Nitrous Problems

[colt45-2007]

OK I recently installed a NOS Sniper Wet Kit on my truck and right now I have it jetted for 100 shot for 20psi fuel pressure and when you first spray it, it picks up fine but when it gets to higher RPM you can feel it losing power and it backfires.... Any ideas of what could be causing this?

[bigsnookmaster]

It sounds like to much fuel to me. I used to spray a 150 plate shot and ran approx 6 to 6 1/2 lbs. of fuel pressure. I know guys that would run as low as 5, but you're coming close to going too lean. I never had any problems or failures at all, and I had a complete separate fuel system also, just for the nitrous. Please feel free to correct me if I'm wrong. And i know you all will !Lol

[scatesracing]

Colt... Im going to say lean... your truck fuel injected???? And does it hold good presser at the higher rpm.... I was thinking the efi kits were set up for closer to thirty lbs but im not 100 percent on that.... it might be spark also the higher cylinder presser could cause a lot of problems if you still run stock ignition... Just a couple of Ideas....

[71Dragtruck]

The only way to tell rich or lean is to do some plug reads after a wide open pull. Have a read through this.

http://www.tuninglinx.com/html/nitro...-tuning-0.html

[t&tkennels]

buudie of mine was running a 125hp kit on an 1985 mustang gt (carburated), & it was doing sothing similar to yours. it had a hairline crack in the spraybar on the carb plate.

[colt45-2007]

Originally Posted by scatesracing

Colt... Im going to say lean... your truck fuel injected???? And does it hold good presser at the higher rpm.... I was thinking the efi kits were set up for closer to thirty lbs but im not 100 percent on that.... it might be spark also the higher cylinder presser could cause a lot of problems if you still run stock ignition... Just a couple of Ideas....

My truck is fuel injected but it only runs 9-13 lbs of fuel pressure and I have it jetted for 20 lbs, the kit I bought can be jetted for 20 psi to 60 psi fuel pressure...... I pulled the plugs out and they were absolutely burnt, I had too hot of a plug in and my timing is too high, I put a basic AC Delco plug in and now I'm trying to hunt down a timing light to adjust it, I'm hoping after I get it timed it will run strong but a few people around here have told me I need a carb injector plate and that having it in the intake tube is what's causing this, BUT I can't put a carb plate on b/c it is throttle body, any ideas on that?

[scatesracing]

Originally Posted by colt45-2007

My truck is fuel injected but it only runs 9-13 lbs of fuel pressure and I have it jetted for 20 lbs, the kit I bought can be jetted for 20 psi to 60 psi fuel pressure...... I pulled the plugs out and they were absolutely burnt, I had too hot of a plug in and my timing is too high, I put a basic AC Delco plug in and now I'm trying to hunt down a timing light to adjust it, I'm hoping after I get it timed it will run strong but a few people around here have told me I need a carb injector plate and that having it in the intake tube is what's causing this, BUT I can't put a carb plate on b/c it is throttle body, any ideas on that?

I think you just answered your own Question you have 13 or less and you are jetted for 20.......... Time for a fuel pump or ajustable regulator to bump the pressure maybe both

[Super73]

Do you have a second regulator that you are dialing your N20 fuel pressure in with, or are you relying on the fuel pressure that is in the rail?


Agree it sounds lean. If your basing your fuel jet off 20lbs of pressure and really only have 9-13lbs of fuel pressure you are going to bit a bit lean.

[Wild83C10]

Like they said lean. Call NOS and see what jet you need for whatever fuel pressure you are running. You also need a colder non-projected spark plug and run 2 degrees less total timing. Don't just check your base timing, check your total. I would start with 32 then go up from there.

[colt45-2007]

Originally Posted by Super73

Do you have a second regulator that you are dialing your N20 fuel pressure in with, or are you relying on the fuel pressure that is in the rail?


Agree it sounds lean. If your basing your fuel jet off 20lbs of pressure and really only have 9-13lbs of fuel pressure you are going to bit a bit lean.

Just running it on the fuel rail pressure right now

[colt45-2007]

Ok I have re jetted the kit and with the jets I had I could only go as low as 15 psi but I feel that will be in a close enough range atleast until I get more jets, I have also installed an AC Delco 42CTS 5/8ths plug and now I just have to retard the timing a few degrees, and then I'm gunna make a test run......as I stated before everyone keeps saying I need a carb or throttle body plate in order for the kit to work properly but a carb plate will not work and a throttle body injector plate is from 270-330 bucks..... I have the nozzle fogger tapped into my intake tube and I'm just wanting to know what yall's opinion is on that

[Wild83C10]

What kind of throttle body are you running? Is it a 4bbl type TB? What does the intake tube look like?

[colt45-2007]

Originally Posted by Wild83C10

What kind of throttle body are you running? Is it a 4bbl type TB? What does the intake tube look like?

It's a 2bbl type throttle body, 490cfm if I'm not mistaken..... The intake tube is a complete round hard plastic tube, its a K&N cold air intake, the fogger is tapped into it about 4-5 inches from where the tube bolts on top of the throttle body

[Wild83C10]

Is it the stock TBI unit from the '88? If so you definitely shouldn't be using a nozzle. You need a plate or run a dry setup. A lot of the fuel is being lost on TB itself.

[colt45-2007]

It is the stock factory throttle body from 88

[scatesracing]

the nozzle will be fine...... just get your fuel right... I have done it on three different efi gm trucks... I used a NX kit... when all else fails call and talk to the pros ( who ever made your kit)... As a rule on nitrous listening to you buddies ( US ) will just get you in trouble....Thats a disclaimer to cover all our butts... LOL...... The nx guys are great to talk to

TRAVIS

[Jim_PA]

I want a dual 480 TBI setup.

[scatesracing]

Originally Posted by Jim_PA

I want a dual 480 TBI setup.

that would be cool... isnt there a guy out of denver that sells something like that..... ILL see if i can find a name

[Jim_PA]

I'm kind of kidding, but kind of not. Sorry to hijack your thread

[colt45-2007]

Well the 305 bite the dust tonite with the nitrous..... I raced an 07 F150 5.4L with an SCT Programmer, Electric Fans, AEM Brute Force Intake, 3200 Stall Converter, and 410 gears..... I sprayed 100 shot and beat him about a truck and a half, we went to run again and it started running funny, I pulled over and started hearing a squek along with blue smoke coming out from under it, I think the rings and main bearings are shot

[scatesracing]

ouch

[Jim_PA]

Originally Posted by colt45-2007

Well the 305 bite the dust tonite with the nitrous..... I raced an 07 F150 5.4L with an SCT Programmer, Electric Fans, AEM Brute Force Intake, 3200 Stall Converter, and 410 gears..... I sprayed 100 shot and beat him about a truck and a half, we went to run again and it started running funny, I pulled over and started hearing a squek along with blue smoke coming out from under it, I think the rings and main bearings are shot

What did it run?

[colt45-2007]

Originally Posted by Jim_PA

What did it run?

I'm really not sure I wasn't at the track lol

[Marv D]

Originally Posted by colt45-2007

I'm really not sure I wasn't at the track lol

<=== bites tounge till it BLEEDS!!!!!