E30 M3 S62 Build - Loads of queries about 4x4 drivtrains

[Turk]

Cheers. I am turkish so I can get away with it. Been my nickname since uni.

[ZM Blue Devil]

Nice project and love the user name!

[Turk]

Try these links. Taking ages to load on the iPhone.

http://www.armchair.mb.ca/~dave/BMW/e34/

[Turk]

No I believe the uk one is the same. It's not in mine either but then again I did download it as a torrent.

Where else could this info be hiding?

[The Dark Side of Will]

The US Bentley doesn't cover the iX... Is there a different one for the UK?

[Turk]

I'm just downloading the e34 bentley manual to see if theres anything in that.

Edit - download failed :(

basic:

http://tis.spaghetticoder.org/s/view.pl?2/04/88

[The Dark Side of Will]

Does the E34 ETM cover the 525iX?

[nando]

I think the ABS computer pretty much controls the entire thing

I don't think there's anything particularily awesome about the E34's electronics, though.

[The Dark Side of Will]

I think an E34 t-case would be relatively easy to control. All you really need is to calculate the % difference in wheel speed between the front and rear (probably an average of the 2 pairs of ABS sensors), and then output a PWM dutycycle to the transfercase to lock the coupling until the %slip falls below your threshold.

How does the T-case control box operate? Does it communicate with the ABS over the bus or piggy-back on the wheel speed sensors?

Working the original E34 system into the E30, if feasible, is going to be a lot easier than reprogramming a megasquirt or ardruino to run the T-case...

The next step will be finding appropriate cv joints for the prop Tcase end and front diff end.

If I use an X5 front diff, will this already have limited slip or does that require electric-tronics too?

I'm expecting to use E30 or E34 outers with E53 inners and custom axle shafts (Moser or similar to produce).

The production X5 diff is open. No electronics, no limited slip.
The Quaife for a Z3 4 cylinder supposedly fits, but will need to be disassembled so that the gears can be turned around for it to work in the front end application.

[Turk]

Lol. If u can let me know what to try I will be happily trial it on a bench. I can post pics of plugs etc once I gave. If you can tell me a bit more about the the actual electronics I will need to rig up I can take it to the guys at work tomorrow and see if they are as good as they say they are :D

Im guessing a couple of wires paralleled into the abs sensors into a microprocessor or chip, then a modulated output, triggering a relay then into the Tcase?

Is there anywhere we can find the actual electrical diagram for these?

Would there be any negative effect if we had the tease permanently locked?

[nando]

damn you suck. :p I looked for one forever, but people want way too much for them if they do pop up.

PWM = pulse width modulation. basically a varied voltage pulse (or ground) that would increase or decrease the lockup based on the duty cycle.

it may actually be on/off, but I doubt it. I wouldn't mind getting my hands on one to bench test with..

[Turk]

I think an E34 t-case would be relatively easy to control. All you really need is to calculate the % difference in wheel speed between the front and rear (probably an average of the 2 pairs of ABS sensors), and then output a PWM dutycycle to the transfercase to lock the coupling until the %slip falls below your threshold.

What is PWM duty cycle? I would have no idea where to begin tricking the electrics to make the tcase lock up. If anyone can tell me what needs to be done I have a bunch of electrical engineers at work who may be able to help.

On another note I have just bought an e34 gearbox with Tcase for pennies. I will be picking it up later this week. I will have plenty to chop up and hopefully the necessary to make things work.

The next step will be finding appropriate cv joints for the prop Tcase end and front diff end.

If I use an X5 front diff, will this already have limited slip or does that require electric-tronics too?

[nando]

I think an E34 t-case would be relatively easy to control. All you really need is to calculate the % difference in wheel speed between the front and rear (probably an average of the 2 pairs of ABS sensors), and then output a PWM dutycycle to the transfercase to lock the coupling until the %slip falls below your threshold.

[The Dark Side of Will]

I know I've seen that picture before, but I looked around and couldn't find the thread.

That transmission is a Richmond 6 speed available in the US.

The T-case appears to be either semi-divorced or offset rear output... neither one will fit the e30 tunnel very well.
The stock E30 T-case is semi-divorced (meaning that it is bolted to the transmission but does not share internal volume) and you *may* have room for a semi-divorced T-case if you stick to a relatively compact transmission like the 265, but that T-case looks way too big.
Try to mate up an E34 T-case to the 265... Getting the electronic control working might be easier than you think... Its old enough that the box is unlikely to be tightly integrated to the rest of the car's computers.

[Turk]

opinions on this?

http://www.ebay.co.uk/itm/Land-Rover-Discovery-Series2-LT230-Transfer-Box-1-211-ratio-18-month-warranty-/260948881991?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3cc1c3f247#ht_500wt_1304