VEMS ECU in a Griff 500

VEMS ECU in a Griff 500

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dnb

Original Poster:

3,330 posts

243 months

Wednesday 14th September 2005
quotequote all
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!

jellison

12,803 posts

278 months

Thursday 15th September 2005
quotequote all
Sound like this will be a good step forward for the RV8 ECU - if it can be done - good luck.

GreenV8S

30,210 posts

285 months

Thursday 15th September 2005
quotequote all
dnb said:

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.


Just being nosy, what are the 'other reasons' for going sequential?

Sounds like you have got a very similar shopping list to mine, except that I am starting with a pre-serpentine front end. I've gone for OMEX 710, which ticks the right boxes but at first glance I'm rather disappointed with the lack of sophistication on the software side. Will wait to see how well it works in anger before I make any judgement though.

dnb

Original Poster:

3,330 posts

243 months

Thursday 15th September 2005
quotequote all
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!

daxtojeiro

741 posts

247 months

Thursday 15th September 2005
quotequote all
Hi there,
no idea how much a VEM's ECU is, but Ive Megasquirted 3 Rover based V8's now, the last one being a TVR 500 and have acheived all that you want, all bar the sequential injection, but then theres no need for that on a road engine, especially on an RV8. But it will be available very soon in MSII. Anyhow, look into Megasquirt before making your decision if you dont want to waste money:
http://megasquirt.sourceforge.net/extra/
www.msefi.com/

Phil

dnb

Original Poster:

3,330 posts

243 months

Friday 16th September 2005
quotequote all
VEMS is based on the MS, but it uses Atmel AVR series chips - which I've used in a few other projects and quite like.

I don't think doing my own reseach will be a waste of money. I haven't listed all of my other reasons yet.

zenkar

68 posts

238 months

Friday 16th September 2005
quotequote all
I have a GEMS ECU on my griff.
TVR Power and Mark Adams told me they have never seen another one on a griff so far (2 chips inside )
What is the difference with VEMS ECU ?

dnb

Original Poster:

3,330 posts

243 months

Sunday 18th September 2005
quotequote all
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.

rev-erend

21,421 posts

285 months

Monday 19th September 2005
quotequote all
I'm sure you can guess but quite a few of us are following this with interest...

GreenV8S

30,210 posts

285 months

Monday 19th September 2005
quotequote all
dnb said:

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.

Mine came from eBay, together with an EFI manifold (that also contributed a couple of flanges towards the new manifold).

dnb

Original Poster:

3,330 posts

243 months

Monday 19th September 2005
quotequote all
Still waiting for things in the post Rev. Should be something to talk about after the weekend even if it's only moving the PAS bottle...

Thanks for the pointer on the fuel rail. I'll have a look.

trackcar

6,453 posts

227 months

Tuesday 20th September 2005
quotequote all
On the fuel rail front .. don't know if you're keeping the original location or moving the injectors, but some early vauxhalls have injectors where the supply pipe is jubilee clipped onto the injector direct, ie the injector doesn't mount into a fixed metal rail .. I've used them before and they're great for making your own injection set-ups from .. well they were until bike throttle bodies became widely available

anonymous-user

55 months

Tuesday 20th September 2005
quotequote all
trackcar said:
.. well they were until bike throttle bodies became widely available
Maybe you should look at a set of these - possibly in a partnership with Dax? It would be a waste to sort out all the timing, fuel, exhuast, etc, and still have it struggling with the current induction.

dnb

Original Poster:

3,330 posts

243 months

Thursday 1st December 2005
quotequote all
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

dnb

Original Poster:

3,330 posts

243 months

Friday 2nd December 2005
quotequote all
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.

trackcar

6,453 posts

227 months

Friday 2nd December 2005
quotequote all
ooo watching this all with interest now ..

I paid the last bit on my rolling road a few days ago, should have been shipped yesterday from america so hopefully will be with me for xmas .. then i can fit my MS to the S and get it mapped. can't wait

dash looks lovely, and you seem to have a whole car-boot-sale's worth of G clamps in your garage

GreenV8S

30,210 posts

285 months

Friday 2nd December 2005
quotequote all
Is that JE trigger for the intermediate/serpentine front cover, or has he started doing one for preserpentine engines now? It looks like a far better sensor mount than the one I've got at the moment.

dnb

Original Poster:

3,330 posts

243 months

Friday 2nd December 2005
quotequote all
The trigger wheel is for a serpentine engine.

Graham

16,368 posts

285 months

Friday 2nd December 2005
quotequote all
Which side does the crank sensor fit. when you look at the front of the engine, from the front of the car is it on the left or the right.

I've got a dry sump on the right, so im hoping its on the left side..

the biggest pain i'll have is that to get the front pully off to mount the trigger wheel i have to take the engine out !!!!

G

GreenV8S

30,210 posts

285 months

Friday 2nd December 2005
quotequote all
The toothed wheel will suit either front end, it's the sensor mount which will vary. When I got mine, I couldn't find anyone who did a sensor mount for the pre-serpentine front end so I had to make my own. That JE mount looks far better though, obviously.