I have been thinking of adding a NO2 kit to the wagon. But first I need to dial in the carb so I can stomp on it an it will go. That is when it gets warmer. Tim
Bump for the spray instant torque punishes the pavement. I am up and running now all systems work so starting some tuning and taking it easy to try study plugs and timing options. I Haven't been to track yet or have a dyno so ear,eye and butt dyno tuning for now and invite your input for the tune. The goal is simple, effective, reliable and econmical power adding. The system is a custom using components from Nitrous Supply, Huntington Beach, CA. Props to those guys as they are very customer service oriented. This is on the 455 / M-22 '70 Skylark Street Sleeper. ~9:1 , 1971 NOS bottom end 70 heads mild street port virtec and intake matched TA 110 cam. Its a wet system, a combination fuel and NO2 jet that is fitted into each of the secondary throats of the Q-Jet. Fuel and NO2 have dedicated solenoids. 6.5 psi in line fuel switch owns the ground for the system to assure its never spraying without fuel. The solenoids are triggered via WOT switch on the throttle plate. A Stage1 mechanical pump does the typical duty and a second in line electric behind it for when he N20 system is armed. I do not have a fuel pressure regulator currently. Timing is all MSD, set at 10* initial, 34* all in using silver springs in the 8517 billet distributor, blaster 3 and 6AL box. Plugs currently AC Delco R45TS gap .040" I have .028", .036" and .040" fuel and N2O jets to choose from. I started using the .036" for the fuel and N2O. There is a bottle heater but no automatic pressure switch on it. The pressure relief is plumbed outside ofthe trunk. Since the car is primarily street driven but will get track time a few times a year, there are two tunes I presume I need to be fluent with. 1) for street driven car when the spray will only see intermittent use, i want to find the best tune for both worlds since 99.9% driving on only motor. I want to have the tune on the ready of coarse to get optimum results while maintaining maximum safeguards. 2) i presume the tune at the track will be different to facilitate the environment. My reading has me looking for new plugs, perhaps AC 44 or 43, or NGK. I dont want too cold so which plug is the optimum plug? Now, to pull some timing out. I prefer not to fuss with programable box at this point, but also dont want to compromise the street driving. I have all the springs for the 8517, and prettty sure the limiter bushings also. What do you recommend for the optimal timing tune? Next, fuel pressure. The fuel pressure gague indicates 6.5 ~7.2 psi with both pumps operating. I dont have a fuel gauge in the car yet, its coming, or an A/F gague. Should I be concerned about non regulated fuel pressure and the bottle blanket without automatic presure control? Thanks for taking the time to read this and offer your experiences to get me going.....not blowing!
You will need to keep the fuel pressure on the nitrous side of the system regulated so the A/F ratio stays constant and safe. I'm sure the system jetting is specified at a specific fuel pressure I'm assuming you are around a 125 shot with the .036" jet. The timing should be pulled back to 30* during nitrous. At the track you can simply set the distributor there but for the street you will need some way of pulling the timing back since you don't want to run around with retarded timing. You can probably run more than 10* initial with the TA C110 cam so you can decrease the mechanical advance by changing the stops. Keep the total at 34* You also don't want the nitrous on below 3000 rpm. The additional torque increases as the rpm decreases and your stock bottom end may have a problem. I usually add an rpm switch between the fuel pressure safety switch and ground. MSD has a couple to choose from Paul
In NHRA Top Sportsman we had to run the MSD 7530T because of their "No Traction Control" ruling. For street nitrous I used the MSD 6530 programmable with the MSD 8969 digital window switch. I far as I know there is no MSD 6 series ignition that combines it all. The Mallory Hyfire 6 Part# 685 looks like it has everything you need. I have never used the Mallory ignitions but they look to have a really nice line up. Paul
Thanks Paul, i studdied more on the MSD offerings and found a decent regulator from NX. Any more input is welcomed.
The best thing you can do is put a gauge on the bottle so you know what the pressure is before you race. The bottle heaters work but can over heat it without the thermostat shutting it off in time and the pressure gets too high. This happened to me and created a nice nitrous explosion when I hit the gas off the line. Monitor pressure and keep it at a constant 1000 lbs and all will be good (950-1050) I ran my timing at 28* and even as low as 26 when using a 125 shot. I would stay on the lower side of the timing when running such a big shot. Past the 125 shot (more like 150) you may have distribution problems within the intake. I run my timing at 32* normally. I use NGK plugs, can't think of number right now but basically the same as the AC plug used in the 1970 motor. I think it is the ur 5 plug. The AC plug did not hold up as well to the nitrous. Gap at 35-40. I posted a website somewhere here on looking at plugs you may find it with a search I will try and find it.
Thanks, there is a gague on the bottle I am running a Performer intake, curious about the distribution concern if I change to the .040" jettting (150 shot). Couldnt imagine doing that unless at the track and have 8lbs of tire air pressure as on the street at WOT shot, the drag force loose traction. I think I read your thread on the plugs, NGK seemed to be the preferrence. I recall also reading several different sources that suggest .035 gap max for nitrous and support the NGK plug preferrence. I'll heed that advice.
I am also curious if i can run both the electric fuel pump and bottle blanket off the same relay or if they should have seperate relays. The N2O system is on its own relay.
Use a separate relay for the blanket. You can add an adjustable pressure switch to the bottle that will activate the relay and keep the bottle pressure within a preset range.
You probably got this handled but I'll post it anyway. The clutch switch is a SPDT snap action plunger style. Omron Z-15GQ-B7-K The switch snaps as soon as you depress the plunger but you can continue to push the plunger in. When the clutch is depressed the nitrous system is deactivated and the 12 volts is routed to the 2 step rev limiter for launch rpm control Set the switch so it re-activates the nitrous system and de-activates the 2 step limiter when the clutch is partially engaged. Paul
