I'm guessing once the bushings are dealt with the weakest link on the rear suspension would now be the shocks right?

[x233]

I am positive someone on this forum had "the real thing" (polyurethane/aluminum combo) installed instead of the OEM subframe bushings and diff mounts. It was discussed a while ago. Use search to find that thread.

I wanted to go that route myself, in fact have a box of solid/polyurethane stuff for the entire suspension/ subframe and diff from SuperPro still sitting in my garage, but decided to pass on it for now after consulting some local race guys. I was told that I could be OK with subframe solid/polyurethane replacements and perhaps even diff solid/polyurethane mounts, and NVH could be OK, but shouldn't bother with everything else (control arms, etc) since I'd end up skipping all over the road on anything less than a perfect road.

[Dylan86]

These cars are a bit soft, in the bushing and suspension department. Otherwise this platform is fantastic for track use based on the m235ir's success and continued use in professional racing. Here's what I have set aside for my winter chassis build. I figured if I'm gonna do it, better to to do it all, one shot..This setup (less BBK) is pretty close to "race car" status and am hoping it will behave somewhat subtle on the streets, when I get the damping set up.. One can dream, but my intention is to run this car pretty hard at the track, for many years to come, and drive it to and from along with weekend mountain tours..

This is my remedy for the soft "feel", should do the trick?:

PowerFlex Rear outer LCA Bushings
Superpro Rear Subframe Bushings
Turner Derlin Solid Diff mounts
Hotchkis F&R Sways w/ up-rated Hotchkis Sway bar end Links
Meagan Racing 4-Link Setup (fully adjustable): Front Camber Arms, Rear Camber Arms, Rear Toe Control Arms, Rear Trailing Arms. This allows for the desired rear geometry once lowered, etc..
All to accompany a set of KW CS's (3 way adj.)

[Estoril6rod]

Originally Posted by Dylan86

These cars are a bit soft, in the bushing and suspension department. Otherwise this platform is fantastic for track use based on the m235ir's success and continued use in professional racing. Here's what I have set aside for my winter chassis build. I figured if I'm gonna do it, better to to do it all, one shot..This setup (less BBK) is pretty close to "race car" status and am hoping it will behave somewhat subtle on the streets, when I get the damping set up.. One can dream, but my intention is to run this car pretty hard at the track, for many years to come, and drive it to and from along with weekend mountain tours..

This is my remedy for the soft "feel", should do the trick?:

PowerFlex Rear outer LCA Bushings
Superpro Rear Subframe Bushings
Turner Derlin Solid Diff mounts
Hotchkis F&R Sways w/ up-rated Hotchkis Sway bar end Links
Meagan Racing 4-Link Setup (fully adjustable): Front Camber Arms, Rear Camber Arms, Rear Toe Control Arms, Rear Trailing Arms. This allows for the desired rear geometry once lowered, etc..
All to accompany a set of KW CS's (3 way adj.)

I just found out about the Superpro full replacement poly bushings.. might go that route instead of just adding the Powerflex inserts to stock bushings.

Is your car x-drive as well Dylan86? Ive also been looking to change sways on my car but most info Ive come across comes from owners with RWD cars.. The bars on an x-drive are around 23mm front and 12mm rear, would changing the rears only say to 19mm or 20mm be suitable with the upgraded poly bushings?

[NISFAN]

Originally Posted by Estoril6rod

Thank you both for the input! It seems that the middle ground between stock and full metal is a polyurethane bushing. I haven't found a full poly replacement only the inserts Lancelot described so I'll be giving those a try and see how it goes.

I'm guessing once the bushings are dealt with the weakest link on the rear suspension would now be the shocks right?

No the shocks (in particular the rears) were the weakest link from day 1......by a factor of 50.

Any damper set up that relies heavily on bump stops is pretty poor. So priory is to get rid of the stock dampers and springs before anything else.

[Dylan86]

Originally Posted by Estoril6rod

I just found out about the Superpro full replacement poly bushings.. might go that route instead of just adding the Powerflex inserts to stock bushings.

Is your car x-drive as well Dylan86? Ive also been looking to change sways on my car but most info Ive come across comes from owners with RWD cars.. The bars on an x-drive are around 23mm front and 12mm rear, would changing the rears only say to 19mm or 20mm be suitable with the upgraded poly bushings?

Yea, I'm RWD as well so won't be much help, also haven't got the feedback to suggest it was worth it, etc. Thing is, I'll be swapping everything, one shot, so I won't be able to comment on exact "sway bar" differences as my coilovers/spring rate/ bushings etc, will all play a factor to the way the car will feel post install..

What I do know, is that the chassis is stiff, the suspension and bushings are not. So any opportunity to change that, I will do it this winter. I feel this will behave like a completely different car, next year. Also need an excuse to mount up the 18x9 ARC-08 track setup anyhow, so why not, right?

[GoldenWest]

Originally Posted by NISFAN

My 2 cents, if you are still running stock EDC dampers, then no point in going solid mount. Solid subframe will add a lot of NVH, possibly even ruining DD duties. So for me at least, would be the last mod after all the other parts are upgraded to a high level.

Not even m235i Racing comes with solid subframe mounts, but it does use stiffer ones.

I (had) installed the Turner solid aluminum SFBs (no longer offered), and at the same time the Dinan 19mm rear anti roll bar set to the medium position.. Massive improvement in turn-in, sharper cornering and improved directional stability; especially when accelerating. There is no added NVH whatsoever; that aspect feels exactly the same as stock.
Since then I had F & R Bilstein B6 damptronic (for edc cars) struts and shocks installed, which further improved ride stability, handling and improved (sharper) steering directness and feel.