Lets say i had 900 psi N2O pressure and 43 psi fuel pressure, what size jets would I need to make 150 horsepower with one nozzle? I found a calculator online that says I need an .058 N2O jet and an .032 fuel jet. How can I approach this safely without problems? I have datamaster, how can ths help me fine tune the jet size? If I get it close, will the O2 sensors and PCM correct the air fuel ratio toi get it right? Am I going to blow my motor up?

 

What type of system are you running plate or nozzle?

Tim Burgess has a formula that he uses and he says it is very accurate. I am running a NOS TPI plate setup and I use a 70 N2O and NOS req. a 53 fuel jet for the 150hp shot. Using the formula from Tim I found that it says to use a 45 jet for fuel. I recorded about 5 runs with a wideband and found the 53 jet to be waaayyy to rich. I bought a 49 jet and plan on hitting the track Friday to see how it does.

I am using a wideband O2 to get try to get the AFR to be around 11.5:1. Right now with the 53 jet I am at 9:1, so I am a great deal off.

Provided you have a upraded fuel system, your motor is in good shape, you run a heat range colder on the plugs and, you taking some timing out you "shouldn't" blow the engine up.

 

I just saw you are running a nozzle. I am not to sure an jet sizes for that. You might want to call NOS and tell them. They are pretty good about helping out.
A good thing to remember when calculating the jet sizes is that your fuel pressure is going to drop significantly while flowing the nitrous/fuel mix. Depending on how the jet formula is set up you might want to input a lower fuel pressure.
I know I run around 42psi under normal conditions and with the nitrous/fuel flowing my fuel pressure dips down to around 24psi.

 

I guess I'll stay towards the rich side as you suggest just to be safe. I don't have a wide band, would the stock sensor be able to tell me anything?

 

Very little,
I would not rely on it for any tuning purpose. You might be able get an idea if your rich or lean but, tuning N2O you need to get a more accurate reading than it will provide. I would just run it richer and keep it alive.
Even with such a rich AFR I shave 2 seconds off of my ET. I am just about to break into the 12s and I think leaning it up a little will net me the results I want. I only need .1 sec. to hit my mark then i will be happy.

 

The only thing I'm worried about on my Camaro is the transmission. It's the trans that came with the motor, a 350 LT1 from a buick roadmaster. It already had a vette servo and I put a transgo kit in it too. I'm hoping if I stay under a 150 shot it will live.

 

I used to hit mine with a 100 shot and it was fine. I would spray just before/after (can't remember) the 1-2 shift. I built the 700r4 up now and I spray it right off the line now. I would have to say that it would probably kill your trans. if you try it.
The torque created is outragous of the line and would probably kill that trans rather quickly.

 

Forgot to mention I also have a nitrous matermind controller that gradually brings the n2o in.
I didn't for the 100 hp shots though. That was just a direct hit.

 

I can build a mean 727 torquflite or TH400, but the 4L60E is new to me, where are the typical weak points?

 

From reading I have found that the 3/4 clutch seems to be a weak link along with the sun gear shell and even the input drum is common for failing. The input drum has a steel splined shaft pressed into an aluminum drum, what happens is the steel wears away at the aluminum splines causing some play and eventually stips/breaks.

From experience I have broke the over run clucth hub. I ran first gear way up in the rpms and had the trans in manual 1st. This made for some massive engine braking which caused the hub to shatter.