SMG Gearboxes

[glendog74]

Originally Posted by shimmy

dear Gorilla and NZ_M3

i do find both of your threads and posts very interesting

I'm off to bed...

[AlexGTT]

Originally Posted by shimmy

dear Gorilla and NZ_M3

i do find both of your threads and posts very interesting and full of technical info that most of us here, and tbh most of the BMW specialists we know would not understand

however you both seem to constantly disagree with each others techinical opinions on nearly every subject even subjects that can only have one answer

now i am not a mechanic or even a person with car knowledge more than a few skils like changing brake pads and wheels and occassionally a disc or two, but i am qualified as a Project Manager and understand when i am being fed bullshit on a monumental scale.

So for my peace of mind and so i get some sleep without worrying if my rear turret is gonna split or if my chassis is gonna twist or if my gearbox and clutch is gonna piss itself all over the floor can which ever one of you that is guessing (note my careful choice of words) please stop and let the other tell us the truth!

Very succinct, yet still diplomatically expressed Shimmy.

I'm off to bed as well!

[The Gorilla]

Hi,

Shimmy- my views are always expressed from first hand
experince and things that have happened to my cars.

Just for the record, a Lightweiight flywheel [12lbs] with
a Sachs Uprated Clutch Disc and cover was fitted to my Car, CSL.

It was dreadful, so the Gearbox ECU was reprogramed with the
latest version of the software, no change.

Then the SMG pump fluid was drained the system was flushed and
refilled. No change still would not engage properly, the upshifts and
downshifts were all hit or miss etc.

So the Lighter flywheel was removed, the dual mass refitted, with
the Sachs clutch, and the car has its moments but by and large its
OK. Can still get a small 'slur' now and then without sport or DSC off.
Now done around 1500 hard miles, its only used for Track days and the
odd local blast when trying things out, and its been OK.

I also have a E30 M3 with a CSL S54 engine Motec M800 and Drenth sequential Gearbox running a Dual disc 184MM Clutch with a 10lb
alloy flywheel, and a central clutch cylinder, which on the 'flatshit'
makes the SMG feel very slow.
This car does not run the 'E,Gas' or Fly by wire, but is running a throttle
cable/Linkage, which out of slower bends does allow a quicker pick up.
The S54 without the dual mass flywheel is far more responsive at lower revs
that its a shame that the SMG will not function correctly
with a lighter flywheel.

I did look into lighter dual mass flywheel in steel, but the savings
were not more than around 2-3 Kg which was not worth the costs.

Pectel have now developed a plug and play standalone for the S54 which
has been mapped specifically for the E.Gas, fly by wire, and in therory
will always have the throttle and air optimised as its rev matched and
picking up signals from engine load etc.
Interestingly they do not recommend SMG on a Car running this system.

Regards,

The Gorilla.

[NZ_M3]

Originally Posted by The Gorilla

I also have a E30 M3 with a CSL S54 engine Motec M800 and Drenth sequential Gearbox running a Dual disc 184MM Clutch with a 10lb
alloy flywheel, and a central clutch cylinder, which on the 'flatshit'
makes the SMG feel very slow.

why Hell ... you win Gorilla ... I can't compete with somebody with a car like that That's awesomeness right there ... even more awesome if you did the work yourself

Would love to see some pictures of that beast !!!

How much did the drenth sequential cost? I've always wondered if it'd take much to convert the SMG in the CSL to the Drenth sequential (for track use of course, one'd be almost crazy to drive that gearbox on the road).

Oh and just for the record so that I am not seen as talking out of my ass ... I am not a mechanic by trade, but am self taught. Mostly to do with Hondas, but the basics are all much the sameness. I've personally done and completed 2 x auto to manual conversions, 2 engine rebuilds, numerous wiring and mechanical jobs on hybrid motor swaps for Hondas (much harder than it sounds) and am competent at changing a clutch on my own in a Honda (I've done it in record time of just under 3 and a half hours by myself on a B series with the engine in the car - dealerships quote 7 hours for the job) - but that's just monkey work I suppose.

I gather most of my knowledge on the M3 from personal experience and from reading training manuals when available - most other sources and knowledge I've built up over the years from reading forums and having 3 close friends who are master BMW mechanics - so what I don't know I just ask.

[_Nathan_]

Drenth is about £10k+VAT, but I can't see how you could get ignition cut for flat shift without a new ECU and therefore loom.

Believe you also need to mess about with starter motor too as the Drenth bell housing moves it I think.

Would love a Drenth + paddle shift mechanism. One day...

[NZ_M3]

Originally Posted by _Nathan_

Drenth is about £10k+VAT, but I can't see how you could get ignition cut for flat shift without a new ECU and therefore loom.

Believe you also need to mess about with starter motor too as the Drenth bell housing moves it I think.

Would love a Drenth + paddle shift mechanism. One day...

Cheers for that.

Yeah I figured to put in a Drenth you'd have to go aftermarket ECU and disable the traction control or run a different software perhaps?

We can always dream !! If only money was no object

[_Nathan_]

Motec will do traction with variable slip so that could be covered if you wanted. You'd also have to consider motorsport ABS units.

Basically a complete rewire of the car with a new loom, not the work of an afternoon!

Approx 50 hour inspection interval too, expensive business.

Occasionally you see second hand DG400s come up in europe but the actual box price isn't quite so significant when you add every thing needed up together.

[The Gorilla]

Hi,

NZ_M3 - There are no winners, we are all just Petrol Heads
spending our hard earned cash on metal boxes that have
components in them that every now and then seem to fail.

If I ever get to NZ to see a colleague on South Island, Conrad,
who races a E30 M3 with 2.5 S14 then the beers are on me.

It was about a 2 year build project on and off, did all myself
except the Paint Sparying and the MOTEC M880 loom, ECU Etc.

Its a S54 CSL running Motec M880 ECU, Plasma Coils, Bosch Ignition
Drivers, Vanos deleted, Dry Sumped with Oil/water heat exchangers.
twin 60mm exhaust with side exit and no Cats.
Drenth 6 speed DG400 Sequential, with DTM Alloy Cased Rear 3.73 LSD,
ZM3 Coupe rear arms with Bilstein Alloy Remote adjust Coil Overs,
fronts are 92 DTM Titanium Uprights, with Remote adjust 2 way coil
overs, Intrax Camber plates, Grp A Adjustable Front Arms, front and
rear ARB's are Cockpit adjustable blades, Manual 2.3 lock to lock rack,
and its runs on 92 DTM 9X18 Centre locks etc.

Shell is full weld in Chromoloy Cage with Carbon wings, bonnet, boot,
Polycarbonite windows, heated front screen,carbon door cards, full
flat floor underneath in Carbon, and it weighs wet without driver 1075kgs.

Its making about 370 BHP, rev limited to 8350, as its turned down a bit
just for engine longtivety, hopefully.

The hardest problem was cutting all the bulkhead and getting
it right so that the S54 engine sits about 70mm further back
than when others have done similar 6 cylinder conversions into
the E30 M3.

I learnt a lot when I did a road E30 M3 with a S50B32/ 6 speed box, which
I have just sold to a Guy in Hong Kong, it was a RHD build.

I will post some pics up shortly, if I can get them to load.

Regards,

The Gorilla.

[AlexGTT]

Would be very interested to see pictures of those motors Gorilla.

[Bealo]

Now that sounds like a hell of a car and a lot of fun on track....