ECU rev limit crystal modification.
- Thread starter SuprAng
- Start date
LOL, IJ, you're right.
Guys, please don't do this. I mean, when you're pushing 500hp on the stock ECU, you're already taking a chance with it. You're talking 2x the output of stock, on a system that was - let's be realistic - NEVER designed for that kind of power output.
Between scaling the airflow ~25% (and hence the TIMING) with the lex/550 combo, and further scaling airflow with a SAFC, and now SKEWING the ecu's perception of time... I mean, it's like taking a perfectly normal person, and cutting out their eyes and ears, and expecting them to perform calculus
Yet... the 7M is plaqued with BHGs and spun bearings... both things that are VERY EASILY caused by the evil detonation wizard.
Scaling airflow, or changing the crystal, or really any kind of sensor mod = timing being changed, and NOBODY seems to want to look at that! I mean, is 80% of the Supra Community in denial that TIMING plays a HUGE part on how long an engine lives?
You want MINIMUM timing needed for MAXIMUM torque through a given range, to keep the engine HEALTHY. - A little extra @ cruise, to help with a slightly leaned mixture is fine, but only when cruising (steady state of airflow)
I mean, I can't be the only one seeing a connection here, am I? I don't see stock, well cared for, or even MILDLY (up to around 300rwhp) 7Ms taking a dump - because, IMHO, these levels of performance are almost always done with an upgraded or stock CT, 11psi, and basic intake/exhaust modifications.
It seems to be mostly the ones scaling airflow, and otherwise mucking up the ECUs eyes and ears, that are plagued with problems....
Now, don't take this as bad-mouthing piggybacks. We all do what we can, with what we've got. I'm planning on picking up a MAFT-Pro ASAP, myself. Mainly for the speed density - but I do NOT plan on changing injectors, and staying as close to the stock maps as I can. Even if I DO end up changing the injectors, and having to scale the airflow meter, THE MAFT-PRO LETS YOU ADJUST YOUR TIMING MAPS TOO! *That* is what will allow a motor to live a longer, healthier life!
Sorry if this seems like a rant. I've been around Supras for about 2.5 years now, and this just makes my jaw hit the floor.
Had to get it off my chest. Now back to your regularly scheduled SM discussion
Guys, please don't do this. I mean, when you're pushing 500hp on the stock ECU, you're already taking a chance with it. You're talking 2x the output of stock, on a system that was - let's be realistic - NEVER designed for that kind of power output.
Between scaling the airflow ~25% (and hence the TIMING) with the lex/550 combo, and further scaling airflow with a SAFC, and now SKEWING the ecu's perception of time... I mean, it's like taking a perfectly normal person, and cutting out their eyes and ears, and expecting them to perform calculus
Yet... the 7M is plaqued with BHGs and spun bearings... both things that are VERY EASILY caused by the evil detonation wizard.
Scaling airflow, or changing the crystal, or really any kind of sensor mod = timing being changed, and NOBODY seems to want to look at that! I mean, is 80% of the Supra Community in denial that TIMING plays a HUGE part on how long an engine lives?
You want MINIMUM timing needed for MAXIMUM torque through a given range, to keep the engine HEALTHY. - A little extra @ cruise, to help with a slightly leaned mixture is fine, but only when cruising (steady state of airflow)
I mean, I can't be the only one seeing a connection here, am I? I don't see stock, well cared for, or even MILDLY (up to around 300rwhp) 7Ms taking a dump - because, IMHO, these levels of performance are almost always done with an upgraded or stock CT, 11psi, and basic intake/exhaust modifications.
It seems to be mostly the ones scaling airflow, and otherwise mucking up the ECUs eyes and ears, that are plagued with problems....
Now, don't take this as bad-mouthing piggybacks. We all do what we can, with what we've got. I'm planning on picking up a MAFT-Pro ASAP, myself. Mainly for the speed density - but I do NOT plan on changing injectors, and staying as close to the stock maps as I can. Even if I DO end up changing the injectors, and having to scale the airflow meter, THE MAFT-PRO LETS YOU ADJUST YOUR TIMING MAPS TOO! *That* is what will allow a motor to live a longer, healthier life!
Sorry if this seems like a rant. I've been around Supras for about 2.5 years now, and this just makes my jaw hit the floor.
Had to get it off my chest.
Now back to your regularly scheduled SM discussion Doward said:LOL, IJ, you're right.
Guys, please don't do this. I mean, when you're pushing 500hp on the stock ECU, you're already taking a chance with it. You're talking 2x the output of stock, on a system that was - let's be realistic - NEVER designed for that kind of power output.
Between scaling the airflow ~25% (and hence the TIMING) with the lex/550 combo, and further scaling airflow with a SAFC, and now SKEWING the ecu's perception of time... I mean, it's like taking a perfectly normal person, and cutting out their eyes and ears, and expecting them to perform calculus
Yet... the 7M is plaqued with BHGs and spun bearings... both things that are VERY EASILY caused by the evil detonation wizard.
Scaling airflow, or changing the crystal, or really any kind of sensor mod = timing being changed, and NOBODY seems to want to look at that! I mean, is 80% of the Supra Community in denial that TIMING plays a HUGE part on how long an engine lives?
You want MINIMUM timing needed for MAXIMUM torque through a given range, to keep the engine HEALTHY. - A little extra @ cruise, to help with a slightly leaned mixture is fine, but only when cruising (steady state of airflow)
I mean, I can't be the only one seeing a connection here, am I? I don't see stock, well cared for, or even MILDLY (up to around 300rwhp) 7Ms taking a dump - because, IMHO, these levels of performance are almost always done with an upgraded or stock CT, 11psi, and basic intake/exhaust modifications.
It seems to be mostly the ones scaling airflow, and otherwise mucking up the ECUs eyes and ears, that are plagued with problems....
Now, don't take this as bad-mouthing piggybacks. We all do what we can, with what we've got. I'm planning on picking up a MAFT-Pro ASAP, myself. Mainly for the speed density - but I do NOT plan on changing injectors, and staying as close to the stock maps as I can. Even if I DO end up changing the injectors, and having to scale the airflow meter, THE MAFT-PRO LETS YOU ADJUST YOUR TIMING MAPS TOO! *That* is what will allow a motor to live a longer, healthier life!
Sorry if this seems like a rant. I've been around Supras for about 2.5 years now, and this just makes my jaw hit the floor.
Had to get it off my chest.
very well said. the whole 500 rwhp on the stock ECU thing still makes me laugh.....
Theres a local guy here in MD that was making 775rwhp and running high 9's at 145mph using the stock ECU and piggy-backs with an increased rev limit. This is an MK4 supra so its not exactly comparing apples too apples. But the stock ECU got the job done (with lots of C16) and allowed the 74mm turbo to make that power at 30+ psi.
I think as long as we can monitor timing and air/fuel, I don;t see anything wrong with trying to raise the rev limit with the stock ECU.
I think as long as we can monitor timing and air/fuel, I don;t see anything wrong with trying to raise the rev limit with the stock ECU.
SuprAng said:
So you're saying the ECU pulls fuel- leans out the
motor to keep it from going lean? Pulling fuel under load, motor=BOOM!
I've heard it pulls the spark, and saves the motor.
^Edited
Does anyone have experience with the MINES'S ECUs? I have one, (not installed).
I know the spark cut is gone, rev lim is raised, and fuel and timing remapped.
But I have no clue what it was tuned for. So I'm just curios about them.
I'm going to be ordering a MAFT pro setup (tonight), and was not aware
about being able to tune timing with it, I thought you could only monitor it.
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jimi87-t said:
realize that any techtom rommed ECU could have any sort of program in it. there wasn't a "normal" tune off the shelf- you typically told them your setup and they altered the ECU as they saw fit....so it's a crap shoot.
yes, the MAFT pro can do timing control now. drop me a line when you're ready to order....
IJ. said:
Exactly, the microprocessor in the ecu goes through read and write cycles that require specific timings between various I/O's that are measured in nano-seconds. Too much or too little latency can cause the system to go into unknown states.
Can you/has anyone datalogged what the ECU does with timing on a nearly stock car with the Pro? I'm not sure that it even has this capability but it would something I would like to see.
Does it pull spark? I was under the impression it CUT FUEL COMPLETELY until the motor came below a certain RPM, then it re-started the injectors.
Pulling the spark when a motor is spinning 6500+ rpm will cause a hell of a lot of gas to go spitting out the exhaust pipe. It's something people would notice!
Pulling the fuel is a safer fuel cut (hmm... FCO... fuel cut off?) because you can't very well combust WHAT ISN'T THERE.
That is all
Pulling the spark when a motor is spinning 6500+ rpm will cause a hell of a lot of gas to go spitting out the exhaust pipe. It's something people would notice!
Pulling the fuel is a safer fuel cut (hmm... FCO... fuel cut off?) because you can't very well combust WHAT ISN'T THERE.
That is all
i don't think fuel cut relys on rpm. My car cuts all over the place depending on the temp outside
JustAnotherVictim
Supramania Contributor
Doward said:Does it pull spark? I was under the impression it CUT FUEL COMPLETELY until the motor came below a certain RPM, then it re-started the injectors.
Pulling the spark when a motor is spinning 6500+ rpm will cause a hell of a lot of gas to go spitting out the exhaust pipe. It's something people would notice!
Pulling the fuel is a safer fuel cut (hmm... FCO... fuel cut off?) because you can't very well combust WHAT ISN'T THERE.
That is all
Well I'm no ECU guru, ( I edited my post, sorry for being an ass ). I've seen many people get jumped on by others more knowledgeable than myself, that it was spark cut and not fuel cut. I bought into it, personally, I don't know, some say fuel some say spark. So which ever it is this is me admitting I fall for misinformation too.
Edit: Another reason I thought this was because MSD boxes cut spark for the rev lim.
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The MSD boxes do use spark to limit rev... it's a soft limit, though (they alternately drop the spark to the cylinders)
It is fuel that is cut - it's been confirmed by someone with a hell of a lot of TCCS knowledge
It is fuel that is cut - it's been confirmed by someone with a hell of a lot of TCCS knowledge
Fuel cut happens a few hundred RPM north of redline.
Those questioning 500rwhp with a stock ECU and not stand alone certainly have a valid point. I know malloynx made it look easy, but how many others have not?
Those questioning 500rwhp with a stock ECU and not stand alone certainly have a valid point. I know malloynx made it look easy, but how many others have not?