Outsourcing

Having originally decided I would do the necessary research and then strip my wiring loom of the unnecessary wire etc I've decided to send it off to John at Speartech in the US, along with the Transmission Control Module (TCM) that lives in the bottom of the Automatic box. In 7 litres of transmission fluid.

So a couple of hours saturday morning and this is the labelled spaghetti in it's unfettered state... and packed in a box ready for shipping.

Next is the turn of the TCM. This proved to be much more challenging, not least because not having an engine stand so working upside down under the dripping internals and being nervous of removing the transmission off the engine (I need to send it to AK intact so they can validate measurements and build the chassis 'around' the engine for fitment.

Luckily Speartech have instructions of how to remove the TCM... but I didn't know I needed a specific Torx Plus socket for some of the internal bolt removals so that caused a delay whilst I located a supplier in the UK.

I've learnt a massive amount about the way the transmission works and about the cooling of it doing this so actually a huge benefit to do so.
I will be replacing the stock GM filter/pickup with an aftermarket one which allows greater transmission fluid flow. (Heat is the primary enemy of this transmissions - any issues are normally related to ineffective cooling)

So what I'm after is in here. Thankfully on the later models GM thought to include a drain plug. On earlier ones they didn't which lead to much merriment and happiness with the US LS swap fratenity ;-)

 

 Even with the drain plug I still managed to cover the floor with a red super slippery swamp... live and learn. Still, the fluid is nice and clear with no rubbish in it meaning I hope I've not bought a donkey.

Chocked and ready for the operation



Sump off, what I need to get off is the brown plastic thing shown below which houses the solenoids and computer - but it is bolted to the valve body from the underside so it all comes out. First the filter which after 3 hours of probing and a panic mail to Speartech I eventually learnt it is a push fit... no bolts :-(

Filter off, passthrough connector tab unlocked (which disengages the unit from the casing) now to locate the correct attachment bolts from the myriad available to undo.

Thank something for iPhones... this was invaluable to help decipher what was where!

Result. After much effort the valvebody /TCM assembly is off - the little 4 hole seal is put back into the underside of casing so it doesn't get lost. now I need to separate the brown plastic bit from the metal bit!

Done. Plenty of fluid left in various parts so I left them to drain at various angles for a week, popped the sump back on the unit and packed up the TCM to go in the box to Speartech.

Update: The TCM and harness arrived in the US at intended destination 30th August. Speartech have alot of work on so not likely to be looked at till late September but I'm not in any rush so this is fine. For clarity they will be doing the following:
Reworking the harness
Supplying an E38 Engine Control Module with a Corvette calibration to enable electronic gear shift (the camaro one does same but it needs the body control module to help 'translate' the messages which is not needed and too much of a faff to get working)
Supply electronic accelerator pedal
Reflash / calibrate TCM to matched Corvette transmission control - much closer to Cobra in weight so will be good match on shift pressures etc.
Supply tapup/tap down gear shift module to hook up to wiring harness

I spoke to John Spear about torque management which is the subject of much debate with the 6L80E transmission. It is a complex area around how much nannying the controller does over the gear changes. i've decided not to fiddle with stock GM tunes until I know more about it and can test for myself.

Just need to build a trolley now and the engine will be ready for AK to collect.

A new decision...

The transmission dimensions have proven to be challenging. My original view when I bought the engine was that I would change it to a manual. GM recommends that displacement on demand is not used with a manual transmission due to the fact that they could not get the manual transmission to absorb the feeling when the engine switches from 8 to 4 and back to 8 cyclinder mode again.
Looking at the costs it was something I was prepared to do from getting the engine at a good price... however, the more I've thought about it the more I wanted to actually make the auto work.
Reasons being
1. The engine and transmission are in their OEM delivered state. Why mess with that if I don't have to.
2. I like the idea of the displacement on demand in a Cobra... perhaps it's a perverse wish but I feel the need to minimise the fuel burning when not required.
3. The new 6 auto speed box will give easy driving on local roads around me which are prone to traffic jams daily but will still allow hooning about on the open road.
4. There's a reason why the US speed fraternity put auto transmission boxes in their drag / street racers. (Strength and durability being two of them)
5. It has electronics built in for electronic driver shifting... flappy paddles on a Cobra I'm sure will have many purist replica affecionados rolling their eyes and shunning me but I'm fine with that.

The downsides are that it's a complicated configuration, not been done with this config in the UK to anyone's knowledge and therefore not much local support. And finally, the transmission is a challenge to fit in the Gardner Douglas...

Which brings me to the main point. I have decided to change manufacturer. So I'm no longer building a GD but an AK. Not going into massive amount of reasons here but I think it will be easier and more flexible for me in the long run.

So, a slightly revised date for kit build - I should hopefully take delivery of chassis and body first week of October.

There is still much to prepare for before then.

Engine harness and Transmission controller need sending off to the US to have some repair / rework done. The harness needs some extraneous wiring removing and the transmission controller needs re-calibrating to a different setup. More on that later.