In this particular moment (tiny trigger wheel) comes good ECU with good build in decoder. My trigger setup is stock diameter wheel (51mm), 12-1 tooth and stock VR sensor. I have very clear and stable rpm readings from 0 to 13000 rpm. And yes only by starting the motor, I can seen some trigger errors, but this dose not effect the starting...just statistic. I have seen problems with Mega to read accurate rpms with different sensors VR or Hall, especially in higher rpms.
Car sensors are not a problem too (personal opinion). I have build in my ECU drivers/calibration for most IAT,ECT, etc. sensors and Lambda controllers. If that is not enough, there is custom Cal. tables that you can create by yourself.
The problem with a lot of OEM car injection stuff, is that while the basic equipment (injectors etc..) are fine, a LOT of the systems are designed to work with LARGE trigger wheels driven from the crankshaft, with BIG, OBVIOUS cut-out's and the engine is being spun over by a BIGASS starter motor which helps maintain cranking RPM in a nice easy "zone".
Then you go and bolt the same stuff onto a bike which needs a tiny little trigger wheel, can have very erratic / variable RPMs when cranking etc... and they dont work properly for shit...
Just because something was built by a car manufacturer doesn't mean its gonna be amazing on a bike... it was DESIGNED to go on a car... in fact, it was DESIGNED to meet a very specific set of requirements, which most bikes DO NOT MEET.... So to anyone who asserts the idea that OEM car stuff is the better way to add EFI to a bike.... Your in just as much chance of it not working as you are with a home-build system such as Mega.... the only difference is with mega, you have more support when it wont work.
Don't get me wrong, Im not trying to turn this into a "use mega or your shit" kinda thread / post, just wanting to point out the problems that can come with adding EFI to old bikes like ours, regardless of the ECU brand / source.
Most of the problems are from the "ancillary" parts of the system , like trigger wheel setup, cam sensor (if you use one) and so forth and getting it all to work reliably on such a small package as a bike.
I here yah, and like you say, if you used a whole system from a car, then, cranking, trigger wheels and packaging would all be issues. This is not what I was trying to point out. More that there is a wealth of fuel pumps, fuel pressure regulators, injectors, throttle position sensors, temperature sensor's, inlet air temperature sensors, MAP sensor's, coils and electrical connectors. Any of which, once assessed could be intergrated into a bike system
To add my opinion on "megasquirt or not" debate I can say that I have been more or less involved with numerous EFI installations with different Megasquirt versions and there is no reason why they wouldn't work. Though you need to pay some attention what version to use. In my opinion the basic versions, (v2.2, v3.0, v3.57 main boards) aren't good for bike use due to bulky size, fragile connectors and some other factors. Fortunately there are also better variants available for example Microsquirt to name one.
Installation budget can vary greatly depending on component selection and where you get them. With some patience and leg work you can source good second hand components from ebay and scrap yards for very little money. On the other hand you can spend fortunes on fancy brand name parts. Also your skills and fabrication possibilities will affect to budget as usual. As rule of thumb I would say that it's better to be prepared to spend about 1000€. That's quite tight budget that will need some careful parts selection and sourcing but you can still get a good result with that.
Slightly related to topic, here is a couple of dyno videos about oil cooled turbo GSX-R with Megasquirt
Another one for microsquirt here. Ive got a 36-1 wheel tigged onto my stock trigger wheel (very kindly done by someone here!) Stock VR sensor Standard GM map sensor (off a MK4 astra 1.4) VAG Ignition amplifier (Taken off an early Audi A4) GM Coolant temp sensor (same MK4 astra) although I may not use it and use a disc type thermistor on the back of the barrels Weber Air temp sensor ( Sierra Cosworth type, purley because I had it lying round!) K2 GSXR 600 throttle bodies and injectors and COP's
K4 GSXR 1000 Fuel Pump, mounted in tank (got a K4 tank and chopped bits out)
I've not had it running yet but the sensors checked out ok and i get readings when i crank it. Just got to beg/borrow/steal a base map and crack on with it!
Hopefully mate! I dont suppose you've got a NA 750 base map have you?
Not really but I do have a few different tunes. With Alpha-n and multiply map tuning though shouldn't really matter as boost value is just a multiplier so should be close for basic NA running.I will see if I can find last 750 one when u got it dynoed as that was pretty good apart from no Ace, but you can work that out I'm sure.