Stiffer chassis = no need for stiffer suspension?

What are people's thoughts on this?

Is stiffening the chassis a good way of improving handling without compromising comfort? Or does it not make enough of a difference on its' own?

Have m-tech suspension + powerflex front/rear at the moment, it's tight yet comfortable. I want to make it as tight as possible without ruining that, so picked up proper front and rear strut braces ( thanks James :) ) and will be getting an x-brace as well before fitting all 3. Do you reckon it'll do the trick?

Will be getting BCs with adjustable dampening in the future but that's not for another while, I would really rather get an Eisenmann first!

id say they will make a small difference but the bc's would defintely be more noticable the stiffer chassis would really be only noticable when the car is literally being pushed to the absolute limits

My car has coilovers, strut brace, powerflex bushes and on the road is very nimble but on the limit you can feel body roll hindering the fun a little so I'd be looking at an ARB kit to cure this.

how old are your arb bush's ger , you might just need a refresh the eibach anti roll bars are around 350 gbp , is there any difference between the m3 anti roll bars and mtech roll bars ?

That's exactly it Ger, most of the time it's nimble, but when I'm really pushing on twisty roads can feel a bit of body roll/chassis flex.

They are not new but they are not bad either, not sure but I think M3 are just a few mm thicker

Fitting a X brace is a good upgrade to stiffen the chases. I have put BC coilovers in the track car and find the great, I am running the damper setting at 7 on front and rear.

A few mm can make a huge difference afaik the difference between se an msport is around 2-3mm eibach are usually 2mm more then sport might be worth looking into m3 ones

A good drop does wonders

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Originally Posted by Gar

how old are your arb bush's ger , you might just need a refresh the eibach anti roll bars are around 350 gbp , is there any difference between the m3 anti roll bars and mtech roll bars ?

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The Mtech antiroll bar size Front 22mm rear 18mm
328 antirollbar size Front 24mm rear 15mm
M3 3.0 antirollbar size Front 22mm rear 19mm
M3 Evo Antriroll bar Size Front 23mm rear 20mm

Eibach upgrade kit size Front 25mm rear 21mm

Cheers rob good info Unusual to see the m's roll bar smaller on the e39 its

Se 22mm
Msport 1 24mm
Msport 2 25mm
M5 25mm
Eibach 27mm

All fronts

Seems the 328 bar is the one to grab

Similar oddities with the E46...
318i SE front 24.6mm
318i Msport front 22.5mm

So I now have the sport springs+ shocks and the bigger arb.... Win.

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Originally Posted by John_D

Similar oddities with the E46...
318i SE front 24.6mm
318i Msport front 22.5mm

So I now have the sport springs+ shocks and the bigger arb.... Win.

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Its a strange one that the SE bars are thicker than the Mtech ones, it was Tomas in Perfect Car that pointed that out to me when I was looking at changing my ARBs.

I want to get strut braces myself, I can feel that car flexing, but maybe its even more pronounced having coilovers in.

Just looking over this again and wondering would the thicker anti roll bars on se models be due to the softer suspension setup? Thus confirming that the stiffer the chassis the less need there is for stiffer suspension? :)

Would it all come down to just the thickness of the bar though or would there be a difference in the metallurgy of the small diameter ones?

I was thinking the same Enda, but I wonder if BMW would complicate things by having the ARBs for each model made of different material rather than just changing the thickness? Maybe it doesn't work that way though, I'm no expert on the subject. But I do find it very interesting.

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Originally Posted by Peter-E36

Just looking over this again and wondering would the thicker anti roll bars on se models be due to the softer suspension setup? Thus confirming that the stiffer the chassis the less need there is for stiffer suspension? :)

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This.

Was thinking about it and the thicker ARBs for softer suspension makes most sense to me.

I've a x brace if anyone needs one I'm going to power flex the vert at the min I've fitted a strut brace and removed the x brace because I'm just to low .. I might do sub frame at some stage just because I can really not for anything else

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Originally Posted by EndaC

Would it all come down to just the thickness of the bar though or would there be a difference in the metallurgy of the small diameter ones?

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was thinking the same but it sounds a bit too high tech IMO.

The anti roll bar is mounted to the body of the shock on an m3 the other models are mounted to the wishbone.

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Originally Posted by Moses

Fitting a X brace is a good upgrade to stiffen the chases. I have put BC coilovers in the track car and find the great, I am running the damper setting at 7 on front and rear.

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Not having a go but you know the rebound goes up to 30 right? Ive mine set to 20 on 12kg springs in a road car and I think ill go a tad harder, id imagine on a track car you would put her the stiffest possible