2 stage timing retard
11-14-2016, 09:44 AM
#1
2 stage timing retard
Guys, I'm sure this has been covered before, I'm looking for the simplest way to control timing for 2 stages of nitrous. My tuner has a IAT relay installed to pull timing for my first kit, I read some yesterday where someone had a thread on how to use more than one relay but I couldn't find it. any info and help will be greatly appreciated TIA
11-14-2016, 11:17 AM
#2
I believe you would just throw another relay into the IAT wire, with a different strength resistor, and this relay would be activated when the second stage went live.
Now both IAT relays would need different resistors, corresponding to the two lowest temp columns in your tune. I don't know what the resistance would be, because with one relay you can simply leave the circuit broken, no resistor required.
Now both IAT relays would need different resistors, corresponding to the two lowest temp columns in your tune. I don't know what the resistance would be, because with one relay you can simply leave the circuit broken, no resistor required.
11-14-2016, 01:57 PM
#3
I wouldnt shoot for the last column and a column right next to it, I would shoot for at least a few columns apart.
Are you adding in the 2nd stage while keeping the first going or are you turning off the first at the same time you turn on the second?
Are you adding in the 2nd stage while keeping the first going or are you turning off the first at the same time you turn on the second?
11-14-2016, 02:41 PM
#5
This should work for what you want. 1st stage should put the IAT in the 5F to -4F column depending on outside temp and the second stage should be in the last column (-40F). I recommend interpolating between these points also in case the resistance moves around a lot there.
You need 5 pin relays to do this, and if you are using a ground to activate your solenoids just switch 85 and 86 labels.
Normally there is no extra resistance so the PCM sees the IAT for what it actually is. When the first stage activates it adds in the 20k ohm resistor moving the IAT to the 5f to -4F range, and when the second stage activates it disconnects entirely (so its infinite resistance) which will go to the last row in the table. If the stage 2 solenoid activates without the first solenoid it will also go to the last row.
You need 5 pin relays to do this, and if you are using a ground to activate your solenoids just switch 85 and 86 labels.
Normally there is no extra resistance so the PCM sees the IAT for what it actually is. When the first stage activates it adds in the 20k ohm resistor moving the IAT to the 5f to -4F range, and when the second stage activates it disconnects entirely (so its infinite resistance) which will go to the last row in the table. If the stage 2 solenoid activates without the first solenoid it will also go to the last row.