shifty35

I would think that the "best" pressure is the highest pressure you can consistently maintain. 1050psi will certainly deliver the most flow, so in that sense it may be the best (most power). But what you want is consistency more than anything.

__________________
-Ben

'00 Honda Insight 1 liter Inline 3 ... 80+ mpg.
'04 Toyota Prius - Wife's car
'94 Civic EG8 Sedan - D16Z6 5spd, Greddy 15g

Old Cars
'97 Civic Hatchback DX - I/H/E D16Y8 - 122 whp / 98 wtq
'95 Civic EJ1 5-spd - 210 whp, 198.7 tq @ 12 psi

wolve

wow alot of misinformation and nonsense at the start of this thread...

especially from some knowledgable people :S

i'll get back on this

wolve

Originally Posted by liveforphysics

Even just a 50shot requires outstanding tuning to avoid doing long-term damage to the engine. Pull the plugs after every pass while you are dialing it in. Nitrous needs a boatload of fuel, seems to need 10:1 A/F before it stops leaving aluminum on the plugs, and even then you gotta watch it like a hawk until you have it dialed in for a given bottle pressure. Retarding timing is also very important. Not just to avoid knock, but because the burn completes so much faster that a lot of timing advance results in less power made and more heat being wasted and absorbed into the pistons. A 50shot of nitrous is much tougher to tune for than an equivalent 50hp gain through turbo or SC boost. On the bright side, it will also make for a faster accelerating engine than the turbo or SC would provide.

outstanding tuning for a 50 shot?
there is nothing simpler then tuning nitrous, you just have to understand what your doing...

10:1 afr?
i always aim for 11-12afr when tuning nitrous setups (12 for the milder shots up to 300whp, 11's for upwards of 300whp on pump gas)

my mate's car i tuned on a 50 shot made 194whp NA and 254whp on spray.
aimed for solid 12's afr. very sharp timing. combustion was reasonably hot as the engine liked heatrange 8 plugs. made over 240whp from 6500-9000rpm.

tuning nitrous is very easy, just need some understanding how it works and there's little room for mistakes.

wolve

Originally Posted by SOHCinWA

Nitrous Oxide has always reccomended that you use 50% of your stock output of your engine to be safe.

the amount you can safely spray mostly depends on tuning, C/R, octane and nitrous/fuel distribution.

you can safely spray 100% of your stock output if above factors are considered.

as little as 25% of your stock output can be fatal if above factors are neglected

dohc_slayer

i run 75 on my 1.5 non v and it has burned over 40 bottles and only melted one valve due to rubbish in the fuel nozzle...i run race gas though 112 octane

wolve

Originally Posted by shifty35

I would think that the "best" pressure is the highest pressure you can consistently maintain. 1050psi will certainly deliver the most flow, so in that sense it may be the best (most power). But what you want is consistency more than anything.

the higher the pressure the worser the pressure drop when spraying, get to high (i believe it's 1070psi from the top of my head) and nitrous will go into supercritical state and it will act like a gaseous liquid. performance and consistency will be compromised.

in terms of what delivers most flow and thus is best, a bigger jet can also solve that

but anyways, i always tune setups at 1000-1050psi (while some say 900psi is ideal) because i tune street driven daily rides. why?

getting the bottle up to 1000-1050psi with a heater is no problem, but getting it down to 900psi in the summer is far harder and not suitable for occasional use on the street as most don't always have way to cool the bottle to lower pressure. purging the bottle seems the only way to lower pressure fast, and even then sometimes i can't get it under 1100psi in the summer.

the temp/pressure ratio of nitrous is a bitch sometimes :P