GEMS Article

[450Nick]

For those who didn't catch my article in last month's Sprint, here is a copy kindly supplied by the TVRCC. I hope you enjoy reading it as much I enjoyed doing it!

Link

[motul1974]

...I bought my brand new ECU off Mr. Adams straight after reading it!

[Sardonicus]

Just out of interest GEMS was also used on the Rover K series model cars albeit in 4 cylinder form thanks for posting up the link Nick I like a read

[Matthew Poxon]

Very interesting and well written article Nick, I enjoyed reading that. Well done for pulling all the information together and taking the time to write the article I am sure it will help a number of people out with their cars.

[Classic Chim]

I've read it three times,, slightly addicted now
Really informative.

[blitzracing]

Gold dust- I just wish the internals of the GEMS units was open source like the 14CUX is now.

[jazzdude]

So this is really for later cars with cross bolted 450s, or did I understand that wrong?

I am planning an ecu upgrade this winter and the comments about the mapping never being right on other systems out there that are available to us is now a concern after reading that.

[Sardonicus]

jazzdude said:

So this is really for later cars with cross bolted 450s, or did I understand that wrong?

I am planning an ecu upgrade this winter and the comments about the mapping never being right on other systems out there that are available to us is now a concern after reading that.

Lets try to keep things in context here the GEMS cannot and does not run a perfect map for all conditions as accurate as it is inc & its ability to show these after-market ECU's a clean pair or heals I also believe the RV8 as too many inherent faults (like so many from that era) to fully appreciate these benefits i.e odd/unequal intake tracts, poor combustion efficiency etc etc, thats not a dig at Nicks conversion or himself personally if he is happy with it and I am sure he is thats good enough for me lets get one thing straight I am not pissing on any ones corn flakes here inc Nicks I also believe that one of the benefits Nick is enjoying is full sequential injection and its benefits something I am a believer of for all drive-ability

Edited by Sardonicus on Friday 4th August 17:27

[Classic Chim]

^^^^^^
Mine was mapped nearly two years ago.
The mapper has looked over mine a couple of times with lap top and everything's spot on.
All these systems tweak the map and fine tune so unless something's gone out of perimeter then it carries on fine tuning. Mine seems like it gets better and better not worse.
I think the fuelling is one thing, the ignition and timing seems to be the one that's so much better with aftermarket. Fires like clockwork and misfires don't ever exist at any revs. Flat out it seems under employed to me.
It reminds me of a high revving motorbike that has a limiter at 6000 revs,,, totally safe.
Air flow ratios are what I like about mine. Consistent and safe.
All these Ecu just do what the CUX does, but with less operating parts and more scope on ignition.
Mine employs mass air pressure sensor in the inlet manifold so more info the Ecu can use I suppose.
It's such a cool thing to have a Tvr firing and fuelling so precisely and more reliably.
Mapping isn't a problem or more would be talking about it I'd have thought.
My ign servicing consists of plugs,,, that's it. Possibly a wipe of the crank sensor with a baby wipe but I've never done that and been through two winters so far.
Awesome

[Classic Chim]

The other week I was talking with another Tvr friend as the engine warmed up on tickover.
After a few minutes he mentioned the way it idled effortlessly. We were actually 25 yards away and it was just in the background. I get used to it but comments like that bring it home.
His car is awesome by the way. Stepper motor wasn't quite right on his so he could really hear the difference.
It's worth its weight in gold for me.

[450Nick]

Sardonicus said:

ets try to keep things in context here the GEMS cannot and does not run a perfect map for all conditions as accurate as it is inc & its ability to show these after-market ECU's a clean pair or heals I also believe the RV8 as too many inherent faults (like so many from that era) to fully appreciate these benefits i.e odd/unequal intake tracts, poor combustion efficiency etc etc, thats not a dig at Nicks conversion or himself personally if he is happy with it and I am sure he is thats good enough for me lets get one thing straight I am not pissing on any ones corn flakes here inc Nicks I also believe that one of the benefits Nick is enjoying is full sequential injection and its benefits something I am a believer of for all drive-ability

Edited by Sardonicus on Friday 4th August 17:27

Don't worry, my cornflakes are still dry Of course, from a technical perspective it will not be perfect for the mechanical reasons that you've mentioned; but in real world terms, it is hard to distinguish it from perfect. It's hard to put into words, but it's the little things, like the fact that it simply does not shunt at all now, and in the areas where you would expect it to shunt, like walking pace in 5th, it does something to soften its take-up of the drive line - it feels a bit like I'm slipping the clutch but I'm not. According to Mark, there are maps for all of these little bits and pieces in there somewhere, and it's these that really polish it's performance. It may be an old design of engine but it is played extremely well by GEMS - I guess because it was designed for the Range Rover, so smoothness is it's aim.

Edited by 450Nick on Monday 7th August 10:13