Yep, but there are more methods to tuning than just in the ECU. In fact, for a 150 shot, I would never run that without an indepth tuning session to make sure it was ultra safely tuned, with conservative AFR's. However, a 75 shot, just tuning though the jets will be fine.

 

I can second the point that with a 75 shot at least there is no sudden shock. In fact the motor runs so smoothly on it that I don't really know it's turned on, until I see the time slips. When I spray in first, I either don't purge, or just it a very short purge. I was also doing this during the tuning process to prevent the lean spike you can get when the nitrous engages (nitrous at 900 psi gets to the nozzle before the fuel at 43 psi). Once I knew it was tuned safe, and started purging, I found that the lean spike is very small anyway.

I did notive however when testing the electrical and DSMlink portion of the setup on the smaller 30 and then 50 shot on pump gas, you can feel it more easily on the pump gas settings. Presumably due to the fact that a fixed size shot will be a larger precentage increase when at lower pump gas power levels and a smaller percentage increase at the higher race gas/high boost power levels.

I personally wouldn't bother with a dry shot, but some people prefer them due to the lower likelyhood of a nitrous backfire blowing apart the intake manifold. If I were to try a dry shot I would compensate for the fuel when it is engaged by using an AEM or even a MAF Translator, so AFR remains appropriate both on and off the nitrous. The MAFt idea is interesting as well, since raising the airflow signal to add fuel will also provide the (in this case) welcome side effect of reducing timing when it's engaged. How much that reduction would be I can't say, but it's an interesting thought IMO.

I have also found that using the two more common online calcs for fuel jet size you end up with a pretty rich AFR for a NA motor, but almost exactly what we are looking for on a turbo motor, mid 11:1s AFR. In only one case did I have to adjust the fuel jet by one size.

 

Well, that about sums it up. I run a WOT switch to prevent the possibility of pooling in the intake manifold and having a backfire. No way anything is pooling up with 23 psi worth of boost rushing past it.

 

I am sorry I thought that Oxygen was an essential part of combustion. Thus making the higher O2 content mixture a fuel that is not only promotes combustion but is part of it, as opposed to water injection which only cools that charge and is not burned. What good is "fuel" without oxygen? Gasoline will not even burn without oxygen. There is more to the word fuel than just gasoline. I was condidering the whole mixture a fuel. Apperently this was not specific enough. I guess I do not know the very basics of a motor. You apparently are much smarter than I.

 

There are still some posibilites that port poeple now and again though, like AEM cycling the solenoids when you start the car (if you left the arming switch on, when you stall at the track perhaps and restart without thinking), or a leaking fuel solenoid. With a dry system these are things you don't have to worry about, making it an attractive option for poeple that are worried about it. I still think a wet kit has benefits that outweight the potential problems, which there are ways around. With the AEM, a redundant WOT swith perhaps, and against leaky solenoids, redundant solenoids, etc.

 

I fail to see a leaking fuel solenoid as a bad thing. All that would do would send the wideband to rich and I have never heard of a rich condition causeing a blown motor, and the nitrous solinoid barely ever is stressed, seeing as there is only pressure on it when you open your bottle, which is for what, 10 miniutes at a time at the most. NX has a lifetime warrenty on their solenoids, which means, bad 'noid, send it back and get a new one no questions asked. I have no idea how to program nitrous through AEM, my setup is simple, and wont spray unless four conditions are met, The throttle has to be at WOT, the arming switch has to be on, the deadmans switch has to be released (makes it easy to use a two step without blowing up on the line, and Im between 4000 and 7000 rpms.