Rear of car "rubbery" under hard acceleration?

[mbintx]

So the good news is = it's not just my car that has this issue.
So the bad news is = it's not just my car that has this issue.

[Dackelone]

Originally Posted by pixelblue

The culprit is the rear sub frame bushings. They are soft. The cure is upgrading them to M3 bushings. It'll firm up all the bounce and squat

I have to agree with Pixelblue. It is totally the soft rubber rear axle bushings.

Next week I am having M3/1M rear bushings installed. They are quite cheap over here in DE. 39 euros list each (you need four). I was quoted 440 euros before any of my "good guy" discounts my dealer(usually) gives me. I am really looking forward to this mod.


I am pretty sure once they are in... it won't be long before I change the front suspension to M3/1M bits and probably the suspension to something more sporting.

[HondaGoneRogue]

I don't have the squat due to the koni yellows set on medium. The rear feels solid except for lane changes, cornering etc. Basically anytime the weight shifts. That I know for sure is the bushings. But I think from what I'm gathering here, that if we were to all put dowm 400ish hp, and stomp on it, our backends would def wonder without the LSD. It may not feel as "rubbery" but it will wag I bet.

I drove my friends car before and after LSD and while he did have the bushings, the LSD just shot the car straight forward, even while coming out of a turn with the weight loaded to one side. I was in love at that point.

[Dackelone]

Originally Posted by HondaGoneRogue

...I drove my friends car before and after LSD and while he did have the bushings, the LSD just shot the car straight forward, even while coming out of a turn with the weight loaded to one side. I was in love at that point.

...and SOLD on a LSD(I bet)!

[HondaGoneRogue]

Yup, but for some reason my Craigslist ad for my kidney didn't get any responses.

[Focusedintntions]

Originally Posted by HondaGoneRogue

Yup, but for some reason my Craigslist ad for my kidney didn't get any responses.

That's bc you need to use ebay...duh

[pixelblue]

Originally Posted by HondaGoneRogue

Yup, but for some reason my Craigslist ad for my kidney didn't get any responses.

I heard the going rate for kidneys is $30K. You should be able to do much more than just LSD

[HondaGoneRogue]

Oooooh a 1M bodykit!!! LMAO.

[cpt97m3]

Originally Posted by HondaGoneRogue

I do have to say though, when I switched to the Dunlop Star Specs, it did make a vast improvement. I would say at least 30% reduced sway from the rear end. Not sure if it was from the traction increase or the stiffness/composition of the tire. I would have thought the RFT's would be stiffer. I wonder how much better it will feel with the subframe bushings?

Did anyone do the bushings before upgrading tires?

Yep, I did the bushings when I still had the OE runflats, and they made a big difference. I now have Star Specs, and they are much nicer than the runflats.

[cpt97m3]

Originally Posted by mike the snake

I've installed the M3 rear bushings, Ohlins coilovers (342/700 springs), Apex wheels with 235/265 Pilot Supersports. All these mods greatly improved the way the car feels, however, under hard excelleration, I still experience the back end wandering. It feels to me like all the links are rubber, and the suspension is giving out under hard load.

In 1st and 2nd, especially in the rain, when excellerating hard, the car lurches right and left, partly due to the E-diff, but it it almost feels like there's rear steering.

It is much improved after the mods, but nowhere near rock solid.

When I win the lottery, I'm getting an LSD, until then I'm OK with my car at this point.

The rear upper links do have rubber bushings. The M3 versions uses a metal ball joint in some spots, and stiffer rubber in others. So you can try the upper M3 arms also. But I'm sure the LSD will help also.

[MZWIE]

OK. I'm going to do this myself (I have the facilities). I've been searching for a good DIY but have not found one.

Help please.

[cpt97m3]

Originally Posted by e34m5

OK. I'm going to do this myself (I have the facilities). I've been searching for a good DIY but have not found one.

Help please.

The one I wrote I think is *decent*

http://www.1addicts.com/forums/showt...e+bushing+rear

[MZWIE]

Has anyone tried the Powerflex bushings? I've used PF on my E46 and they were very good.

[///Machiavelli]

Originally Posted by Dackelone

Next week I am having M3/1M rear bushings installed.

I am pretty sure once they are in... it won't be long before I change the front suspension to M3/1M bits and probably the suspension to something more sporting.

Please update us with your impressions.

I'm concerned that by stiffening only the bushings the "rubbery under acceleration" and "waggle over bumps" issues will only transfer into the suspension, links until which time you end up having those replaced as well.

Originally Posted by cpt97m3

The rear upper links do have rubber bushings. The M3 versions uses a metal ball joint in some spots, and stiffer rubber in others. So you can try the upper M3 arms also. But I'm sure the LSD will help also.

From my understanding, the Ohlins suspension set-up is not compatible with the m3 rear upper links unfortunately.

[Dackelone]

Originally Posted by machiavelli9988

Please update us with your impressions.

I'm concerned that by stiffening only the bushings the "rubbery under acceleration" and "waggle over bumps" issues will only transfer into the suspension, links until which time you end up having those replaced as well...

I will update you(all) when I get my car back from my shop.

To my knowledge I don't think anyone has only done rear M3/1M bushing alone as a mod. I am also curious how the car will feel and handle. Especially in a turn with bump steer or over rough roads while cornering with some speed.

[Dackelone]

Originally Posted by e34m5

Has anyone tried the Powerflex bushings? I've used PF on my E46 and they were very good.

I looked on Bav-Auto's website and those Powerflex bushings were $$$($470 I think). Way more than the M3 (subframe)ones. I'd rather go with M stuff than aftermarket.

[HondaGoneRogue]

While turning the bump steer is almost completely eliminated with the M3 FSB (i have the e93) but while hitting bumps straight, the car "jiggles" to the sides, which I attribute to the bushings.

[Dackelone]

Originally Posted by HondaGoneRogue

While turning the bump steer is almost completely eliminated with the M3 FSB (i have the e93) but while hitting bumps straight, the car "jiggles" to the sides, which I attribute to the bushings.

yes, its that side jiggle that drives me nuts too. Like when I go over man-hole covers over here, the whole rear end moves around. I'm hoping the M bushings willl get rid of that.

[HondaGoneRogue]

Yes! Exactly! The manhole covers are the worst. It is exagerated greatly with the koni yellows/H&R sports set to medium. It almost feels if something is disconnected. If the bushings can eliminate that, I'm sold for sure.

[mike the snake]

With the stock sport suspension and bushings, my car would "skip" after hitting manhole covers, and also had a resulting shudder, which was uncomfortable, and had me driving around every bump i knew about or could see.

After installing my Ohlins coilovers and rear bushings, while stiff, my car hits bumps like these with a sharper, but much shorter reverberation, which is vastly more comfortable.
I think the improvement in feeling is from all three additions, springs rates, good shocks, and bushings.

My car still shifts to the sides under very hard excelleration in 1st and 2nd though, and also the rear still squats and bobs a little when excellerating hard, but I think that playing with the shock adjustments may help with this, as i haven't touched the settings.

[Dackelone]

Originally Posted by mike the snake

With the stock sport suspension and bushings, my car would "skip" after hitting manhole covers, and also had a resulting shudder, which was uncomfortable, and had me driving around every bump i knew about or could see.

After installing my Ohlins coilovers and rear bushings, while stiff, my car hits bumps like these with a sharper, but much shorter reverberation, which is vastly more comfortable.
I think the improvement in feeling is from all three additions, springs rates, good shocks, and bushings.

My car still shifts to the sides under very hard excelleration in 1st and 2nd though, and also the rear still squats and bobs a little when excellerating hard, but I think that playing with the shock adjustments may help with this, as i haven't touched the settings.

Do you still have RFT's ???

[mike the snake]

No, I'm running the Apex wheels with Pilot Supersports 235/265.