How to set your WOT timing from the drivers seat.
How to set your WOT timing from the drivers seat. OK guys here is the deal.
Things you'll need:
LS1 Edit
Variable Potentiometer 0-10k OHMS
several feet of 18 gage wire
Autotap or equivaltent
1. disconnect the IAT
2. Connect wire to IAT connector
3. connect wires to Potentiometer
4. Mount Potentiometer wherever you want
5. With the motor not running, and the key on use auto tap to determine the temperatures indicated (in celcius) at various potentiometer positions. I dentify ten spots that correlate to multiples of 10 degrees C. (i.e. 40c, 50c, etc.) Mark these spots on the dial.
6. Useing LS1 Edit version 1.05 under the ignition tab. Go to the IAT vs. MAP table and set the timing, at the degrees you have marked on the potentiometer, to add or subtract timeing as you want.
7. Try it out! You should be able to manually make changes for Nitrous or boost based on your seting of the false IAT sensor.
For the POT I used a 10K ohm volume control from radio shack $3.
Ryan K. <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />
BTW I didn't come up with this totaly, its a shared logic from a post that 383LQ4SS and I worked out.
<small>[ June 08, 2002, 12:50 AM: Message edited by: Ryan Karasek ]</small>
Things you'll need:
LS1 Edit
Variable Potentiometer 0-10k OHMS
several feet of 18 gage wire
Autotap or equivaltent
1. disconnect the IAT
2. Connect wire to IAT connector
3. connect wires to Potentiometer
4. Mount Potentiometer wherever you want
5. With the motor not running, and the key on use auto tap to determine the temperatures indicated (in celcius) at various potentiometer positions. I dentify ten spots that correlate to multiples of 10 degrees C. (i.e. 40c, 50c, etc.) Mark these spots on the dial.
6. Useing LS1 Edit version 1.05 under the ignition tab. Go to the IAT vs. MAP table and set the timing, at the degrees you have marked on the potentiometer, to add or subtract timeing as you want.
7. Try it out! You should be able to manually make changes for Nitrous or boost based on your seting of the false IAT sensor.
For the POT I used a 10K ohm volume control from radio shack $3.
Ryan K. <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />
BTW I didn't come up with this totaly, its a shared logic from a post that 383LQ4SS and I worked out.
<small>[ June 08, 2002, 12:50 AM: Message edited by: Ryan Karasek ]</small>
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Joined: Nov 2001
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From: Bellevue, Wa
Re: How to set your WOT timing from the drivers seat. your one sly ***** f....... shut your mouth!!! <img border="0" alt="[jester]" title="" src="graemlins/gr_jest.gif" />
what a great idea.
so you have verfied this works or is it still in theory mode?
what a great idea.
so you have verfied this works or is it still in theory mode?
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Joined: Jan 2002
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From: USA
Re: How to set your WOT timing from the drivers seat. This is not a new idea, I published a circuit back about 1 year ago and did a lot of testing on this subject
IATuner circuit
You cannot leave the resistor inline at all times esp during startup or a cold engine for that value will have ill effect to PCM calibration (esp if pot value is setting temp value too hot or cold) each time engine is started and PCM calibrates to new STFTs.
With the relay part of the circuit it allows the stock IAT sensor to do its job and after engine has gone the 1st 10 minutes of STFT read cycle, then when relay is turned on the sensor is taken out of the circuit and pot is switched in place of the sensor.
IATuner circuit
You cannot leave the resistor inline at all times esp during startup or a cold engine for that value will have ill effect to PCM calibration (esp if pot value is setting temp value too hot or cold) each time engine is started and PCM calibrates to new STFTs.
With the relay part of the circuit it allows the stock IAT sensor to do its job and after engine has gone the 1st 10 minutes of STFT read cycle, then when relay is turned on the sensor is taken out of the circuit and pot is switched in place of the sensor.
TECH Resident
Joined: Jan 2002
Posts: 754
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From: USA
Re: How to set your WOT timing from the drivers seat. GM states :
IAT
Range -39°C to 140°C (-38°F to 284°F). The PCM converts the resistance of the intake air temperature sensor to degrees.
The PCM uses the Intake Air Temperature (IAT) in order to adjust fuel delivery and spark timing according to incoming air temperature.
--------------------
If a resistor value fooling the PCM that IAT is lets say 56 degrees, on startup it WILL have an effect to what the STFT values will be and thus will slant the AFR rich, less timing.
This could have an ill effect to car being launched off the line at a drag strip.
On the other hand allowing IAT sensor to be active during the start or engine will allow STFTs to have proper values for PCM during the time STFT is being built ( since the registers are erased out of RAM when engine is shut off) and then kicking in the pot will allow a proper tricking of IAT value.
I know I tested this for months, cold, hot, drags, track, dyno, etc and best performance for forcing timing changes are when IAT sensor is allowed to function during start up and then switching to a constant value via the pot.
If using LS1edit, then there is no need to have the circuit except for a quick real time need to do the tricking like staging at a drag strip where intake has heat soaked, also heating up IAT and the value it is reporting.
<small>[ June 08, 2002, 01:11 PM: Message edited by: Team ZR-1 ]</small>
IAT
Range -39°C to 140°C (-38°F to 284°F). The PCM converts the resistance of the intake air temperature sensor to degrees.
The PCM uses the Intake Air Temperature (IAT) in order to adjust fuel delivery and spark timing according to incoming air temperature.
--------------------
If a resistor value fooling the PCM that IAT is lets say 56 degrees, on startup it WILL have an effect to what the STFT values will be and thus will slant the AFR rich, less timing.
This could have an ill effect to car being launched off the line at a drag strip.
On the other hand allowing IAT sensor to be active during the start or engine will allow STFTs to have proper values for PCM during the time STFT is being built ( since the registers are erased out of RAM when engine is shut off) and then kicking in the pot will allow a proper tricking of IAT value.
I know I tested this for months, cold, hot, drags, track, dyno, etc and best performance for forcing timing changes are when IAT sensor is allowed to function during start up and then switching to a constant value via the pot.
If using LS1edit, then there is no need to have the circuit except for a quick real time need to do the tricking like staging at a drag strip where intake has heat soaked, also heating up IAT and the value it is reporting.
<small>[ June 08, 2002, 01:11 PM: Message edited by: Team ZR-1 ]</small>
Re: How to set your WOT timing from the drivers seat. John are you still stuck on that book some son of a GM guy wrote? All I have is my actual GM manual and a brain. Through my testing, the IAT has had ZERO effect on how the PCM adjusts LTFT and STFT's.
And it is usefull to people who run both NA and Nitrous on the same day. One setting for NA, One for Nitrous. No computer upload needed. Also if you are changing jets from smaller shots to larger shots you can do it w/o an upload.
Ryan K.
<small>[ June 08, 2002, 01:19 PM: Message edited by: Ryan Karasek ]</small>
And it is usefull to people who run both NA and Nitrous on the same day. One setting for NA, One for Nitrous. No computer upload needed. Also if you are changing jets from smaller shots to larger shots you can do it w/o an upload.
Ryan K.
<small>[ June 08, 2002, 01:19 PM: Message edited by: Ryan Karasek ]</small>
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Joined: Feb 2002
Posts: 414
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From: the moon
Re: How to set your WOT timing from the drivers seat. I have done a lot of testing also with the iat sensor and resistors.
I have not found a effect on the fuel trims.
Not saying there is none, but if there is it is very small.
I have a supercharged car. This is a great idea for me and you could have quite a range of timing caps to be able to play with.
You could also use relays to have a high speed timing retard in top gear.
I think this is a great idea.
I have not found a effect on the fuel trims.
Not saying there is none, but if there is it is very small.
I have a supercharged car. This is a great idea for me and you could have quite a range of timing caps to be able to play with.
You could also use relays to have a high speed timing retard in top gear.
I think this is a great idea.
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Adkoonerstrator
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Re: How to set your WOT timing from the drivers seat. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by SJH:
<strong>I have done a lot of testing also with the iat sensor and resistors.
I have not found a effect on the fuel trims.
Not saying there is none, but if there is it is very small.
I have a supercharged car. This is a great idea for me and you could have quite a range of timing caps to be able to play with.
You could also use relays to have a high speed timing retard in top gear.
I think this is a great idea.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Steve, your slipping man. You let somebody else come up with a cool idea before you. <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
This sounds like a great idea for a nitrous/boosted car, you could have a timing setup for "high boost/pump gas", "high boost/race gas", "low boost/pump gas" at the flick of a ****. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
BTW - how's the car doing these days?
John
<strong>I have done a lot of testing also with the iat sensor and resistors.
I have not found a effect on the fuel trims.
Not saying there is none, but if there is it is very small.
I have a supercharged car. This is a great idea for me and you could have quite a range of timing caps to be able to play with.
You could also use relays to have a high speed timing retard in top gear.
I think this is a great idea.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Steve, your slipping man. You let somebody else come up with a cool idea before you. <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
This sounds like a great idea for a nitrous/boosted car, you could have a timing setup for "high boost/pump gas", "high boost/race gas", "low boost/pump gas" at the flick of a ****. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
BTW - how's the car doing these days?
John
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Verdad Gallardo Re: How to set your WOT timing from the drivers seat. Well Hey thats Great! Unfortuneatley, you were not doing anything by setting your IATemps different. IN fact, the table has ZERO effect below 40c and only removes timing at high MAP and high temps. So anything you would have done before being able to actually change the values didn't do SQUAT.
Now that you have the editor, you can actually do something like changing timing for a given temp input. This works perfectly as a Retard Box for boost or Nitrous.
And I don't belive that IAT does poop with the STFT's.
The Manual states the IAT is used to adjust igniton timing according to incoming air density.
Ryan K. <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />
<small>[ June 08, 2002, 12:16 PM: Message edited by: Ryan Karasek ]</small>
Now that you have the editor, you can actually do something like changing timing for a given temp input. This works perfectly as a Retard Box for boost or Nitrous.
And I don't belive that IAT does poop with the STFT's.
The Manual states the IAT is used to adjust igniton timing according to incoming air density.
Ryan K. <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />
<small>[ June 08, 2002, 12:16 PM: Message edited by: Ryan Karasek ]</small>