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

[Turk]

the issue is keeping the can bus networked to stop the case from falling into limp mode. You can get it to "run" with the dme, general module ews and clocks, but not as you'd want it!

[nando]

I think it really depends on two things:
-what *actually* happens with DSC disconnected from the DME (it definitely throws a code, but how is engine operation affected?).
-how much y ou care about emissions related codes (you can still retrieve codes, but since your check/MIL light would always be on, you'd likely want to remove the LED).

other than DSC, there's nothing really tied to the DME that you'd have to convert (all those extra sensors are only for DSC).

[Turk]

no, you would need a fair bit more to even stand a chance. Including steering column, wheel speed sensors, can bus network, abs, dsc... The lot. Far less hassle to pay £1000 odd and have it all plug and play, sell the bit you would have used to offset the cost and save yourself headache.

But yes, start your own thread and I'm sure people will give feedback!

[jevijavi]

Sorry to use your thread to ask this question.

Is it possible to carry out an s62 swap into an e30 without having to hack into the DME?
I have the key, ews, dme, s62(with its harness) + tranny.
If i were to get an e39 main harness, electronic throttle by wire, antenna, cluster could i carry out the swap into the e30 (as for as electronics are concerned)?

[Turk]

also, I really thing a model based on the speed difference of the front and rear wheels is ideal.

This is ideal, BUT, How do I get this to work?

Obviously the car has the abs sensors, Which could potentially be used to feed a standalone tease management system. I don't think the electronics can be that complicated! Surely a microprocessor will suffice in calculating the relevant sums and giving an output.

Even if the tcase was permanently locked surely it would still drive ok as with an LSD front and rear diff controlling slip mechanically differences in wheel speeds will fall within the Slip tolerances?

Would the Tcase burn out if I had it on permanently on say 9v?

[Turk]

http://www.ebay.de/itm/BMW-E34-525iX-Touring-Verteilergetriebe-Getriebe-Allrad-/180774326689?pt=DE_Autoteile&hash=item2a16fd51a1#ht_500wt_1071

[nando]

also, I really thing a model based on the speed difference of the front and rear wheels is ideal. that's pretty much exactly what a viscous coupling does mechanically.

the biggest problem with using an accelerometer is you really won't have good control over slip. lets say you're drag racing and you dump your clutch - for whatever reason, your front left wheel has twice as much traction as the other 3 wheels. all your torque will go out the wheels with less traction (spinning), and the traction wheel will be stationary. and since you won't be moving, the accelerometer won't register. your center diff won't lock and you'll effectively be stuck.

now, that's a bit of an extreme example (although possible!) - most likely *some* acceleration would be measured, but it will look like a peak when you release the clutch, and then drop off dramatically a couple hundred ms later. still, your center diff would go to full lock, then release to something like 50% right when you need it to stay locked. not good.

and there are definitely instances where you'll want it to lock under lighter acceleration. I'm assuming it rains in the UK as it does here - having the AWD always working makes the car way more fun to drive in the rain. :D

You've already got 4 wheel speed sensors (well, 3, but maybe you'd want to consider using an ix ABS computer). Why not take advantage of them? :) comparing the difference in wheel speed can't be that hard, and all you'd need to do was increase the lockup % (as a function of PWM duty cycle) as the % speed difference got larger.

anyway, you really have me thinking. I was going to make an adapter to use the 325ix transfercase with the 525ix transmission. but maybe it would be better to use a 525ix transfercase as well.. got any leads? wanna ship one to the USA for me? :D

[Turk]

Yes that was what I was trying to say :)

[nando]

It never drops to rwd - it will *always* be awd. The only question is if it will be an open diff or not.

[Turk]

Apparently skylines utilise a system called attessa which may work for controlling the slippage. Anyone know bout it?

My next thought is to use an in car accelerometer wired into a time lapsed switch with dimming out feature. Ie if I put the car into first gear and give a little blip on the throttle and clutch the g meter will increase decrease the resistance thus increasing "lock", Then the harder I push the car the more it locks up. If then i am cruising along with no dramas it will in effect drop back to rwd.

I found this:

http://www.ebay.co.uk/itm/GY-29-Digital-Accelerometer-Sensor-Module-Low-Power-New-/180691533455?pt=UK_BOI_Industrial_Automation_Control_ET&hash=item2a120dfe8f#ht_1694wt_1071

I imagine ill need a microprocessor and a variable resistored output device of some sort. Plus maybe a delay timer?

Do we have any electrical engineers who can advise how I might rig up a circuit like this? I would initially wire in a bulb inside the car and see how it reacts to accelerating/braking/cornering.

[Turk]

Cheap tcase for some one. Ask for postage to us tho!

http://item.mobileweb.ebay.co.uk/viewitem?itemId=180829753952

[Turk]

Ok, putting the Tcase issues aside for a moment, I flipped the engine over today and started taking the sump off, The m5 has a 2x part sump (upper and lower) the lower one has to come off first as the bolts holding the oil pump in also hold the upper sump in around 4 locations from why I can tell.

The Magnetic sump oil guide switches had to come out first, I will have to discard these if the x5 sump is infact used (99%) The functionality of these will be programmed out by my ecu guy. He has confirmed its easily done and with the lack of the chassis accelerometer (g-meter) we don't think the system of selective oil pumping would work anyways.



some interesting oil channels leading to shallow part of sump.



I haven't yet removed the oil pump, as i just wanted to enquire as to whether or not the m5 oil pump will fit the x5 pan?

I can see there is a cover over the chain and i can envisage a single nut under there holding the sprocket in place (just like the 24V swaps) Im hoping the sprocket can also be used. I will chuck a cable tie on the chain to make sure it doesn't jump a tooth or anything, Not sure if the chain position effects the oil pump but better safe then sorry.

[jevijavi]

However, if the final product has an M3 VIN, it will be worth FAR more than if it did not.

tru dat

[The Dark Side of Will]

How much is a one-eyed, one-horned, flying purple people-eater worth?

Immaculate, Concours-quality M3's with low mileage and complete maintenance records top out between $20K and $30K.
In the US, if you can get a rust-free rolling chassis with complete interior but no powertrain for $4K, you got a pretty good deal.

www.S14.net is a better site for M3-specific questions.

[Turk]

However, if the final product has an M3 VIN, it will be worth FAR more than if it did not.

Exactly this /\

Anyone have an estimate of how much an immaculate 5.0 V8 E30 M3 AWD will be worth?