rear subframe bushes

[TimMc]

Originally Posted by BMW86

Hi Tim, how come you would put the stock Front SB back in? I thought the bigger Front SB reduced understeer?

Also, which rear SB are you looking at? I think I'll do the same and switch out the rear bushes and rear SB at the same time to save on labour costs.

So many variables here but most "experts" tell you that a larger front bar will increase understeer & larger rear will increase oversteer. Now I've got a LSD (no spinning of the inside wheel out of corners) I'm happy to put a larger rear bar on. With the lowered KWs flattening out the cornering anyway, maybe the standard 135 bars F&R will be fine? Not sure. If I did put in a heavier rear bar I'd probably put in a E92 M3 bar to match the front.

[TimMc]

Originally Posted by ansch

cool.. so still doesn't help much with the understeer?

Must help a bit. Maybe it's just that my new track tyres are slipperier on the front than they are on the back? I only properly broke traction once at the rear, when I lost it coming out of the Carousel in 3rd and spun off backwards...

[BMW86]

Originally Posted by TimMc

So many variables here but most "experts" tell you that a larger front bar will increase understeer & larger rear will increase oversteer. Now I've got a LSD (no spinning of the inside wheel out of corners) I'm happy to put a larger rear bar on. With the lowered KWs flattening out the cornering anyway, maybe the standard 135 bars F&R will be fine? Not sure. If I did put in a heavier rear bar I'd probably put in a E92 M3 bar to match the front.

From what I understood the M3 sway bar reduced understeer. I've got KW V2's and LSD too. I installed the KW V2's before the M3 front SB so I didn't notice as much difference, but it definitely felt a lot flatter. It felt like it improved turn in for me and reduced understeer slightly, but it was a long time ago.

I'd like to know what the 1M has, if it's exactly the same as the M3 then I'll probably go down that route and do a 1M/M3 conversion. I'm not sure if I'll get the E92 or E93 rear SB though. Most likely E93 so it matches up with the front.

[TimMc]

Originally Posted by BMW86

From what I understood the M3 sway bar reduced understeer. I've got KW V2's and LSD too. I installed the KW V2's before the M3 front SB so I didn't notice as much difference, but it definitely felt a lot flatter. It felt like it improved turn in for me and reduced understeer slightly, but it was a long time ago.

I'd like to know what the 1M has, if it's exactly the same as the M3 then I'll probably go down that route and do a 1M/M3 conversion. I'm not sure if I'll get the E92 or E93 rear SB though. Most likely E93 so it matches up with the front.

Yeah, E93 M3 bar sounds like it may be the rear bar for you. Of course both the 1M & M3 have wider tracks than our cars due to their lesser wheel offsets. The M3 also has a longer wheelbase & a lower height. So what's right for them may not be what's right for us. By the way, fitting a LSD on it's own will increase understeer as the diff will try & stop the car turning! A locked diff (Detroit locker) as used on some race cars is much worse again.

I'm babbling on. I'm no suspension expert...

[BMW86]

Originally Posted by TimMc

Yeah, E93 M3 bar sounds like it may be the rear bar for you. Of course both the 1M & M3 have wider tracks than our cars due to their lesser wheel offsets. The M3 also has a longer wheelbase & a lower height. So what's right for them may not be what's right for us. By the way, fitting a LSD on it's own will increase understeer as the diff will try & stop the car turning! A locked diff (Detroit locker) as used on some race cars is much worse again.

I'm babbling on. I'm no suspension expert...

Thanks Tim, appreciate your input as you've completed a few track days and know your stuff.

I think I will get the E93 rear SB. I would have been disappointed if my E93 front SB made any less of a difference, as overall it was quite minimal.

I'm trying to take advantage of the fact that the rear subframe will be dropped to put in the rear bushes, and the rear SB is only $250 anyway.

[luster]

Just dont do what I did and order ALL the M3 parts, deliver it to your mechanic and realise you are missing just 1 rubber mount for the rear sway bar.

ARGH!

Tried to order from BMW spare parts here in Sydney and they said that the part number had NEVER been ordered before and would take 3 weeks.

Such a shame to express a $20 part from the USA for $60 in shipping...

You learn i guess

[_Ryan_]

Has anyone done h&r swaybars when they have done the subframe bushes?

Not keen on dropping it twice...

[luster]

I did my sway bars at the same time, yes

[BMW86]

Originally Posted by luster

I did my sway bars at the same time, yes

which rear sway did you use?

[luster]

M3 Rear swaybar

[BMW86]

Originally Posted by luster

M3 Rear swaybar

ah okay, which 92 or 93? any other suspension mods? lsd?

[luster]

e92

i've done:


Wavetrac LSD
Front Sway Bar with brackets & bushings
Left Front Wishbone link—31102283577
Right Front Wishbone link—31102283578
Left Front Tension link—31102283575
Right Front Tension link—31102283576
Headlight Regulating Rod—37142283867
Rear Sway Bar with brackets & bushings
Left Rear Wishbone link—33322283545
Right Rear Wishbone link—33322283546
Left Rear Guide Arm link—33322283547
Right Rear Guide Arm link—33322283548
Rear subframe bushings 33312283382 (front, 2x)
33312283383 (rear, 2x)
K&W V2 Coilovers

[BMW86]

Originally Posted by luster

e92

i've done:


Wavetrac LSD
Front Sway Bar with brackets & bushings
Left Front Wishbone link—31102283577
Right Front Wishbone link—31102283578
Left Front Tension link—31102283575
Right Front Tension link—31102283576
Headlight Regulating Rod—37142283867
Rear Sway Bar with brackets & bushings
Left Rear Wishbone link—33322283545
Right Rear Wishbone link—33322283546
Left Rear Guide Arm link—33322283547
Right Rear Guide Arm link—33322283548
Rear subframe bushings 33312283382 (front, 2x)
33312283383 (rear, 2x)
K&W V2 Coilovers

Nice list. I've done Wavetrac LSD, KW V2, M3 front sway. So similar mods but you've done the full m3 conversion.

I'm doing M3 front control arms, M3 rear bushings, not sure if it's worth doing the rest. Do you recommend doing the other bits?

Also Harold from HPA told me the 1M doesn't use the rear M3 sway bar.

[luster]

I haven't registered my car yet, just on the last stages of work on it.

Once registered, I'll get to drive it a little more

[Bim135AUS]

I've just had my M3 rear subframe bushes done to at the same time as installing front Koni Yellows and am very happy with the result

I track my car a fair bit and was getting fed up with High Speed Brake squat and with the dreaded rear end wiggle that all you guys correctly talk about

These annoyances have now gone and the car is much more chuckable on the track with much better mid corner speed. I can now put the power down far earlier with out the rear going all over the place.

I think these mods are a must if you are serious about tracking

And they were installed by Andrew and Jimmy at SouthernBM with their usual first class level of professionalism
Highly Recommended

[Gumball]

I ordered the rear bushings last week from Harold @ HPA and he told me not to get the rear sway changed as he said the car is easier to drive and power can be put down earlier with the stock sway with bushes and a lsd.

I'm gonna order the front arms in the future.

I'm not a fast track driver by any means but I love turning this car into something special.

[TimMc]

Originally Posted by Gumball

I ordered the rear bushings last week from Harold @ HPA and he told me not to get the rear sway changed as he said the car is easier to drive and power can be put down earlier with the stock sway with bushes and a lsd.

Interesting. As I've still got a bit of understeer at the track I'm keen to put a larger rear bar (& bushes) on. Agree that stock or no rear bar will always allow better power down though, even with LSD.

[Bim135AUS]

I don't agree with keeping the stock rear sway

The chassis is far more composed with the H&R front and rear sway and the rear sway, in particular has a major effect in dialing out the understeer

I can see no downside, particularly when the rear M3 subframe bushes are done

My car is pretty nuetral on the track now- no complaints

[_Ryan_]

Originally Posted by Bim135AUS

I don't agree with keeping the stock rear sway

The chassis is far more composed with the H&R front and rear sway and the rear sway, in particular has a major effect in dialing out the understeer

I can see no downside, particularly when the rear M3 subframe bushes are done

My car is pretty nuetral on the track now- no complaints

Which spring/shock setup are you running?

[Nugget]

I've noticed a rather unsettling handling characteristic of the car, when changing direction at high speed there is a moment hesitation like it is loading up to one side before it actually responds. Is that because of soft bushes like these?
I changed a bunch of bushes on my last car (Audi S3) and it made it feel like a go kart, but ruined the ride and made it shake at idle.

[BMW86]

Originally Posted by Gumball

I ordered the rear bushings last week from Harold @ HPA and he told me not to get the rear sway changed as he said the car is easier to drive and power can be put down earlier with the stock sway with bushes and a lsd.

I'm gonna order the front arms in the future.

I'm not a fast track driver by any means but I love turning this car into something special.

Originally Posted by TimMc

Interesting. As I've still got a bit of understeer at the track I'm keen to put a larger rear bar (& bushes) on. Agree that stock or no rear bar will always allow better power down though, even with LSD.

Harold from HPA told me the smaller of the rear M3 bars will work. Didn't say whether I needed it or not though.

[_Ryan_]

Originally Posted by Nugget

I've noticed a rather unsettling handling characteristic of the car, when changing direction at high speed there is a moment hesitation like it is loading up to one side before it actually responds. Is that because of soft bushes like these?
I changed a bunch of bushes on my last car (Audi S3) and it made it feel like a go kart, but ruined the ride and made it shake at idle.

Same, hence looking at ARB's and subframe bushes.