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I'm using a 100 shot of nitrous on a stock motor except for the tuning is customized by Bryan at pcmforless. He said that he had advanced the timing by 4 degrees in the programming and recommends pulling that back out when using nitrous. I know they have devices from ramchargers and others but surely there is a way to do the same for considerably less money! Some I've heard are using a simple resister wired into a relay that works great. What of value of resister are they using and what wire are they tapped into?
Stand by... I am going to try using a relay and a resistor in the IAT circuit to trick the PCM into thinking the temp is 90* C ONLY when the nitrous is sprayed. I believe our stock C5 tables pull 6* of timing at this IAT temp.
I also bought a potentiometer, so I can swing the resistance on the IAT sensor wire to whatever I choose. I might mount this on my switch panel so I can adjust timing retard as I see fit (i.e if I run race gas).
For $5 I am now retarding 6 degrees of timing when the nitrous hits. For 3 dollars more I can choose how much timing to retard (up to 6 degrees with stock timing tables).
I used a relay to activate when the nitrous is armed. When armed, the relay switches the IAT sensor over to a 330 ohm resistor to simulate 180*F IATs. I could have used a 10k ohm potentiometer and mounted it in cabin to adjust timing retard in real time. I verified with EFILive and my timing is down at 22-23* now instead of 28-29 on the nitrous. It stays at 28-29 N/A.
THis is nothing I made up - it's all over another LS1 board - but it works great!
I have a little wiring diagram if anyone wants it - I can email it.
For $5 I am now retarding 6 degrees of timing when the nitrous hits. For 3 dollars more I can choose how much timing to retard (up to 6 degrees with stock timing tables).
I used a relay to activate when the nitrous is armed. When armed, the relay switches the IAT sensor over to a 330 ohm resistor to simulate 180*F IATs. I could have used a 10k ohm potentiometer and mounted it in cabin to adjust timing retard in real time. I verified with EFILive and my timing is down at 22-23* now instead of 28-29 on the nitrous. It stays at 28-29 N/A.
THis is nothing I made up - it's all over another LS1 board - but it works great!
I have a little wiring diagram if anyone wants it - I can email it.
great stuff, why drive on the street with 6-8 pulled out.
i imagine this would also work for high compression motors. if you tuned your car on race gas and then dialed timing back for street use and standard gas.
Yes. You could also use Edit or HP tuners to set timing advance for different IAT points. Then use a potentiometer instead of a resistor to dial in the timing based on the gas and power adder conditions. The Pot would be wired in at the same spot as the resistor in the diagram, but you could have it in the cabin to adjust while driving even.
Now my problem is that with this third relay in my system, the 2nd stage nitrous shot aint workin no more lol. I wonder if they are trying to pull too much current from the Breathless TPS switch (all three relay coils - 2 for nitrous and 1 for IAT tricker - are in parallel off the TPS switch).
Great stuff! Send me details on diagram, and where/what to get all the needed parts. Once I do my 100-150shot, I was thinking about redoing the tune that 21MC did for the H/C install, but this way, the car is the same N/A, and can switch over to Nitrous mode without spending several hundred on a device or re-tune!!
Re: TIMING RETARD DEVICE FOR NITROUS? (TexCorvette)
i use the ramchargers box and it works great!!! you cna also use it as a window switch for the spray as well as a delay function. you cna add or remove timing on the spray as well as hard set for NA... best of all NO wiring plugs directly into your crank sensor..
I'll be happy to answer any questions if you need.. just email..