Nitrous question

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MOPARCODY

MOPARCODY

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I just picked up a nos cheater kit and I'm curious to what size fuel pump do I need to support a 150 shot on a 400 ish hp engine?

I also purchased an rpm window switch and a fuel pressure cut off switch just to be safe.

The car currently has a Holley blue electric fuel pump in it but it's pretty old and I'm looking to replace it.
 
Some guys run a 150 shot off the mechanical pump but I wouldn't recommend it. The Holley blue pump and regulator is more than adequate, if yours is tired a new one might not be a bad idea.
 
I'm not sure that it's tired but it's about 10 years old. I am running a regulator and plan on t-ing it off for the wet side.
 
You'll likely need a second regulator for your fuel side of nitrous system.

The juice unit will want a lower pressure than your carb in most every case.

Beware of the recommended jetting if the fuel jet is same size or larger than the nitrous jet. That's a fat tune.
 
I think the fuel pump you need weighs about a pound.
 
RustyRatRod said:
I think the fuel pump you need weighs about a pound.
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Wtf?

If you are considering a new pump get a Holley black, it will do a better job, hang on to the blue for when you get addicted and want to spray a lot and need a stand alone system.
You definitely need two regulators, unless you have some tiny fuel jet.

I could go on and on and on lol
 
Holley Blue will work. I used to have a similar setup years ago (mild 360, OOTB Edelbrocks, Air-gap, 750dp, MP 509 cam, Blue pump, cheater kit, MSD everything, 27° timing, NGK R5671A-8 plugs), it worked fine. It ran 11.1 @ 122 at Bandimere Speedway in Colorado with this setup at a 180 shot. I imagine that would be a mid 10 at low altitude. The 150 shot would run 11.4-11.5 @ 118 ish....on just motor is was usually in the high to mid 13's thanks to the lousy 9000+ feet DA.
 
The car runs 11.80s at around 112 right now, in sure the 150 shot will put it into the 10s
So why would I need 2 regulators with a small 150 shot?
 
The car runs 11.80s at around 112 right now, in sure the 150 shot will put it into the 10s
So why would I need 2 regulators with a small 150 shot?
 
The fuel side of the nitrous kit will want less fuel pressure than the carb. It will be pig rich on spray with the high fuel pressure.

On 150hp (try starting around a 63n/57f jet) I'd guess from experience it goes 10.60
 
SpareParts said:
The fuel side of the nitrous kit will want less fuel pressure than the carb. It will be pig rich on spray with the high fuel pressure.

On 150hp (try starting around a 63n/57f jet) I'd guess from experience it goes 10.60
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Ok I understand now, so can I just run a line from my existing fpr to another one or would I need a dedicated like from the pump?
 
It will work fine just adding a 2nd regulator. Fuel pressure will want to be around 6psi flowing through the regulator. That is a good starting point along with the jet spread I mentioned above. If you plan on getting into more nitrous look into a flow gauge kit from Induction Solutions or NOS for the fuel side.
 
I've been doing a lot of research about timing in comparison to the air fuel ratio and detonation. Is it true that I can add fuel rather than pulling timing? I currently run 36* so if I were to hit it with a 150 shot I'd want to run around 30* . Would it be possible to run say 33-34* with a 175 shot worth of fuel on a 150 gas shot?
 
MOPARCODY said:
I've been doing a lot of research about timing in comparison to the air fuel ratio and detonation. Is it true that I can add fuel rather than pulling timing? I currently run 36* so if I were to hit it with a 150 shot I'd want to run around 30* . Would it be possible to run say 33-34* with a 175 shot worth of fuel on a 150 gas shot?
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Ummmm... NOOOOOOO!!!!!!

Tune it properly.

Would you flood the engine while naturally aspirated with fuel to cover up detonation?

Tune it flooding it with fuel and you'll likely be picking up a pile of junk parts, namely pistons/ring lands. that type of tuning is where the comments about n2o torched my stuff. It wasn't the juice, it's the dumbass tune that killed the parts.

My basic comment. If you aren't willing to tune the juice properly, don't EVER bother to install it on your car. PERIOD!
 
It's not a bad idea to have an AFR gauge. Not necessary, but, wouldn't hurt if you are flying blind.

You want the engine at basically the same AFR as it is when making it's best pass without juice.
 
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