Question about stepping up the nitrous...

[GTA_V6_Mustang]

Ok well I was thinking about going up to a 150 shot.... I know I started with the 75 then quickly to the 100 and now i want the 150, lol. This ****s addicting. Anyway when I looked into the upgrade NOS kit the only difference I see is they have the obviously bigger nozzle. And a fuel pressure booster pump. But this is all NOS provides for stock engines and stock fuel systems. Well I already use 24lbers and 255lph high pressure high volume pump so would the fuel booster pump really be needed. I was thinking getting the vacuum T that has the interchangeable nozzle to change fuel pressure increases because the T my kit came with is non adjustable with a fixed orifice. What do you guys think?

 

[revhead347]

You could probably get away with a stock pump. You need about 95psi of fuel pressure for a 150 shot. I think as high as I could get with my 255lph in tank was a 125 shot, and then it started to bleed off pressure. I run a T-Rex inline pump. You also have to put this little shim in the fuel pressure boosting regulator under the spring. NOS sells the shim, but you can make one out of a beer can if you don't want to spend the money.

Kurt

 

[GTA_V6_Mustang]

You could probably get away with a stock pump. You need about 95psi of fuel pressure for a 150 shot. I think as high as I could get with my 255lph in tank was a 125 shot, and then it started to bleed off pressure. I run a T-Rex inline pump. You also have to put this little shim in the fuel pressure boosting regulator under the spring. NOS sells the shim, but you can make one out of a beer can if you don't want to spend the money.

Kurt

Well I am at 100 right now with 255lph in tank pump. What would I have to do to get it to 125. And would that still be safe as far as running out of fuel goes?

 

[revhead347]

Well I am at 100 right now with 255lph in tank pump. What would I have to do to get it to 125. And would that still be safe as far as running out of fuel goes?

If you are stepping up to a 150 shot, I recommend having a fuel pressure gauge. You need about 95psi. At that shot, the fuel pressure safety switch becomes useless, because it maxes out at 60psi. If the fuel pressure drops back down to 60 psi before the nitrous turns off, it's already running way to lean. My honest opinion is that you will have enough fuel with the 255lph in tank pump, and your setup. Instead of going right out and buying a fuel pump, I would spend the money on the fuel pressure gauge instead. You need to change the jets up to 150 jets. I would start by backing out the base timing 8 degrees, and run a jet about 2 sizes smaller than recommended on the bypass for starters. Until you can get it on the dyno with a wideband, better to go on the safe side. You're also going to need the regulator shim. Bring down the gap on the plugs a bit too. I would start out with about .035" on the plug gap. Other than that, you shouldn't have to chagne anything else.

When you get on the spray, make sure the fuel pressure spikes and stays there. It will usually jump right up to the correct pressure, even if the pump is undersized. If the fuel system is inadequate, the fuel pressure will start to drop off. Obviously, if it starts to drop off, then you need to let out of it.

Kurt

 

[GTA_V6_Mustang]

If you are stepping up to a 150 shot, I recommend having a fuel pressure gauge. You need about 95psi. At that shot, the fuel pressure safety switch becomes useless, because it maxes out at 60psi. If the fuel pressure drops back down to 60 psi before the nitrous turns off, it's already running way to lean. My honest opinion is that you will have enough fuel with the 255lph in tank pump, and your setup. Instead of going right out and buying a fuel pump, I would spend the money on the fuel pressure gauge instead. You need to change the jets up to 150 jets. I would start by backing out the base timing 8 degrees, and run a jet about 2 sizes smaller than recommended on the bypass for starters. Until you can get it on the dyno with a wideband, better to go on the safe side. You're also going to need the regulator shim. Bring down the gap on the plugs a bit too. I would start out with about .035" on the plug gap. Other than that, you shouldn't have to chagne anything else.

When you get on the spray, make sure the fuel pressure spikes and stays there. It will usually jump right up to the correct pressure, even if the pump is undersized. If the fuel system is inadequate, the fuel pressure will start to drop off. Obviously, if it starts to drop off, then you need to let out of it.

Kurt

Awesome info. I just need to figure out where to get the fuel pressure regulator Tee that has the interchangeable jets because mine doesnt come apart it just has a fixed orifice. And I was planning on getting a wideband anyway. So that if I see it lean out AT ALL I can back off right away to avoid any damage at all.

 

[revhead347]

I just looked through the fittings on NOS. I didn't realize they switched to a fixed orrifice T-fitting. $28, what a rip. I'd call NOS, and see if they still offer the T with removable jets.

Kurt

 

[GTA_V6_Mustang]

I just looked through the fittings on NOS. I didn't realize they switched to a fixed orrifice T-fitting. $28, what a rip. I'd call NOS, and see if they still offer the T with removable jets.

Kurt

ok well I just looked into it and I did find 2 different bypass regulator t-fittings. They have a .059 and a .042. What do you think?

 

[revhead347]

Yeah, I saw both of those fittings. Honestly I would call them and see if they still offer the T-fitting with the removable jet.

Kurt