Timing retard using IAC?
Timing retard using IAC? So I finally found someone local who does nitrous installs for a reasonable price. The guy used to have a shop but recently started just doing it out of his home while maintaining an out of state warehouse.
He mentioned that he normally uses the IAC to retard timing when the kit installed instead of using a timing controller like the LNC 2000 which I was set on. Is this safe? Are there any caveats to doing this? The car is speed density tuned. I am only looking to spray a 75-100 shot using a wet plate kit. I'll be using a NOS mini as a window switch, have already bought a FPSS, and have colder BR7 plugs. A Racetronix pump with a hotwire kit is also already on order.
He mentioned that he normally uses the IAC to retard timing when the kit installed instead of using a timing controller like the LNC 2000 which I was set on. Is this safe? Are there any caveats to doing this? The car is speed density tuned. I am only looking to spray a 75-100 shot using a wet plate kit. I'll be using a NOS mini as a window switch, have already bought a FPSS, and have colder BR7 plugs. A Racetronix pump with a hotwire kit is also already on order.
The problem with timing boxes like the LNC is you cant see the timing being pulled. so when something happens during a run you just assume timing was pulled and look elsewhere for the problem. IAT trickers only work as good as the tune put in for it and you can actually see timing being pulled in the log. You wouldnt put a stroker motor in your car and run a stock tune and expect it to work perfect so why would you think your car would run right when telling it its 122 degreea out when its actually 85. When done right VE, Maf, timing and some other little stuff needs copied over form the normal opperating temps to the selected temp for the tricker.
I have heard with Speed density that the tricker is a bad idea. Never tried it myself but dont see why it couldnt be when set up right.
I have heard with Speed density that the tricker is a bad idea. Never tried it myself but dont see why it couldnt be when set up right.
Another difference between the two is that when you want to change horsepower settings, you will have to take the car back to him and have the timing changed. With the LNC, it's as easy as turning the dial to change the amount of timing being pulled.
This is true and could easily be worked around when setting up the tricker or trickers. I'm not saying one way is better than the other, just saying there is options. I personally have a LNC2000 and a HSW Interface and have decided I'm just going to pull timing in the tune on this car I'm doing now.
I should specify that this is a street car with the nitrous being used sparingly. The car can sometimes be a pain on a cold start and I've heard this can be because of the IAC- and I don't know if its related to the Ebay TB I have on the car or not. Does that present any additional risk? I plan on staying at a 75 shot.
Can I get any more input on if the car being speed density tuned makes this a bigger risk?
Can I get any more input on if the car being speed density tuned makes this a bigger risk?
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From: Ohio
I use my IAT sensor for a lot of turbo related things.
For example, my water/meth injection keeps IATs down below 100 even on a full pass. I have the columns above 100 degrees set up so that if the water injection fails, it will see the high IATS and pull timing as a safety measure.
Doing the same on nitrous would work. If it sees IATs below normal, you can have it pull timing. The biggest concern is that you'll have to mount the IAT sensor after the nitrous nozzle/plate. Very easy to do on a truck intake, not as easy to go on a car intake.
For example, my water/meth injection keeps IATs down below 100 even on a full pass. I have the columns above 100 degrees set up so that if the water injection fails, it will see the high IATS and pull timing as a safety measure.
Doing the same on nitrous would work. If it sees IATs below normal, you can have it pull timing. The biggest concern is that you'll have to mount the IAT sensor after the nitrous nozzle/plate. Very easy to do on a truck intake, not as easy to go on a car intake.
This is a pretty good idea. The tuner SHOULD know how to implement this.
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From: Ohio
Two ways of doing it, though.
One, put the IAT after the nitrous. When your IAT reads below 50 degrees, fill in that column and every column before it with how much timing you want pulled. As soon as you spray, IATs will drop and timing will be pulled.
Two, use the nitrous relay to control another relay. Have the NC pin on the nitrous relay feed power to a 2nd relay. When the nitrous relay activates, its cuts power to the 2nd relay in order to send power to the nitrous setup instead. On the 2nd relay, you'll have the IAT signal coming from the sensor into pin 30. On the NO pin, it'll send a wire to the IAT signal pin on the ECU. But when the relay loses power, it disconnects the IAT signal from the ECU. This will default your IAT temps to the far left column on the IAT spark correction table, where you can enter in how much timing to be pulled. This solves the issue with method 1 where you end up having really low timing in the winter months unless you use the IAT multiplier table to simply turn on/off the IAT timing offsets.
One, put the IAT after the nitrous. When your IAT reads below 50 degrees, fill in that column and every column before it with how much timing you want pulled. As soon as you spray, IATs will drop and timing will be pulled.
Two, use the nitrous relay to control another relay. Have the NC pin on the nitrous relay feed power to a 2nd relay. When the nitrous relay activates, its cuts power to the 2nd relay in order to send power to the nitrous setup instead. On the 2nd relay, you'll have the IAT signal coming from the sensor into pin 30. On the NO pin, it'll send a wire to the IAT signal pin on the ECU. But when the relay loses power, it disconnects the IAT signal from the ECU. This will default your IAT temps to the far left column on the IAT spark correction table, where you can enter in how much timing to be pulled. This solves the issue with method 1 where you end up having really low timing in the winter months unless you use the IAT multiplier table to simply turn on/off the IAT timing offsets.
So I finally found someone local who does nitrous installs for a reasonable price. The guy used to have a shop but recently started just doing it out of his home while maintaining an out of state warehouse.
He mentioned that he normally uses the IAC to retard timing when the kit installed instead of using a timing controller like the LNC 2000 which I was set on. Is this safe? Are there any caveats to doing this? The car is speed density tuned. I am only looking to spray a 75-100 shot using a wet plate kit. I'll be using a NOS mini as a window switch, have already bought a FPSS, and have colder BR7 plugs. A Racetronix pump with a hotwire kit is also already on order.
He mentioned that he normally uses the IAC to retard timing when the kit installed instead of using a timing controller like the LNC 2000 which I was set on. Is this safe? Are there any caveats to doing this? The car is speed density tuned. I am only looking to spray a 75-100 shot using a wet plate kit. I'll be using a NOS mini as a window switch, have already bought a FPSS, and have colder BR7 plugs. A Racetronix pump with a hotwire kit is also already on order.
https://ls1tech.com/forums/nitrous-o...l-nitrous.html
If you update your PCM software to 2002 (assuming your PCM software is older) you can actually log it with HP tuners by pulling timing that way. Anyone who knows how to use the PIN 53 method to retard timing is most likely a good tuner. Here's how mine is wired up. Excuse the crappy M$ paint drawing. I'm no electrical engineer.
Last edited by 5.7stroker; Nov 4, 2016 at 06:59 PM.
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If you use IAT method of going to 40C with speed density you lose the ability of the iat to adjust fuel for day to day temp variations it will just be set for the temp you tuned it at.
If he is actually using IAC I have no idea how that would actually work.
If he is actually using IAC I have no idea how that would actually work.
you can adjust the multiplier to offset that. or mess with the fuel jets.
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What multiplier is it in hpt? The only one I see is based on IAT that lets you tune it that day but if you are changing the tune at the track anyway you don't need an IAT tricker you can just pull the timing you can just change the tune.
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From: From Ohio now in that state up north
Timing Boxes OK, Idle Air Controller (IAC) = MAT Manifold Air Temperature NOW clear ! (yea, me too).
I would USE the IAT/MAT, same sensor just different names.
The reason is the UNKNOWN method that the LNC 2000 implements.
Thus the chance for Timing Lag/Dwell Control inaccuracy is GREAT.
The LNC 2000 states a 40Mz with TPU "micro" which could work though there would be a "lag" of the commanded events.
The method for the retard of the Spark Instant is NOT stated, longer coil dwell?
As IS stated, the "TTL" logic from the EOM ECU is intercepted, delayed, changed, by unknown values.
A MORE correct method would be to "decode" the CS measurement of the fitted Target Wheel.
Thus why I like the IAT/MAT method.
Lance
I would USE the IAT/MAT, same sensor just different names.
The reason is the UNKNOWN method that the LNC 2000 implements.
Thus the chance for Timing Lag/Dwell Control inaccuracy is GREAT.
The LNC 2000 states a 40Mz with TPU "micro" which could work though there would be a "lag" of the commanded events.
The method for the retard of the Spark Instant is NOT stated, longer coil dwell?
As IS stated, the "TTL" logic from the EOM ECU is intercepted, delayed, changed, by unknown values.
A MORE correct method would be to "decode" the CS measurement of the fitted Target Wheel.
Thus why I like the IAT/MAT method.
Lance
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Joined: Oct 2002
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From: Decatur, IN
timing retard analog output of LNC-2000 Just to clarify, you can see the amount of timing retard being removed by the LNC, you just can't see it in the ECM/PCM scan tool/diagnostic outputs because the ECM/PCM doesn't know the timing is being removed.
You can read the amount of timing being taken out via the analog output wire from the LNC-2000 (or LNC-2001 or LNC-2014). You can view this with a simple voltmeter or you can add it as an input to an EFILive V2 cable or HPTuners Pro cable. EFILive even has the variable already defined as an auxiliary input so it does the voltage to timing retard conversion for you.
You can read the amount of timing being taken out via the analog output wire from the LNC-2000 (or LNC-2001 or LNC-2014). You can view this with a simple voltmeter or you can add it as an input to an EFILive V2 cable or HPTuners Pro cable. EFILive even has the variable already defined as an auxiliary input so it does the voltage to timing retard conversion for you.
The problem with timing boxes like the LNC is you cant see the timing being pulled. so when something happens during a run you just assume timing was pulled and look elsewhere for the problem. IAT trickers only work as good as the tune put in for it and you can actually see timing being pulled in the log. You wouldnt put a stroker motor in your car and run a stock tune and expect it to work perfect so why would you think your car would run right when telling it its 122 degreea out when its actually 85. When done right VE, Maf, timing and some other little stuff needs copied over form the normal opperating temps to the selected temp for the tricker.
I have heard with Speed density that the tricker is a bad idea. Never tried it myself but dont see why it couldnt be when set up right.
I have heard with Speed density that the tricker is a bad idea. Never tried it myself but dont see why it couldnt be when set up right.
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Joined: Oct 2002
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From: Decatur, IN
Timing retard for nitrous Two other options for timing retard for nitrous:
- Use a custom operating system (OS) for your ECM/PCM from EFILive or others that enables the timing retard via a pin on the ECU that usually activates another set of timing tables (usually the E85 tables). This option requires that EFILive or others have written a custom OS that works in place of your existing OS.
- Use the LPE ethanol sensor simulator module (ECSS-001) with a switched input from your nitrous controller or activation switch etc. When the switch is active it makes the ECM/PCM think you have what ever E85% you configured the module for and then you can change timing (and fueling) using the E85 tables in the ECM/PCM. This option requires that you have an ECM/PCM capable of reading an E85 sensor (fuel composition sensor).
Two ways of doing it, though.
One, put the IAT after the nitrous. When your IAT reads below 50 degrees, fill in that column and every column before it with how much timing you want pulled. As soon as you spray, IATs will drop and timing will be pulled.
Two, use the nitrous relay to control another relay. Have the NC pin on the nitrous relay feed power to a 2nd relay. When the nitrous relay activates, its cuts power to the 2nd relay in order to send power to the nitrous setup instead. On the 2nd relay, you'll have the IAT signal coming from the sensor into pin 30. On the NO pin, it'll send a wire to the IAT signal pin on the ECU. But when the relay loses power, it disconnects the IAT signal from the ECU. This will default your IAT temps to the far left column on the IAT spark correction table, where you can enter in how much timing to be pulled. This solves the issue with method 1 where you end up having really low timing in the winter months unless you use the IAT multiplier table to simply turn on/off the IAT timing offsets.
One, put the IAT after the nitrous. When your IAT reads below 50 degrees, fill in that column and every column before it with how much timing you want pulled. As soon as you spray, IATs will drop and timing will be pulled.
Two, use the nitrous relay to control another relay. Have the NC pin on the nitrous relay feed power to a 2nd relay. When the nitrous relay activates, its cuts power to the 2nd relay in order to send power to the nitrous setup instead. On the 2nd relay, you'll have the IAT signal coming from the sensor into pin 30. On the NO pin, it'll send a wire to the IAT signal pin on the ECU. But when the relay loses power, it disconnects the IAT signal from the ECU. This will default your IAT temps to the far left column on the IAT spark correction table, where you can enter in how much timing to be pulled. This solves the issue with method 1 where you end up having really low timing in the winter months unless you use the IAT multiplier table to simply turn on/off the IAT timing offsets.