well lets start by saying that my silonoids are a little on the old side. Anyway my car has the following: Thunder 224 cam, ls2 timing chain, thunder valvesprings, mti lid, ls1 edit courtesy of slowhawk, slp loudmouth exhaust. My nitrous setup consists of the following: Top gun silonoids, top gun nozzle, msd window switch(3000 on 6000 off), and a full throttle switch. The fuel system is stock. Now my problem is when I first turn on the nitrous my car has a slight hessitation when I first hit it. I went to the track last week and when I launched the car it came outta the hole and then when it hit 3000rpm the car fell on its face, and then it took off like a bat outta hell. It does this everytime i use it. Iam not too sure if I need a new fuel pump or if one of the noids is sticking. Oh yeah Iam spraying a 125 wet shot. It almost seems like iam leaning it out, or going really rich. And I do have a purge, and use it.

 

what jet sizes?

 

I am using a .065 for the nitrous and a .038 for the fuel.

 

Do you have a fuel pressure gauge?
If not put one on. Look and see if the fuel pressure is droping when the nitrous comes in.

Second if you do not have a way of checking airfuel its time to learn how to read spark plugs..

Dave

 

No fuel pressure gauge. I do have a air/fuel gauge on the a pillar. Ive had the spray on the car for about a 1 1/2 years and have had Don change my plugs. The last time he changed them they all looked pretty good except for some small black dots near the white part of the plug. When he saw that he said there might be a small amout of detonation going on. So he put the car on the laptop and took out about 2 degrees of timing to be on the safe side. He told me not to worry about it. and that it could of been from some bad gas. The air fuel guage isnt on a wide band. But doesnt really go lean when i hit the spray. And my dyno sheet doesnt really show it eaither.

 

bump.

 

Did you try the obvious stuff like cleaning the intake/TB/and injectors? New fuel filter?

 

Yeah the car gets a fresh tuneup every april before i start to spray it again.

 

I'd check my F/P and get a newer higher volume fuel pump. I run a TR 224 cam also and my stock pump was ok but I think at 50k when I replaced it with a Racetronix it was getting tired of trying to keep up. On motor passes it would fall on its face around 3rd gear like was leaning out/sucking the rails dry. I never ran the car on nitrous before the new pump, I was strongly cautioned by friends to wait until I had a higher volume pump before running any nitrous though the motor. I did it their way and so far the car runs VERY consistent on nitrous, almost more consistent than all motor passes.

 

Hey ws6hummer thanks, thats exactly what ive been thinking. I think i will try the pump and see what happens. I just hate to spend money on the injectors and new rails and such and have it not fix the problem.

 

You're welcome, in my opinion I dont think it's in the rails or injectors either. At least if you go the fuel pump route youre investing in something you really needed anyway.

 

Yeah thats a good way to think of it. Weather I need now or next year when I have more power, Iam difenatly going to need it sooner or later.