lexus v8 into p38 range rover?

[scott120160]

hi good like minded fellows? i have a 4.6 1999 range rover with the normal problem cracked block! so i want to put another engine in it i was thinking (dangerous i know) of the lexus v8 as for their size they are reasonably powerful and most of all reliable, any one done it? this range rover as we all know has electric and an ecu for everything? fly by wire, electronic gearbox etc etc! i want to try and use as much of the range rover as poss but dont mind using the lexus gearbox as long as i can get an adaptor for the transfer box? thanks for any advice. or any other engine swops etc, i phoned the conversion people that took over from milners and they can do an adaptor plate for a chevy to my gearbox and drive plate but that is it? so i also rang overfinch but because my car is so old they didn't want to know and couldn't tell me anything about that conversion from 1999 when mine was new!! thanks ian

[Eliot]

I want to put a chevy in my P38, but dealing with the ECU is a problem.
The earlier GEMS ecu probably offers the best chance because the ECU talks to the BECM using discrete lines, whereas the later BOSCH system uses CAN - which means unless you are very skilled at creating electronics which can talk the same protocols you wont be able to interface it.
For example the RPM signal from the ECU goes to the BECM which then sends it to the Instrument binnacle and the gearbox ECU.
My idea with an engine swap was to try and send signals to the GEMS ecu to think the engine is still there, such as a 36-1 pickup for revs and Throttle position for the gearbox shift points etc.
Of course if you want to pay Mark Adams to remap the GEMS ecu you could just make that ECU drive the Lexus or any other engine (i think overfinch did this)
Personally any conversion needs to be mappable by myself - so my current plan is to retain the Rover engine and see if I can piggy back a megasquirt onto the engine to control fuel and sparks, whilst the GEMS still believes its in control, which will provide all the correct signals back to the BECM and other ECUs such as ABS and Gearbox.
It will probably throw an engine light permanently because it won’t be able to maintain what it thinks is lambda (Even though we are maintaining it)
If I can get fuel and sparks under control, I can then look at forced induction.

[kiwicar]

Hi Elliot,
Your plan sounds like a very good aproach, should work a treat I can't see why the lambdas to the GEMs should be a problem though, can't you just send a voltage from a variable resistor back up to the ECU set to a suitable level to keep it happy? You send the real lambda signal back to the MS ecu, you don't have to tell the GEMS the truth, just what it wants to know to keep it happy! Infact you can do that for pretty much all the sensors if you need to.
Just re-read this, have I just turned into a politician ?
Best regards
Mike

[Eliot]

Most ECU's, including the GEMS as I remember are actually looking for the Lambda sensors to switch rapidly between high and low which indicates that stoic has been achieved, rather than a simple .5v
And with the post cat sensors they are actually comparing the phase shift in that wave form between the front and back sensors - hence why i suspect it will take a dump.
I intend to leave the OEM lambdas in place and weld an extra boss in for a wideband anyway - so it may work.

[kevcon]

Here we go.
Found the old post I posted a link on. Guy on LRO has done the swop on a classic Range Rover.
Might be able to answer some of your question for you.

http://www.v8forum.co.uk/forum/viewtopi ... sc&start=0

kev

[scott120160]

hi chaps! thanks for the answers so for i read the one re p5 conversion but he wont have to many probs with ecu's where i have ecus for every dam thing plus the main control unit? thanks for the other info etc i was considering the chevy route that is why i contacted overfinch, but was unsure of what year engine to use? i.e a later engine with fuel injection etc, i know there are a couple of differant types of efi on chevys but i didn't know which one will be simplier to use? i like the lexus engine because of its reliability etc? as for as the problems you were quoting can you or do you know anyone who can sort these for me? thanks ian

[DaveEFI]

hi chaps! thanks for the answers so for i read the one re p5 conversion but he wont have to many probs with ecu's where i have ecus for every dam thing plus the main control unit? thanks for the other info etc i was considering the chevy route that is why i contacted overfinch, but was unsure of what year engine to use? i.e a later engine with fuel injection etc, i know there are a couple of differant types of efi on chevys but i didn't know which one will be simplier to use? i like the lexus engine because of its reliability etc? as for as the problems you were quoting can you or do you know anyone who can sort these for me? thanks ian

To be perfectly frank, it would be much better to flog yours and convert an earlier one without all the fancy electronics. Unless someone already offers an interface kit for what you need.