I dynoed recently on the nitrous just to see what kind of power I could make on a stock bottom half motor with just heads and cam.

Then guy who was running the dyno stuck the sniffer in the pipe while I sprayed it. The ratio got as low as 12.8:1 and stayed steady as a rock there. The guy at the dyno said that was great. Is that true? Is that as safe as it should be on a 150 shot?

Thanks,
Jeff

 

FRDnem,
I have heard of ratios as rich as 9.xx:1 with 400+ hp shots. I'd think that with only a 150 shot, you should be OK, but it wouldn't be a bad idea to richen it a little. Just be careful on your total timing. If you step it up to a bigger shot, I'd recommend going a bit richer. It's always better to start on the rich side.
Just my humble opinion.
Kevin

 

I tuned mine for 11.5:1 on the juice+boost. 12.5:1 on boost alone.

Rich Krause

 

If I fatten up the fuel jet (NX kit) will I run a bigger risk of a nitrous backfire?

From what I have heard NX runs their kits on the fat side as it is. The car made 406RWHP 395RWTQ (Standard)

On a 150 shot it only picked up to 522RWHP 550RWTQ.

Thats only a 116 HP & 127 TQ. on a 150hp shot. I have heard NX rates their kits at the rear wheels.

 

They rate them the same as anyone else, by the size of the N2O jets. How much hp a given combo will see has a lot of variables. In my case, a 150hp hp shot got 125rwhp with some timing taken out. So I wouldn't say you are too far off. What was the bottle pressure when you made your run? Nitrous delivery is a function of bottle pressure, as well as jet size.

Rich Krause

 

Rich,
I had the bottle pressure at about 1,000 - 1,050 psi.

 

You would have made a bit more power with another 100psi or so.

Rich Krause

 

With a full 10pound bottle and a 150 shot of 1,100psi how many 1/4 mile passes should I be able to get?????

 

General rule of thumb: 100hp = 0.8lbs/10 sec. I can get 4-5 passes out of a 10lb bottle with a 150hp shot.

Rich Krause

 

Which brand bottle heater are you using?

 

NX. Seems to work fine.

Rich Krause