When to inject nitrous? rev limiter? - Nitrous Oxide Forum

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When to inject nitrous? rev limiter?
Wednesday, December 09, 2009 12:15 AM
Hi, after a number of suggestions I decided to upgrade from my dry nitrous system to a wet one, without ever even spraying (i wanna make it as safe as possible)

This Thursday im going back to the track and I was wandering at what time, gear or rpm range would you recommended me to spray.

I have a 2000 Cavalier z24 with an ld9 engine with an automatic transmission (which i believe is a 4 gear). the engine is pretty much stock (headers, short ram intake, TB spacer and magnaflow exhaust).

Also..I would like to know what the rev limiter is on my car so I wont spray over it and blow my engine. I'm going for a 50hp shot first, then a 60hp if everything goes OK

Thanks for your help

Re: When to inject nitrous? rev limiter?
Wednesday, December 09, 2009 2:34 AM
Which kit and brand are you using?

You have an auto so, the rev limiter isn't going to be a problem. Think about it. Have you ever hit the rev limiter before? If you have, then you need to stop pretending you have a 5spd and let it shift itself. Though some kit makers say spraying through a gear change could hurt the trans, lots of auto guys on here have done it. Maybe if you had a built engine and spraying large amounts. But, if you were doing that you'd have a built auto trans too.

How are you activating the nitrous? Button or WOT micro switch? Most kit makers recommend starting at 2500-3000 rpm. Since you are using an auto, I'd suggest the higher end at 3k. Good luck.




Re: When to inject nitrous? rev limiter?
Friday, December 11, 2009 2:51 AM
its an NOS kit, to activate it I have to be at WOT (wot switch) and press a button.

So ill go all motor til i reach 3000 rpm on 3rth then ill activate it. I forgot to mention they are 1/8 mile races jaja Ill see if i can get there before the 1/8 is over. running 10.59 sec.

Your help is appreciated Eddie
Re: When to inject nitrous? rev limiter?
Friday, December 11, 2009 9:05 AM
i'd find a 1/4 mile to run on personally. have you gotten a bottle heater?



Re: When to inject nitrous? rev limiter?
Friday, December 11, 2009 6:56 PM
No, no bottle heater, im in a valley (Imperial Valley) south of California, its more usual to find us puting ice on the tanks to bring down the pressure most of the year. In this time of year a bottle blanket is all Ive needed to keep the pressure at 900.
Re: When to inject nitrous? rev limiter?
Friday, December 11, 2009 11:58 PM
what about n2o pressure gauge? window switch since ur runnin an auto? and maybe it's just me but i would still look into a bottle heater, u really wanna keep it at the correct pressure.



Edited 1 time(s). Last edited Saturday, December 12, 2009 12:22 AM


Re: When to inject nitrous? rev limiter?
Sunday, December 13, 2009 2:57 PM
What's he's saying blucavy, is it's freaking hot there. Pressure in the bottle is interchangable with temp. The reason why we use a heater to raise the pressure

Try a bottle blanket to keep the heat from having such a dramatic effect on the bottle.




Re: When to inject nitrous? rev limiter?
Thursday, December 17, 2009 1:23 PM
Is a heater really necessary with just a 50 shot?
With such a little shot, I wouldn't think that it would.

I plan on doing something similar once I finally get the engine built and 5 speed swap along with the M45 which is on the way as I type.
I rarely plan on using it but at that time of necessity, it's going to be the equalizer at the strip or occasional street race.

Oops, I said street race.


Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!





Re: When to inject nitrous? rev limiter?
Thursday, December 17, 2009 3:00 PM
The size or amount of nitrous injected has nothing to do with the whether you need a heater or not. YES, you need a heater. The heater raises the bottle's contents to the correct pressure so you get smooth, hard hitting jolts of nitrous.

Nitrous naturally wants to be a gas. We use heat and pressure to keep it in a liquid form. The liquid form of nitrous gives you all the benefits of n2o that it's famous for. If you're spraying gaseous nitrous you're just shorting yourself of what the system could be.




Re: When to inject nitrous? rev limiter?
Tuesday, December 22, 2009 2:17 PM
If you have N20 you should have a heater it will keep your bottle at its optimum pressure even if that means raising it a couple hundred degrees for you guys in Southern California. As for when to spray, your auto and a low shot I'd hit it right after first at first until you got used to it and then try a little earlier. It's going to depend on traction, me for example I can't spray unless I'm out of first because I will just spin (my tires are done and need to be replaced).





Re: When to inject nitrous? rev limiter?
Monday, January 04, 2010 1:02 PM
Point made above:

With Nitrous systems you need to keep the pressure high to make the most power out of your system. Allowing the heat to drop will make pressure drop low and you will run way rich, lowering your air/fluel ratios kills power and makes it harder to fully light off a good spark.

The best way to show this effect is to with a spray can of paint:

When you shake a can of paint you are mixing the areosol( can't spell sorry) and the paint.
The pressure in the can is high and when you press the top the pressure forces the paint and aresol mix out the end of a tube right?

Now what happens when you turn that same can upside down and repeat? The aresol comes out due to the pressure but no paint, that beacuse the pressure is still there just isn't enough to
force the paint out of the can, you keep doing this long enough and the aresol will run out and you have a can full of paint you can't use, it will just trickel and spit out.

Same effect with nitrous you don't have that gas forcing it out the tube, IT IS THE GAS!
in order to liquify N20 you need to freeze it and/or compress it down just like propane gas in a tank.

Once it is in the tank and sealed you need to build enough pressure to force that liquid out the the tube and down your lines into the jets, with nitrous the the warmer it is the less liquified it tends to be and builds more pressure
as it returns to its gas stage, if the gas builds to high and pressure gets too high you get the N20 too lean (the density of the N20 is to thin) then you will get a very high air/fuel ratio, and you could cause knocking and a big bang if done long enough.

The blanket is used to keep the bottle at the right pressure so it can force it out the bottle at a high enough rate to provide for the jets, but can be turned off to keep it from over heating and leaning out.
Also if you plan to run with your nitrous at high speeds make sure you mount the bottle right. I've seen people try to put in a bottle sideways and at bad angles, this will be like turning that can of paint upside down!
It needs to be mounted with the valve at about a 45 degree angle and facing the front of the car. The tube in the bottle is placed at an angle towards the edge of the bottle to pick up the N20. If you don't mount it right at higher speed
the N20 will be forced into the back of the bottle, so mounting it sideways will force it way from the pick up line and you will run way rich.





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Re: When to inject nitrous? rev limiter?
Tuesday, January 05, 2010 4:04 PM
I had an LD-9 in my 97 Z24. I used a timer to hit the nitrous. Knowing what my 60' times were off the juice I set the timer at about 25% of the time it took for my car to go 60'. 2.000 60' timer .500. Unless when the nitrous hit I spun the tires. Then I went to a longer delay. My problem ended up being the 107 mph speed limiter. I got my car to run almost 104 mph in the 1/4. That was my limit - besides backfiring catching fire and buring up. And I ran more than a 50 wet Nitrous express shot. But only god and nitrous express knows how much I ran on the LD-9.
Re: When to inject nitrous? rev limiter?
Tuesday, January 05, 2010 4:18 PM
What kind of times were you running at the track with the 50 shot?
I plan on running a 50 shot with the M45 for that little extra edge needed to stay ahead if you know what I mean.



Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!





Re: When to inject nitrous? rev limiter?
Tuesday, January 05, 2010 4:38 PM
y not go with a 75?



Re: When to inject nitrous? rev limiter?
Tuesday, January 05, 2010 7:27 PM
Too much and 50 is all I'm looking for when it comes to winning that race.


Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!





Re: When to inject nitrous? rev limiter?
Wednesday, January 06, 2010 5:28 AM
there's no such thing as too much......



Re: When to inject nitrous? rev limiter?
Wednesday, January 06, 2010 6:31 PM
you won't be satisfied with 50, and when you put that 75 on, you are gonna be like, well..... maybe just one step moar! MUWAHAHAHAHAHHAHAA!



Re: When to inject nitrous? rev limiter?
Thursday, January 07, 2010 2:33 AM
Misnblu wrote:

Too much and 50 is all I'm looking for when it comes to winning that race.


Well if 50 will make you win... than 100 would make you DOUBLE WIN!....don't you want to double win?
Re: When to inject nitrous? rev limiter?
Thursday, January 07, 2010 3:53 PM
Lol, no it won't.
With the car already being supercharged, why add more?
It's for that occasional heads up race at the track which allows you to go heads up with whomever you want to race.
There's even been times when I was drag racing that people would come up to me wanting to go heads up with me because I was driving the Cavalier and thought that they could beat it.
So for those times in a situation like that and you're losing by just a little, you can give it that shot to equal things out.

Plus I plan on completely hiding the setup so that when the hood is popped, you're not going to see it unless you go underneath the car in which you'll then see the nozzles and solenoids so no one will know or see it.


Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!





Re: When to inject nitrous? rev limiter?
Thursday, January 07, 2010 3:58 PM
how do u plan on doing that? running it thru the inside of the manifold?



Re: When to inject nitrous? rev limiter?
Thursday, January 07, 2010 4:11 PM
Direct injection to each port using smaller nozzles so that they'd be equal to the 50 shot in one nozzle.
I've not done the research on this yet but it's feasible to do while keeping it completely stealth.
-3AN lines are small enough to conceal under the supercharger while the solenoids can be positioned inside the cowl area.
Also, I use black split loom for everything I do under the hood so it would just blend in nicely into the engine bay with little or no noticeable clue as to what's inside the loom.
The only thing they'll see is the Devils Own water/ meth injection at the throttlebody or tb spacer that I also plan to use for the meth setup.
I've even had the idea of having the nitrous lines hidden inside fuel line to make it look like something to do with the fuel system so once I get to that point, it's going to be done.




Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!






Re: When to inject nitrous? rev limiter?
Thursday, January 07, 2010 4:46 PM
interesting, eddie might b able to help you out on this one, but i'm thinking that if you're doing a dp anyone with any knowledge of n2o is going to be able to spot it for what it is, even with the blower above it.

just my guess though.



Re: When to inject nitrous? rev limiter?
Thursday, January 07, 2010 5:32 PM
Unless you actually look up into the engine from the ground, you'll never see it.
Like anything I do with the Cavy, I'll be sure to have a write up about it when that time comes.


Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!





Re: When to inject nitrous? rev limiter?
Thursday, January 07, 2010 5:43 PM
make sure to post pics pwease



Re: When to inject nitrous? rev limiter?
Thursday, January 07, 2010 6:53 PM
Oh yeah, you know I will and do.


Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!





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