Could somebody please help me figure this out. I have a NX Wet system. I ran 12.07 at 112MPH with the 75HP jet. Then after installing the 100HP jets, the car ran a 12.41 at 109MPH. What are all the possibilities for this???

 

what kinda tires are you running and what are your 60ft's on both runs? Are you getting any KR on the runs? alot of things could cause it. give us more info please.

 

did it go lean? was it too rich? what about traction? wetaher?

 

Temp was 81 derees, the DA was about 2527. These were back t back runs. Tires are ET streets, I didn't have a data logger set up so I don't have any idea what the O2's or timing were reading. Fuel pressure safety switch is set at 38lbs, fuel pressure regulator is set at 45lbs.
1st run:
60 ft. 1.69
1/8 7.68 @ 88.76MPH
1/4 1.07 @ 112.22

2nd run:
60 ft. 1.84
1/8 7.94 @ 87.21MPH
1/4 12.42 @ 109.76

Best time on motor is 12.39 but that's with a DA of -900 last fall. So, even with the poor 60 ft time (on the 2nd run), wouldn't the MPH be higher with the larger nitrous shot?

 

Any chance you got the jets reversed - nitrous jet in fuel line, fuel jet in nitrous line?

 

I double checked to make sure i was installing the proper jets. Even checked them again when I set it back to the 75HP jets. Maybe it was a fluke. I'm going to put the 100HP jets back in, hook up the Auto X-ray scanner and make another pass. I'll tell you what, when I did run with the 100 jets on that 2nd run, it sure felt like it was pulling harder than the first run!