megasquirt
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cj011
- Posts: 287
- Joined: Mon Feb 26, 2001 12:01 am
megasquirt
can this system be used on indivdual throttle bodies or does it have to use one plenium like the 5.0 throttle body on dunebuggy.coms build up.
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turbo6bar
- Posts: 601
- Joined: Mon Dec 18, 2000 12:01 am
megasquirt
Can run either system. You just need to make certain the vacuum signal in an IR setup is adequate and not erratic. That would be a concern regardless of the ECU you use. For street use, I recommend MAP for load sensing. You could use TPS for load sensing, but it's best for strip.
jay
jay
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cj011
- Posts: 287
- Joined: Mon Feb 26, 2001 12:01 am
megasquirt
does tps stand for throtle position sensor. basically does the computer calculate injector flow according to where the tps is angled at. with the megasquirt, could i have it make adjustment according to a wide range o2 sensor. or is that outside the parameters of the system.
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turbo6bar
- Posts: 601
- Joined: Mon Dec 18, 2000 12:01 am
megasquirt
That's right on the tps.
I haven't read the web pages in a while, but the ECU calculates injector flow based on MAP reading, and intake air temp. Possibly another variable is thrown in there. The tps is used for acceleration enrichment and clearing floods. The engine temp sensor is used for warmup enrichment.
The only two systems I know of which can process wideband O2 data is Autronic and Motec. The Megasquirt cannot directly read a wideband O2 sensor, but neither can the other two systems. There is ongoing work to allow one to map their system based on the datalog of a wideband O2 setup. Then, you would process the datalog in a short program, and you would then have new points at your desired AFR. It does require user intervention, but once it's done, you are golden.
I would only recommend the Megasquirt if you are willing to make a significant time investment. It is not plug-n-play. However, the development is not unremarkable. These guys are making superb improvements to the system. At their rate of progress, the Megasquirt could rival quite a few commercial systems. For a bunch of DIYers, that's great.
jay
I haven't read the web pages in a while, but the ECU calculates injector flow based on MAP reading, and intake air temp. Possibly another variable is thrown in there. The tps is used for acceleration enrichment and clearing floods. The engine temp sensor is used for warmup enrichment.
The only two systems I know of which can process wideband O2 data is Autronic and Motec. The Megasquirt cannot directly read a wideband O2 sensor, but neither can the other two systems. There is ongoing work to allow one to map their system based on the datalog of a wideband O2 setup. Then, you would process the datalog in a short program, and you would then have new points at your desired AFR. It does require user intervention, but once it's done, you are golden.
I would only recommend the Megasquirt if you are willing to make a significant time investment. It is not plug-n-play. However, the development is not unremarkable. These guys are making superb improvements to the system. At their rate of progress, the Megasquirt could rival quite a few commercial systems. For a bunch of DIYers, that's great.
jay
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Mueller
- Posts: 278
- Joined: Wed Jul 11, 2001 12:01 am
megasquirt
alpha-n is TPS (position) based more than the speed density of the megasquirt....
in fact the megasquirt can and has been setup to run without the tps, but acceleration has suffered since the tps gives the signal for acceleration and more fuel when the pedal is stepped on.....
my megasquirt installation is so close, but life keeps getting in the way
in fact the megasquirt can and has been setup to run without the tps, but acceleration has suffered since the tps gives the signal for acceleration and more fuel when the pedal is stepped on.....
my megasquirt installation is so close, but life keeps getting in the way
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danimal
- Posts: 958
- Joined: Wed Jun 13, 2001 12:01 am
megasquirt
a plenum is no guarantee of a clean vacuum signal... the cam will have a big effect on it also.
robert hemphill runs a stock vw f.i. throttle body and intake manifold... but the only way he could get a useable map signal was to filter it first, by running it thru a super-small hole.
after hearing that, it was just another reason for me to get the cb dual throttlebodies.
a plenum intake on a vw motor may also limit how radical a cam you can realistically run on the street.
dan
oceanstreetvideo.com
robert hemphill runs a stock vw f.i. throttle body and intake manifold... but the only way he could get a useable map signal was to filter it first, by running it thru a super-small hole.
after hearing that, it was just another reason for me to get the cb dual throttlebodies.
a plenum intake on a vw motor may also limit how radical a cam you can realistically run on the street.
dan
oceanstreetvideo.com
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cj011
- Posts: 287
- Joined: Mon Feb 26, 2001 12:01 am
megasquirt
on a individual throttle body system, what is there to monitor the airflow and make calculations to that. or does the programmer figure that out by himself. on the imports, all i see is the injector and i think a tps. is that all is necessary. how does one start the programming cure on that sort of system without melting a motor or turning it pitch black.
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Mueller
- Posts: 278
- Joined: Wed Jul 11, 2001 12:01 am
megasquirt
cj011,
the electronic FI systems that use a seperate butterfly for each cylinder normally use a MAP sensor (manifold air pressure)....
the megasquirt will measure the air temp inside the manifold (inside the intake plenum), the manifold pressure (vacumm or boost)..the system is set up with a look up table that you program to tell the comp. how much fuel to give the motor for each 100 or so rpm, the sensors tell the computer to add or remove fuel from the figures in the table to compensate for heat or vaccum.
the electronic FI systems that use a seperate butterfly for each cylinder normally use a MAP sensor (manifold air pressure)....
the megasquirt will measure the air temp inside the manifold (inside the intake plenum), the manifold pressure (vacumm or boost)..the system is set up with a look up table that you program to tell the comp. how much fuel to give the motor for each 100 or so rpm, the sensors tell the computer to add or remove fuel from the figures in the table to compensate for heat or vaccum.