Questions for the nitrous guru's
 

So I want to put together a nitrous system and would love some advice. I have used nitrous for years in street cars and playing around at 1/8 mile airport flashlight drags. Currently I have an LQ9 with a FAST 102 intake, cam and ported heads in a street car. I'm running this with a Holley Terminator X Max. I want to try a direct port single stage dry progressive shot. At most I'm going to go to a 200 shot but I'm going to start out with way less just to make sure I get the tune figured out being that this is the first dry and the first progressive system I have ever used.

My questions are about the hardware itself. The Holley ECU will output a NPN signal to run a solid state relay to pulse the solenoids. So I was thinking about running 3 solenoids. From what I've been reading a progressive system works better with smaller solenoids. So could I use two of the small Holley style 150 hp solenoids. One feeding a 100 hp shot to bank 1 and the other to bank 2. Then have a larger 3rd solenoid that wouldn't be progressive. It would just open or close when the other solenoids are pulsed as an added layer of safety. I was thinking of setting up the Holley output to only allow the nitrous to flow if conditions are met. It has a flex sensor so ethanol would have to be over a certain point, along with other factors like bottle pressure and AFR.

Before anyone asks yes the rings are gaped for spray as per Hastings spec's. Also I'm going to use a plug with a non-protruding ground strap that is 2 heat ranges lower than stock.

So any advice? Am I on the right track?

I think you are making it more complicated than it should be. While yes, a smaller solenoid will be more progressive friendly, that setup is no more than probably 650-700whp on a 200. I would focus more on your tire and suspension tune up with the holley and if anything, delay the hit to get some wheel speed for half a second to a second and let it all come in, or come in on a very short progressive (no more than half a second to get to full boogie). With 1/8 mile stuff, the key is to get into it as quickly without knocking the tires loose (obviously a no brainer). I bet you could make it work bringing the whole 200 in sooner than you think. I would use one standard size solenoid per bank and be done with it.

Thanks for the advice. I agree that the suspension and tires need a lot of attention. I still need to get front wheel speed sensors wired in. But at the end of the day this car is a street car that sees some occasional airport runways. So this is just for fun. I'm not trying to squeeze the fastest time out of it.....yet.

So do you think I could get away with just two small solenoids? To be honest even with the Holley solid state relay this system is definitely budget friendly. I found single jet dry nozzles for $15 each online. If I only need two small solenoids I could have this whole thing wrapped up for under $500 :D

Do NOT separate solenoids bank to bank. This will guarantee a blown motor if one of them fails. Better to have both feeding both banks. Best case, failure gets shut down in time. Worst case, still a blown motor. Problem with separating bank to bank is if one bank blows, your motor is still blown. You only have half the time "or less" to keep it from happening.

That's what I was wondering. I'm going to be putting this system together later this summer. I still have a lot of tuning to get figured out for the new motor before I even start on nitrous. So I'm figuring out what I need now. So do you think 1 good quality trashcan style solenoid would be a good choice for a progressive 200 shot in a street car?

Nitrous racers run one solenoid per bank ALL THE TIME for fogger setups
This is super common.

Why do you think it'll be some big issue?

Because new people who are asking newby questions either cheap out on components or make wiring mistakes all the time. Formula 1 teams run some of the most complex shit you can imagine on their motors, and I bet the average new guy would be lucky to crank a motor with that same equipment. My rule of thumb is, if a person is asking, steer them to the simplest way to not blow their shit up.

I appreciate that. Nitrous Outlet has a dry fogger kit that comes with everything except the tank. I'm going to give them a call and see if they recommend the solenoid that comes with that kit be used in a progressive system.