[Digitalize]

I've had front non RFTs for a few months now but finally got the backs done as well, Eagle F1s. The back feels awful! So vague and a bit like it's steering itself, when doing a bit of slaloming it's like there's a lag where the back is still going the original way, which wasn't there on the RFTs. Had tracking done, all spot on and new rear control arms.

Is this just regular tyres being that much softer? Running the rears at 3.1bar like it's recommended.

Supposedly my rear dampers are getting a bit tired, but it feels more like the back is actually moving rather than lazy damping.

Side note, they haven't got my bloody steering wheel straight! Very annoying.

[AtlantaDude]

RFT have very hard sidewalls. Non RFT's don't, depending on the tire you choose. I'm not 100% on the Goodyears, but what you're probably feeling is the sidewall collapsing while going through a corner. THIS IS NORMAL. The only real fix, is to run a tire with a hard sidewall.

[John320d]

Suggest more tyre pressure. My rear pressures are a recomended 3.7 bar and ride ok.

[Digitalize]

I've obviously driven cars with non RFT, on track etc, but this feels much worse than this!

John where are you getting 3.7 bar? Mine says 3.1 on the door for 255/35/18s

[Sparky68]

Mate have a look at my thread, i have been chasing handling issues for months. New suspension, replaced rear sub frame bushes with Whiteline bushes, loads of geometry set ups new alloys/tyres and still struggling.

[Jase 320d]

When i went to non rft's it was awesome!

Grip and handling are improved no end!

Id try new shocks on the back, especially at the mileage you have.


They aren't too dear for the rears

[Digitalize]

I'd be tempted to go straight to coilovers if I was to change them. But it could be that the RFT stiffness was hiding the softness at the rear.

The backend won't step out anymore, so much more grip.

[Jase 320d]

Oh yeah the grip is unbelievable.

Rft's seem to have very little grip.


I wouldn't go for coilovers, i've just sacked a set of h&r springs off in favour of msport ones.

Far superior in every way. Coilovers are not really for the road imo. Fair enough for track days but day to day driving they send you bonkers

[Sparky68]

Originally Posted by Jase 320d

Oh yeah the grip is unbelievable.

Rft's seem to have very little grip.


I wouldn't go for coilovers, i've just sacked a set of h&r springs off in favour of msport ones.

Far superior in every way. Coilovers are not really for the road imo. Fair enough for track days but day to day driving they send you bonkers

Sorry, but, that is utter bollox.

[Digitalize]

M Sport suspension is awful. I probably wouldn't be able to afford decent coils though.

[Jase 320d]

What part mate?


Coilovers are crap for comfort. I've had decent ones at decent height (ohlins and kw's) on previous cars and they do your brain in after a while.

And i have non rft's fitted which are not a premium brand. Mid range and they have vast amounts more grip compared to bridgestone rft's.

[Terryk]

Originally Posted by Digitalize

I've obviously driven cars with non RFT, on track etc, but this feels much worse than this!...............

it is said that the whole r&d of our suspensions was based on RFT. all the parts of our suspension system designed to operate with RFT...but in reality they are stupid tires and you ll get use of your new ones in 2 weeks time probably. we all had the same feeling with you when changed from RFT to non ones...RFT are great for Germany's autobahn though

[mob17]

Its normal what you are feeling on these BMWs.

What you can do to help is replace the rear arms (upper links and guide rods) with M3 ones and replace the rear subframe bushings with M3 ones. The bushes are a big job though.

[acerboo]

if your steering wheel is not straight then the tracking is not spot on did bmw do it? I have goodyears and they are fantastic tyres. having said that I also have runflat Pirellis and they are superb tyres. its not the m suspension or the runflats that are the problem its the cart track road surface we have to contend with. get any of these cars on proper tarmac and they are totally different. I can thoroughly recommend bmw performance suspension as a good all round improvement over the m, but the lci m runs it very close.

[Digitalize]

The steering wheel can be off centre but the tracking still be correct, all it means is that I have slightly less lock one way and it's annoying, but it's only just out. When held centre the tracking is correct, just the wheel isn't straight.

I'm gonna give it a few weeks before I do anything.

I've just replaced the control arms with new standard ones.

Don't really want to be changing bushes, although at 173k they'll all be pretty soft, but none excessively after a good poke around and wiggle with a tyre bar.

Will look in to new dampers and maybe lowering springs. I'd like to get it a bit lower. Might do new dampers all round. However the cars just had £700 spent on it, just for tyres and tracking and replacing seized parts to get the tracking done. Which is why it's disappointing that it feels worse! I honestly think I should have kept RFTs atm.

[John320d]

Originally Posted by Digitalize

I've obviously driven cars with non RFT, on track etc, but this feels much worse than this!

John where are you getting 3.7 bar? Mine says 3.1 on the door for 255/35/18s

Sorry, typo. My vert is 3.3bar fully laden

[Digitalize]

Might try 3.3, but seems quite high to me already? I know the E91/3 share aftermarket spring rates usually.