Thread: BMW N57 8hp to TD5 Auto adapter kit

Originally Posted by twr7cx

How does the transfer box fit onto the output of the 8HP? Will custom driveshafts be required due to different lengths/positions?

The 6HP/LT230 adaptor is the same as for the 8HP.

Originally Posted by twr7cx

Nice!

How to intend to control the 8HP? Will you use a Compushift or a BMW TCM? Will the Td5 ECU and the TCM need to be able to speak to each other? Or does the Td5 ECU get programmed as a manual gearbox specification so that it's not tying to work in conjunction with the TCM?

How does the transfer box fit onto the output of the 8HP? Will custom driveshafts be required due to different lengths/positions?

I have been watching on Youtube the Zero to 60 channel, they do a lot of 8hp installs (drift cars and V8 cruiser utes) and use the Turbolamik controller, again about $2k but seems to be a pretty good bit of kit with just some basic parameters it learns as you go and has something like 5 modes (might be 8, it's been a while)

RRT how do you think the diffs will handle the new power level? I've been looking at later model GU Patrol diffs (they have ABS that should work) massive brakes as stock and as everyone knows, pretty much bullet proof all round

will definitely be following this thread/build

cheers

Redd

The difference from the 4 to the 8speed will shock you all...
In my RRS during upshifts there is NO discernible change felt...
No jarring during auto downshifts whether under power or by braking..
and thats with 750Nm moving 6T..
(The SDV8 and 8HP= )

Originally Posted by loanrangie

Unless the conversion changes the vehicle structurally, swapping gearboxes doesn't require engineering.

That's not what the vsb14's say, atleast in WA you can only do a manufacturer's alternative gearbox as a basic inspection. Anything else requires certification

so many questions and yet already many of the answers have been provided!! Yes Pedro, having driven an 2019 X5 with the 8hp box, changes are almost non existent as to shifts and the power comes on (even more than I will ever have) seamlessly.

The controller is the most important aspect and my first choice is the HTG one, but the cost of choice is around the same. As to why it would appear to be one of belief, I know, not a great starting point but in having read over the last year or so re controllers i am leaning towards the HTG. Just around the point they seem to do more varied installations with great reported results. I am holding off until the last moment for this, but will keep searching for info as to installs and associated problems.

Either way have to turn the box upside down and rewire it but this will not be done by these incompetent hands.

As to the 4.37 diffs, they are Ashcroft as well as the Ashcroft ATB's I have confidence with these and probably more importantly with the much bigger CV's, and the upgrade of all drive shafts with Ashcroft and the front Cardon shaft, at the front the drivetrain, if they break, just park it and sell the parts! I have put in upgraded discs front and rear with the yellow pads on this has been a more than discernible improvement from the D1 Tdi as to control down the steep tracks (never drove the TD5 without this upgrade but it is better than my D2a on the road)

The weight of the adaptor is around 20kg's shipped but the gearbox is around the same weight, give or take a few kg's but this is all central so not too concerned as to more weight, but the gearing will more than allow for this to be of no consequence.

Funny I am more interested in the fuel consumption improvement, sure wont get down to 8's but this will be interesting. Yep all those more modern machines with 6+ speeds etc. are great on the tracks shifting and modulating the torque. The TD5 has been close to Colorado's and the Rangers out in the VHC and little desert on the tracks, probably less so on the open road due to the diffs.

The ratio by the way is 68 to 1, went back to Ashcroft's and put the ratios of the lower gears and upper gears in their calculator Ratio Calculator - Ashcroft Transmissions.pdf this is the upper and lower gears missing I think it was 4&5. The speeds on road are with 33's.

Gearbox Control Unit – HTG tuning

Originally Posted by admiralranga

That's not what the vsb14's say, atleast in WA you can only do a manufacturer's alternative gearbox as a basic inspection. Anything else requires certification

Victoria follows the same rules. Changing the gearbox to something that was not offered as an option needs modification approval. Same applies to changes to rear diff ratio’s to something not offered as an option.

This is the relevant VSB:
https://www.infrastructure.gov.au/si...01Jan_2011.pdf

There is a checklist which shows getting engineering sign off should be fairly straightforward as there is nothing too onerous that needs to be complied with, as long as you are not also modifying the engine at the same time to crank up the power output by more than 20%.

It would be a nice mod!

Yeah it kinda amuses me you can sneak some of the lower spec m57's (would also be curious if can base that of the 4.6's hp given it was available elsewhere) in with just an inspection but the gearbox requires the engineering.