ECU choices? - Long post
Discussion
There's not a lot wrong with the Griffith as it stands, but there are many small things that could potentially be improved with some modern technology and thought...
1 - I'd like the engine to be a bit more friendly in traffic. I currently think this is down to ECU mapping and the Lucas injectors.
2 - I'd like a bit more economy. Nothing dramatic, but I don't believe we're seeing the best possible from the car. I believe again this is down to the ignition advance mapping/setup.
3 - I'd like the car to be as easy to maintain & diagnose as possible, given it is a 1 hour ferry ride and 1.5 hours drive to the nearest specialist I trust for servicing. (Not that the car has let me down yet)
4 - I'd like any future upgrades to be as easy to integrate into the car as possible. E.g. exhaust & camshaft upgrade. Both of these parts wear out, and it is as well to replace them with the best quality bits you can get. Not to mention air intake improvements...
I have considered a Tornado chip, and that should fix item 1 and possibly 2. Item 3 could then be fixed by either reverse engineering the ECU and diagnostics equipment (possibility for selling resulting technology, but no chance while I'm so busy at work, with the house and with mapping old Impreza ECUs. I'd be limited in my options for 4 then, as whatever I did would require a remap to make the best of it at additional cost.
So, the other option is an aftermarket ECU.
This seems to have benefits for all 4 of my items eg. being able to use the cheaper zirconia lambda sensors and other easily available sensors - not having to struggle to find the potentially obsolete TVR part and having an easy route to ECU diagnostics & fault codes.
This would be difficult to install, but would only have to be done once. (I'm an electronics engineer and have some experience of ECUs so I am not daunted by doing this.) I have several questions:
Is sequential injection a benefit worth paying a little more to have?
Is getting rid of the dizzy in favour of a 4 coil wasted spark ingition system worth doing, or can the dizzy be convinced to give fully mapable timing?
What extra sensors are required for timing purposes? eg crank/cam position sensors, knock sensor etc.
MAF based or MAP based ECU?
Which ECUs have people tried on the RV8 type engines? (Haltech, Motec, Gems, Autronics, others???)
I have mapped quite a number of Impreza turbos and Hondas now, and have a fair bit of equipment for doing this (wideband AFR, det cans, data logging equipment etc.) but it would be nice to know there is support out there if I get stuck, so this impacts on the choice too.
The budget is flexible, and is based on the likely costs of continuing to own the Griff for at least another 3 years. I expect that if I don't change the ECU, £1000 or so will be expended in things associating with it. So the ECU change budget would have to be around this for it to be cost effective.
The time scales are approximately the same as DustyC buying a Griff...
Does anyone want to offer an opinion?
Even to tell me I'm mad!
1 - I'd like the engine to be a bit more friendly in traffic. I currently think this is down to ECU mapping and the Lucas injectors.
2 - I'd like a bit more economy. Nothing dramatic, but I don't believe we're seeing the best possible from the car. I believe again this is down to the ignition advance mapping/setup.
3 - I'd like the car to be as easy to maintain & diagnose as possible, given it is a 1 hour ferry ride and 1.5 hours drive to the nearest specialist I trust for servicing. (Not that the car has let me down yet)
4 - I'd like any future upgrades to be as easy to integrate into the car as possible. E.g. exhaust & camshaft upgrade. Both of these parts wear out, and it is as well to replace them with the best quality bits you can get. Not to mention air intake improvements...
I have considered a Tornado chip, and that should fix item 1 and possibly 2. Item 3 could then be fixed by either reverse engineering the ECU and diagnostics equipment (possibility for selling resulting technology, but no chance while I'm so busy at work, with the house and with mapping old Impreza ECUs. I'd be limited in my options for 4 then, as whatever I did would require a remap to make the best of it at additional cost.
So, the other option is an aftermarket ECU.
This seems to have benefits for all 4 of my items eg. being able to use the cheaper zirconia lambda sensors and other easily available sensors - not having to struggle to find the potentially obsolete TVR part and having an easy route to ECU diagnostics & fault codes.
This would be difficult to install, but would only have to be done once. (I'm an electronics engineer and have some experience of ECUs so I am not daunted by doing this.) I have several questions:
Is sequential injection a benefit worth paying a little more to have?
Is getting rid of the dizzy in favour of a 4 coil wasted spark ingition system worth doing, or can the dizzy be convinced to give fully mapable timing?
What extra sensors are required for timing purposes? eg crank/cam position sensors, knock sensor etc.
MAF based or MAP based ECU?
Which ECUs have people tried on the RV8 type engines? (Haltech, Motec, Gems, Autronics, others???)
I have mapped quite a number of Impreza turbos and Hondas now, and have a fair bit of equipment for doing this (wideband AFR, det cans, data logging equipment etc.) but it would be nice to know there is support out there if I get stuck, so this impacts on the choice too.
The budget is flexible, and is based on the likely costs of continuing to own the Griff for at least another 3 years. I expect that if I don't change the ECU, £1000 or so will be expended in things associating with it. So the ECU change budget would have to be around this for it to be cost effective.
The time scales are approximately the same as DustyC buying a Griff...
Does anyone want to offer an opinion?
Even to tell me I'm mad!
I've swapped the Lucas for an Autronic SM2 with R500 wasted spark CDI ignition. The new Bosch injectors are fired sequential. Together with ATC carbon induction and sports headers the original injectors are simply not big enough. In the SM2 is also a 2 stage temperature and vehicle-speed dependent fan control among others.
There are some parts to make to get crank position and cam position, and re-wiring is also a big job as you need som extra wires.. Tuning is relative easy with autotuning of fuel (Lamda numbers), but ignition and injection end point among others must be done manually.
I did this as service is not possible to get in No(r)way, and I felt I had to do this to learn and secure results for future modifications, and besides I got traction control! With the Autronic and a laptop you have full programming possibilities and logging of any parameter.
Since I did this last winter, Autronic has launched the SM4, the one to go for today. A good alternative is the Motec M800. Did 10.000 kms last summer, fuel as before, nicer at low rews, going well
Cost? 
Stay with Mark Adams! pt
There are some parts to make to get crank position and cam position, and re-wiring is also a big job as you need som extra wires.. Tuning is relative easy with autotuning of fuel (Lamda numbers), but ignition and injection end point among others must be done manually.
I did this as service is not possible to get in No(r)way, and I felt I had to do this to learn and secure results for future modifications, and besides I got traction control! With the Autronic and a laptop you have full programming possibilities and logging of any parameter.
Since I did this last winter, Autronic has launched the SM4, the one to go for today. A good alternative is the Motec M800. Did 10.000 kms last summer, fuel as before, nicer at low rews, going well
Cost? Stay with Mark Adams! ptThanks Pete - Would be interested in how you did your crank/cam position sensors. I'm told that there is already a Hall probe type crank sensor in the Serpentine engines... Getting stuff made isn't a problem either.
I've always liked the Autronics kit, but it is out of my price range. I have found an ECU that is a bit cheaper that should suit my needs. (Not as many features as the Autronics, but more than the 14CUX)
Rewiring not a problem - I work with electonics (defence industry, so it may well get done with Mil spec connectors )
Remember that I'm an incurable car modifier and want similar benefits to what you have regards fault diagnosis, integration future mods and ease of service.
I've always liked the Autronics kit, but it is out of my price range. I have found an ECU that is a bit cheaper that should suit my needs. (Not as many features as the Autronics, but more than the 14CUX)
Rewiring not a problem - I work with electonics (defence industry, so it may well get done with Mil spec connectors
) Remember that I'm an incurable car modifier and want similar benefits to what you have regards fault diagnosis, integration future mods and ease of service.
There is a sensor located in the distributor (not a Hall type I think), giving pulses for ignition and ECU, but none on the crank. If you not are going sequential you can use this one, but make sure the new ECU can read this type of signal. If not you need both a crank sensor (giving 4 pulses for each revolution on a V8) and a sensor in the distributor for syncro whith ignition on cyl #1. But, it's a lot of power in a free programmable ignition system! I would certainly take that into consideration when swapping ECU. You are welcome to contact me directly!
dnb
Sounds like a fantastic project your undertaking, when i have a bit more money would mind having a go myself. I don't know if you've heard of the megasquirt ecu, but this is very cheap and seems to have the functionality your looking for.
Sounds like a fantastic project your undertaking, when i have a bit more money would mind having a go myself. I don't know if you've heard of the megasquirt ecu, but this is very cheap and seems to have the functionality your looking for.
That VEMS system sounds very good as well.
Just a thought for the cam position sensor, the serpentine front cover has a boss for the sensor in the casting which was later used on the Series 2 Range Rover using the GEMS ecu system. It maybe possible to machine a S2 R.Rover cam sprocket to be accepted onto the existing camshaft and also drill & tap the front cover for the sensor. However after reading it back to myself this sounds kind of risky.
The dizzy does have the VR sensor for use on the ignition module, maybe you could go for a 7 pin ignition module to control the ignition dwell.
Anyway best of luck, look forward to hearing about it in the future.
Just a thought for the cam position sensor, the serpentine front cover has a boss for the sensor in the casting which was later used on the Series 2 Range Rover using the GEMS ecu system. It maybe possible to machine a S2 R.Rover cam sprocket to be accepted onto the existing camshaft and also drill & tap the front cover for the sensor. However after reading it back to myself this sounds kind of risky.
The dizzy does have the VR sensor for use on the ignition module, maybe you could go for a 7 pin ignition module to control the ignition dwell.
Anyway best of luck, look forward to hearing about it in the future.
Hmm, if I managed the cam sprocket idea, then I could potentially revove the dizzy entirey. It'll save weight (hopefully enough to offset the coil-over-plug ignition), save a fraction of a horsepower in parasitic drag on the engine and help keep the plan simple so there is less to go wrong.
Nice idea
Nice idea
Also a pre-serp front cover wouldn't have the cam position sensor boss in the casting either.
Looking at the rimmmerbros website there is also a 7/16" camshaft bolt with a teflon head for controlling camshaft endfloat. May come in handy.
A crank position sensor on the later engine is at the back of the engine there must be a TDC sensor on the flywheel, the boss is there on the casting. However without removing the engine this doesn't look possible. Maybe a 36-1 wheel on the crankpulley might be possible. You've definitely got me interested!
>> Edited by wheeljack888 on Tuesday 18th January 21:50
Looking at the rimmmerbros website there is also a 7/16" camshaft bolt with a teflon head for controlling camshaft endfloat. May come in handy.
A crank position sensor on the later engine is at the back of the engine there must be a TDC sensor on the flywheel, the boss is there on the casting. However without removing the engine this doesn't look possible. Maybe a 36-1 wheel on the crankpulley might be possible. You've definitely got me interested!
>> Edited by wheeljack888 on Tuesday 18th January 21:50
Luckily mine is a serpentine.
I'm looking for a spare serpentine crank pulley (are these that much different to the pre-serp?), along with a 36-1 wheel.
The trigger wheels and sensors for them are common enough as they're used in lots of Fords with EDIS.
Interesting about the TDC sensor. I wonder what it could be used for? I want the crank to be the primary trigger as it is more accurate.
Next stop the local scrapyard...
I'm looking for a spare serpentine crank pulley (are these that much different to the pre-serp?), along with a 36-1 wheel.
The trigger wheels and sensors for them are common enough as they're used in lots of Fords with EDIS.
Interesting about the TDC sensor. I wonder what it could be used for? I want the crank to be the primary trigger as it is more accurate.
Next stop the local scrapyard...
Hi guys!
WOW you guys got me interested! I'm bridging this issue myself at the moment!
I've got a '97 Serp engine fromm a Chim500 going into my TR7. I've got the engine sitting on the workshop floor complete with ECU and loom etc so I COULD wire it in with the 14CUX etc and all would be fine. I do anticipate swapping this engine out for a ground-up built rover in a couple of years once the rest of the car is finished and this may include Twin Turbos so I want to have the option of doing this without rewiring the whole shabang and replacing the ECU etc.
The unit I'm looking at is the Motec M48 (just like the top-range M800 but slightly stripped down with less datalogging stuff, but still some, and less auxilary outputs etc)
I want to run full sequential injection, and I'd LOVE to go to a distributorless system with individual spark control on each cylinder and hence throw the distributor in the bin. I've heard that MSD do a system (for the LS1) that can be adapted to the RV8 that's a complete replacement for the distributor (looks like a dizzy but ain't) that uses the dizzy drive to give the cam position and hence the #1TDC. The Serp engine MUST have a crank sennsor somewhere eh? or does it get this from the distributor too? I wanna have all my fuelling and ignition controlled through the ECU so that when I plug in my other engine later on, I can add turbos, nitrous etc and still have the computing grunt to handle it. The Motec systems (and the Autech too) has the facility for traction control when wheel-speed sensors are used and I think this is worthwhile as they also have a "launch control" facility and also when used with a gear position sensor can mean full-throttle gearchanges too.
All of these facilities probably won't be used but I'd like to have the infrastructure there if I need it.
Does anyone have some definitive answers as to what sensor gear is already on the serp engine and furthermore, which ones need to be added and where? Some of this has been answered above but some of it seems contradictory (does it have a crank-angle sensor or not?)
Sounds like we're all working towards a common goal If I'm lucky, all this extra effort should mean more tuneability (no emissions laws here... can make the engine as dirty as I like to make more power) and hence no catalytic converters.
Another advantage withthe Motec system is that I can even run fuel mapping profiles, one for the street when I'm running 98 octane and another for the track when there's avgas in the tank. Also things like restrictive rev and speed limiters for when I take it in to be MOT'd so that I know that the workshop boy ain't taking it for a nice long test drive :P
Any info gratefully received!
WOW you guys got me interested! I'm bridging this issue myself at the moment!
I've got a '97 Serp engine fromm a Chim500 going into my TR7. I've got the engine sitting on the workshop floor complete with ECU and loom etc so I COULD wire it in with the 14CUX etc and all would be fine. I do anticipate swapping this engine out for a ground-up built rover in a couple of years once the rest of the car is finished and this may include Twin Turbos so I want to have the option of doing this without rewiring the whole shabang and replacing the ECU etc.
The unit I'm looking at is the Motec M48 (just like the top-range M800 but slightly stripped down with less datalogging stuff, but still some, and less auxilary outputs etc)
I want to run full sequential injection, and I'd LOVE to go to a distributorless system with individual spark control on each cylinder and hence throw the distributor in the bin. I've heard that MSD do a system (for the LS1) that can be adapted to the RV8 that's a complete replacement for the distributor (looks like a dizzy but ain't) that uses the dizzy drive to give the cam position and hence the #1TDC. The Serp engine MUST have a crank sennsor somewhere eh? or does it get this from the distributor too? I wanna have all my fuelling and ignition controlled through the ECU so that when I plug in my other engine later on, I can add turbos, nitrous etc and still have the computing grunt to handle it. The Motec systems (and the Autech too) has the facility for traction control when wheel-speed sensors are used and I think this is worthwhile as they also have a "launch control" facility and also when used with a gear position sensor can mean full-throttle gearchanges too.
All of these facilities probably won't be used but I'd like to have the infrastructure there if I need it.
Does anyone have some definitive answers as to what sensor gear is already on the serp engine and furthermore, which ones need to be added and where? Some of this has been answered above but some of it seems contradictory (does it have a crank-angle sensor or not?)
Sounds like we're all working towards a common goal
If I'm lucky, all this extra effort should mean more tuneability (no emissions laws here... can make the engine as dirty as I like to make more power) and hence no catalytic converters. Another advantage withthe Motec system is that I can even run fuel mapping profiles, one for the street when I'm running 98 octane and another for the track when there's avgas in the tank. Also things like restrictive rev and speed limiters for when I take it in to be MOT'd so that I know that the workshop boy ain't taking it for a nice long test drive :P
Any info gratefully received!
Apologies if I'm teaching to suck eggs, but:
To get individual coils for each cylinder and sequential injection you need the crank sensor for TDC (or relative TDC) position and a cam-sensor for position in engine cycle. The later GEMS engines have both of these sensors. The crank TDC sensor on the cyl-block flywheel housing on the left hand side triggered by a magnet on the flywheel. The cam sensor is on the front cover triggered by the camshaft sprocket. The problem is trying to retrofit these parts onto a TVR serpentine engine.
The TVR serp appears to have these features in the block and frontcover castings but they haven't been machined. To get the cranksensor you would have to machine the block and either swap the flywheel or modify it to get a trigger. I really don't like this idea because you have to remove the powertrain and also butcher the block with no guarantee of positional or perpendicularity for the sensor window & tapping. Anyway a 36-1 wheel somehow put onto the crankpulley would do the same job.
The camshaft position sensor seems a bit more promising because you can remove frontcover fairly easily to properly jig and machine it. The camshaft sprocket on the GEMS engine will not fit onto the TVR camshaft because of the distributer drive. It maybe possible to modify the GEMS camshaft sprocket to be accepted onto the camshaft with machining and the relevant spacers, however when machining the sprocket concentricity of the hub to the gear is absolutely critical.
The only usable position sensor I know of on the TVR engine is the variable reluctance sensor on the distributor which instructs the ignition module, but the mechanical & vacuum advance mechanism remains. These would have to be locked and also it doesn't provide the most robust position sensor through tolerance stack and backlash.
To get individual coils for each cylinder and sequential injection you need the crank sensor for TDC (or relative TDC) position and a cam-sensor for position in engine cycle. The later GEMS engines have both of these sensors. The crank TDC sensor on the cyl-block flywheel housing on the left hand side triggered by a magnet on the flywheel. The cam sensor is on the front cover triggered by the camshaft sprocket. The problem is trying to retrofit these parts onto a TVR serpentine engine.
The TVR serp appears to have these features in the block and frontcover castings but they haven't been machined. To get the cranksensor you would have to machine the block and either swap the flywheel or modify it to get a trigger. I really don't like this idea because you have to remove the powertrain and also butcher the block with no guarantee of positional or perpendicularity for the sensor window & tapping. Anyway a 36-1 wheel somehow put onto the crankpulley would do the same job.
The camshaft position sensor seems a bit more promising because you can remove frontcover fairly easily to properly jig and machine it. The camshaft sprocket on the GEMS engine will not fit onto the TVR camshaft because of the distributer drive. It maybe possible to modify the GEMS camshaft sprocket to be accepted onto the camshaft with machining and the relevant spacers, however when machining the sprocket concentricity of the hub to the gear is absolutely critical.
The only usable position sensor I know of on the TVR engine is the variable reluctance sensor on the distributor which instructs the ignition module, but the mechanical & vacuum advance mechanism remains. These would have to be locked and also it doesn't provide the most robust position sensor through tolerance stack and backlash.
Initially I thought of using the GEMS triggers for my project, but I soon found out that they are damned hard to find and as already said will be difficult to fit.
I would like to be rid of the dizzy entirely if possible - lots of good reasons for this:
More space to play with
Save a bit of weight
Less drag on the engine
It may be easier to look at adding a sensor to the TVR cam wheel. Or even to use semi-sequential injection and wasted spark ignition. No need for a cam trigger then.
Using the dizzy as a position reference is not the best idea for a performance engine for reasons already stated (mainly accuracy)
I beleive it would be straight forward to modify a TVR cam wheel to house the required sensor.
I would like to be rid of the dizzy entirely if possible - lots of good reasons for this:
More space to play with
Save a bit of weight
Less drag on the engine
It may be easier to look at adding a sensor to the TVR cam wheel. Or even to use semi-sequential injection and wasted spark ignition. No need for a cam trigger then.
Using the dizzy as a position reference is not the best idea for a performance engine for reasons already stated (mainly accuracy)
I beleive it would be straight forward to modify a TVR cam wheel to house the required sensor.
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