VEMS ECU in a Griff 500
Discussion
Plus a load of other stuff that will happen along the way :)
[b]The plan:[/b]
We all know TVR electrics have their moments, and the Griff ECU and dizzy are certainly a few years behind the times. (Not to mention on ours with 94k miles on the clock, they're a little worn)
So, on a budget of about £500 and whatever parts I find in my workshop, I'm going to see what I can do to improve things. The goals are for easy maintenance & fault diagnosis, more power, more fuel economy, a smoother drive and tolerance for future mods.
[b]Where I'm at now:[/b]
Most of the paper design is done, and suppliers found for 70% of the parts. (Still just within budget too...) There's a floor to lay in the kitchen and some walls to paint, and a crisis to overcome at work - I've got permission to start in November (and will have several weeks of accrued leave to use up...)
[b]Current Spec. (subject to change as funding and feature creep dictates!):[/b]
John Eales crank trigger (36-1 tooth wheel and ready made adaptor bits, all for a good price)
Cam sensor will be fabricated from a spare dead dizzy for now - at least until the cam needs changing.
Fully sequential ignition using 8 coil-near-plug coils driven from the VEMS ECU.
VEMS is a Speed-density based ECU, so no more problems with sourcing unobtainium element MAF sensors ;)
Fully sequential injection using some 500cc/min (ish) Bosch injectors. (Mainly for cruise economy & smoothness, but there are other reasons)
Knock corection facility using piezo electric mics on the block. This should give me a safety margin for mapping. In the main, it'll not do much.
Two wideband lambda sensors so I can run closed loop fuelling for as much of the time as possible.
ECU controlled fans. No more silly otter switches for me...
[b]Some stuff that will happen along the way...[/b]
Probably won't fit in the budget, but that's why credit cards were invented... ;)
Probably some form of sports exhaust. It would be rude not to, wouldn't it?
Renew the fuel lines in braided hose and aeroquip style fittings (and think about locating the fuel filter some place more accessible - I've seen some nice cleanable ones with -6AN fittings...)
Either new manifolds or wrapping the old ones and a bit of fiddling to get the engine temperature to be stable ALL the time.
Fit a nice new modular fuseboard (not worth reusing the old one as much will be changing. And draw an ACCURATE WIRING DIAGRAM.
Relocating the PAS bottle. It's in the way near the plenum, and it gets boiled too. Not ideal, so I'll probably move this to somewhere near the expansion tank.
Full respray. It'll need it more than ever after the work is done.
Interior re-trim. Again, it'll probably need this after things have been ripped out and replaced a few times.
Wish me luck. I'll take plenty of photos!
[b]The plan:[/b]
We all know TVR electrics have their moments, and the Griff ECU and dizzy are certainly a few years behind the times. (Not to mention on ours with 94k miles on the clock, they're a little worn)
So, on a budget of about £500 and whatever parts I find in my workshop, I'm going to see what I can do to improve things. The goals are for easy maintenance & fault diagnosis, more power, more fuel economy, a smoother drive and tolerance for future mods.
[b]Where I'm at now:[/b]
Most of the paper design is done, and suppliers found for 70% of the parts. (Still just within budget too...) There's a floor to lay in the kitchen and some walls to paint, and a crisis to overcome at work - I've got permission to start in November (and will have several weeks of accrued leave to use up...)
[b]Current Spec. (subject to change as funding and feature creep dictates!):[/b]
John Eales crank trigger (36-1 tooth wheel and ready made adaptor bits, all for a good price)
Cam sensor will be fabricated from a spare dead dizzy for now - at least until the cam needs changing.
Fully sequential ignition using 8 coil-near-plug coils driven from the VEMS ECU.
VEMS is a Speed-density based ECU, so no more problems with sourcing unobtainium element MAF sensors ;)
Fully sequential injection using some 500cc/min (ish) Bosch injectors. (Mainly for cruise economy & smoothness, but there are other reasons)
Knock corection facility using piezo electric mics on the block. This should give me a safety margin for mapping. In the main, it'll not do much.
Two wideband lambda sensors so I can run closed loop fuelling for as much of the time as possible.
ECU controlled fans. No more silly otter switches for me...
[b]Some stuff that will happen along the way...[/b]
Probably won't fit in the budget, but that's why credit cards were invented... ;)
Probably some form of sports exhaust. It would be rude not to, wouldn't it?
Renew the fuel lines in braided hose and aeroquip style fittings (and think about locating the fuel filter some place more accessible - I've seen some nice cleanable ones with -6AN fittings...)
Either new manifolds or wrapping the old ones and a bit of fiddling to get the engine temperature to be stable ALL the time.
Fit a nice new modular fuseboard (not worth reusing the old one as much will be changing. And draw an ACCURATE WIRING DIAGRAM.
Relocating the PAS bottle. It's in the way near the plenum, and it gets boiled too. Not ideal, so I'll probably move this to somewhere near the expansion tank.
Full respray. It'll need it more than ever after the work is done.
Interior re-trim. Again, it'll probably need this after things have been ripped out and replaced a few times.
Wish me luck. I'll take plenty of photos!
Since I'm a habitual tinkerer, I picked an ECU that will allow me to get at the code as well as the map. 
My "other reasons" include proofing the electronics against future mods - I am tempted to investigate what happens when you use an islolated runner manifold for instance. But not this year!
My "other reasons" include proofing the electronics against future mods - I am tempted to investigate what happens when you use an islolated runner manifold for instance. But not this year!
VEMS stands for "Versatile Engine Management System". It's an open-source ECU (in the same vain as Megasquirt) and is quite a bit cheaper than GEMS!
Unfortunately, I spent the whole weekend building a trailer and not working on this project. (But I do need a trailer to take the TVR places when it goes wrong...)
Does anyone have an idea where to get a spare fuel rail from? It needn't have any injectors or fittings, it's going to be modified... There's nothing in the local scrapyards.
Unfortunately, I spent the whole weekend building a trailer and not working on this project. (But I do need a trailer to take the TVR places when it goes wrong...)
Does anyone have an idea where to get a spare fuel rail from? It needn't have any injectors or fittings, it's going to be modified... There's nothing in the local scrapyards.
I suppose it's time for an update... Quite a lot has happened, but mostly not on the car. 
I've done a few tidying up jobs like making the alarm window closer work, and general tidying up.
I've also put new veneer on the dash. Hopefully it'll last a while this time. (Well, I used glue where TVR didn't seem to...) The new veneer is rosewood. It'll be unique if nothing else.
It didn't take long to get the old dash into this state!
I borrowed every G clamp I could find to do the gluing.
It took a little bit of thought to get the clamps off again and remove the bracing, as the glue had foamed everywhere. Should be a good joint.
Cutting out the holes took a a good number of hours after the glue dried
Cutting done now - ready for a few coats of Rustins.
Will post some pics of the completed job when I take them.
>> Edited by dnb on Friday 2nd December 00:02
I've done a few tidying up jobs like making the alarm window closer work, and general tidying up.
I've also put new veneer on the dash. Hopefully it'll last a while this time. (Well, I used glue where TVR didn't seem to...) The new veneer is rosewood. It'll be unique if nothing else.
It didn't take long to get the old dash into this state!
I borrowed every G clamp I could find to do the gluing.
It took a little bit of thought to get the clamps off again and remove the bracing, as the glue had foamed everywhere. Should be a good joint.
Cutting out the holes took a a good number of hours after the glue dried
Cutting done now - ready for a few coats of Rustins.
Will post some pics of the completed job when I take them.
>> Edited by dnb on Friday 2nd December 00:02
Back on topic now.
I've calibrated all the sensors ready for VEMS now.
Here's my half-baked test rig for coolant temperature.
It seemed to work too, which is something...
Real ECU bits have arrived too.
Here's a John Eales crank trigger for those who haven't seen one...
Nicely made and decently adjustable.
PAS relocation is happening too. No pics yet.
I've calibrated all the sensors ready for VEMS now.
Here's my half-baked test rig for coolant temperature.
It seemed to work too, which is something...
Real ECU bits have arrived too.
Here's a John Eales crank trigger for those who haven't seen one...
Nicely made and decently adjustable.
PAS relocation is happening too. No pics yet.
Well, not a lot happened again...
I refitted the thermostat housing having flattened off the mating surface, Hopefully it won't leak now. While doing this, I noticed one of the wires to the altenator had gone brittle and snapped. Yet another job.
Still, it'll soon have a new engine loom - so no more problem
On with the PAS bottle relocation:
I made the new bracket for the PAS bottle...
The bottle actually fits on it without hitting anything else...
And as a bonus, the bonnet still closes!
Now I've got to finish the pipe routing.
I refitted the thermostat housing having flattened off the mating surface, Hopefully it won't leak now. While doing this, I noticed one of the wires to the altenator had gone brittle and snapped. Yet another job.
Still, it'll soon have a new engine loom - so no more problem On with the PAS bottle relocation:
I made the new bracket for the PAS bottle...
The bottle actually fits on it without hitting anything else...
And as a bonus, the bonnet still closes!
Now I've got to finish the pipe routing.
Glad yours is working out too
I got most of the wiring loom assembled tonight. No pics as the camera's flat and they'd not be that interesting. I think I bought too much wire, so if anyone wants a custom RV8 loom for VEMS making, let me know...
Had to actually pay for the ECU today (aren't credit cards wonderful things), so no more spending for the month I think I'd better map a few Imprezas to top the funds up.
The relocated PAS bottle seems to work better than the old one. I don't get loads of fluid poured all over the engine now (or even over the rad), and the odd effect of the steering getting heavier when the car is fully warm - presumably due to hot fluid - has gone away. It even passed its MOT.
I got most of the wiring loom assembled tonight. No pics as the camera's flat and they'd not be that interesting. I think I bought too much wire, so if anyone wants a custom RV8 loom for VEMS making, let me know...
Had to actually pay for the ECU today (aren't credit cards wonderful things), so no more spending for the month
I think I'd better map a few Imprezas to top the funds up. The relocated PAS bottle seems to work better than the old one. I don't get loads of fluid poured all over the engine now (or even over the rad), and the odd effect of the steering getting heavier when the car is fully warm - presumably due to hot fluid - has gone away. It even passed its MOT.
Rev-erend - that's kind of the whole point of the thread "In theory, it'll work." Is the closest I can get to saying yes.
Not got the latest update written yet Been too busy earning money to pay for the parts. (Mapping old Imprezas) 
Accoustic knock sensing ought to work reasonably well - there are ASICs for doing this available off the shelf, so it wouldn't surprise me to find one in the OMEX box. Just connect up a sensor (Bosch part no 0261 231 006 for the curious people)
"In theory, it'll work." Is the closest I can get to saying yes. Not got the latest update written yet
Been too busy earning money to pay for the parts. (Mapping old Imprezas) Accoustic knock sensing ought to work reasonably well - there are ASICs for doing this available off the shelf, so it wouldn't surprise me to find one in the OMEX box. Just connect up a sensor
(Bosch part no 0261 231 006 for the curious people) Bench testing the ECU (over a glass of whisky ) when it arrived a few weeks ago.
The trigger wheel was fitted after bench testing the ECU. What a pain that was - They don't come out of the chassis easily, so I took the Y section of exhaust off in the end. I found the bolts holding the puley and balancer together most amusing. They didn't go back because I prefer cap screws - you don't have to make a special thin-wall socket to undo them.
1st time the ECU saw the car. The old ECU is still in charge, but VEMS is watching what it does.
Trigger wheel and sensor produced a poor signal the first time I tried it, as the shielding on the wire wasn't very good. I fixed this and I get a very good signal - with no recorded errors. At least the other sensors ought to be less fussy about noise than this one.
It's too cold & dark to be outside when I get home at the moment, so it's not advanced much recently. Shame, as I wanted it properly running for Viginia Water.
) when it arrived a few weeks ago. The trigger wheel was fitted after bench testing the ECU. What a pain that was - They don't come out of the chassis easily, so I took the Y section of exhaust off in the end. I found the bolts holding the puley and balancer together most amusing. They didn't go back because I prefer cap screws - you don't have to make a special thin-wall socket to undo them.
1st time the ECU saw the car. The old ECU is still in charge, but VEMS is watching what it does.
Trigger wheel and sensor produced a poor signal the first time I tried it, as the shielding on the wire wasn't very good. I fixed this and I get a very good signal - with no recorded errors. At least the other sensors ought to be less fussy about noise than this one.
It's too cold & dark to be outside when I get home at the moment, so it's not advanced much recently. Shame, as I wanted it properly running for Viginia Water.
Progress! It was fins this afternoon, so I abandoned all my good intentions of boarding the loft in favour of playing with the TVR.
Got all the wiring in for the remaining sensors (except the wideband O2) and the injectors.
With a bit of luck, it'll run on VEMS tomorrow.
I wonder exactly how many sensors the Lucas ECU actually needs to run the car? It only has the AFM and the old RPM trigger now, and it still starts the car...
Got all the wiring in for the remaining sensors (except the wideband O2) and the injectors.
With a bit of luck, it'll run on VEMS tomorrow.
I wonder exactly how many sensors the Lucas ECU actually needs to run the car? It only has the AFM and the old RPM trigger now, and it still starts the car...
It does still work. In fact, the steering feel is a little bit lighter than it was, as the fluid isn't getting as hot. The pump seems to suck the fluid up well enough to work.
Just make sure you shield the PAS bottle overflow vent thingy from being able to spray a nice mist of combustable PAS fluid on to the exhaust. I have a bit of thin stainless sheet wrapped round the top of the bottle (not shown in the pic) as a safety measure.
Just make sure you shield the PAS bottle overflow vent thingy from being able to spray a nice mist of combustable PAS fluid on to the exhaust. I have a bit of thin stainless sheet wrapped round the top of the bottle (not shown in the pic) as a safety measure.
I finally sourced a nice air temperature sender - cost me £1 from the local scrappy Now it's mounted in a tapped hole in the manifold. That's the last of the intake side sensors. Just the wideband lambdas to go in. (This means manifold mods... 
)
The wiring's mostly finished now.
I still need to:
tidy up the fan triggering
tidy up the power and ground connectors (just bodged in the old loom at the moment )
Fix the idle stepper
get rid of the Lucas stuff
But it was complete enough to test the car this evening, running with "semi-sequential" (batches of 2) injection. It started first time!! Even though half the parameters are total guesses! It won't idle, but that's not surprising given the stepper isn't configured. The main point is that it ran, so phase 1 is very nearly complete.
There's a few more photos to put up, but right now, it's time for a
Here's to phase 2 - getting ignition & full sequential injection working.
Now it's mounted in a tapped hole in the manifold. That's the last of the intake side sensors. Just the wideband lambdas to go in. (This means manifold mods... ) The wiring's mostly finished now.
I still need to:
tidy up the fan triggering
tidy up the power and ground connectors (just bodged in the old loom at the moment
) Fix the idle stepper
get rid of the Lucas stuff
But it was complete enough to test the car this evening, running with "semi-sequential" (batches of 2) injection. It started first time!! Even though half the parameters are total guesses! It won't idle, but that's not surprising given the stepper isn't configured. The main point is that it ran, so phase 1 is very nearly complete.
There's a few more photos to put up, but right now, it's time for a
Here's to phase 2 - getting ignition & full sequential injection working.
Injectors are 600cc/min Siemens items sourced from RaceTronix in the US - cost was just over £200 (depending on exchange rate) They're end feed high impedance type.
Still using the Rover idle valve - it works OK, although I may change to the Ford type I saw on Pete500's car at the Growl
Still using the Rover idle valve - it works OK, although I may change to the Ford type I saw on Pete500's car at the Growl
Edited by dnb on Tuesday 8th August 21:00
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