nitrous on a big block

[bel_mor]

have been thinking of buying a nitrous kit for awhile. but having an engine with mostly stock parts (ie. cast crank, stock rods, factory forged pistons.)I am a bit nervous as to how much (if any) of nitrous I can safely use with out any catastrophic failures. The engine is a 402 it has stock heads(299241 i believe) and stock bottom end it has 10.5:1 compression it has a comp cam 288ar solid roller camshaft. the car runs 12.40's in the 1\4 mile on a mt 26x8.5 drag slick. would like to get it into the high to mid 11's if possible. any input would be great

[shmoov69]

Any entry level powershot or 125-150hp kit will be just fine.... JUST KEEP IT OUT OF DETONATION!!! If it isn't running just right, LET OUT! It won't fix itself.
I'd recommend a small fuel cell up front somewhere with a generic Holley (or whovevers) electric pump and have it filled with Race gas dedicated for the N2O only. Slow the timing by a few degrees and blast away!!

BTW- should be good for mid to lower 11's IMO.

[sam 74]

i'd stick with 125 or less, i've run nitrous for years without any problems, you'll want to pull between 2 and 4 degress out of your total timming depending on what shot you run. i've run with a seperate cell for race gas and i've run directly from my main tank, the key is keeping your fuel pressure right while the solinoid is open. you may want to back your plugs off i step colder with a 125 shot.

[Zspoiler]

Like any power adder nitrous ,blower, turbos, etc.It depends on how your engine is built for the application. on a stock system you have to lean toward the very conservative side. Because if you don`t it will bite in the a**.

[Derek@ModernSpeed]

I'd feel comfortable with a 125 shot, and it should be fairly easy to reach your mid 11's goal. As others have stated, take a little timing out, and make sure you have adequate fuel supply.

[Todd in Vancouver]

I ran a bigger fogger system on my SBC and this is what I did;

I ran a new 1/2" fuel line and pick up for my carbs with a dedicated electric pump. This in itself really helped the car as the factory line could not deliver enough gas for my set up.

Then, I added a second electric fuel pump that only turned on when I "armed" my NOS and I used the smaller factory fuel line to feed my NOS system. I plumbed fuel pressure gauges for both and made sure I had everything set up right. There are a couple books out there about using NOS that are helpful.

This set-up worked well for me for years on my street car which later on in years became my dedicated race only car using the same system. Never had an issue but as others stated do your homework and I'd start with a book all about NOS.

BTW it is an absolute hoot to use and I will be adding a kit to my current build as well just for kicks and giggles.

[Aficionado]

When I had it on a 350 (Zex 100 shot) I ran an upgraded electrical fuel pump and a low fuel pressure kill switch and separate warning light to keep it from going lean and burning stuff up.

[snappytravis]

I had a bb with 125 back in the early 90's It ran pretty good, also had a buddy that had it on a bb with tunnel ram and two fours, We blew the top of the piston right off it, Ran it low on fuel pressure, just make sure your fuel system is good to keep it from going lean, and it should be a lot of fun, good luck