gems ECU

[wycoller]

Considering upgrading Lucas ECU to GEMS anyone had experience with Gems ECU appreciate
Ive been off forums for a while but still have 500SC griff thats never going to be sold.
My retirement will be to ship home a Super Snake Shelby 500GT
cheers

[blitzracing]

Its not an easy upgrade- you need the correct timing cover for the cranks sensor to start with. Apart from the mechanical issues, the biggest hurdle is the immobilizer thats built in and is locked in some way to the Range Rover it belongs to- so you have to rechip. Its around £650 for the required chipping (with a remap) from Mr Adams, really makes this a no go. Its pity as its a really smart ECU, but you are better off with something more open source.

[MPoxon]

I did speak to Mark Adams regarding a GEMS ECU a while back. The ECU is well ahead of its time and has fast processors, knock control, fully sequential fuelling and ignition and an ODBII interface. According to Mark the ECU is self mapping so no need to visit the rolling road each time you modify.

Mark can re-code the ECUs using his tornado EPROM software to get around the immobiliser etc. I was tempted as the ECUs you can pick up from eBay quite cheaply. Fitting is not straight forward I believe you need a GEMS cam.

If you don't fancy fitting a new cam then perhaps something like a Motec would offer the same functionality, at a price though unfortunately.

[wycoller]

blitzracing said:

Its not an easy upgrade- you need the correct timing cover for the cranks sensor to start with. Apart from the mechanical issues, the biggest hurdle is the immobilizer thats built in and is locked in some way to the Range Rover it belongs to- so you have to rechip. Its around £650 for the required chipping (with a remap) from Mr Adams, really makes this a no go. Its pity as its a really smart ECU, but you are better off with something more open source.

Thanks Mark i,m working away so Trackv Road will install etc they,ve already completed 2 installations and are in contact with the software design engineer etc they say its self mapping I,m still considering as its not a cheap installation and as i work live abroad its got to be done by 3rd party. my main concern is to prevent running lean and also even running.

[wycoller]

MPoxon said:

I did speak to Mark Adams regarding a GEMS ECU a while back. The ECU is well ahead of its time and has fast processors, knock control, fully sequential fuelling and ignition and an ODBII interface. According to Mark the ECU is self mapping so no need to visit the rolling road each time you modify.

Mark can re-code the ECUs using his tornado EPROM software to get around the immobiliser etc. I was tempted as the ECUs you can pick up from eBay quite cheaply. Fitting is not straight forward I believe you need a GEMS cam.

If you don't fancy fitting a new cam then perhaps something like a Motec would offer the same functionality, at a price though unfortunately.

thanks Mathew
Ian at Trackv Road has installed 2 with good results good info regards immobiliser if i have installed will have that function inactive
i,m still undecided as its quite an expensive outlay .
Gems Cam ? i,ll check on that although i,d thought could be mapped to any cam or am i missing something here
cheers

[blitzracing]

Its the mechanical differences due to not having a dizzy from memory. I think the ECU itself comes in various revisions, some more sutible than others- but as for the self mapping bit, I do believe it runs wideband Lambda, and I suspect you would still have to set the target AFR for your requirements, and I think it runs closed loop all the time. Ive got some details on it somewhere- Ill dig them out.

[MPoxon]

wycoller said:

thanks Mathew
Ian at Trackv Road has installed 2 with good results good info regards immobiliser if i have installed will have that function inactive
i,m still undecided as its quite an expensive outlay .
Gems Cam ? i,ll check on that although i,d thought could be mapped to any cam or am i missing something here
cheers

I didn't realise Track v Road could re-programme GEMS ECUs. I assume were are talking about the Lucas-Sagem GEMS ECU and not the lesser known aftermarket GEMS ECU.

Have a little read through this thread it might be useful:
http://www.pistonheads.com/gassing/topic.asp?h=3&a...

I might have the cam bit wrong as I do not understand why you would need a new cam but I a sure I was told I needed a new cam. You also need the later cross-bolted block which has the bosses for the 2 knock sensors although I am sure something could be fabricated if not.

I would be very interested to hear how you here how you get on and what you decide. I have always quite fancied a GEMS ECU but have been put off by the work involved.

[MPoxon]

blitzracing said:

Its the mechanical differences due to not having a dizzy from memory. I think the ECU itself comes in various revisions, some more sutible than others- but as for the self mapping bit, I do believe it runs wideband Lambda, and I suspect you would still have to set the target AFR for your requirements, and I think it runs closed loop all the time. Ive got some details on it somewhere- Ill dig them out.

I wouldn't mind some more info if you do manage to dig something out please Mark. There really isn't much info on the web about the GEMS-8 ECU and I would like to understand it a bit better.

[blitzracing]

There is quite a lot of Generic stuff in the Des Hammill "How to power tune the Rover V8", I suspect mostly written by Mark Adams, basically saying what a great ECU it is and how it all works, but no nuts and bolts fitting details- and you do need to tune the target AFRS for your particular application. It basically comes in two major types- the Land Rover one- without an extra alarm unit- so this is the one you want over the more complex Range Rover unit. It does have knock sensor that are block / engine size specific, so you need to get this correct and it still needs the immobiliser turned of however, as part of the chipping. If there are chips around that wont cost £600 then it would become more do able.

You can read most of it here, page 182 onwards

http://books.google.co.uk/books?id=gmSavy1RPxEC&am...

[MPoxon]

Cheers Mark. I have that book somewhere I'll rake it out.

[Sardonicus]

I can say for sure this is not no easy install and it def aint cheap even if the ECU is

[wycoller]

blitzracing said:

There is quite a lot of Generic stuff in the Des Hammill "How to power tune the Rover V8", I suspect mostly written by Mark Adams, basically saying what a great ECU it is and how it all works, but no nuts and bolts fitting details- and you do need to tune the target AFRS for your particular application. It basically comes in two major types- the Land Rover one- without an extra alarm unit- so this is the one you want over the more complex Range Rover unit. It does have knock sensor that are block / engine size specific, so you need to get this correct and it still needs the immobiliser turned of however, as part of the chipping. If there are chips around that wont cost £600 then it would become more do able.

You can read most of it here, page 182 onwards
cheers make good reading
http://books.google.co.uk/books?id=gmSavy1RPxEC&am...

cheers mark

[wycoller]

MPoxon said:

I didn't realise Track v Road could re-programme GEMS ECUs. I assume were are talking about the Lucas-Sagem GEMS ECU and not the lesser known aftermarket GEMS ECU.

Have a little read through this thread it might be useful:
http://www.pistonheads.com/gassing/topic.asp?h=3&a...

I might have the cam bit wrong as I do not understand why you would need a new cam but I a sure I was told I needed a new cam. You also need the later cross-bolted block which has the bosses for the 2 knock sensors although I am sure something could be fabricated if not.

I would be very interested to hear how you here how you get on and what you decide. I have always quite fancied a GEMS ECU but have been put off by the work involved.

heres the link Mathew Ian at TRACK v ROAD WILL INSTALL they have a software tech whos marketing the unit will do the mapping. I,M UNDECIDED AS YET AS ITS QUITE EXPENSIVE but if i have it done i,ll let you know .

http://www.lloydspecialistdevelopments.co.uk/fully...

[900T-R]

Something I really don't understand is this - why is it wholly acceptable to pay anything between £600-2500 for 'a more open source' system that needs bespoke wiring and a trip to the rolling road every time something major is changed in the engine configuration, while paying a specialist £ 650 to unlock the GEMS ECU - which costs next to nowt on the second hand market as they don't break and only requires an OEM (V8 Defender) loom which is available brand new for £ 150 or so - suddendly a no goer?

Or more in general - why is it OK to spend a certain amount on a box of chips to replace a boxc of chips you already have, but not a similar amount for someones time and expertise?

I genuinely struggle to understand the ethos behind this.

The more serious hindrance to installing GEMS on intermediate serpentine (AKA TVR from 1994/5 onwards) engines is replacing the front cover bits with those from a late LR/RR RV8, making it more viable for rebuilds or other cases where the engine is out, anyway.

[wycoller]

blitzracing said:

There is quite a lot of Generic stuff in the Des Hammill "How to power tune the Rover V8", I suspect mostly written by Mark Adams, basically saying what a great ECU it is and how it all works, but no nuts and bolts fitting details- and you do need to tune the target AFRS for your particular application. It basically comes in two major types- the Land Rover one- without an extra alarm unit- so this is the one you want over the more complex Range Rover unit. It does have knock sensor that are block / engine size specific, so you need to get this correct and it still needs the immobiliser turned of however, as part of the chipping. If there are chips around that wont cost £600 then it would become more do able.

You can read most of it here, page 182 onwards

http://books.google.co.uk/books?id=gmSavy1RPxEC&am...

thanks Mark good reading

[spend]

900T-R said:

The more serious hindrance to installing GEMS on intermediate serpentine (AKA TVR from 1994/5 onwards) engines is replacing the front cover bits with those from a late LR/RR RV8, making it more viable for rebuilds or other cases where the engine is out, anyway.

Only the cams, timing chains & gear are all different ~ cam nose is redesigned & only Gems style fixed cam gear can be used. You cant have verniers.... cam choice very limited...

Starts ballooning beyond the simple mod it sounds like you are supporting, it reads like MArgins & percentages have more to do with your point of view than engineering.

Anyway are you back in the UK Jim?

[blitzracing]

I wonder if you could get an aftermarket trigger wheel to match the GEMS one, and simply bolt it onto the pully with a crank sensor on a bracket- a load easier than replacing the timing cover etc. After all its only 36 segments on the flywheel, or 10' intervals, less the one missing point for 20'

Edited by blitzracing on Wednesday 12th February 15:17

[spend]

blitzracing said:

I wonder if you could get an aftermarket trigger wheel to match the GEMS one, and simply bolt it onto the pully with a crank sensor on a bracket- a load easier than replacing the timing cover etc. After all its only 36 segments on the flywheel, or 10' intervals, less the one missing point for 20'

Edited by blitzracing on Wednesday 12th February 15:17

Trigger wheel is not the problem.... just bolt a 60-2 on the front instead of the normal 36-1 & time it up.

Its the cam phase sensor which is built into the cam gear & front cover that is the problem when you look into it.. Oh I forgot to mention the Gems timing cover also means you have to install a gems sump as well, the dependencies just keep snowballing along.....

[900T-R]

spend said:

Starts ballooning beyond the simple mod it sounds like you are supporting, it reads like MArgins & percentages have more to do with your point of view than engineering.

Eh?? From a salesman's perspective GEMS is far less attactive thsn pushing <insert aftermarket box of chips du jour> and actually it sounds like you're agreeing with me that GEMS is a viable proposition only when rebuilding/specifying a 'new' engine. From an engineering perspective, however, it's a lot more attractive than acting as a Guinea pig for someone else's aftermarket ECU install if you're into driving rather than tinkering, a lot easier to 'sell' to road authorities with regards to compliance issues, too.

[wycoller]

spend said:

Only the cams, timing chains & gear are all different ~ cam nose is redesigned & only Gems style fixed cam gear can be used. You cant have verniers.... cam choice very limited...

Starts ballooning beyond the simple mod it sounds like you are supporting, it reads like MArgins & percentages have more to do with your point of view than engineering.

Anyway are you back in the UK Jim?

David was until yesterday now back in Singapore.
Thanks all for the good info, i,ll stay with what ive got just need to sort out lean running in upper rev range.
I,ll get fuel pressure gauge installed. Other than that engine is strong , cracks up first time after 8 months sat on its arse.
, bloody diff bush has gone again need to check why thats happening,
But again thanks for all the info i,ll start asking questions regards cam etc. but i,ve feeling your right as i was being sidelined into fitting a new cam.
cheers
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