Drawing / Fabrication of engine gearbox adapter

Hi!

I'm about to start measuring and drawing my VR6 to BMW "530xd" (GS6X-53DZ) gearbox adapter.

I'm going to use a 034motorsports flywheel, because then I already have a lightweight single mass flywheel and starter combo that lines up. Also have a Sachs 707 pressure plate that fits this flywheel.

I have the VR6 to Audi 01E adapter to use as reference for engine side of things.

Thinking about making thick enough adaptor plate, to make room for double 240mm discs.

What are your thoughts on a dual 240mm disc setup?

Any experience with steel types for the middle spacer, and also how much preload/deck height should I account for if going that route?

Any other tips or pitfalls welcome :)

You may run into a problem with the pilot/spigot bearing in the crankshaft that the gearbox input/1st motion shaft fits into to support it.

Whether to use the current single plate clutch assembly, or go to dual, will depend on the expected engine torque and the capacity* of the clutch you have - you may be able to have the pressure plate diaphram spring replaced with a stronger one as the easiest and most economical up-grade. Normally, dual plate clutches are designed to fit in the same, or slightly larger, space of the single plate they're replacing - you may not need a thiker adaptor, and it reduced the chance of the pilot being a problem. I would actually be planning the adaptor around the pilot bearing engagement and then the clutch - that may require a custom input shaft (might be able to use one from a different manufacturer that uses the same basic gearbox** but a longer input?) - maybe even dispensing with the 'adaptor plate' and instead machining off the bellhousing a little less than the plate thicness, so you can skim both surfaces for flatness and parallelism. Don't forget, it is critical the centre-lines of the gearbox and crankshaft line up as perfectly as you can manage - take your time and get it right as if you don't get it VERY close you will be looking at clutch drag, difficult gear changing, excessive gearbox wear, etc.

Oh, forgot, don't forget to check the splies size and number matches up to the gearbox.

*Clutches are rated by two things - torque capacity and burst rpm - "power" is NOT the way to rate them and, personally, I would generally avoid a company that advertised their product that way.

** That gearbox is an AWD version, but the input should be the common with the 2WD ZF versions.

Hi!

Yes, there are several things to keep track of, I'd have to measure thoroughly that all will fit through and into the bearing, good point.

I found 240mm discs from Tenaci, unsprung, with offset center, to allow more compact design. Of course the spline lenght of the gearbox must be correct.

Yes, it's AWD, but as you say, the bellhousing/offsets should be the same, so people with 2wd will also be able to use it.

I was thinking the other way round, you would be able to use RWD versions - what I failed to mention is that the constant mesh gears (input to countershaft) may be different ratios, with a different tooth count, so something to watch out for.

Im building a 4wd car, others may use this adaptor if the use vr6 and zf gearbox too :)