Board logo

Using a modern donor engine AND ecu in a kit?
interestedparty - 5/8/10 at 01:24 PM

A friend of mine is thinking of getting a Pilgrim Sumo cobra replica, and wants to put an XK8 engine and gearbox in it. That engine only comes with an automatic box, but that would be a big advantage for him (his left leg isn’t so good).

We’ve been looking into this and there’s a lot of integration between the auto gearbox, which is electronic, and the main ecu, so using the Jag ecu is pretty much essential. What is worrying is the way modern cars have CAN buses and all sorts of other tricky stuff, so is it likely that this set up could be made to work in a kit car?

Any advice much appreciated

Miks15 - 5/8/10 at 01:34 PM

I would think you would need to use the jag clocks etc as this would use the signals from the ECU.

Anythings possible i guess, its just how much time do you want to put in to the loom? I would think your best bet would be to use the Jag loom and get rid of bits you dont need. So it would be a matter of taking a week with the jag wiring diagram, working out bits you dont need, finding them in the loom and removing carefully.

liam.mccaffrey - 5/8/10 at 01:39 PM

alternatively use an older less integrated jag autobox that doesn't talk to the ECU

interestedparty - 5/8/10 at 02:03 PM

quote:
Originally posted by liam.mccaffrey
alternatively use an older less integrated jag autobox that doesn't talk to the ECU



You would have to go back a LONG way for that, probably back to the days of the 3 speed Borg Warners. Nothing that an XK8 engine would fit onto anyway, or not that I know of that is.

If the donor ecu could be made to work then that would open up the possibilty of using the FBW throttle etc, maybe even cruise control.

Miks15 - 5/8/10 at 02:09 PM

yep you could certainly use quite a few of the safety features!

Might even be able to use a few airbags! haha

jollygreengiant - 5/8/10 at 03:03 PM

The other thing that you would probably have causing some problems is that the ecu's on modern cars are usually tied into the alarm/imobiliser and if the alarm does not 'see' specific items it will shut down all the ECU's. Finding out what these items are likely to be will be next to imposiible.

mark chandler - 5/8/10 at 03:18 PM

I think you would struggle without taking all the bits and bobs, the bell housing is not the same as earlier jag boxes.

My XK8 has loads of relays and widgits, it uses CAN comms between the devices, if you poke the sport button it seems to change both the engine and gearbox, if you get any issues it goes into limp mode, no more than 3000rpm, the triggers for this even include leaving the bonnet up.

I had a relay come loose which was todo with the cruise, it would not run then...

No reason not to run an aftermarket ECU for the engine, the gearbox is the challenge if you do this.

Great engines BTW

interestedparty - 5/8/10 at 03:27 PM

quote:
Originally posted by mark chandler


No reason not to run an aftermarket ECU for the engine, the gearbox is the challenge if you do this.


If there was some way of controlling the box externally that would be a good solution (probably the best) and would allow an aftermarket ecu for the engine.

Thing is, nobody seems to make anything to do this, I suppose wanting to transplant an engine like this into another car doesn't crop up usually.

I will have a look at some US forums, people over there aren't so horrified at the thought of an auto in a kit car.

mcerd1 - 5/8/10 at 05:09 PM

you could run the engine on an aftermarket ECU and have a look for a more modern auto box (but one that's still independent) that you could make fit the jag engine

its probably easier to sort out a modified/custom bellhousing than it is to do all the electronics


having said that an older engine would make the emissions test easier (no cat needed)


[Edited on 5/8/2010 by mcerd1]

mark chandler - 5/8/10 at 05:18 PM

I think its a merc gearbox BTW, either that or a ZF, not jag specific apart from the bolt pattern.

interestedparty - 5/8/10 at 05:19 PM

quote:
Originally posted by mcerd1
you could run the engine on an aftermarket ECU and have a look for a more modern auto box (but one that's still independent) that you could make fit the jag engine
]



Modern auto boxes are all electronic, unfortunately, every single one. Some of them have their own ecu but they still need info from the engine ecu

mcerd1 - 5/8/10 at 06:02 PM

quote:
Originally posted by interestedparty
Modern auto boxes are all electronic, unfortunately, every single one. Some of them have their own ecu but they still need info from the engine ecu


I was just thinking that there must be one out there you could work with....

interestedparty - 5/8/10 at 06:22 PM

quote:
Originally posted by mcerd1
quote:
Originally posted by interestedparty
Modern auto boxes are all electronic, unfortunately, every single one. Some of them have their own ecu but they still need info from the engine ecu


I was just thinking that there must be one out there you could work with....



Nice of you to think that. I reckon the best way forward, if the project was going to work at all, would be to run the engine with an aftermarket ecu, and get someone who was clever with electronics to run up a control unit which would allow it to work in a tiptronic style.

Interesting.

mcerd1 - 5/8/10 at 11:40 PM

there has to be some way round it - otherwise the yanks wouldn't be able to change the ECU on most of there cars
(not very helpful I know, but I'm looking into it)

nz_climber - 6/8/10 at 01:36 AM

Whats so wrong with transplating everything including all the ecu's and the wiring needed into the kit car. Sure it would be a bit of work and might need the clocks and a few extra wires and maybe a imobilizer. If you had a donor car then this should be pretty easy to do.

There is also a couple of aftermarket auto box controllers out there that could be used in conjunction with an aftermarket ecu (but then things get expensive)

Would really need to ask a few questions on some Jag forums and get some wiring diagrams.

bimbleuk - 6/8/10 at 10:46 AM

quote:
Originally posted by mcerd1
there has to be some way round it - otherwise the yanks wouldn't be able to change the ECU on most of there cars
(not very helpful I know, but I'm looking into it)


GM for example have been using a common PCM across a lot of their vehicles. Very capable hardware which is locked but programmable with the right software. Later versions separated the transmission to a BCM and linked them with codes over a CAN buss.

For my LS1 V8 conversion I imported a pre-programmed PCM which had the security, emmisions and self learning (prevents any future mods) features disabled to stop error codes and the dreaded limp mode. $175 delivered was a bargain.

So maybe there is an equivalent package to access the Jag control modules out there?

[Edited on 6-8-10 by bimbleuk]