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Old 10-07-2019, 07:46 PM
gazmataz gazmataz is offline
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Join Date: Jul 2019
Posts: 1
Default Noob questions, why 5 speed gearbox?....

Hey folks

I drove a lovely S50 last week and just couldn't help but be amazed and i've driven much faster cars than this. It felt quite soul stirring, a refreshing change to modern motors...

I just have a few questions (probably noobie questions but I can't seem to find the answers!).

Why was the 5 Speed used in the S50 and the S54? I thought it was due to the limited space within the Z3 chassis, but then I've read of people retro-fitting the 6 Speed gearboxes?

I'm under the illusion that the engineers had to fabricate a smaller exhaust manifold for the S54 to fit it into the narrower engine bay (which accounts for the lower power figure over the E46 M3)?

Are the brake calipers floating single pots on floating brake discs? It was hard to see on the car I drove but I was informed the discs were 2-piece? (This is a UK car).

Is the 1/4 locking limited slip diff lifted from the E36 M3 too?

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Old 11-07-2019, 08:14 AM
Dave P's Avatar
Dave P Dave P is offline
Join Date: Dec 2008
Location: Cheshire
Posts: 26,538

Welcome to the forum

5 speed was used as they said the transmission tunnel would not take the 6 speed but the evo or E46 6 speeds will fit fine. The front brakes are a single piston fitted to a floating disc (Euro cars not US)

and the diff is taken from the E30 M3 as with most of the rear suspension.

The S54 was fitted with a lower rev limited which was said to cure the bearing shell issue on early engines and stopped BMW from having to recall and fit uprated shells which they did on the E46 M3's.

Manifold is the same I think ? but I have read the E46 m3's have a better flowing exhaust system over the ZM
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Old 11-07-2019, 07:44 PM
c_wgallery c_wgallery is offline
Join Date: Jun 2011
Posts: 88

I thought BMW's line was that the M Coupe wasn't affected by the recall because of the lower rev limit they put on it to peg the power back from taking any shine off the E46 M3.

One benefit of the 5sp is it's lighter than the 6 and supposed to be a bit better shifting. That said BMW also told a few lies with it not "fitting" even though it would. I bet they could have also put the z-axle in there too like the old Z1, but the Z3 roadster it's based on was a budget roadster so the Coupe inherited the trailing arm setup.
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Old 17-07-2019, 09:58 PM
ragerover's Avatar
ragerover ragerover is offline
Senior Member
Join Date: May 2007
Location: newcastle upon tyne
Posts: 3,081

6 speed fits ( not too bad of a job either )
They didn’t fit it as it would have been faster than the M3
All ratios are identical to MCoupe except 6th obviously

Best set up is high ratio diff and 6 speed box

The bearing thing is bollox they still go, both M3 and coupe get replaced
Under a recall in the states. Not here though
And it’s not the revs that kill it
Shells and bolts is not too hard a job if you’ve got a ramp
Top quality oil and propper warm up is the way forward.
And not water temp but oil temp
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Old 18-07-2019, 06:43 AM
mnbrennan mnbrennan is offline
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Join Date: Jan 2014
Posts: 1,062

I haven't had chance to for the 6 speed yet, but excited!
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