RPM Problems - TD with Nitrous

BEarnest · 09-23-2013, 02:29 PM

I have a Top Dragster with a 565 Reher-Morrison motor with two stages of nitrous. The motor, trans and converter were freshened, but then parked for five years, as I bought a business. I decided to go racing this year and had the car completely rewired, with a new K & R autostart, K & R Pro Cube and Auto Start.
When I took the car out for my license passes, my RacePak did not work, so I did my three partial passes and the first full pass was an 8.35 at 155. With no Racepak I attributed the slow ET to a very tight converter.
The second weekend, I ran an 8.35, 8.40 and 8.50. I was trying to turn on the nitrous but had a series of separate wiring problems preventing it from working, but the RPM was limited to 6,000 - 6,100 RPM, per the RacePak. The slowing ET was explained by gradually increasing the NOS timers, which reduced the engine timing, but did not turn on the NOS.
Yesterday I made one pass with 2.5 seconds of nitrous at the start. The car launched hard, with a 1.07 60' time, but again the engine RPM flatlined at 6,000-6,100 RPM.
The RPM limit is not from a chip, as the car is not missing. I thought maybe the Auto Start was coming on downtrack, but tested all of the timers in the garage prior to going out, and the Auto Start did not engage after the launch. It worked properly on the launch. I have wide open throttle mechanically.
The motor sounds fine and launches hard, but it will not RPM. Thoughts? Internal problem with the 7 AL-3? Trying to figure out what might be limiting the RPM without hitting a chip. Coincidentally, I think, the burnout chip is at 6100, but, again, it is not hitting the chip. Mechanically, I have wide open throttle. It seems like some sort of electronic RPM limit, since the NOS didn't change anything.
Thanks for any help or ideas you may have!

09-23-2013, 02:29 PM	#1
BEarnest Junior Member Join Date: Sep 2013 Posts: 1 Likes: 0 Liked 0 Times in 0 Posts	RPM Problems - TD with Nitrous I have a Top Dragster with a 565 Reher-Morrison motor with two stages of nitrous. The motor, trans and converter were freshened, but then parked for five years, as I bought a business. I decided to go racing this year and had the car completely rewired, with a new K & R autostart, K & R Pro Cube and Auto Start. When I took the car out for my license passes, my RacePak did not work, so I did my three partial passes and the first full pass was an 8.35 at 155. With no Racepak I attributed the slow ET to a very tight converter. The second weekend, I ran an 8.35, 8.40 and 8.50. I was trying to turn on the nitrous but had a series of separate wiring problems preventing it from working, but the RPM was limited to 6,000 - 6,100 RPM, per the RacePak. The slowing ET was explained by gradually increasing the NOS timers, which reduced the engine timing, but did not turn on the NOS. Yesterday I made one pass with 2.5 seconds of nitrous at the start. The car launched hard, with a 1.07 60' time, but again the engine RPM flatlined at 6,000-6,100 RPM. The RPM limit is not from a chip, as the car is not missing. I thought maybe the Auto Start was coming on downtrack, but tested all of the timers in the garage prior to going out, and the Auto Start did not engage after the launch. It worked properly on the launch. I have wide open throttle mechanically. The motor sounds fine and launches hard, but it will not RPM. Thoughts? Internal problem with the 7 AL-3? Trying to figure out what might be limiting the RPM without hitting a chip. Coincidentally, I think, the burnout chip is at 6100, but, again, it is not hitting the chip. Mechanically, I have wide open throttle. It seems like some sort of electronic RPM limit, since the NOS didn't change anything. Thanks for any help or ideas you may have!