Timing retard trick

[DBRODS]

Ok I am seriously thinking about doing this in the near future. Looking for input from anyone with any experience with this. Basically you wire up a seperate circuit for the IAT sensor, you flip a switch and it bypasses the IAT sensor to whatever ohm resister you put inline to trick the computer to think its a different temp air coming in. Then you set that ''X'' table to pull ''X'' timing for the N20. That way you can run max timing all the time N/A till its time to spray someone in ''Mexico'', flip a switch and you have your N20 tune ready to go... Here is a diagram of how its wired in..

[mean05]

It works very well and allows you to run a motor tune and a nitous tune, I think the 750ohm is 149* on the iat chart

[sprayedenali]

I figured you had just come up with a way to see how fast Tyler did something...

But this is cool too! I'd be interested in trying it

[DBRODS]

It works very well and allows you to run a motor tune and a nitous tune, I think the 750ohm is 149* on the iat chart

Is 149 a safe one to use in TX...I think 130 is the hottest I've ever seen on the interceptor. Here is a link that I found with more info on it...

Roberts Nitrous Service - NITROUS WIRING (schematics)

[Botlfed]

sweet deal might have to look into this.

[mean05]

Is 149 a safe one to use in TX...I think 130 is the hottest I've ever seen on the interceptor. Here is a link that I found with more info on it...

Roberts Nitrous Service - NITROUS WIRING (schematics)

yeah if you see more then 130 then you need to figure out something else to do for a CAI lol. I have a friend here that makes them sometimes, always wanted to have him make me one but never cared to worry about it, i race on bottle way more then motor

[oleshifty]

couple things.

1) don't forget resistance in wires of circuit
2) resistors are normally give or take 10%, so you can't JUST set that resistance/temperature, you'll need to do a values from table above/below the actual resistor being used
3) a tuner might step in here...but i BELIEVE if the computer reads values that don't make sense with the other sensors, it'll bypass that one sensor.

i know a lot of guys in my last forum used to put resistors inplace of iat sensor to always get a few degrees without a tune. After a while, the computer just ignored the value, and used a default. Wouldn't want it to do this mid spray.

I actually have mine run in series with the iat, so that the computer thinks its like 30* colder then it actually is...you might be able to do something with that, and just use an EXTREME.

i would think that there would be a way to have a push button go to some pin, and have that change the tune. The grand prix guys all have it, a 'normal' and 'race' setting...as do most diesels, but i haven't looked into tuning these trucks much.

[ducky]

So this is your grand scheme to run both tunes at once, and get the most power out of both..

[mean05]

What Jon has posted about the resistors have been used time and time again...in our tunes there is a IAT table the directly related to amount of timing added or pulled vs the amount of air coming into the motor... 750ohm resistor tricks the pcm into thinking the IAT's are 149* so therefore you go to the 149 column and just put a -6 (Jon's case) to have it pull 6* of timing and when you activate the nitrous it then activates that relay and that turns on the resistor and then the pcm sees the 149* IAT

[DBRODS]

couple things.

1) don't forget resistance in wires of circuit
2) resistors are normally give or take 10%, so you can't JUST set that resistance/temperature, you'll need to do a values from table above/below the actual resistor being used
3) a tuner might step in here...but i BELIEVE if the computer reads values that don't make sense with the other sensors, it'll bypass that one sensor.

i know a lot of guys in my last forum used to put resistors inplace of iat sensor to always get a few degrees without a tune. After a while, the computer just ignored the value, and used a default. Wouldn't want it to do this mid spray.

I actually have mine run in series with the iat, so that the computer thinks its like 30* colder then it actually is...you might be able to do something with that, and just use an EXTREME.

i would think that there would be a way to have a push button go to some pin, and have that change the tune. The grand prix guys all have it, a 'normal' and 'race' setting...as do most diesels, but i haven't looked into tuning these trucks much.

thanks for the heads up....I actually have a degree in electronic engineering so the wiring is no big deal, if I can remember how to turn on a meter...
This trick has been around for a long time...
Im using a SD tune so thats all the computer has to go off of...