My friend just put a what is suppose to be a 75hp wet kit/ NOS fogger on. Here's the problem: when he starts off from 3k in 2nd gear and floors it, it pulls strong and smooth. When he is going down the street, floors it and after it downshifts, it starts surging and stumbling (he sprays it after the downshift). It doesn't seem to be detonation, so could this be because it is excessively rich. Also, he has tr55 plugs. Should he get the tr6's? He is not going to be running more than a 75shot.
Two things which we don't have for the weekend are an air/fuel gauge and a tank pressure gauge. (will be getting on monday) He is not going to use it again until we get these two gauges.
The jets he is using are 38nit/22fuel. Are these correct for a 75hp kit?
Any suggestions or ideas on why it is stumbling/studdering/(hopefully not detonating )?
Any help would be greatly appreciated.
Ryan

 

Does he have a fuel pressure safety switch?

 

No, he doesn't have a fuel pressure safety switch. What we are going to do though is hook up my laptop that has some free-scanning software and we will watch the fuel pressure to see if it drops.

 

ttt

 

Fuel pressure can't be scanned, there aren't any pressure sensor on the fuel system. O2 sensors will give you a good idea if they are healthy.