think baby needs a bottle
- Thread starter OiiiiiiO
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thanson_mopar
Well-Known Member
what engine? stock? how was it built?
bOb shingler
Well-Known Member
if your going to only use it on the top end you'll be missing most of the fun.
1968FormulaS340
Well-Known Member
A 150 shot is no big deal. Just make SURE you will not have ANY detonation.
Normally (and i have ran it)...... When something goes wrong, it goes VERY wrong.
Normally (and i have ran it)...... When something goes wrong, it goes VERY wrong.
ramcharger
Dismember
You must have an absolutely 100% reliable fuel system than can supply enough fuel for the NOS without dropping pressure, vapor locking, etc. A "T" behind your stock mechanical fuel pump is not going to cut it with a 150 kit.
You need to pull out 2 degrees of timing for every 50 hp if you're running pump gas. It can be done manually, but performance off the bottle will suffer, or you can do it via a seperate or built in automatic timing retard.
A fuel pressure cut-off switch is really mandatory IMHO. If you go lean, you WILL burn a hole in a piston.
Don't ever, ever hit the rev limiter while on the bottle. Your intake manifold may be found in the next state. Most people use a "window switch" to prevent this form ever happening.
That's all I can think of for now.
You need to pull out 2 degrees of timing for every 50 hp if you're running pump gas. It can be done manually, but performance off the bottle will suffer, or you can do it via a seperate or built in automatic timing retard.
A fuel pressure cut-off switch is really mandatory IMHO. If you go lean, you WILL burn a hole in a piston.
Don't ever, ever hit the rev limiter while on the bottle. Your intake manifold may be found in the next state. Most people use a "window switch" to prevent this form ever happening.
That's all I can think of for now.
mshred
The Green Manalishi
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You must have an absolutely 100% reliable fuel system than can supply enough fuel for the NOS without dropping pressure, vapor locking, etc. A "T" behind your stock mechanical fuel pump is not going to cut it with a 150 kit.
You need to pull out 2 degrees of timing for every 50 hp if you're running pump gas. It can be done manually, but performance off the bottle will suffer, or you can do it via a seperate or built in automatic timing retard.
A fuel pressure cut-off switch is really mandatory IMHO. If you go lean, you WILL burn a hole in a piston.
Don't ever, ever hit the rev limiter while on the bottle. Your intake manifold may be found in the next state. Most people use a "window switch" to prevent this form ever happening.
That's all I can think of for now.
Hey Ramcharger, great info on this...ive ben thinking about some squeeze for my 340 too...would the type of internals make a difference on how much you would be able to spray? lets say i have a 340, 10.5:1 cr , iron heads and wanted to spray a 100shot...would i be able to go more and avoid detonation or should i run less? oh and why does hitting the rev limiter while on the bottle destroy the manifold? thats something ive never heard before and am curious to know more:read2:
1968FormulaS340
Well-Known Member
You can run 100 shot easy on a stock 340. The more you go the more the risk.
10.5 is pushing it on pump gas. A little detonation goes a long way when running NOS, and a little lean is just as bad.
If you go lean or detonate plan on rebuilding.
On the rev-limiter thing..... The big deal is when you have a limiter that cuts fuel. This changes the NOS/fuel ratio and can blow your intake through your hood.
With that said.... Cutting the spark isn't a great idea.....
Like i said and others.... You need things right because when they go wrong, they go VERY wrong.
10.5 is pushing it on pump gas. A little detonation goes a long way when running NOS, and a little lean is just as bad.
If you go lean or detonate plan on rebuilding.
On the rev-limiter thing..... The big deal is when you have a limiter that cuts fuel. This changes the NOS/fuel ratio and can blow your intake through your hood.
With that said.... Cutting the spark isn't a great idea.....
Like i said and others.... You need things right because when they go wrong, they go VERY wrong.
bOb shingler
Well-Known Member
the low fuel pressure switch is wired in to pull the grounds off the nos and fuel solenoids to shut the system down, not just shut the fuel off.
ramcharger
Dismember
The rev limiter stops the engine from accelerating and allows N2O to back up in the intake manifold and exhaust system and "BAM!". Like formula1968 said, newer cars with "dry" nitrous systems that cut fuel are more prone to intake explosions then our older stuff, but exhaust explosions are just as prevalent. Also, once the engine drops in rpm and comes back into full ignition the sudden "whack effect" on the pistons can cause some serious damage.
A few more things to keep in mind:
If you hit the nitrous with the car off, DO NOT try to start it! Engine damage will result.
There is a siphon tube in the bottle that picks up the nitrous. This means that the bottle must be mounted in a specific position recommended by the manufacturer.
Don't use telfon tape on the threaded connections. It can break off and clog the jets, delivery tubes, etc causing a lean condition.
The bottle should be at about 85 degrees for a pressure of about 900 psi. Don't hit the button on a cold morning, it'll just gag. There are bottle warmers that solve this problem. Don't use a torch like the idiots on Pinks.
I suggest a entirely seperate fuel system with it's own fuel tank filled with race fuel for applications using a 150 hp or larger shot.
I hope this helps!
ramcharger
Dismember
Bob, I'm pretty sure Formula was talking about newer cars who's built in rev limiter will cut fuel.
Yes, you are 100% correct in that the purpose of a low fuel pressure safety switch is to cut power to both solenoids.
moper
Well-Known Member
If it's just a typical Power Shot or similar, you can use it on a stock V8 with little issue. As was said, the engine has to be in good shape already. But it takes a lot to blow an engine on the smaller kits and they are jetted to be over rich on purpose. I know of a few clandestine cars that run 150hp with no mods. One is a 307 Olds, which is really a turd motor...lol. I ran a stock piston 340 and stock piston 383 on the same kit at the 175hp level for years. But you do need a good fuel system and pull the timing out of it. It gets addictive BTW
All good suggestions. Pay attention to the directions from the manufacturer. They have built in the saftey margine. When I ran ours, there was little improvement from coming off the line as opposed to hitting the switch just after 2nd gear. A true nos launch needs a converter commited to a motor on the juice. A second regulator is manditory, along with a low fuel cut-off switch. A timer and the retard box is not an absolute but does simplify things.
1qwikScamp
Well-Known Member
i love my bottle i had a 175 shot on my car now its a 200 it really makes a huge diffrence i have seen stock motors have a 125 shot on them forever and never have any problems 150 i think you will be very safe
another thing you can do is run a window switch, it will turn the solenoids on from rpm ranges that you set.
Adjustable timing and a seperate fuel system for nitrous is a good idea.
Fuel pressure cut off switch are nice but I have had problems with them before reading right.
Two big things dont get greedy and stay off the button as much as you can. IE no playing on the street for more than 10-15 seconds at a time.
stock bottom ends can usually handle 150 hp all day but go with a 100 shot to be safe.
Air fuel meters are also nice to have and strongly recommended when doing nitrous, if you go lean it will cost you. oh and not some cheap autometer narrow band crap one..get a good wide band. It will cost you 300+ for the meter.
To run nitrous right plan on spending 1500.00 for everything.
I have run nitrous for 5 years on my dak and will run it on my dart some day.
Adjustable timing and a seperate fuel system for nitrous is a good idea.
Fuel pressure cut off switch are nice but I have had problems with them before reading right.
Two big things dont get greedy and stay off the button as much as you can. IE no playing on the street for more than 10-15 seconds at a time.
stock bottom ends can usually handle 150 hp all day but go with a 100 shot to be safe.
Air fuel meters are also nice to have and strongly recommended when doing nitrous, if you go lean it will cost you. oh and not some cheap autometer narrow band crap one..get a good wide band. It will cost you 300+ for the meter.
To run nitrous right plan on spending 1500.00 for everything.
I have run nitrous for 5 years on my dak and will run it on my dart some day.
mshred
The Green Manalishi
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wow guys real great info from everyone here...definatly all great advice to keep in mind for running nitrous...my bottom end consists of forged pistons with .30 overbore(i think they are speed pro but im not sure), forged crank, and factory reconditioned rods...I am going to be running the 685 box from mallory regardless due to the two step and me running a stick, and that nitrous retard feature is a great part of it that i always thought would come in handy some day...i figured id have to run a high octane or race fuel in my car if i wanted nitrous (or any other power adder for that matter) since my cr is quite high...just trying to get an idea of what i would be looking at for nitrous and the info has helped...maybe one day ill strap on a 150 shot and play!
1qwikScamp
Well-Known Member
what CR do are you going to have and what elevation will you typically be running for a manual car i would go with a full throttle switch so you can be in and out of the hose as need be
ramcharger
Dismember
Mshred,
You'll be fine with that set-up with up to a 150 shot no problem. As long as you are not detonating now and set the Mallory box to pull out 4 degrees of timing, you'll be good to go. That box has a built in window switch too.
Most N2O kits come with a full throttle switch anyway, so you won't have to worry about that either. If you want to get adventurous, you can add back timing a degree at a time and see if your mph improves but I'd pull the plugs and check for silvery specs on the insulator. IMHO it's not worth it for the extra 10 hp you might gain..... If you like your car anyway, lol.
1qwikScamp
Well-Known Member
10 hp?
ramcharger
Dismember
For a 1 degree timing increase, yes. And that's a big maybe. :read2:
dragnknights
Well-Known Member
I've toyed around with the idea of nitrous a bunch of times, and I've learned that a 75shot is about as big as you should go with a stock motor. Step up the system as you step up the motor, and fuel system. Good Luck!
An overly rich condition on N2O is way worse than lean. The tunes in the kits are fat but not crazy fat.
I've never pulled timing out of a car with anything under about a 150 shot. If you start burning the electrodes on the plugs, you got too much timing.
A good fuel supply is a must.
I've never pulled timing out of a car with anything under about a 150 shot. If you start burning the electrodes on the plugs, you got too much timing.
A good fuel supply is a must.
moper
Well-Known Member
He's got forged pistons.. They are the weak link. Spray away dude. That setup will handle 250hp with the right fuel and ignition systems to run it. When I mean "stock" lower end I typically mean pistons. Because the other parts in a Mopar are plenty beefy. The pistons are too, but can't handle a lot of tune up error (as in lean or too much timing or too hot of a plug). You've got no problem running what you want to with what you listed.
ramcharger
Dismember
Hey Moper,
Think he'd be OK with the stock rods and slicks with a 250 shot? I think the crank would be OK with short dragstrip bursts. If he's making 400 hp right now, which he could be, that would be 650hp.
mshred
The Green Manalishi
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hey guys thanks for all the tips...if the mallory box has what i need and most nitrous kits come with a window switch, maybe nitrous will be in order some time in the future when more power is nescessary...i dont know if i would spray more than 150 without being a little scared lol...obviously i would have to get a good fuel system as well, but this is all stuff that i was going to eventually do anyways....its just the 10.5 cr that kills me since i would have to run real expensive gas to get away with the juice...oh, and by the way desktop dyno says im making 417 at the crank right now, so hopefully that number is somewhat accurate
moper
Well-Known Member
Yup, I think stock rods at 250 are fine. Not for 7K shifts... but off the line they wont be hurt. It's rpm and reciprocating weight that tear the factory rods up. IMO, they aren't good for shifts over 6000 with those heavy slugs. Mopar rods are very strong factory rods.
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