Where is my n20 mph?

[shortdog]

I'll try to give as much info as possible.

Mods: All boltons, Tsp tv2/5.3 h/c pkg, Edge 3400 stall, 3.73s, Racetronix pump & Lucas 42 lb injectors. Full weight car at around 3650 lbs.

Before my passes, I've installed a new n20 line, filter, no.4 line from the noid to the nozzle cleaned the filter in the noid with a air compressor.

Track temp was around 55-60 degrees, 40% humidity give or take. Window switch pills set at 3200 on, 6400 off.

Wed, I got in four passes, two n/a and two n20. My h/c car ran a new best of 11.86 @ 114, 1.64 60' on motor which is still low. Now, on the spray, it ran a best 11.07 @ 119, 1.53 60', 1/8 6.98 @ 96.50. So close to those darn 10s.. This was on a nx 150 shot. Though, I dropped 8 tenths, it only picked up 5 mph from my n/a mph. The psi was at 1000 and the bottle was about 1/2-3/4 full. I know the faster you are on motor, the more it takes the car to pick up on n20, but not this bad. I was running that mph on a 100 shot with a stock cam, stock ported heads and tci 3800+! Something's not right, so what could be the problem?

[Jessedale98]

Looks to be the 60ft, when you spin off the line (1.6 isnt really spinning) it gives you more MPH, so the 1.5 gave you better ET but took a little MPH off the top end, thats my guess. It was always that way with my car.

What size tires are you running?

[Attaus]

Do you have a pressure gauge on the bottle? It might not be the right temp.

[shortdog]

Believe it or not, I always GAINED mph when I got a better 60'. I'm running 255-50-r16 Et street radials.

I do have a pressure gauge on the bottle which is nomore that a year old.

I checked a few plugs after my pass and they looked fine. Greyish with no detonation spots on the white porcelin.

My timing is set at 27*, but I do have a switch to reduce the timing by 4* when spraying. I forgot to turn it on n20 mode at the track Wed.

The tuner hooked it up to a wideband several weeks back and we made some wot passes. The A/f is around 12.6 n/a, but was very rich on the bottle. The a/f was in the low 10s on a 175 shot, so we leaned it out by putting in a .033 150 shot jet and that put it at around 11.3-11.5 wot. BUT, it was hot outside and my bottle psi was very high, around 1150. Nx mentioned that the nitrous noid could possibly not open if the pressure is too high, causing the system to run rich. I was "probably" getting an inaccurate reading due to that, but i'm not sure though. I thought it would be too lean with the pressure that high. We also tested the noid when cleaning the filter. It "seemed" to work fine.

[Jessedale98]

well i wouldn't worry about it too much, i mean.... you did gain .8 and thats awsome.

[Attaus]

Yeah.. 1150 is way too high.. I would shoot for 950. I guarantee you that if you get it at 950 you will dip well into the 10s's.

For the record.. I knocked more than a second off my Honda (back when I had it) with a 55 shot at 850 psi. So yes, he's capable to knock much more off.

[Jessedale98]

Ive seen 1.5 knocked off with a Dodge Stratus, but we're not talking Honda's or Dodges. This happens to be a MARO, lol which wont get more than a second off of an ET with just 150 shot at his current level.