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Sept 21, 2022 11:02:52 GMT
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My 87 Range rover has the Lucas 4cu / flapper system, generally it runs very well but I have had to re-solder the ECU a few times and it's playing up again, I have a spare which has had similar problems as well, reading up on line it seems to be very common as they get older. The 4cu is basically an analogue system which uses resistors, transistors and capacitors to derive a injector pulse, when it works it drives very well but being open loop the fuelling is far from perfect and it does smell a bit especially when cold (worse than my TR7V8 on SU's).
So my thought is to make a drop in ECU using a aftermarket ECU in one of the original cases, using most of the original installation (even pegging the AFM open and using the original thermo sensor), and only add a Oxygen sensor, pipe to a map sensor in the ecu and wire to control the fuel pump. It would use the original distributor, mechanical idle speed control, TPS, take the ignition pulse from the coil, temperatures from the original sensors and power the original injectors via the original ballast resistor. I am also thinking about adding a catalyst afterwards as well to clean it up a bit.
This brings me to which ecu to use, on cost grounds I have narrowed it down to a speeduino or a Megasquirt, both it seems can support an ignition coil pulse for engine speed so would seem to be suitable, both also seem to have the ability to self map the fuel based on the oxygen sensor feedback.
Anyone any thoughts on the how well the self mapping works and reliability etc of the 2?
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16grit
Part of things
Posts: 213
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Sept 21, 2022 12:42:42 GMT
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Speeduino currently has a much more vibrant ++international++ (and not US-centric) community and eco-system around it. Don't quote me but I don't think much is/has been happening with Megasquirt development wise recently?
There's heaps of bits available for the RV8 and of course experience here and abroad with both systems and suitable trigger wheels and mounts etc are commonly available. Compared to the cost of a new wideband, the other sensors (new) and a trigger wheel are small beer so I would guess that most people's advice would be to run a fresh instal with a complete new system rather than trying to connect old with new.
Auto-mapping is a function of the TunerStudio software that they both run, and only in the slightly more expensive versions.
There's a pretty active facebook group.
The 'Dropbear' unit might be one to research. It's a little pricey and you might have to wait on availability from AUS (next batch / chip shortage) but is the current lovechild of speeduino originator Josh Steward with great 8-channel compatibility for big Vs etc.
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Sept 22, 2022 12:49:19 GMT
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Personally, by experiences with Megasquirt are far more positive than my Speeduino one.
Mainly because the MS documentation and forum support is very much better than Speeduino. Also, although there are quite a few MS variants at different price points, the Speeduino family seems almost unlimited, making it harder to unscramble if you do get issues.
With Speeduino we had many issues with electrical noise and getting a reliable tacho signal, which took literally years to resolve.
Nick
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1967 Triumph Vitesse convertible (old friend)
1996 Audi A6 2.5 TDI Avant (still durability testing)
1972 GT6 Mk3 (Restored after loong rest & getting the hang of being a car again)
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Sept 22, 2022 16:27:49 GMT
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If you do go down this route get the ms/arduino ecu looking after only the ignition first and leave fuelling on the original ecu til you have it running ok.
Is frustrating when debugging and it could be ignition or fuelling, and you built the ecu yourself so are wondering if its working properly.
Do people still build their own megasquirts?
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goldnrust
West Midlands
Minimalist
Posts: 1,872
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Sept 22, 2022 19:09:27 GMT
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I’ve built several Megasquirt 1 and Megasquirt 2 ECUs for me and my friends, and have been dropping my toes into Speeduino recently.
First off, make sure you want an electrical project before you embark on either. I find it interesting to do the problem solving and learning on both the hard wear and soft wear side, but it’s a steep learning curve and if you just want the car to ‘work’ then I think you’d be better off looking for another solution.
With that out of the way!… My Speeduino is not complete yet, but so far I feel the Megasquirt documentation is easier to follow, especially for a beginner. The guides and info found on msextra.com and the neatly organised and packaged parts you get from suppliers like diyautotune (in the USA but worth the wait / customs charge imo) have been so good I’ve nearly ever needed to look at a forum for help.
On the hardware side, Megasquirt 2 (which I presume you’re looking at as cost comparable to Speeduino) is more flexible than Speeduino in terms of different input and output signal types, supporting more unusual trigger wheels, sensors and injector types. BUT as far as I know there’s nothing especially unusual about the requirements of running a rover v8 and I’m sure it’s a commonly supported engine in both systems. On the upside for Speeduino most versions support things like 4 ignition output channels (with which you could run wasted spark and ditch the distributer) as assembled from the kit. The Megasquirt 2 system relies upon several ‘mod kits’ that you solder on the back of the board to expand its outputs. This can end up a bit confusing to follow.
I’m sure the pros outweigh the cons for each system. The main thing for me is to have a good grounding in electronics, or a willingness to learn, before taking either on!
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Sept 23, 2022 7:52:20 GMT
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I would have thought a Microsquirt would be fine for a simple install. Certainly an upgrade from the original system.
I'm using one on my Pop project and so far it's been a fairly easy job.
They are small, cheap and the documentation is good. They can be set up to have four ignition outputs (so wasted spark with no dizzy) and run batch fired injection.
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Proton Jumbuck-deceased :-(
2005 Kia Sorento the parts hauling heap
V8 Humber Hawk
1948 Standard12 pickup SOLD
1953 Pop build (wifey's BIVA build).
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Sept 23, 2022 11:45:43 GMT
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Microsquirt certainly looks a good option, I want to start with fuel only using all of the original sensors so I can go back to the old ECM if required, only thing which doesn't seem compatible is the vane air meter type maf sensor, I plan to go speed density so won't need it to measure air flow, as far as I can see I can replace it with a piece of tube with an Air temp sensor in it or peg the flap open and use the original internal air temp sensor.
Once it runs well on fuel only I might add wasted spark ignition etc.
Looks like I will also need a wideband O2 sensor controller and Map sensor any recommendations for the wideband controller?
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Sept 23, 2022 12:54:54 GMT
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I am using a Spartan wide band controller from efiextras (supplied my Microsquirt as well). I got a map sensor from Trigger wheels UK.
Happy with the price and service from both.
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Proton Jumbuck-deceased :-(
2005 Kia Sorento the parts hauling heap
V8 Humber Hawk
1948 Standard12 pickup SOLD
1953 Pop build (wifey's BIVA build).
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