Ignition timingtable that uses TPS not MAP
- Thread starter Mick
- Start date
My guess, that would be linear based on rpm.
38 degree total at 4000rpm starting from 1200 rpm.
So if you run 12 degree at idle (0-1190rpm) then ad 26 degree linear to 4000 rpm.
Cant do that fully tps as tps has no load calcalculations (hence map or maf).
Ill guess you'r not having any stepper motors to control any idle rpm so do not start advance comming in to early as idle may vary on weather conditions which can create bouncing effects as advance is comming in to early.
38 degree total at 4000rpm starting from 1200 rpm.
So if you run 12 degree at idle (0-1190rpm) then ad 26 degree linear to 4000 rpm.
Cant do that fully tps as tps has no load calcalculations (hence map or maf).
Ill guess you'r not having any stepper motors to control any idle rpm so do not start advance comming in to early as idle may vary on weather conditions which can create bouncing effects as advance is comming in to early.
Can't you make a provision in one runner to take a 1/8 npt barb fitting to hook up a MAP sensor as with TPS is used to questimate the load on the engine and hooking up an universal map sensor (these are dirt cheap) it makes things much easyer to set up and create way more drivebilety. X%tps Y%map.
Running map will make fueling a lot better to in relation to idle, cruise & WOT.
Or use your Motec to run stand alone fuel only with a dyzzy to run ignition side, but still I rather have load also calculated in my VE table as TPS only.
Running map will make fueling a lot better to in relation to idle, cruise & WOT.
Or use your Motec to run stand alone fuel only with a dyzzy to run ignition side, but still I rather have load also calculated in my VE table as TPS only.
Here you go Mick. Not for motec but off of my 347 ITB / TPS load referenced system.
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Thanks JP
I have an old Motec M48 MAP sensor is not fast enough for ITBs tried it some years ago and now nobody is using the DOS based system any more. it worked well until recently and could weather could have something to do with it
it pulled the TPS (magnetic) and noticed the spring tensioner used when press fitting it onto the ITB shaft was loose so I replaced it should stop any variation from creeping in. I thought I would do some fine tuning based on what some of the guys have done recently.
Mick
I have an old Motec M48 MAP sensor is not fast enough for ITBs tried it some years ago and now nobody is using the DOS based system any more. it worked well until recently and could weather could have something to do with it
it pulled the TPS (magnetic) and noticed the spring tensioner used when press fitting it onto the ITB shaft was loose so I replaced it should stop any variation from creeping in. I thought I would do some fine tuning based on what some of the guys have done recently.Mick
Thanks Rick that perfect assume your using this table, 347 will be way tourquier, mine revs doesn't start making power until 4000rpm and comes on with a bang so Im guessing I may need to add a bit in further up the table, Dyno time doesn't help it has to be done on the road with a lap top and thats hard when you cant do over 100 kph .
Hi Mick, just some questions from my side here. (I installed full sequential EFI/coil-on-plug ignition on my CAV GT40, not ITB though)
MAP (Speed-density tuning) is typically not great for ITB systems at low MAP pressures. (Idle, off throttle situations etc.)
however, TPS (alpha-n tuning) is not very accurate during accel and high load conditions. (not enough resolution.. throughout the RPM/power band, your volumetric efficiency changes on the motor, but your constantly on wide-open-throttle for example).
Therefore, most modern(ish) ECU's have the option to mix MAP and TPS tunes. On low load conditions it uses TPS, at higher load conditions it switches to MAP. This combination gives great drivability and more accurate fuelling and optimised spark timing. Meaning more torque and no risk of lean or rich conditions.
Let me know if you want to know more, i'm doing EFI tuning as a side hustle.
MAP (Speed-density tuning) is typically not great for ITB systems at low MAP pressures. (Idle, off throttle situations etc.)
however, TPS (alpha-n tuning) is not very accurate during accel and high load conditions. (not enough resolution.. throughout the RPM/power band, your volumetric efficiency changes on the motor, but your constantly on wide-open-throttle for example).
Therefore, most modern(ish) ECU's have the option to mix MAP and TPS tunes. On low load conditions it uses TPS, at higher load conditions it switches to MAP. This combination gives great drivability and more accurate fuelling and optimised spark timing. Meaning more torque and no risk of lean or rich conditions.
Let me know if you want to know more, i'm doing EFI tuning as a side hustle
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Hi Jasper,
I have spoken to Motec directly pretty much no way of using vacuum to control anything accurately with ITBs as long as I'm using the M4-48 ECU. apparently the ECU cant get the MAP sensor to react quickly enough, the explanation I was given was the its very difficult to measure vacuum accurately using ITBs (no direct connection available) also compounded by my cam it has a large overlap so it produces almost no vacuum at idle . I would love any help you can give.
I have spoken to Motec directly pretty much no way of using vacuum to control anything accurately with ITBs as long as I'm using the M4-48 ECU. apparently the ECU cant get the MAP sensor to react quickly enough, the explanation I was given was the its very difficult to measure vacuum accurately using ITBs (no direct connection available) also compounded by my cam it has a large overlap so it produces almost no vacuum at idle . I would love any help you can give.
The above is true at idle, that's exactly the problem with ITB's. I'll have to look into your ECU specifics to see if you can blend speed-density with alpha-n tuning (two different load maps), that would be the way to make it work in idle and full throttle.
You have an M4 or M48, they are different in the amount of injector and coil outputs they can control?
You have an M4 or M48, they are different in the amount of injector and coil outputs they can control?
Hi Randy
Thats the bom I have a vacuum plenum below my runners still not much good with the M48 Motec it just cant read any MAP changes fast enough. I think I sorted what was causing my issue my TPS is a con-tactless Magnetic unit so it doesn't wear like the mechanical types but it has a small spring clip that keeps tension on the throttle plate shaft when its slides onto the end I revised the tension and took out any chance of slack. Also revised the Lambda table and timing, generally when things change out of the blue it will be a sensor usually the TPS or ignition Leads or plugs.
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