00buckshot

iTrader: (5)

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

Bowtiedford

iTrader: (9)

I just have my total timing set total whether I run 1 stage or 2. Never really thought it would make much of a difference. How much are you planning on spraying on the 2nd stage?

00buckshot

iTrader: (5)

150 in stinger plate then 200 in the fogger

JoeNova

200 total or 200 in the fogger alone?
If its 200 total, I would pull an extra couple degrees in the tune and leave it.

If its an extra 200 and you really do want a 2nd stage, you can use a resistor or the IAT disconnect method (whichever one you are NOT using now) by installing the 2nd relay inline with the 1st.

Basically, the IAT signal goes through pin 87a on the first relay. When Nitrous is activated and 1st relay turns on, it'll switch to pin 87, which will then feed pin 30 on the 2nd relay (So IAT signal is now at the 2nd relay when nitrous is on. From there, pin 87a will be for your stinger plate, and pin 87 will be for the fogger. I would probably put pin 87a with a resistor inline to send a signal to ECU to make it think IAT is 250 degrees and pulls X timing, and then when fogger activates, it will disconnect IAT all together and make ECU think IAT is extremely cold, where you can have it pull even more timing using the furthest left column on the IAT spark table.

No that complicated ROFLMAO

brandon6.0

iTrader: (32)

U comin for that turbo truck?! U know i need a rematch!

tug686spd

iTrader: (11)

Joe, I like the way your starting to think about this now.

The only thing that i would do different though is running a resistor for both stages to hit 2 temp columns beside each other. Not sure if a cars computer will do the same as some of my work equipment (with more sophisticated electronics) but when trying to make big moves in a sensors range the computer it would catch or put some fragments of data in between the 2 points commanded. This would suck if it caught full timing for a fraction of a second on a 200+ hit.

RixTrix

Tricking the ECU will work fine until it doesn't.

Messing with the IAT changes fueling more than it changes timing.

brandon6.0

iTrader: (32)

Have tuner pull a few degrees for the 150hit and use resister trick for second stage.

JoeNova

You can very easily tune out IAT fueling changes. If you're able to change IAT offset timing, you shouldn't have any trouble changing the fueling bias.

You could even use it to your advantage and ADD fuel to the engine when spraying nitrous as a safety measure.

You're not tricking the ECU, you're forcing which columns of the IAT table it uses. Unless yours has built in AI, its not going to decide on its own to ignore you. It WILL work. If it ever gets to the point where it doesn't, it will be tuner error, not because of the IAT or ECU.

LIL SS

iTrader: (9)

Very crude quick drawing but this would work for 2 stages through iat.

uraloser2me2

You could always use a Daytona Sensors smart spark to control timing. They are able to do 2 stages of retard. MSD makes the adapters to piggy back it to your factory ecu.

Bowtiedford

iTrader: (9)

I don't think the Daytona box would work for fi??

uraloser2me2

It will control timing only with these adapters. MSD Part#8886

https://www.msdperformance.com/produ...ses/parts/8886

MaroonMonsterLS1

I believe you could do a dual sensor setup. Tune the first kit using the iat, then tune the second kit using the coolant temp sensor.

Another option is to change the rpm multiplier. There is a table that changes the amount of spark addition (or in this case subtraction) via rpm. If you have the second kit to come in at a set rpm, just change the multiplier from there up to adjust timing.