Country Boy

iTrader: (24)

That is true. Higher the bottle pressure the more likely to detionate, reason being is that the N2O is becomming greater in the air/fuel ratio the more bottle pressure. Think of it this way. Fill up a ballon to say 50 PSI and fill up another one at say 100 PSI. Open the ends for exactly one second. The 100 PSI ballon will push more air than the 50 PSI ballon because of the force behind it (pressure)

Granted you will make more power with more pressure (dry kit, providing the fuel system can handle it) but you also run leaner in the AF ratio (wet kit).

A wet kit is VERY dependent on bottle pressure. The more pressure, the leaner the A/F because you have a steady 58 PSI of fuel flowing and the jets are made to use a certain N2O pressure with a certain fuel pressure ( say 58 PSI fuel and 950 PSI N2O) if you raise the N2O pressure, your going to shove more N2O into the mix than what it was calibrated for.

In other words, to be safe, run ~ 850 to 900 PSI N2O. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
<img border="0" alt="[Camaro]" title="" src="graemlins/camaro.gif" />

383LQ4SS

iTrader: (33)

You have it correct Fofo. Wether the enigine is running rich or lean is just the ratio or fuel to oxidizer (oxygen). If you raise bottle pressure...you will be flowing more through the same size jet(orifice) than at a lower pressure. More oxidizer = leaner, hotter, faster burn. More prone to detonate.

For the size of the shot you will be running...i would also think bottle pressure should be near 900 psi or so. I can jack mine up to 1200 and get a good hit....but the pressure drop is great if using a bottle heater. I could do the same shot by running a larger jet at lower pressure and see less of a pressure drop over a run keeping AF ratio more even throughtout the runs.

fofo

I'd appreciate any comments to help me understnad the impact of bottle pressure on nitrous performance. As an example, how is nitrous performance affected with bottle pressure at 800 psi vs. 1000 psi? Is detonation likely to occur with MORE or LESS bottle pressure? My performance shop feels bottle pressure should be toward the lower end of what is generally suggested (i.e. 850-900 psi) in order to protect the motor from running lean and avoiding detonation. Higher bottle pressure = LEAN, & lower bottle pressure = RICH? Thoughts are appreciated. My primary concern is to protect my motor, not how much HP I can get.

FoFo
'96 Corvette Grand Sport "Clone" 454 / 400 N2O

fofo

Thanks guys.

FoFo

383LQ4SS

iTrader: (33)

Fofo...when are you gonna run that damn thing. I want video too <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Its gonne be a hell of a ride. <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />

BIG NUGGETS

Here's my question. What bottle pressure do nitrous companies rate there jets at? I would assume 900 but not sure.

383LQ4SS

iTrader: (33)

I dont know for sure...but each kit has instructions to operate the kit from XXX-XXX pressure. So I would assume the kit was designed around the recommended pressure in the manuals.

AzzHauler

iTrader: (3)

The card that comes with tnt jets says 1050psi. I think I've been told that nos says ~900 for theirs.

fofo

I should have some results, and hopefully pics, within the next thirty days. My e.t. & mph targets are about 10.75 & 130. Again, I have about 475 NA HP & assume about another 375-400 with 400 Big Shot, for a total NA HP of about 800. That should give me about 675 or so to the rear wheels. My understanding is that it will take about 600 rear RWHP to get near 10.75 & 130. Does this sound accurate?

My motor's compression is about 10. My cam is a Crane "mild street rod" hydraulic roller (specs 214/222 duration with .553 & .576 lift) designed for N2O. These other mods should help the full roller Gen VI 454...Brodix heads, 770 cfm Holley Street Avenger, Hedman Headers & Flowmaster exhaust & Magnaflow mufflers, B&M Shifter, Art Carr-prepared 700r (with a 2200 stall speed converter)that's rated to handle 800 RWHP, Dana 44 with 3.45 gears, BFG Drag Radials (17/315), Jacobs Mastermind, MSD Ignition, etc. I'm thinking of setting the N2O controller to start @ 2500 rpms with 180 HP (45%)and increasing to full 400 HP (100%) 5500 rpms. My shift point is about 5500, & redline is about 6000.

My friend has a 1976 Vette with a 454 & a 350 N20 shot, and his best is right at 10.40 e.t. I'd like to give him a run for his money!

Any comments are welcomed!

FoFo
'96 Corvette GS "Clone" 454 / 400 N2O

fofo

Hey, sorry guys, but I also have dual 10 lb. N2O bottles with heater on a remote switch, and plan to run the pressure at about 850-900 as that seems to be optimum for my set-up. I have two fuels pumps, a Red Holley (7 psi & 97 gph) for non-N2O runs & a Blue Holley with a regulator (14 psi & 110 gph) dedicated for the N2O-aided runs. Finally, I have all kinds of gauges such as A/F, Pyrometer, Trans Temp, N2O Pressure, Fuel Pressure, etc. & plan on running race fuel with about a 112 octane rating. All of this is to protect my motor from running lean & the dreadful "D" word. Oh yea, I have a NOS Purge system through near the windshield wipers.

Again, comments are welcomed.

FoFo