well im about to put on my bottle and im kinda scared!!! my engine is putting out 300 rwhp so im guessing between 360-380 at the motor. im only going to run a 100 shot with this short block. heres what ive got in my bottom end. hyperutectic pistons with the rings gapped a little wide. stock reconditioned rods and a cast crank, the bottom end is fresh and has very good oil pressure and i always run mobil 1 oil. is this thing going to scatter or will i be "OK". i will make sure it doesnt go lean and ill probly mix in some race fuel and back off a couple degrees of timing when the juice is flowing. what do you nitrous boys think?

you dont have anything to worry about i have ran 150 shot nitrous on old 100,000 mile 350 sbc for the hell of it. what fun it is.........i have ran them on cast piston unbalanced stock bottom end bbc engines for years........as long as you can carry more then 4.5 psi fuel pressure then your good to go.......i myself have always made sure i had at least 5.5psi at peak rpm. even with 100 hp shot i just ran timming as i would noramlly run my combo and just run 91 or 92 octane pump fuel........the 100 hp setting is very very forgiving......they have the fuel side way rich from the factory so you will see black smoke comming out the exhaust when you have it activated.........

at 150 hp mark i like to retard my timming about 4 degrees and go 2 steps colder in plugs and run 91 octane with a booster additive......

john an old friend of mine use to race his 86 summerset, it had a bone stock 4 cylinder in it and it was front wheel drive with 120,000 miles on it. he installed a 75hp kit into the car for bracket racing. on the motor it would run high 19's alot of 19.80's and with nitrous engaged from the start line it would crank out some stupid 16's second 1/4's. he was a sand bagging dog with that car in the street class. it was kinda cool to watch the old man (late 50's) hit the nitrous to do some dry hops in the stagging lanes. it would sqwal the tires off the line for about 30 feet or so and just go......he ran this car for about 3 years and won alot of races........he then finally puched a hole in one of the pistons and he replaced it and went back out and ran it for another year....... ..


to me nitrous is not a big deal since i use it and have been around it for awhile......the most i have ever used on one engine is 300 hp and that was with two plates stacked on each other 150 to leave on the line and 150 about 60 ft out. what a ride........

you should be just fine if your worried run your race fuel and retard your timming and close some of your spark plug gap. and make sure you have plenty of fuel pressure......

Well I hardly fear the bottle myself and I'm a guy who has blown up a motor on the stuff, but the fact is if you take some precausions and don't start tweaking your kit too lean for more power you will be fine.

To get to your application.... one thing pops out to me and that is your pistons. I would not spray a motor with hyperutectic pistons myself. If you dentinate or have problems going lean, those pistons don't melt... they shatter to pieces and love to ruin the rest of the motor with it. Sorry to break it to ya, but this is my experience.

If you choose to do this MAKE SURE you retard enough timing out for the shot you plan to run and make sure BEFORE you run the nitrous system that the fuel side of the nitrous system is up to par and has no pressure drops. There are guys who have sprayed on hyper's, but I don't think you will find many that recomend it.

It is hard to recomend spraying with hypers...but as long as the ring gap is greater than .004 per inch..Id say .006 and the fuel delivery is good. The timing on a 100 shot isnt as desperatly important as a 150 or 200 shot..but retard it 4º anyways(nitrous likes retarded timing) you should be fine

3/8" graemlins/sad.gif or 7/16" ;) rod bolts??? Don't lean out even with 100 shot and those pistons

ddennis if you don't mind me asking what kind of engine setup did you have the 300 shot on? Im assuming it was a forged bottom end.

Something I don't think was mentioned is to make sure you DO NOT have any activation at lower RPM. Preferably only above 4000 in your case. Nitrous causes extreme cylinder pressure the lower the RPM is. I spray 125-150 on top of about 430 flywheel and have been ok, but I take every precaution possible, have wideband O2 on my EFI, and retard the timing. I have KB pistons and stock rods and crank, although all the fasteners are ARP. I stepped up to 100% race gas when I went to a 150 shot which may be overkill be she's still alive with questionable bottom end parts.

In your case I would limit to a 100 shot just to be safe along with taking all the precautions.

Originally posted by Chopper:
ddennis if you don't mind me asking what kind of engine setup did you have the 300 shot on? Im assuming it was a forged bottom end. forged trw pistons.....cast crank turned 30/40 under....stock rods and bolts.....2 bolt main with stock bolts.........396 bbc....... with .030" plug gap, plugs extended tips 2 steps colder......timming at 30* total.........92 octane for the motor with the first hit of 150 hp plate.......second plate hit with 114 race fuel.........hit 150 hp of the line and about 60 ft out with second plate....held to end of 1/4 mile 10.70's at 129 mph.......only did it for one time out for test and tune...just for the hell of it.........got my warning for not having roll bar and saftey jacket......