Meth injection : Help me clarify some basic term
Thread Starter
Burning Brakes
Joined: Dec 2006
Posts: 1,164
Likes: 20
From: Somewhere in Québec, Canada
Meth injection : Help me clarify some basic term
My dyno session is getting close so i would like to understand something on my boost controller.I got a snow controller stage 3 .It will be triggered by the injector duty cycle since after some research and some discussion with some member it seems to be more precise.
But i just dont undertsand why do i got 4 windows of adjustement for this.Lets says that i want it to start @ 35 % duty cycle and max @ 100% duty cycle .I was gonna use the window 6a to start it @ 35% and would use the window 6c to set the max at 100% .
But what is the 6b and 6d do???
The Efi start increase and decrease window description are the same and the Efi full increase and decrease window description are also the same ???
Copy/paste from snow performance and i see those 4 window on my controller:
Thanks
Eric
Screen 6a
EFI START INCREASE
This screen sets the injector PW point when injection will start through
the nozzle. Typical start points are in the 35% range.
Screen 6B
EFI START DECREASE
This screen sets the injector PW when injection will start through the
nozzle.
Screen 6C
EFI FULL INCREASE
This screen sets the fuel injector PW full point when maximum injection
through the nozzle will be reached. Typical EFI full points are 60-80%.
Screen 6D
EFI FULL DECREASE
This screen sets the fuel injector PW full point when maximum injection
through the nozzle will be reached.
But i just dont undertsand why do i got 4 windows of adjustement for this.Lets says that i want it to start @ 35 % duty cycle and max @ 100% duty cycle .I was gonna use the window 6a to start it @ 35% and would use the window 6c to set the max at 100% .
But what is the 6b and 6d do???
The Efi start increase and decrease window description are the same and the Efi full increase and decrease window description are also the same ???
Copy/paste from snow performance and i see those 4 window on my controller:
Thanks
Eric
Screen 6a
EFI START INCREASE
This screen sets the injector PW point when injection will start through
the nozzle. Typical start points are in the 35% range.
Screen 6B
EFI START DECREASE
This screen sets the injector PW when injection will start through the
nozzle.
Screen 6C
EFI FULL INCREASE
This screen sets the fuel injector PW full point when maximum injection
through the nozzle will be reached. Typical EFI full points are 60-80%.
Screen 6D
EFI FULL DECREASE
This screen sets the fuel injector PW full point when maximum injection
through the nozzle will be reached.
Last edited by always faster; Aug 28, 2015 at 06:29 AM.
ISIS SUCKS FAT CHOAD
Joined: Oct 2008
Posts: 8,124
Likes: 53
From: Earth, United States
Hi, I don't personally know of any C5 or 6 owners who are running the factory PCM and injecting meth based on injector duty cycle nor do I really know or see any benefit to injecting methanol based on injector duty cycle. I'm not saying it's bad, I'm simply saying I don't see any benefit as far as accuracy between using IDC and intake manifold pressure. To me, it would make the most sense to inject the methanol based on engine speed, intake air temperature and manifold pressure.
Anyway, the screens with in your methanol injection controller appear to be set up in a manner which will progressively inject and or cease injection of methanol into your intake.
Start increase is the injector duty cycle point at which the methanol system activates the pump and begins to flow methanol into your intake. Full increase is the injector duty cycle at which your methanol system (pump) is at full operation. In other words it's at its max flow.
Your system is a progressive one. You have 4 settings. One is when the meth starts to come on. The other is when the meth is fully on. The other is the point at which the meh starts to turn off or inject less the other is when it's fully off or injecting nothing.
Since the manual says and start increase at 35% IDC and be full by 60% IDC, here's what I would do.
Start decrease id use 59% IDC and have full decrease by 34%
Side note, though one of the by products of running 100% methanol in your system is that the methanol acts like a fuel, please don't run the system simply to compensate for an inadequate fuel system. It's not good practice for obvious reasons.
Does this thing reference manifold pressure at all?
Hope this helped you.
Anyway, the screens with in your methanol injection controller appear to be set up in a manner which will progressively inject and or cease injection of methanol into your intake.
Start increase is the injector duty cycle point at which the methanol system activates the pump and begins to flow methanol into your intake. Full increase is the injector duty cycle at which your methanol system (pump) is at full operation. In other words it's at its max flow.
Your system is a progressive one. You have 4 settings. One is when the meth starts to come on. The other is when the meth is fully on. The other is the point at which the meh starts to turn off or inject less the other is when it's fully off or injecting nothing.
Since the manual says and start increase at 35% IDC and be full by 60% IDC, here's what I would do.
Start decrease id use 59% IDC and have full decrease by 34%
Side note, though one of the by products of running 100% methanol in your system is that the methanol acts like a fuel, please don't run the system simply to compensate for an inadequate fuel system. It's not good practice for obvious reasons.
Does this thing reference manifold pressure at all?
Hope this helped you.
Last edited by MVP'S ZO6; Aug 28, 2015 at 08:12 AM.
Melting Slicks
Joined: Mar 2005
Posts: 2,225
Likes: 42
From: Okinawa
Hi, I don't personally know of any C5 or 6 owners who are running the factory PCM and injecting meth based on injector duty cycle nor do I really know or see any benefit to injecting methanol based on injector duty cycle. I'm not saying it's bad, I'm simply saying I don't see any benefit as far as accuracy between using IDC and intake manifold pressure. To me, it would make the most sense to inject the methanol based on engine speed, intake air temperature and manifold pressure.
Anyway, the screens with in your methanol injection controller appear to be set up in a manner which will progressively inject and or cease injection of methanol into your intake.
Start increase is the injector duty cycle point at which the methanol system activates the pump and begins to flow methanol into your intake. Full increase is the injector duty cycle at which your methanol system (pump) is at full operation. In other words it's at its max flow.
The decrease is the opposite of your increase. (It's a progressive meth injection system)
Id start my decrease at 34% IDC and have full decrease by 30%
As for the increase, Do what the manual says and start at 35% IDC and be full by 60% IDC and play with it from there.
Side note, though one of the by products of running 100% methanol in your system is that the methanol acts like a fuel, please don't run the system simply to compensate for an inadequate fuel system. It's not good practice for obvious reasons.
Does this thing reference manifold pressure at all?
Hope this helped you.
Anyway, the screens with in your methanol injection controller appear to be set up in a manner which will progressively inject and or cease injection of methanol into your intake.
Start increase is the injector duty cycle point at which the methanol system activates the pump and begins to flow methanol into your intake. Full increase is the injector duty cycle at which your methanol system (pump) is at full operation. In other words it's at its max flow.
The decrease is the opposite of your increase. (It's a progressive meth injection system)
Id start my decrease at 34% IDC and have full decrease by 30%
As for the increase, Do what the manual says and start at 35% IDC and be full by 60% IDC and play with it from there.
Side note, though one of the by products of running 100% methanol in your system is that the methanol acts like a fuel, please don't run the system simply to compensate for an inadequate fuel system. It's not good practice for obvious reasons.
Does this thing reference manifold pressure at all?
Hope this helped you.
ISIS SUCKS FAT CHOAD
Joined: Oct 2008
Posts: 8,124
Likes: 53
From: Earth, United States
Before you know it they're going to start taking surface temperature of the streets and saying that in conjunction with other things is the most precise method of injection. 
Thread Starter
Burning Brakes
Joined: Dec 2006
Posts: 1,164
Likes: 20
From: Somewhere in Québec, Canada
Hi, I don't personally know of any C5 or 6 owners who are running the factory PCM and injecting meth based on injector duty cycle nor do I really know or see any benefit to injecting methanol based on injector duty cycle. I'm not saying it's bad, I'm simply saying I don't see any benefit as far as accuracy between using IDC and intake manifold pressure. To me, it would make the most sense to inject the methanol based on engine speed, intake air temperature and manifold pressure.
Anyway, the screens with in your methanol injection controller appear to be set up in a manner which will progressively inject and or cease injection of methanol into your intake.
Start increase is the injector duty cycle point at which the methanol system activates the pump and begins to flow methanol into your intake. Full increase is the injector duty cycle at which your methanol system (pump) is at full operation. In other words it's at its max flow.
Your system is a progressive one. You have 4 settings. One is when the meth starts to come on. The other is when the meth is fully on. The other is the point at which the meh starts to turn off or inject less the other is when it's fully off or injecting nothing.
Since the manual says and start increase at 35% IDC and be full by 60% IDC, here's what I would do.
Start decrease id use 59% IDC and have full decrease by 34%
Side note, though one of the by products of running 100% methanol in your system is that the methanol acts like a fuel, please don't run the system simply to compensate for an inadequate fuel system. It's not good practice for obvious reasons.
Does this thing reference manifold pressure at all?
Hope this helped you.
Anyway, the screens with in your methanol injection controller appear to be set up in a manner which will progressively inject and or cease injection of methanol into your intake.
Start increase is the injector duty cycle point at which the methanol system activates the pump and begins to flow methanol into your intake. Full increase is the injector duty cycle at which your methanol system (pump) is at full operation. In other words it's at its max flow.
Your system is a progressive one. You have 4 settings. One is when the meth starts to come on. The other is when the meth is fully on. The other is the point at which the meh starts to turn off or inject less the other is when it's fully off or injecting nothing.
Since the manual says and start increase at 35% IDC and be full by 60% IDC, here's what I would do.
Start decrease id use 59% IDC and have full decrease by 34%
Side note, though one of the by products of running 100% methanol in your system is that the methanol acts like a fuel, please don't run the system simply to compensate for an inadequate fuel system. It's not good practice for obvious reasons.
Does this thing reference manifold pressure at all?
Hope this helped you.
So if im understanding the decrease point is to make the controller inject less meth has soon has my duty cycle go down instead of shooting maximum flow and only shut it off when i reach low duty cycle point (like 34%)
The controller got boost reference and duty cycle reference.They both got 4 tables.Will be running 50/50 mix(-40 windshield washer here in canada) only to keep the IAT down.
I wont push my timing or boost to gain hp.Has a exemple close to reality.I will have my car tune to 10:8 AFR.Then add .5 AFR of meth.It will bring my AFR to 10:3 .I ll have my tune corrected again to 10:8.So if my pump ever go bad and i dont realise it quick enough i will only be at 11:3AFR so on the safe side.Again only to keep IAT happy, not gonna loose a engine for little more pony .
Thread that was open by me to talk about boost refrence and duty cycle reference.
Thanks for your input
Last edited by always faster; Aug 31, 2015 at 08:51 AM.
ISIS SUCKS FAT CHOAD
Joined: Oct 2008
Posts: 8,124
Likes: 53
From: Earth, United States
Basically yes.
By the way it looks, the meth pump / controller has basically a partial on and full on states.
The instructions you posted say that generally people start the pump at 35% IDC and have it on full at 60-80% IDC so in essence you have a good starting place to try for the meth activation part.
As an example, if you set your partial on to 35% IDC and your full on to 60% IDC then you could start your pump decrease at lets say 48% IDC (that's half way between 35 & 60) and have full decrease set to 34% IDC (that's 1% IDC below your partial on IDC of 35%.
Another option if you have HP Tuners would be to log your injector duty cycle and play with the meth settings based on what you see in the log files. (RPM, IAT, AFR, MAP and so on) and just play with the meth partial and full on and off points until your happy with it.
By the way it looks, the meth pump / controller has basically a partial on and full on states.
The instructions you posted say that generally people start the pump at 35% IDC and have it on full at 60-80% IDC so in essence you have a good starting place to try for the meth activation part.
As an example, if you set your partial on to 35% IDC and your full on to 60% IDC then you could start your pump decrease at lets say 48% IDC (that's half way between 35 & 60) and have full decrease set to 34% IDC (that's 1% IDC below your partial on IDC of 35%.
Another option if you have HP Tuners would be to log your injector duty cycle and play with the meth settings based on what you see in the log files. (RPM, IAT, AFR, MAP and so on) and just play with the meth partial and full on and off points until your happy with it.
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
Hi, I don't personally know of any C5 or 6 owners who are running the factory PCM and injecting meth based on injector duty cycle nor do I really know or see any benefit to injecting methanol based on injector duty cycle. I'm not saying it's bad, I'm simply saying I don't see any benefit as far as accuracy between using IDC and intake manifold pressure. To me, it would make the most sense to inject the methanol based on engine speed, intake air temperature and manifold pressure.
Using manifold pressure alone as most kits do isnt a solid load reference like injector duty or pw is.
