Assistance with N2O and launching

[DarkShadow]

For those of you with Nitrous:

My buddy has an `03 GT and has jsut finished installing a 100 shot ZEX kit. We went to a 1/8th track this weekend and the best run he had was a 8.68.

Is this reasonable for a 100 shot with no other mods? We were thinking it would be a bit more like a 8.5 flat. He is still playing around with when he should spray.

So if any of you guys have experience with launching and nitrous, when is the best time to start spraying? If he sprayed in first he had problems with traction, but if he waited for 2nd it seemed pretty sluggish. Oh and it was cold and his bottle pressure was barely 900 most of the night. How much of an effect would that have had on his times?

[MarkuzLS1]

It needs more pressure, to start. If he doesn't get good traction spraying in 1st, he needs better tires...

[bluemustang]

um does he not have a bottle warming jacket for the bottle? cause it sure does sounds like he doesnt. I believe running a bottle at 900 your arent getting the full shot there.

When i was running nitrous I was usually spraying off the line. I did have traction issues but I just ended up lowering my psi on the tires to where it did catch traction.

Its something you gotta toy around with to get honestly. but yeah def get a bottle warmer cause it will result in intake puddling and its no good

[Thomas91169]

he definately needs a bottle warmer. as for when and where to spray, i have the slightest. spray is not my bag baby.

[DarkShadow]

He was going to get a warmer sometime this Fall. He wasn't planning on needing one this year since it is April in Alabama, it's not supposed to get below 40.

[yellowgtstang18]

tell him to get some drags and spray right off the line.....

[bluemustang]

Quote: Originally Posted by DarkShadow He was going to get a warmer sometime this Fall. He wasn't planning on needing one this year since it is April in Alabama, it's not supposed to get below 40.

it doesnt matter where you live. that bottle needs to be warmed on contact to contact

if hes gonna continue spraying at 900 psi his shit is 100% not gonna last

trust me

[Herbstang]

Quote: Originally Posted by bluemustang it doesnt matter where you live. that bottle needs to be warmed on contact to contact if hes gonna continue spraying at 900 psi his shit is 100% not gonna last trust me

Get the bottle warmer or break out the blowtorch

[DarkShadow]

Quote: Originally Posted by bluemustang it doesnt matter where you live. that bottle needs to be warmed on contact to contact if hes gonna continue spraying at 900 psi his shit is 100% not gonna last trust me

Ideal bottle pressure is supposed to be anywhere from 900-1000 psi (he's wanting right at a 1000 or a tiny bit less for track runs) so if he is only spraying at 900, his engine is actually running a bit richer making it SAFER for the engine. The real danger is too much N2O being sprayed over not enough fuel to mix it.

[bluemustang]

Quote: Originally Posted by DarkShadow Ideal bottle pressure is supposed to be anywhere from 900-1000 psi (he's wanting right at a 1000 or a tiny bit less for track runs) so if he is only spraying at 900, his engine is actually running a bit richer making it SAFER for the engine. The real danger is too much N2O being sprayed over not enough fuel to mix it.

I was told idle bottle pressure for a full maxium shot is 1000-1050 psi

anything lower WILL result in puddling in the intake. Gotta member the lower the psi the less nitrous coming out with more fuel being spray thats where puddling is gonna happen.

Ever see the pics of that yellow vette that had the intake completely blow off his motor and through the hood? yea thats the result of not enough nitrous to much fuel.

I mean its your buddy im just offering advice so he wont fall under the % of nitrous messed my car up.

[Thomas91169]

Quote: Originally Posted by bluemustang anything lower WILL result in puddling in the intake. Gotta member the lower the psi the less nitrous coming out with more fuel being spray thats where puddling is gonna happen. Ever see the pics of that yellow vette that had the intake completely blow off his motor and through the hood? yea thats the result of not enough nitrous to much fuel.

pudding happens due to poor pressure behind the nozzle so it gets dripped into the airstream as opposed to sprayed. also the design of the nozzle as well as its placement can effect possibilities of pooling. then again, with nitrous, there really is no 100% safe setup, even wet kits can cause problems.

btw i think it was the other way around, too much nitrous, not enough fuel. but if it blew his intake off it was likely a backfire due to nitrous pooling up, a backfire could have been caused by the a/f ratio leaning out (not enough fuel) and causing a hotspot on the valve which ignited any pooled nitrous, or predetonation could have done it as well. when you do nitrous, there are so many things that can go wrong.

[bullitt482]

Quote: Originally Posted by Thomas91169 then again, with nitrous, there really is no 100% safe setup, even wet kits can cause problems.

Dammit if I here this again I will... .something..... If that's the case why do people still opt for it over forced induction . People who talk bad about nitrous know nothing about it, or just enough to make them make nitrous look bad.




Well to put things in perspective, I ran an 8.79 at 79 mph with nothing but a shifter and exhaust in the Bullitt. With tires and spraying out the hole, I would think 8.20's--ESPECIALLY with a ZEX kit, they have a great setup--would not be out of the question... It's all about traction when you get to those torque levels(nitrous may only be a 100 shot, but you can get up to almost twice that in torque).

[Zim]

Quote: Originally Posted by Thomas91169 btw i think it was the other way around, too much nitrous, not enough fuel. but if it blew his intake off it was likely a backfire due to nitrous pooling up, a backfire could have been caused by the a/f ratio leaning out (not enough fuel) and causing a hotspot on the valve which ignited any pooled nitrous, or predetonation could have done it as well. when you do nitrous, there are so many things that can go wrong.

No, nitrous isn't flammable... it just accelerates combustion. If its blowing an intake off, there's too much fuel thats puddling up. The jets on a wet kit should always have a bigger fuel jet than nitrous.

I would start spraying at about 3 grand... and ideal bottle pressure is anywhere from 950-1150 psi. Don't run it if you're not in that range, its bad. There are automatic zex bottle heaters on ebay for 112 bucks... get one of those and go back to the track on a warmer day. The nice thing about nitrous is it cools down your intake temps big time. So the extra heat wont really affect the motor and the tires will be stickier.

[bluemustang]

Quote: Originally Posted by bullitt482 Dammit if I here this again I will... .something..... If that's the case why do people still opt for it over forced induction . People who talk bad about nitrous know nothing about it, or just enough to make them make nitrous look bad.

Quote: Originally Posted by Zim No, nitrous isn't flammable... it just accelerates combustion. If its blowing an intake off, there's too much fuel thats puddling up. The jets on a wet kit should always have a bigger fuel jet than nitrous. I would start spraying at about 3 grand... and ideal bottle pressure is anywhere from 950-1150 psi. Don't run it if you're not in that range, its bad. There are automatic zex bottle heaters on ebay for 112 bucks... get one of those and go back to the track on a warmer day. The nice thing about nitrous is it cools down your intake temps big time. So the extra heat wont really affect the motor and the tires will be stickier.

[1996stang]

If he wants help with launching get some sticky tires and drive it like he stole it.

[bullitt482]

Quote: Originally Posted by Thomas91169 pudding happens due to poor pressure behind the nozzle so it gets dripped into the airstream as opposed to sprayed.

Your kidding right? You think nitrous oxide puddles??? OMG, now THAT IS FUNNY MY FRIENDS!!!!!!!!!

Remember what I said about knowing enough to make nitrous seem bad? LOL.
I'd say the average intake charge of a car at running temperature is, oh say, 90-110 degrees on an average 70 degree day(that is if your car is pulling air from the engine bay). You do realize that nitrous oxide's boiling point is a negative 127 degrees F right? Even if it was "dripped" into the airstream, it would be a gas about the time it was release from the nozzle.

9 times out of 10 it is the nitrous backfires that I've heard/seen are from a missed shift and the car hits the rev limiter. Now, if you are using the factory rev limiter, it will cut fuel causing the system to run lean and preignite and backfire through the intake causing havoc on the throttle body and upper/lower intake. A buddy of mine has a "butterflied" throttle body blade from back in the day when he wasn't too bright with his nitrous sytems. He missed a shift, the nitrous was spraying, with his foot on the floor, not in gear. Predetonated, then fired back through the intake. A simple window switch--which will allow the nitrous to be sprayed from x rpm to x rpm--will prevent the nitrous from spraying at the the revlimiter and will prevent previously stated situation. The other is to get an ignition box that will set the rev limiter by preventing spark, causing all the fuel/air/nitrous mix to be exited through the exhaust.

From what I know, nitrous backfires happen when it runs lean and then predetonates, not from running rich, but not from "pooling" or "puddling" in the intake, but from predetonation.