Obviously, the more power you have, the more quicker your MPH in the 1/4 mile will be (and ET as well assuming good traction, shifting, etc.). But how much does it affect it per horsepower? What I'm trying to figure out is how much a shot of nitrous will improve my time. I know that a 150 shot on a 16 second car will make a much larger difference than on a 12 second car like mine. I realize that the faster your ET is, the more power it takes to drop that extra second. So how can I make a guess without going to the track? Thanks in advance.

 

It's an exponential number. A 16 second car may see a 1.5 second increase while a 12 second car may only see a 1 - 0.75 increase. The only way to know for sure is to take it to the track since every car is different.

 

Stephen is of course completely right in what he is saying, but the 'rule of thumb' that some people go by....... rightly or wrongly..... is that 10bhp equals roughly one-tenth in the 1/4 mile.

Though in a 12-second car like yours CamaroX84 I'd figure on a 150 shot being worth a second pessimistically. If you're pessimistic then you've less chance of being dissapointed.

Be sure to let us know what gain you actually see!

 

With nothing more than bottle pressure and track conditions the NOS on my 15.0 second truck usually lets it run high 13's although one day when the bottle pressure was very high and conditions were perfect, it ran a 13.28. Not too bad for a 4600 pound truck. That was a 1.75 second increase over NA and I've never changed the NOS jetting. I think it's jetted for 150hp although most of the time I only saw a 100hp increase based on mph.

The HP rating is assuming you have at least 1200 psi in the bottle, minimum 92 octane fuel and the engine is in good working condition. As soon as you use the NOS the bottle pressure drops. Most of the time mine was around 900 psi. I never did invest in a bottle warmer.

I always hit the NOS right off the line and my 454SS truck could empty a 10 pound bottle in 7-10 1/4 mile runs.