GEMS Update - Calling 450Nick - Project Review Request
Discussion
Please excuse the knock on your door 450Nick but this is quite possibly the most interesting topic for years and a potential game changer for many, as such I'm sure we would all love a complete and detailed presentation on the project now you're up and running with the fully sequential GEMS system. I appreciate you're still in the appraisal phase but as the car is running I'm assuming the key development work on the conversion has been completed to your satisfaction so a bit more detail would be welcomed by us all.
Clearly the idea of fitting a GEMS engine management system to a Chimaera burdened with the 14CUX and distributor has many many advantages, and even offers advantages over the common stand alone engine management offerings that have been around for a long while now, it also seems highly likely the GEMS system could be the best way to improve anything from bog standard 4.0 litre to the most highly modified RV8 TVR.
Some questions:
I'm in no doubt there's a lot more to it than a trip your local Range Rover breaker to harvest the cheap to buy ECU & loom, which is why I'm hoping you can give us a full overview of the conversion, whats involved, and the true end cost of it all. Mark Adams clearly has the skills to solve all the inevitable detail challenges and if he's planning on offering GEMS conversions I'd be surprised if it didn't become the default choice for anyone considering updating their Chimaera from the old 14CUX and distributor.
I can see why Mark's 14CUX chip and tuning business may have slowed significantly in recent years, is this his way to recover his position as the go-to TVR RV8 mapper? If Mr Adams can offer the conversion at a price that competes with or even beats the MBE, Canems or Emerald options I could see him doing just that.
Thanks in advance for any update you can offer, I do get there's always an element of 'I did it first' competitiveness on PH but I'd hope as you've now indeed 'done it first' you might now be ready and willing to share a bit more on this very interesting and promising conversion?
Dave.
Clearly the idea of fitting a GEMS engine management system to a Chimaera burdened with the 14CUX and distributor has many many advantages, and even offers advantages over the common stand alone engine management offerings that have been around for a long while now, it also seems highly likely the GEMS system could be the best way to improve anything from bog standard 4.0 litre to the most highly modified RV8 TVR.
Some questions:
- Is the software used to view and calibrate the GEMS readily available?
- In your opinion is the software user friendly?
- While I appreciate the system is largely self learning how straightforward is it to change the base calibrations which I'd assume would be essential to configure, prior to the self learning phase?
- Is the GEMs conversion something Mark Adams is planning to offer TVR owners?
- Will GEMS users be tied to Mark Adams for the base calibration and future changes to the base calibration should the owner makes significant changes to his engine spec?
I'm in no doubt there's a lot more to it than a trip your local Range Rover breaker to harvest the cheap to buy ECU & loom, which is why I'm hoping you can give us a full overview of the conversion, whats involved, and the true end cost of it all. Mark Adams clearly has the skills to solve all the inevitable detail challenges and if he's planning on offering GEMS conversions I'd be surprised if it didn't become the default choice for anyone considering updating their Chimaera from the old 14CUX and distributor.
I can see why Mark's 14CUX chip and tuning business may have slowed significantly in recent years, is this his way to recover his position as the go-to TVR RV8 mapper? If Mr Adams can offer the conversion at a price that competes with or even beats the MBE, Canems or Emerald options I could see him doing just that.
Thanks in advance for any update you can offer, I do get there's always an element of 'I did it first' competitiveness on PH but I'd hope as you've now indeed 'done it first' you might now be ready and willing to share a bit more on this very interesting and promising conversion?
Dave.
I thought all the details of this was going to be published in a Sprint article. I no longer receive Sprint so don't know if it's appeared, I'm sure I read somewhere it was meant to be published around March time but as there's been no discussions over this I assume it hasn't !
Maybe it's still in the testing stage.
Maybe it's still in the testing stage.
Mark's very much involved with this but I'm not sure about conversions. I think something may be in the pipeline though. I recently did a gems conversion on a small block chevy to enable it to speak with the range rover gearbox. Mark should be providing a chip at some stage. It's definately viable for an RV8.
I'm hoping to be perhaps the second TVR GEMS conversion although my progress is painfully slow at the moment. (I thought I read somewhere a long time ago that David Beer had fitted GEMS to his Griff?)
Nick and I collaborated on designing a suitable trigger disc to fit the dizzy cam nose with a JP timing gear and this is working in his car, but i think Nick has done so much legwork and 'banging head against the wall' on all the other stuff to make it work he deserves a medal.
The biggest hurdle for most TVR conversions will be whether the block is the 38A cross bolted type fitted in the P38 range rovers as these have the lugs and fittings for knock sensors etc. This is going to be the deciding factor I think on whether a GEMS install is doable or not. Luckily when I had a new engine from V8D I opted for a large journal cross bolted block so although I didn't have a GEMS install in mind at the time I do have a 38A block.
Over the last two or three years I've collected all the parts required mostly very cheaply although the parts available on eBay do seem to be getting scarcer. Bear in mind the last GEMS engined Range Rovers are now approaching 20 years old.
All I need to do now is put together a wiring loom so I'm planning to finally do the install over the next winter season.
I haven't seen Nick's article in Sprint yet, hopefully it'll be covered soon, might spur me on to get the wiring loom going
Nick and I collaborated on designing a suitable trigger disc to fit the dizzy cam nose with a JP timing gear and this is working in his car, but i think Nick has done so much legwork and 'banging head against the wall' on all the other stuff to make it work he deserves a medal.
The biggest hurdle for most TVR conversions will be whether the block is the 38A cross bolted type fitted in the P38 range rovers as these have the lugs and fittings for knock sensors etc. This is going to be the deciding factor I think on whether a GEMS install is doable or not. Luckily when I had a new engine from V8D I opted for a large journal cross bolted block so although I didn't have a GEMS install in mind at the time I do have a 38A block.
Over the last two or three years I've collected all the parts required mostly very cheaply although the parts available on eBay do seem to be getting scarcer. Bear in mind the last GEMS engined Range Rovers are now approaching 20 years old.
All I need to do now is put together a wiring loom so I'm planning to finally do the install over the next winter season.
I haven't seen Nick's article in Sprint yet, hopefully it'll be covered soon, might spur me on to get the wiring loom going
Edited by MisterT on Friday 2nd June 16:17
I don't get the Sprint magazine either, they have approached me to do something on my terribly exciting LPG conversion but Piston Heads seems a much more accessible platform that's open to many more people.
To me (after a small dabble with the failed Blatters) PH is the place to present something new and interesting like the GEMS conversion, more will see it, more will comment on it, and more will benefit from the good work 450Nick & MisterT have done to make it a reality.
The idea clearly has lots of promise, but I'm yet to be fully convinced its a viable alternative to the other stand alone ECU options.
Saying that I just don't know enough about it right now, hence my questions.
To me (after a small dabble with the failed Blatters) PH is the place to present something new and interesting like the GEMS conversion, more will see it, more will comment on it, and more will benefit from the good work 450Nick & MisterT have done to make it a reality.
The idea clearly has lots of promise, but I'm yet to be fully convinced its a viable alternative to the other stand alone ECU options.
Saying that I just don't know enough about it right now, hence my questions.
Tell you what. I'll join if you do a proper COG write up of your lpg system in Sprint,,, on one condition,,,, you feature my Brembos in another topic Sprint have to agree to splash allover the pages 
I agree the Gems should be openly discussed here but I can also see why people want to get it right before committing themselves to it.
Hopefully when it's been proven to work over countless different conditions can anyone be sure, that must takes months surely. I can only assume there's issues with it if it's been held back but that could just be Sprints run order taking time to get it out! I reved mine to the limiter enough times the other week, it's controlled so well it can't go towards pinking if you ask me. Seems safe up there, Bullet proof, I'm sure it's not but it seems to fuel the same at the top as at the bottom and sounds smooth as you like,,,, not fast enough compared to the racers around me but they are the best around so no shame.
I'm not sure knock sensors are needed for my engine unless I tuned it and opened it up more.
I agree the Gems should be openly discussed here but I can also see why people want to get it right before committing themselves to it.
Hopefully when it's been proven to work over countless different conditions can anyone be sure, that must takes months surely. I can only assume there's issues with it if it's been held back but that could just be Sprints run order taking time to get it out! I reved mine to the limiter enough times the other week, it's controlled so well it can't go towards pinking if you ask me. Seems safe up there, Bullet proof, I'm sure it's not but it seems to fuel the same at the top as at the bottom and sounds smooth as you like,,,, not fast enough compared to the racers around me but they are the best around so no shame.
I'm not sure knock sensors are needed for my engine unless I tuned it and opened it up more.
Interested to know a bit more too.
I am in week 2 of Emerald K6 ownership, after 35,000 miles on the 14CUX.
Seems excellent to me.
Wasted spark, proper control over all functions.
All was fine from the start except I had a hot restart issue, nothing else.
Quick call to Jools, who came over yesterday to mine and re-mapped that part of the fuelling map to remove the issue. On all three switchable maps.
Drove to Scotland today. Three hot restarts during the trip, plus a lot of hot idling in grim Friday afternoon traffic. Engine impeccable, despite the extra heat of the turbo. Never overheated. Went straight to 900 rpm on restart. Utterly delighted. And 23 mpg from a 4.6 turbo, with a fair bit of hard acceleration and lots of crawling in traffic.
So what does the GEMS offer over the current after market systems?
I am in week 2 of Emerald K6 ownership, after 35,000 miles on the 14CUX.
Seems excellent to me.
Wasted spark, proper control over all functions.
All was fine from the start except I had a hot restart issue, nothing else.
Quick call to Jools, who came over yesterday to mine and re-mapped that part of the fuelling map to remove the issue. On all three switchable maps.
Drove to Scotland today. Three hot restarts during the trip, plus a lot of hot idling in grim Friday afternoon traffic. Engine impeccable, despite the extra heat of the turbo. Never overheated. Went straight to 900 rpm on restart. Utterly delighted. And 23 mpg from a 4.6 turbo, with a fair bit of hard acceleration and lots of crawling in traffic.
So what does the GEMS offer over the current after market systems?
Really chuffed 
Knock sensors I think, I've been reading about them and although our engines aren't noisy it's also difficult to set them up to detect pinking and not some other engine noise.
The roller rocker cam looks good doesn't it, maybe together you can create a wold class smooth engine that can Rev its head off and control pinking with confidence. Dom and Jay are developing all this with MBE but it's world class expensive
Knock sensors I think, I've been reading about them and although our engines aren't noisy it's also difficult to set them up to detect pinking and not some other engine noise.
The roller rocker cam looks good doesn't it, maybe together you can create a wold class smooth engine that can Rev its head off and control pinking with confidence. Dom and Jay are developing all this with MBE but it's world class expensive
QBee said:
So what does the GEMS offer over the current after market systems?
For a start it's fully sequential so that's going to give you an even smoother idle, better low speed drivability, and lower emissions at idle and around town when a comparison is made with batch fired injection, in your stop start traffic scenario I would expect the car to be marginally more economical too.Finally it makes a nice pairing with forced induction because with knock control you can let the ECU take care of safety rather than rely on what you mapper has given you, which invariably will be a calibration that sits on the side of caution.
Potentially this means more boost, and more boost means a faster car, so in theory there are drivability benefits, fuel economy benefits and performance benefits to boot, the emissions thing I'm sure is of little or no interest here.
These benefits might be small, but there are enough of them to warrant a closer evaluation.
ChimpOnGas said:
QBee said:
So what does the GEMS offer over the current after market systems?
For a start it's fully sequential so that's going to give you an even smoother idle, better low speed drivability, and lower emissions at idle and around town when a comparison is made with batch fired injection, in your stop start traffic scenario I would expect the car to be marginally more economical too.Finally it makes a nice pairing with forced induction because with knock control you can let the ECU take care of safety rather than rely on what you mapper has given you, which invariably will be a calibration that sits on the side of caution.
Potentially this means more boost, and more boost means a faster car, so in theory there are drivability benefits, fuel economy benefits and performance benefits to boot, the emissions thing I'm sure is of little or no interest here.
These benefits might be small, but there are enough of them to warrant a closer evaluation.
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