[ALEX P]

Hey spuggy, firstly, big thanks for taking the time to answer my questions in such good detail, it is much appreciated.

Originally Posted by spuggy

I see no mention of an LSD. IMHO, you'd really appreciate a 60/40 LSD set to about 80 ft/lbs in that car. Best money I've ever spent on either of my transmissions.
A Guard Transmission (GT) clutch LSD is probably the very best available, but pretty spendy in the UK with import duty/taxes.
The Gripper guys told me they've made G50 LSDs before (and will again if asked), they just don't list them on their web site.
However, with a Gripper, you need someone who knows how to tune one to set it up for you for your intended use, as well as to install it. Because those guys just make diffs.
Mike Bainbridge has worked with those (Gripper) diffs extensively.

If I do this then I was only planning on tacking one project at a time so LSD wasn’t really going to be on the list until maybe a bit further down the road. I know it makes perfect sense to do it while you’re in there and the box is apart but it would be what, at least another $1500 or more. I’ve spoken to Mike a couple of times before (he used to work in the same town I live in) and he or Nick Fulljames of Redtek would be top of my list to do any gearbox work.

Originally Posted by spuggy

You may still have to at least cut the cover away to get the extra half inch you need. My '77 did.
There's a one photo on this thread that'll give you an "oh, OK" moment: Verify a G50 is shortened?
The welded cover is just a welded cover. It's OK to cut some of that away.
Some cars don't need it; I've heard of earlier ('74) and later (SCs) with G50's that didn't need this, no-one seems to know quite why some do and some don't....

It’s funny isn’t it – you would think they were all the same!
So if you cut the torsion bar cover away as in the photo below then do you just leave it open?
Does it have any adverse affect on the strength? If it literally is just cutting a window in the tube and treating it to some rust prevention then that’s not too bad but didn’t really want to start breaking out the welded as it always seems a slippery slope!

Originally Posted by spuggy

All the N/A, 2WD, 5 speeds are same length I believe, if fitted with the early (pre-964) nose cone. You can't convert the 964 4WD box to 2WD nicely, don't bother even though they're cheap as chips.

Yeah, shame that ‘87-‘89 911 G50 it would be then.

Originally Posted by spuggy

87-89 pedal box. 964 one doesn't fit.

I think for most parts I would find a ’87-’89 G50 car being parted out.

Originally Posted by spuggy

Shortening the bell housing moves the slave further away from the master - in the same way that the shift coupler also needs to be extended by the same amount/same reason.
Patrick Motorsports make an extended, full-length hose. Or a short extension hose (just source new stock hoses locally).
PMS also make a coupler extension. They can provide a full package of parts/fiddly bits.

Patrick Motorsport do seem to be the place to go to get all the conversion bits, maybe I’ll fire them an email. I run their flywheel already on my 3.6 conversion.

Originally Posted by spuggy

When the 915 was built up for the 930, I bought a hi-torque starter motor (Edge) from Cambridge Motor Sports in 2006 - and just re-fitted that to the G50.

I run a high torque starter on my 915 but didn’t realise they were transferrable – Aren’t G50 starters different?

Originally Posted by spuggy

Most certainly. I don't know if the weld-on 1st gear needs to come off, but I believe you should certainly re-harden the main shaft after machining.

Yes, I read that the main shaft needs to be hardened and ground to 15mm dia

Originally Posted by spuggy

LOL. No, that figure doesn't include stripping the box. 600-1000 USD is pretty much the price for performing the machining on your parts. Or, in other words, parts not included.

Damn! Maybe I’d end up doing more than planned myself!

Originally Posted by spuggy

BTW, even though 915 rebuilds have been edging up for years, G50 boxes are way more expensive to go through. A G50 with 120,000 may actually need a fair bit if the spec is "replace wear parts if questionable".
But then I expect to be stuffing over 500HP through mine.
If I were you, I'd talk to Mike Bainbridge of MB Engineering. I'm sure I discussed the machining for this with him years ago when he built up the 915 I used until the G50 became necessary - and he could do pretty much all of it.
PM me if you aren't clear how much all this costs, or need more details.

Thanks spuggy

Originally Posted by spuggy

Frankly, with "only" a 3.6, I think I'd put the car on an aggressive diet, build up a couple of serious 915's with LSDs, internal oiling (spray bars) and stiff cover plates/bearing retainers etc, uprate the stub axles so you can use G50 axles. And still have multiple buckets of cash left over instead...
Unless you drive it seriously hard (like competitively), it probably just doesn't make sense for that power level.

The car isn’t driven especially hard (i.e. competitively) but she does like to get out and stretch her legs. Last time she was on the scales it was 1030kg (270lb). The engine is ‘only’ a 3.6 but it has a few little extras so puts out a little extra!

The thing that worries me about rebuilding the 915 is a friend recently rebuilt his at Mike Bainbridges and did some sensible upgrades, LSD, spray bars, stiffening etc and do do that sort of job I would be looking at $6500-8000 and I'd want to be pretty damn sure that I'd be very satisfied at the end of it.
Obviously buying a used G50 is also rolling the dice in a big way and as you say they're expensive to rebuild.
It's kinda why I'm trying to do a side by side comparison to help me make my mind up!