Suspension upgrades for Track use: Control Arms, Toe Arms, Solid Mounts, ...

i think the arms are plenty strong, it seems the bushings are not equally matched. i have had my alignment checked 3 times over 4000 miles and the camber is dead on, yet the toe has been out of spec each time. my dealer is checking with the engineers. i have a sedan, not a coupe.

Am I the only one who thinks these items are entirely unnecessary for a new well maintained car? I run my car competitively in NASA and don't think the car has any deficiencies that would cured by these parts. The only part I think would actually help the car go faster would be solid subframe bushings if you go crazy with rear spring rates.
Once the stock bushings start to wear out, these items would be a good upgrade, but for a new platform like the e90, I'd argue that they would produce any tangible difference.

i agree. i think it should suffice. however, my toe will not stay in spec. hopefully puma case will resolve it.

RickyBobby wrote

Am I the only one who thinks these items are entirely unnecessary for a new well maintained car? I run my car competitively in NASA and don't think the car has any deficiencies that would cured by these parts. The only part I think would actually help the car go faster would be solid subframe bushings if you go crazy with rear spring rates.
Once the stock bushings start to wear out, these items would be a good upgrade, but for a new platform like the e90, I'd argue that they would produce any tangible difference.

I agree. Some think stiffer is always better (that's what she said) but definitely not the case as I've found out with the poly E46 RTABs. I do think that some well thought out upgrades will make a difference...like the solid rear subframe bushings.

The E9X seems to like to rotate more than the E46 in stock form...which is what most people try to achieve in the E46 through upgrades...less understeer.

I think this car is surprisingly tail happy for a BMW. Which is why I want to try the toe links.

+1
Judging by the little difference in "performance numbers" between the GTS and the competition package E92, it really does make you wonder.

+1

Anybody running any of these parts and willing to write some feedback?

lukester wrote  

Anybody running any of these parts and willing to write some feedback?

Had the monoball control arms and delrin subframe bushings put in the car this fall as well as RD sport sways F&R and love the upgrades. Will right a more thorough review, but with the control arms, steering feels heavier, like servo is set to sport when in normal, and car is definitely more solid feeling with the bushings and feel the car is a bit flatter with the sways. Looking forward to others impressions as well...

Forgot to add some feedback. I had the dinan toe links in and they are totally unnecessary. Re-installed the OEM arms and sold the dinans. I guess if you are constantly adjusting rear toe then they would be great but who does that?

The only major upgrade I'll do are the solid subframe bushings. Otherwise all seems fine.

bigjae1976 wrote

Forgot to add some feedback. I had the dinan toe links in and they are totally unnecessary. Re-installed the OEM arms and sold the dinans. I guess if you are constantly adjusting rear toe then they would be great but who does that?

The only major upgrade I'll do are the solid subframe bushings. Otherwise all seems fine.

Disappointed to hear that, but I'll see what I think this spring. I had the Dinan rear toe links and front monoball kit installed a couple of months ago while my middle exhaust and software were being done (Dinan was running a 15%-off promotion:D).

paradocs98 wrote

Disappointed to hear that, but I'll see what I think this spring. I had the Dinan rear toe links and front monoball kit installed a couple of months ago while my middle exhaust and software were being done (Dinan was running a 15%-off promotion:D).

I saw a video from a car that was behind me when I dropped a wheel. I could see the back end just really squat under acceleration and then I dropped a wheel off the pavement and the backend just bounced like a pogo stick. I'm even more convinced that the non EDC rear suspension is (even with dinan springs) is too soft. I guess that Dinan made the toe links to add some stability...which I think it might help...but the toe links aren't the problem. The problem is the weight and the soft rear suspension.

When I put the OEM links back in...I really couldn't tell a difference.

Question, is there any difference between the rear subframe (apart from solid bushings) and unibody of the GTS and the production M3? I'm hesitant of putting solid subframe bushings as logic would suggest additional strain on the rear unibody subframe mounting points with solid bushings.

mlhj83 wrote  

Question, is there any difference between the rear subframe (apart from solid bushings) and unibody of the GTS and the production M3? I'm hesitant of putting solid subframe bushings as logic would suggest additional strain on the rear unibody subframe mounting points with solid bushings.

I'm fairly certain that solid mounts would actually put less stress on the unibody than rubber. Think of it this way: if the mounts don't give, force is applied in a relatively equal manner across the subframe. But if the mounts DO give force can be isolated in one area of the subframe, generating more shear force, and tensile force, on the bolt ad the mounting position on the unibody.

I could be totally wrong. Just thought I'd implement what I've gathered from my first semester of engineering classes. Haha

Awesome thread

Might pull the plug on the rear bushings.

In for more!

Amazing thread! will never get old. Amazing how many e9x M3 getting tracked, so few with experience with this suspension products. Thanks guys

Powerflex now produce a 'black' version for a number of M3 bushes including the rear subframe.

I recently installed the TMS solid sub frame bushings and Delrin diff bushings and a KW sleeve kit ( insert comments) I know but I wanted to keep the EDC! Also installed Challenge rear toe arms and a Dinan front sway and camber plates and rear upper shock mount for added travel and lastly a H&R rear sway. I do not track a lot it is my daily driver and I live in WI so it sees lots of varying driving conditions. I am totally pleased with it. There is more NVH but it is not that bad! The rear end feels more planted and the feedback is way better! It was all installed at iND great customer service and exceptional workmanship!

RickyBobby wrote

Am I the only one who thinks these items are entirely unnecessary for a new well maintained car? I run my car competitively in NASA and don't think the car has any deficiencies that would cured by these parts. The only part I think would actually help the car go faster would be solid subframe bushings if you go crazy with rear spring rates.
Once the stock bushings start to wear out, these items would be a good upgrade, but for a new platform like the e90, I'd argue that they would produce any tangible difference.

Thanks for the input. You can't seriously recommend improving the driver instead of "improving" the car???!! Blasphemy!!

bigjae1976 wrote

Forgot to add some feedback. I had the dinan toe links in and they are totally unnecessary. Re-installed the OEM arms and sold the dinans. I guess if you are constantly adjusting rear toe then they would be great but who does that?

The only major upgrade I'll do are the solid subframe bushings. Otherwise all seems fine.

Good info. I was thinking of getting some toe links.

Ant Man wrote

Powerflex now produce a 'black' version for a number of M3 bushes including the rear subframe.

Are the Black one's stiffer??

.

bryan292009 wrote

I recently installed the TMS solid sub frame bushings and Delrin diff bushings and a KW sleeve kit ( insert comments) I know but I wanted to keep the EDC! Also installed Challenge rear toe arms and a Dinan front sway and camber plates and rear upper shock mount for added travel and lastly a H&R rear sway. I do not track a lot it is my daily driver and I live in WI so it sees lots of varying driving conditions. I am totally pleased with it. There is more NVH but it is not that bad! The rear end feels more planted and the feedback is way better! It was all installed at iND great customer service and exceptional workmanship!

How many miles do you have on the car? I have same mods (for now) minus the Challenge arm and have RD Sport Sways, and KW Springs on for ~15k miles already (car now has 73k miles) and I feel the rear end now does not stay connected when turning fast and the road is slightly uneven. I have some oversteer now, I think the shocks might be on their last legs.

italyix wrote  

bryan292009 wrote

I recently installed the TMS solid sub frame bushings and Delrin diff bushings and a KW sleeve kit ( insert comments) I know but I wanted to keep the EDC! Also installed Challenge rear toe arms and a Dinan front sway and camber plates and rear upper shock mount for added travel and lastly a H&R rear sway. I do not track a lot it is my daily driver and I live in WI so it sees lots of varying driving conditions. I am totally pleased with it. There is more NVH but it is not that bad! The rear end feels more planted and the feedback is way better! It was all installed at iND great customer service and exceptional workmanship!

How many miles do you have on the car? I have same mods (for now) minus the Challenge arm and have RD Sport Sways, and KW Springs on for ~15k miles already (car now has 73k miles) and I feel the rear end now does not stay connected when turning fast and the road is slightly uneven. I have some oversteer now, I think the shocks might be on their last legs.

I have 45,000 on it now!

Yea, have read that the EDC shocks start to wear out around 75,000!