M3 v 325i sport uspention set up

[Clarkie_GT]

ive herd the M3 ha a completely different set up to regular e30s
is this true? if so what set up does the m3 have? am i right in thinking regular e30s have single wishbones at the front?

[maxfield]

It's basically the same set up, but with wider track, alterations in camber, caster and toe.

The M3 does use the single wishbone up front and the semi trailing arm set up at the rear.

[march109]

Its not difficult (just time consumoing) to modify the rear beam of a standard e30 so that camber and toe can be adjusted within range.

Ireland Engineering do a kit, Flying brick peformance and Chris on E30Tech are authorised resellers, and more reliable than IE in my experience.

[Clarkie_GT]

ah right, cheers guys. i was under the impresion the M3 was completely different

[Fushion_Julz]

Rear suspension on the M3 is pretty much the same as on the other models...Different springs and dampers and thicker A/R bar

Front suspension is different, though...
Struts are different with the different pick-up points for the A/R bar...eccentric bushes and again different springs and dampers.

Not strictly suspension, but the hubs and brakes are totally different, although sharing many components with E28 528/535 models...

Different steering rack, too, and the M3 one is only available in LHD...

[Clarkie_GT]

are there quicker RHD racks avalible, aftermarket etc. im guessing the M3 rack is alot quicker than a regular e30?

[Fushion_Julz]

There are..Z3 1.9 rack, is the one IIRC...

The M3 one is quicker (less turns lock to lock, too) than the standard E30 power steering rack...

[Clarkie_GT]

is the m3 not power assisted then? i assume the z3 one is?

[Fushion_Julz]

M3 are all power assisted...so is Z3 one

Not all other E30 racks are, though

[78dude]

Front suspesion arms are made by alloy and not steel on an M3

[pacerpete]

Fact = early M3s had standard steel wishbones and standard concentric wihbone bushes . I believe eccentric bushes were introduced for 88/89 and alloy wishbones for 89/90.

[Jhonno]

not all of them.. only after a certain date

[Clarkie_GT]

Front suspesion arms are made by alloy and not steel on an M3

this to save 'unsprung' weight?

is there much difference in feel from the m3 v sport? ie how do they compare to drive?

can a stock e30 be modified to handle as well as an M3, would imagen things this wishbones etc would have to be changed?

[jaistanley]

The rear suspension of an M3 is the same. It just has different hubs. Any changes in geometry are due to the lower factory ride height.

The front suspension geometry is only subtly different. 325i sport has 8degree 30 minutes of castor and approx 1 degree of camber. The M3 has about 1 degree more castor and slightly less camber (very slighty, about 5 minutes less). The toe you can adjust.

The alloy M3 front TCA's add 10 minutes of castor and are lighter.

The M3 has the front anti-roll bar pick up pooints on the strut (a very worthwhile mod for a 325i). This makes them more effective and provide more driver feedback.

Fit M3 offset bushes, weld on tangs for you arb's to your struts and get your tracking done and you'll more or les have M3 geometry.

M3's have the bonus of being able to remove the strut without undoing the lower ball joints, and they have the larger front wheel bearings but if you can live without that the 325i suspension set up is perfectly good with a few tweaks.

The faster rack is WELL worth it.

Hope all this helps. I've recently been looking into the differences in all the geometries of the various E30's and E36's as I'm playing around wwith my M3 suspension ans what I shall be/shant be putting on my project car. It's all fresh in my head. I'll have forgotten it again soon...

As for the 325i ever handling as well as am M3.. Well it'll be easy enough to get the same road holding. As for handling you can get pretty close. The different centre of mass of the M3 and the (only slightly) lighter engine coupled with a stiffer shell make ot feel different and change direction very well. A load of M3 purists will tell you you'll never get a 6 pot to hadle as well. That's not true and a lot of that info is based on press opinion from the 80's. Just setting it up has to be different and you're always going to suffer having the weight of the engine further forward. Different feeling; not neccasarily better or worse.

[Clarkie_GT]

thanx for the advice jai. suspension geomentry has always fastenated me.
motoring presenters alway go on about the m3 being probably the most comunitive handling car ever, just wondered if it were much different to standard e30

thanx again

[Fushion_Julz]

My 325 isn't a sport...
However, I do have both a 325 and an M3 and use both regularly....

The 325 is a standard 1988 SE 4dr...standard springs, brakes (OE), dampers (OE) and the motor is standard save for a remapped chip by Chipped UK and RR tested to 189bhp with a Magnex SS exhaust..

The M3 has fully polybushed suspension, Faulkner springs, AVO adjustable dampers, strut brace, Black diamond combi front discs, OE rears and Ferodo DS2500 pads all round. The engine is freshly rebuilt and mostly standard except for a 272 Schrick Inlet cam and polished/ported head and TBs

They feel totally different cars....
The M3 is harder, more "raw" but with huge levels of grip and adhesion...It feels sharper and a lot more positive and focused.
On the other hand the 325 is a lot easier to drive fast...It has to be revved a lot less, it is much better suited to poor surfaces, but doesn't have the sharp and stuck to the road feel that the M3 does...

I've driven a race-prepped ex-rally 325 with a 2.7litre motor on kugelfischer and slide throttles with M3 suspension and wilwood brakes and compared it to a similar powered race-prepped M3 on CF induction and Alpha N with adjustable suspension and Blake Diamond competition brakes...

I'd say that the M3 is faster by around 1.5s a lap around Brands Indy....But the 325 is overweight and is easier to feel like you are getting the best from it.
So yes, I think you can get the 325 to be *almost* as good as an M3...

[Morat]

so hangon, 325i on bog stock suspension vs M3 with road/track tweaks? I'm not surprised! Fair enough though, you've put the money in the right place but I don't think its a fair comparison.
But don't worry, I'm not trying to do the M3 down - i'd give my left nut for one.

[Brianmoooore]

Front suspesion arms are made by alloy and not steel on an M3

These are fitted to 325 tourings as well.

[harry_p]

is there much weight difference? also, the steel ones are supposedly stronger, and you can replace just the ball joints on the steel ones, rather than having to replace the entire (pretty pricey) arm

[Morat]

btw, if BMW had done an E30 M3 Touring - Brian would own all of them by now