tuning for wet nitrous
#1
tuning for wet nitrous
I was told that with a good tune n/a once i spray a 100 shot the computer is able to pick up the extra load, cylinder density, or whatever i forget what he said. Is this true? and how does it calculate it, its a wet kit so im not spraying tthrough the maf. Or is it best to use the resistor trick? I cant really find a clear answer and idk know anything about how the GM PCM works
#2
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If you run a wet shot it bypasses the computer. Dry shots can be read by the MAF until it maxes, but wet shots are a different story. The only way to safely run a wet shot is with a separate tune, tricking the timing, or running a higher octane fuel that supresses detonation under the extra load.
#4
You basically tune for max NA power and then pull roughly 2* of timing for every 50hp of nitrous increase. If you want an EXCELLENT and simple to use timing tuner that is only active when the system is actually spraying (giving you full timing up until the point of spray and after) check out the Harris Speed Works Interface. It also works great with their "all in one" nitrous controller the MicroEdge.
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The computer will not know there is nitrous being sprayed. I ran a similar setup with my vette except I was running a 150 shot. What I did was tune the engine for n/a, then tune the fuel jet for the nitrous. The timing is a different story. It will not know to pull timing. You have 3 options. ONE: You'll have to pull timing (about 4 degrees) and run it like that all the time. TWO: flash the computer with 4 less degrees when you know you are going to spray. THREE: run a separate timing "tricker" to pull timing when the nitrous is engaged. When I say -4 degrees that is based on an optimum max timing for n/a minus 4. For example, I ran a max of 29 degrees timing n/a on my vette. When I sprayed I pulled timing to about 25 degrees max. I had an integrated iat/ maf sensor so I couldn't run a resistor mod. As far as I can remember all F-bodies run a separate iat sensor so the resistor mod is an option for you. Then again if you are running stock timing you should be fine as far as timing goes because I think the computer (besides the 98 model) only runs about 25 degrees total. PM me if you would like to know more.
#7
I also run a 150 wet kit. I run -6 degree's and load program when I spray. I tune my AFR with VE table & run open loop SD. Seams to be a better way for me to get my AFR tuned closer to what I want than changing fuel jets.
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#8
so you also use load to pull the timing, correct. im going to have i tuned as if i didnt have spray and get as close as i can with the jets and do fine tuning as you did yours.
#9
You basically tune for max NA power and then pull roughly 2* of timing for every 50hp of nitrous increase. If you want an EXCELLENT and simple to use timing tuner that is only active when the system is actually spraying (giving you full timing up until the point of spray and after) check out the Harris Speed Works Interface. It also works great with their "all in one" nitrous controller the MicroEdge.
#10
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You can't do that with a wet kit only a dry kit. The engine has no way of knowing there is extra air entering hence the nitrous AND fuel being sprayed, because the maf is bypassed. The dry kit measures the extra load by spraying through the maf, people log the load tables used when spraying and pull timing in those tables. You need to do a resister mod to the IAT that comes on when the nitrous unit is powered up.
Last edited by JDMC5; 08-30-2009 at 02:57 AM. Reason: I was being kind of a dick