I did a search for this but was unable to find results here are on the net. Maybe somebody here with better seaching skills could point me in the right direction to answer this question:
I was wondering how much nitrous is used during 1/4 mile pass according to horsepower. Like 150hp of nitrous uses how many pound of nitrous per 1/4 mile pass. Is there a calculator or chart on the internet for this that would show say from 100hp to 500hp in 50hp increments?

 

You need the amount of "on" time to calculate. For example, is it a 50 shot for 13 seconds.. a 75 for 12 seconds... or a 200 for 11 seconds?

 

175 shot for 8.9 seconds

 

The old general rule of thumb use to be...

100hp=1lb in 10seconds

so, say
200=2lbs in 10 seconds
50=.5lb in 10 seconds
500=5lbs in 10 seconds

so if you go 15 seconds just multiply 1.5 times your lb useage! A 200 shot would be 3lbs in 15 seconds useage....

One other thing to know.....a 10lb bottle would last 100 second at 100 hp. However, must sytems don't perform well below 20% full (just think of a standard 10lb bottle is really at 8lbs, useage). So, say 80 seconds instead of a 100 seconds. The less shot you have the less you'll notice the bottle surge in the last 20%. Import guys hit so little they may not even notice N2O bottle surge

This is assuming standard rich jetting numbers that the big companies quote you. A leaner setting might get you 10% or so, more power (on Nitrous power). But could go boom..and there is little room for error.

175 at 8.9 seconds = .89lbs for 100hp...so, 1.75 times .89...= 1.55 lbs per run. On a full 10lb bottle, 5 runs should be good (shooting for 8lbs useage max out of the bottle)....You really don't have to calculate out if you just remember the general rule it will get you close!!!

Jimbob

 

The formula for calculating your nitrous usage is: 0.8 lbs N2O X 10 seconds =
100 horsepower. 175 shot will use 1.4 pounds in 10 sec. So 175 for 8.9 sec should be about 1.25 pounds.

 

Thanks for the info guys. On another racing forum I visit this guy's car runs 8.90s in the 1/4. He claims he is only spraying a 175 shot but using 3 pounds of nitrous per run. People accused this guy or someone else of drilling his nitrous jet. I'm not getting into the middle of that one but it made me curious to find out what normal nitrous usages was. Thanks again.

 

100 shot I get 4 good hits off of it( ) and the 5th is strong at first but trails off.

 

Thats for the 1/4 btw 3 runs from 0-120 runs I get 3 out of it on a 10# bottle.

 

I would say somewhere in the .8 to 1lb every 10 seconds is close to the truth. When Me and Ryan used to use ours at the track we would see just about a 1lb per 10 second useage based on the scales that come with the NX fill station. He, however was using the MAF prototype from NX, and I was using older spray Nozzle design from the 90"s era. So, we where none to efficent back a few years ago, and I always like to keep the jetting on the stock Rich side.

three83 If your guy their, is using 3lbs in 8.9 seconds, he's shooting some serious N2O. Something like 350 to 400 depending on useage. If he purges a lot though, before the actual run, it might be 300 to 350 a run...Still a big shot!!

Jimbob

 

Thanks for the info.