Praise to Tornado Systems and Sportmotive
Discussion
I can't remember if this was GEMS or not (was a while ago), but I'm sure Mark A told me it was able to measure the radial acceleration of the crank with each cylinder detonation through use of a very large trigger wheel which is fixed directly to the outer perimeter of the flywheel, giving quite high resolution on position. Slightly into storytime there but that seems plausible to me. If it's a mechanical system and you put a bang at one end and measure rate of acceleration out the other side then you should be able to work out if altering the timing or size of the bang is having a positive or negative effect on progress given the fixed system in between.
I didn't say it was self mapping - this may be feasible now with machine learning algorithms doing something clever with the above but certainly not in 1994. Of course it needs a base map, which is where all the Rover engineering development and testing time went, but it has trim factors that can adjust from base position. In the case of GEMS, I believe the range is quite large (+-50%) so it can make quite big changes, though I don't know how many trims there are.
What Mark does is get the base map inside GEMS as close as possible to your standard tune (to leave as much of the 50% adjustment available for the trim factors) through re-scaling the injector size which shifts the whole map up or down. He makes a few more changes to let the ECU know it's in a TVR, not a range rover (I think there's a setting for vehicle weight, allowable acceleration rate of change, speed limit etc) so he makes these more "sporting" - they're turned down to keep the RR feeling like a RR.
I seem to remember him saying there are pages and pages of settings in there for things like the mechanical dimensions of the engine (cylinder size, stroke dimensions, volumetric efficiency etc etc) which theoretically allow it to be set up for all sorts of stuff - no idea if he uses these.
As an example of the sort of thing it does do, he told me a story about a guy who used a GEMS engine in an off road racing car of some sort. They had a slight problem with the car (something like lap time erosion which pointed to a slight drop in power). The engine sounded sweet and nothing appeared wrong. After a lot of digging they eventually found that one of the injectors was very heavily blocked or damaged, but GEMS had adapted to make the best of what it had available. It was right at the edge of its adjustment limit so hadn't yet called out to the driver for a check engine warning and error code which is what you want for a road car (don't bother me unless you really mean it!) but perhaps less ideal for a racer. Quite impressive though I thought, Mark is full of amazing stories about its capabilities and examples of it doing crazy things.
After discussing with him for many hours I was totally sold and couldn't believe no one ever bothered offering a TVR conversion kit before. Apparently I was the first person to ever actually do it other than TVR themselves for 2 cars destined for Switzerland in the 90s and it really wasn't that hard (with Mark's help of course).
The beauty of it really is:
- It's properly fit and forget
- OEM quality (the ECU is pressurised with inert gas and is actually water-proof)
- Specifically designed for this engine
- If all hooked up then fully Euro IV compliant emissions
- Was fitted as standard (albeit only twice due to high cost and special circumstances) by TVR themselves so can be considered a factory approach
- Uses OBD2 diagnostics so can be plugged in with any bluetooth or wifi dongle and accessed by your phone or ipad, or can be read by any garage to check standard fault codes if there ever is a problem
- It re-adjusts and applies what it's learned every time you turn the car back on from the previous drive. This constant refinement keeps it spot on in any season, location or if you change a component, something wears
- You never need to get it mapped (just set up)
- You never need to get it remapped.
- If you get a new cam (for example), you just drive it a few times and you feel it dial its self in. So cool.
I didn't say it was self mapping - this may be feasible now with machine learning algorithms doing something clever with the above but certainly not in 1994. Of course it needs a base map, which is where all the Rover engineering development and testing time went, but it has trim factors that can adjust from base position. In the case of GEMS, I believe the range is quite large (+-50%) so it can make quite big changes, though I don't know how many trims there are.
What Mark does is get the base map inside GEMS as close as possible to your standard tune (to leave as much of the 50% adjustment available for the trim factors) through re-scaling the injector size which shifts the whole map up or down. He makes a few more changes to let the ECU know it's in a TVR, not a range rover (I think there's a setting for vehicle weight, allowable acceleration rate of change, speed limit etc) so he makes these more "sporting" - they're turned down to keep the RR feeling like a RR.
I seem to remember him saying there are pages and pages of settings in there for things like the mechanical dimensions of the engine (cylinder size, stroke dimensions, volumetric efficiency etc etc) which theoretically allow it to be set up for all sorts of stuff - no idea if he uses these.
As an example of the sort of thing it does do, he told me a story about a guy who used a GEMS engine in an off road racing car of some sort. They had a slight problem with the car (something like lap time erosion which pointed to a slight drop in power). The engine sounded sweet and nothing appeared wrong. After a lot of digging they eventually found that one of the injectors was very heavily blocked or damaged, but GEMS had adapted to make the best of what it had available. It was right at the edge of its adjustment limit so hadn't yet called out to the driver for a check engine warning and error code which is what you want for a road car (don't bother me unless you really mean it!) but perhaps less ideal for a racer. Quite impressive though I thought, Mark is full of amazing stories about its capabilities and examples of it doing crazy things.
After discussing with him for many hours I was totally sold and couldn't believe no one ever bothered offering a TVR conversion kit before. Apparently I was the first person to ever actually do it other than TVR themselves for 2 cars destined for Switzerland in the 90s and it really wasn't that hard (with Mark's help of course).
The beauty of it really is:
- It's properly fit and forget
- OEM quality (the ECU is pressurised with inert gas and is actually water-proof)
- Specifically designed for this engine
- If all hooked up then fully Euro IV compliant emissions
- Was fitted as standard (albeit only twice due to high cost and special circumstances) by TVR themselves so can be considered a factory approach
- Uses OBD2 diagnostics so can be plugged in with any bluetooth or wifi dongle and accessed by your phone or ipad, or can be read by any garage to check standard fault codes if there ever is a problem
- It re-adjusts and applies what it's learned every time you turn the car back on from the previous drive. This constant refinement keeps it spot on in any season, location or if you change a component, something wears
- You never need to get it mapped (just set up)
- You never need to get it remapped.
- If you get a new cam (for example), you just drive it a few times and you feel it dial its self in. So cool.
Agreed Nick would of made a cracking TVR supplied ecu even if the very early Chimaera and Griffith missed it 92/93 for example 
yes misfire detection is how you explained it this is used presently on vehicles i.e crankshaft acceleration/deceleration cross ref to what cylinder being fired
yes misfire detection is how you explained it this is used presently on vehicles i.e crankshaft acceleration/deceleration cross ref to what cylinder being firedSILICONEKID 357HP said:
I don't understand why you need it .
I just turn the key and my car starts up and works perfectly .
If I did have any problems Jools would sort it out .
Do we need all this for a sports car which does very low mileage ?
If you're happy with your car and it does what it's supposed to do then I agree, don't change it! I only went this route as my car is heavily modified and required extensive re-mapping and in my opinion the 14CUX was not an optimal choice to do this safely (several people with supercharged cars have had massive issues with the 14CUX and I didn't want to go that route).I just turn the key and my car starts up and works perfectly .
If I did have any problems Jools would sort it out .
Do we need all this for a sports car which does very low mileage ?
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