Fitting a Standalone ECU
- Thread starter rik1083
- Start date
rik1083
Senior Member
Re: Fitting the megasquirt ecu
I fitted an elise throttle linkage at the weekend.. (the pic above didnt give enough movement and got in the way of my big feet)
I had some help from a friend who is some kind of design person for an aerospace company, but he wasn't much use, just kept taking useless photos
this goes under the dash and amplifies the pedal movement
need bigger inlet tube and filter now
wiring tidied away a bit
test to see if clam still fits
I fitted an elise throttle linkage at the weekend.. (the pic above didnt give enough movement and got in the way of my big feet)
I had some help from a friend who is some kind of design person for an aerospace company, but he wasn't much use, just kept taking useless photos
this goes under the dash and amplifies the pedal movement
need bigger inlet tube and filter now
wiring tidied away a bit
test to see if clam still fits
rik1083
Senior Member
Re: Fitting the megasquirt ecu
the fuel table has an auto-generate thing where you put in your maximum manifold pressures and expected peak torque and peak hp at x revs and y pressure.. but it seems to be a bit useless.
Am I right in thinking that more fuel is proportinal to torque? If so, then it looks like there's not going to be much of a curve in fueling as the torque curve is very straight on these sc'd cars. The auto generator is predicting a huge torque curve.. I've basically been drastically reducing the table as it want's to put more and more fuel in the further to peak torque it goes.
I've only driven in the bottom left 1/4 of the map so far.. should I be expecting a big rise in fuel later on? or will the fuel curve be quite similar to my torque curve?
Cheers
Richard
the fuel table has an auto-generate thing where you put in your maximum manifold pressures and expected peak torque and peak hp at x revs and y pressure.. but it seems to be a bit useless.
Am I right in thinking that more fuel is proportinal to torque? If so, then it looks like there's not going to be much of a curve in fueling as the torque curve is very straight on these sc'd cars. The auto generator is predicting a huge torque curve.. I've basically been drastically reducing the table as it want's to put more and more fuel in the further to peak torque it goes.
I've only driven in the bottom left 1/4 of the map so far.. should I be expecting a big rise in fuel later on? or will the fuel curve be quite similar to my torque curve?
Cheers
Richard
Re: Fitting the megasquirt ecu
right then (cant post on .org as work is mean lol)
Your fueling will kinda track the torque curve (or prescribe it if you limit things with fuel) until peak torque. Peak torque is maximum cylinder filling of air for the given engine setup, meaning thats in theory the highest fuel consuiming point. BUT after peak torque you are then running in power terms (air consumed in X time) which reduces the explicit fuel requirement, but increases generated heat. Heat generated can be cooled with fuel (stops the exhaust valves getting the hump and leaving) hence why it will sort of plateau off or even increase at the higher loads.
Also as with everthing engine related, its never that simple. In short calibrate to what you want the thing to do and then smooth the maps to make them easy on the eye (That is something the guy teaching me passed on, smooooooth is good once you have the rough point).
As for RR time, I can see the problem in that they wont want some oik on there not using their mapping time money. Got a mate who you can trust to drive EXACTLY how you ask them? IME calibrating on the road is 90% of the work as you ge tto feel the driveability and then the last 10% of bits on the dyno for pub talk
right then (cant post on .org as work is mean lol)
Your fueling will kinda track the torque curve (or prescribe it if you limit things with fuel) until peak torque. Peak torque is maximum cylinder filling of air for the given engine setup, meaning thats in theory the highest fuel consuiming point. BUT after peak torque you are then running in power terms (air consumed in X time) which reduces the explicit fuel requirement, but increases generated heat. Heat generated can be cooled with fuel (stops the exhaust valves getting the hump and leaving) hence why it will sort of plateau off or even increase at the higher loads.
Also as with everthing engine related, its never that simple. In short calibrate to what you want the thing to do and then smooth the maps to make them easy on the eye (That is something the guy teaching me passed on, smooooooth is good once you have the rough point).
As for RR time, I can see the problem in that they wont want some oik on there not using their mapping time money. Got a mate who you can trust to drive EXACTLY how you ask them? IME calibrating on the road is 90% of the work as you ge tto feel the driveability and then the last 10% of bits on the dyno for pub talk
rik1083
Senior Member
Re: Fitting the megasquirt ecu
thanks for the explanation, it makes a lot of sense and follows what I have discovered so far.
meet megalog viewer:
Suprisingly (or maybe not?), I'm at the point already where autotune is making no changes, i've done about 90 miles so far. It had pretty much sorted the "cruising range" yesterday, so on the way home today I saw no reason to run it.. but I did log the session in megatune. Now if I import my configuration and the logfile into megalog viewer.. it's able to calculate recommended fuel for the points that you may not stay at long enough to cause autotune to do it's thing.. and also does quite a bit of the smoothing process
I had to change the spark map slightly after this morning (currently running alanoo's safe map but modified a bit in the boost region).. as it was causing stuttering in 5th then trying to accelerate moderately, but I had to add more advance not less, so looks like it is quite safe and leaves a lot of room for playing.. but other than that it's exactly what I needed.. cheers alanoo!
thanks for the explanation, it makes a lot of sense and follows what I have discovered so far.
meet megalog viewer:
Suprisingly (or maybe not?), I'm at the point already where autotune is making no changes, i've done about 90 miles so far. It had pretty much sorted the "cruising range" yesterday, so on the way home today I saw no reason to run it.. but I did log the session in megatune. Now if I import my configuration and the logfile into megalog viewer.. it's able to calculate recommended fuel for the points that you may not stay at long enough to cause autotune to do it's thing.. and also does quite a bit of the smoothing process
I had to change the spark map slightly after this morning (currently running alanoo's safe map but modified a bit in the boost region).. as it was causing stuttering in 5th then trying to accelerate moderately, but I had to add more advance not less, so looks like it is quite safe and leaves a lot of room for playing.. but other than that it's exactly what I needed.. cheers alanoo!
Re: Fitting the megasquirt ecu
how much advance have you got (max) ? ignoring any other compensation tables.
I noticed on the scangauge I've borrowed it lobs in nearly 40deg of advance when gunning it.... ok its a std N/A but if the engine is boosted right then there shouldnt be a huge world of difference
how much advance have you got (max) ? ignoring any other compensation tables.
I noticed on the scangauge I've borrowed it lobs in nearly 40deg of advance when gunning it.... ok its a std N/A but if the engine is boosted right then there shouldnt be a huge world of difference
rik1083
Senior Member
Re: Fitting the megasquirt ecu
anyone wanna help figure out what's wrong?
I'm getting a problem going over 4000 rpm with boost (approx 140kpa at this rpm and in 3rd gear)
I've tried adding and removing fuel and adding and removing advance but it always seems to happen at the same point.
I tried in 1st driving over 4000rpm with low load and it easily revs past this which I suppose means the trigger wheel is working ok
I've attached 2 samples with different msq files (different fuel and spark) and two log files while driving these maps.
anyone wanna help figure out what's wrong?
I'm getting a problem going over 4000 rpm with boost (approx 140kpa at this rpm and in 3rd gear)
I've tried adding and removing fuel and adding and removing advance but it always seems to happen at the same point.
I tried in 1st driving over 4000rpm with low load and it easily revs past this which I suppose means the trigger wheel is working ok
I've attached 2 samples with different msq files (different fuel and spark) and two log files while driving these maps.
rik1083
Senior Member
Re: Fitting the megasquirt ecu
will give that a go..
but look at this screen shot of the problem area.. I don't think that's the problem
afr already at 14.5 before the stuttering starts... it should be much lower
fuel pulse width stays the same, but it gets leaner and leaner then it starts
I'm thinking fuel pressure or something? notsure.gif
will give that a go..
but look at this screen shot of the problem area.. I don't think that's the problem
afr already at 14.5 before the stuttering starts... it should be much lower
fuel pulse width stays the same, but it gets leaner and leaner then it starts
I'm thinking fuel pressure or something? notsure.gif