PDA

View Full Version : Dry Nitrous & Fuel: Question



PaulFiveOh
03-22-2007, 12:00 AM
Here is my question:

If I am running a dry shot of nitrous and I have a stock computer in the car, when I spray the nitrous, does the car then require extra fuel to be injected, and if it does, what tells the computer to spray more fuel in?

That might be a stupid question, but regardless, i dont know the answer.

Thanks for you input.

Kevin Doe
03-22-2007, 12:08 AM
Yes, a dry kit reqires more fuel from the fuel injectors. I'm not sure how its traditionally done with a dry kit, maybe raising the fuel pressure?

I've never had nitrous, but I've alwasy been a fan of a wet kit, and will likely have one on my next car. With a wet kit you can easily tune the fuel and nitrous via the jets in the nozzle.

Maybe someone more familiar with how a dry kit usually adds the required fuel can jump in.

Rick93coupe
03-22-2007, 12:21 AM
If I'm not mistaken, a dry kit closes off the return line of the fuel system to spike fuel pressure. I could look it up, but my brain is fried. If nobody answers by tomorrow evening I'll let you know for sure.

PaulFiveOh
03-22-2007, 12:37 AM
Thanks Kevin and Rick

Any additional information would be great

zombis
03-22-2007, 01:19 AM
when u use the dry shot on a fuel injected car, the o2 sensor notices the engine running lean and automatically adds fuel

PaulFiveOh
03-22-2007, 01:21 AM
when u use the dry shot on a fuel injected car, the o2 sensor notices the engine running lean and automatically adds fuel

Is this reliable enough to maintain a safe operating situation for the engine?

Kevin Doe
03-22-2007, 01:21 AM
Wrong. O2 sensor feedback is not used on WOT. The computer goes into open loop on WOT.

Kevin Doe
03-22-2007, 01:22 AM
Is this reliable enough to maintain a safe operating situation for the engine?

Absolutely not. Good way to blow your shit up, don't listen to that advice.

zombis
03-22-2007, 01:38 AM
sorry, just what i was told

PaulFiveOh
03-22-2007, 05:30 AM
No worries man, good were getting the kinks out now, instead of when Im tearing the motor down after a run haha.

Rick93coupe
03-22-2007, 07:05 AM
when u use the dry shot on a fuel injected car, the o2 sensor notices the engine running lean and automatically adds fuel

Wouldn't that be nice, there'd be no reason to buy aftermarket fuel injection parts, just throw a 500 shot at it..lol.:lol:

mach_u
03-22-2007, 08:00 AM
I know Quiklx (Joe) has been running 125 shot on his stock 5.0 for the last year or so with I believe the stock fuel system. He hasn't had any problems? I would think you should be ok without going with a much bigger shot and running colder plugs. Obviously anytime you running a power adder your taken a risk but I would think you would be fine with that?

Black Hole
03-22-2007, 08:30 AM
Wanna be safe? Get a tune...

mach_u
03-22-2007, 09:08 AM
Wanna be safe? Get a tune...
Yeah, good point! haha Hell I'm running N/A with no major motor mods and I have a tune. It never hurts to play it safe!

Timido
03-22-2007, 10:04 AM
The dry kit uses a pressure regulator that sends pressure to the stock FPR to allow it to spike the pressure. Spraying only Nitrous without adding more fuel will lean the engine out and you will hurt the engine. One good thing about a Dry kit is the additional fuel is not run all the way through the intake so it cannot puddle up and that can cause backfires which can be bad. Wet and Dry kits both when properly done can make good consistant power. I get my Nitrous parts and fills at CincySpeed you get more than a Fair price Craig has a lot of knowledge about Nitrous system. He helped me design my system for what I wanted.

black90lx
03-22-2007, 11:40 AM
Yes, a dry kit reqires more fuel from the fuel injectors. I'm not sure how its traditionally done with a dry kit, maybe raising the fuel pressure?

I've never had nitrous, but I've alwasy been a fan of a wet kit, and will likely have one on my next car. With a wet kit you can easily tune the fuel and nitrous via the jets in the nozzle.

Maybe someone more familiar with how a dry kit usually adds the required fuel can jump in.

you can adjust fuel to with a dry kit to. it has a tee with the kit that you can change the jets in to adjust how much you spike the fuel pressure. a dry kit uses bottle pressure to spike fuel pressure to like 80 psi and up depending on what size jet you have in the tee.

did you buy the kit new or used?

i had a wet kit and i hate them. they are bad for nitrous backfires from the fuel puddling up, the only way they are safe is if you buy all the extras for it. you can go with a bigger shot with a wet kit though

Kevin Doe
03-22-2007, 11:44 AM
Just so that you guys know, the fuel flow characteristics of fuel pumps are proportional to pressue.

The higher the pressure, the less the flow. So, it is plausable that you could squeeze more hp out of a wet kit before you run out of pump flow.

Also the spray pattern can be adversely affected by the higher pressure. Much higher pressure delta across the injector than it was designed for.

I'm sure dry kit works, and there is proof that they do. I really do think a wet kit has several advantages though.

Timido
03-22-2007, 11:55 AM
I have never used a Dry kit. I had a wet kit on a injected 5.0 with a stick and the Wet plate on my carbed capri.

quik lx
03-22-2007, 12:21 PM
My ZEX kit taps into the regulator to increase fuel pressure as the nitrous in sprayin. For my engines sake I crank fuel pressure up to 45PSI and only spray with 91 octane gas and with a 104 octane booster in the tank. And never go above 10 degrees timing. All this equals 12.2@111MPH on a stock engine with only headers,pulley's and an UPR big mouth air filter!;)

conley1000000
03-22-2007, 12:32 PM
I've got the Dry Kit on my mustang and it works fine for me...rscoupe runs a nitrous car in the Real Street division of NMRA...He uses a modified Dry kit...I've got a bigger fuel pump and thats it, and the only reason I did that is because the stocker went out well before the NOS was put on...And if your going Dry, I recommend the original, The NOS dry kit, the Zex kit is a very gimickey kit(no offense) but its not as "safe" as it claims to be...

Heres a Dry Nitrous Info Page:
http://www.drynitrous.com/index.html

Heres a link on the Zex...
http://forums.gemcitystangs.com/showthread.php?t=3615

Hopefully that helps?

smytty
03-22-2007, 01:29 PM
I use a dry kit on my car , its after maf though which requires a tune, but on newer cars that spray pre maf the Ecu adjust for the drop in air temp and adds fuel as needed... Alot say a 50 shot is good for that as anything higher would freeze the maf....
I use a dry shot and it was very easy to install.... I dont know what the car wouldve gained off a wet shot of the same jet but being dry, a 60 shot netted 98 rwhp and 193 lb of trq...

Timido
03-22-2007, 03:09 PM
My ZEX kit taps into the regulator to increase fuel pressure as the nitrous in sprayin. For my engines sake I crank fuel pressure up to 45PSI and only spray with 91 octane gas and with a 104 octane booster in the tank. And never go above 10 degrees timing. All this equals 12.2@111MPH on a stock engine with only headers,pulley's and an UPR big mouth air filter!;)

You are doing good to keep things safe but with nitrous if the Air Fuel is really rich it can cause problems also.