Guys,
I am running an NXL kit with accumulator on a LS1 with headers and Vararam. Took it to the dyno today for some tuing work. The engine tuned well. 12.9 AFR across the board and 340 RWHP. Started the nitrous with the 180 pills (26N/12F). The car ran real lean, nearly 16.0 and fuel pressure dropped to 55 psi. Then put the 120 pills (20N, 10F) in. Car ran lean again, but not as bad. Ended up swapping the 10F pills for the 12F pills and ran it again. AFR looked better this time, but I only picked up about 80 rwhp gain. Has anyone else had any problems with the jetting or achieving the advertised gains? Any ideas to what to try next. I am going to see if I can get some 16 fuel jets and try for the 180 again.
Thanks
Chris

 

The jetting on the NXL is conservitite. The 180 should have gone rich. When you say the fuel pressure went down to 55psi what did it start with. I would make sure there is not a fuel delivery problem. Fuel pump, filter etc. I looked at all the tune ups for the NXL and they should be rich not lean.

 

EXACTLY my reason for getting rid of the NXL kit. I was either too lean or too rich. Even after numerous calls to NX and hundreds of dollars in extra parts, tuning, time on the dyno we still could not get it right.

I am going back to "Keeping it simple" with their single nozzle kit or MAF setup.

Oh, on the 180 shot, the dyno only showed a 100HP increase or so. The kit looks nice, I get LOTs of compliments, but it just does not perform. NX makes awesome stuff, but I think they missed the boat on this one.

I have a TON of different jets if you want to borrow some to experiment around (as long as you send them back - if they work you can buy em from me) I already spent the money to get them, I would hate to see you keep tossing money away in jets.

 

I would make sure that your fuel solenoids are opening. I had the same problem (car running lean on nitrous and not making advertise hp gains) and found out that fuel solenoids were not opening. That was a construction problem of the rails/solenoids as solenoid were seated so deeply in the rails that they simply could not open. Some thicker gaskets solved the problem.

 

Chris thanks for calling friday.We will get it strait.However we defintly need to get a fuel pump in there before going back to the 180 shot.
Dave