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Discussion Starter · #1 ·
I have had zero experience with nitrous. From what I have read, if you don't over use it, it doesn't do too much damage to the engine. This is what I have found out so far from reading other posts. If something is inaccurate, please let me know.

1. A wet system is better for forced induction cars.
2. A 50 shot is probably safe to use.
3. The system can be turned off and on to save nitrous.
4. The Venom system is programmable, but it costs more.
5. It's legal for the drag strip.

Now the stuff I don't know.

How do you use it?
Is the spray duration manual or automatic?
When do you spray, before the launch or after?
Since it increases the oxygen available for combustion, how do you keep your engine from running too lean and hot?
Where you install the injectors, before or after the turbocharger?
Since it's cold, can it crack the hot turbo or engine?
How much does it cost to fill a bottle?
How long does it last?
 

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I don't have any nitrous experience on my WRX, but have used it extensively in the past... So please take my answers with a grain of salt and I'm sure some of the more experienced WRX nitrous users can help me out later...

1. A wet system is better for forced induction cars.

*true*

2. A 50 shot is probably safe to use.

*true*

3. The system can be turned off and on to save nitrous.

*If you mean it's not in use all the time - true.*

4. The Venom system is programmable, but it costs more.

*unsure re: Venom* - I've heard great things about NX and NOS. (Personal experience is with systems from NOS on carbureted and EFI vehicles)

5. It's legal for the drag strip.

*If installed properly (i.e. secured, certified/pressure-tested bottle, blow-down tube, etc. etc.) then you should not have any trouble at the strip*

How do you use it?

*There are a number of ways to activate the systems. I've always used a master "arming" switch - and at least a full throttle-activated switch (usually referred to as a WOT switch). If it's on a manual-transmission equipped car I've used a momentary-on switch attached to the shifter or the steering wheel somehow in addition to the first two activation devices mentioned.*

Is the spray duration manual or automatic?

*Manual in all of the installations I've made. There are automatic NOS controllers - but those are more for bracket racing cars*

When do you spray, before the launch or after?

*Depends on the car. With the manual trans on the WRX taking the abuse of 4-wheel traction I'd say wait until you get rolling - but I used to spray off the line on the cars that I've run nitrous on. Please note they had significantly strenghtened drivetrains to withstand INSTANT torque and great traction (slicks)*

Since it increases the oxygen available for combustion, how do you keep your engine from running too lean and hot?

*The system injects additional fuel in a ratio that the company that manufactured the kit determines to be safe. They usually err on the "rich" (IMHO safe) side but it's always best to watch EGT's or A/F ration on the "juice".*

Where you install the injectors, before or after the turbocharger?

*After the turbo and intercooler, before the intake manifold/throttle body*

Since it's cold, can it crack the hot turbo or engine?

*Not if injected in the proper spot*

How much does it cost to fill a bottle?

*Not sure everywhere - but ~$4.50/lb. here so ~$45 for a 10lb bottle*

How long does it last?

*Depends on the jetting. Running a 175hp shot on my 351 cubic inch V-8 got me 4 1/4 mile runs out of a 10lb. bottle. I'm sure it's MUCH more on a WRX. I would just have to assume if 175shot uses 2.5lb per pass then a 50 shot would get at least 8-9 runs out of a bottle*
 

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Discussion Starter · #3 ·
Thanks for all the info. I checked the price on the Venom and it's close to $1200. I think I'll go with NX or NOS. I think NX offers a lifetime warranty on their jets.

If there's anything I left out, please let me know.

Again, I appreciate all the info.
 

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What is2scooby said!

I'll just add that I do use the Nitrous during launching at the drag strip. This makes the launch extremely violent, and gives great 60 foot times (knocks about 3 tenths off my 60'). However, if you are launching on Nitrous you need to take a little extra care so that you don't spray while the vehicle is stationary, and so that you don't fry the clutch from slipping too much, etc. etc. It is going to put considerably more strain on the drivetrain, so you have to be confident that you're not going to screw up. I wait until the car has begun it's motion off the line, and then I go WOT to spray immediately.

You will want to pick up some extra accessories for your Nitrous install. The most important is a bottle warmer to keep your line pressure up. I don't yet have one and my trap speeds rapidly deteriorate once I get below a half bottle of Nitrous. A nice to have is a remote bottle opener, as there will be times when your bottle is turned off and you want to smoke that Z-06 that pulled alongside you at the traffic light. If you have a wagon, you will need a blow down tube and adapter to run at the drag strip. These are not included in most kits and will run you about $50. The master switch that comes with the NX and NOS kit is also naff, so I picked up a nice Zex switch that runs about $25.

A 50-shot on a WRX will give you a couple of minutes worth of spray with a 10lb bottle IIRC. It will run you about $35 to refill a 10lb bottle. A bottle lasts me four to six weeks depending upon how often I visit the drag strip. If you spray regularly on the street, be prepared to refill on a weekly basis. FYI: It is illegal to use or even transport a Nitrous bottle in most states, unless you are on your way to a racing event in which case the bottle must not be connected. Don't get caught. ;)

-Pace
 

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You will also want to get some colder range spark plugs as well.

I finally got mine in this weekend and the car really woke up on the bottle.

Still runs just as good off the bottle too.
 

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It's important to note that the prime operating temp for nitrous is around 84-86 degrees. Even warmer climates drop below this at night. Even a small drop in temperature to, say, 70 degrees will have the adverse effect of reducing your bottle pressure by about 1/3rd. So that will knock 1/3rd off of your power output on the bottle. You can get a bottle heater on Ebay (like I did) for around $100, and believe me, it makes a HUGE difference. If you're gonna squeeze, I can't recommend one highly enough.
 

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PlatinumWRX said:


Jimb,

How often is your throttle going to get stuck with you nitrous spraying and the tranny pops out of gear?

Yeah, exactly.

-Jim
Apparently it happens often enough for someone to post a picture of it. :) By the way, I didn't post that as a warning against using nitrous or say it was a common occurance. Just a little 'reality check', if you will. You spraying Jim?

jb
 

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An intake explosion is a far less costly and damaging occurance than leaning out b/c a boost controller fails or you over boosted, or an injector fails.
 

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jimb said:
Apparently it happens often enough for someone to post a picture of it. :) By the way, I didn't post that as a warning against using nitrous or say it was a common occurance. Just a little 'reality check', if you will. You spraying Jim?

jb
Not yet and not likely. I'd get sooo addicted and end up spending half my pay check to spray. No thanks. 300HP at the wheels will be JUST FINE. :D

-Jim
 

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PlatinumWRX said:


Not yet and not likely. I'd get sooo addicted and end up spending half my pay check to spray. No thanks. 300HP at the wheels will be JUST FINE. :D

-Jim
It's fine for a week or two. Then you want more!
 

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jimb said:


Apparently it happens often enough for someone to post a picture of it. :) By the way, I didn't post that as a warning against using nitrous or say it was a common occurance. Just a little 'reality check', if you will. You spraying Jim?

jb
Just for the record; I have been a member of both forums for around a year and in that time this is the first such occurrence of a catastrophic Nitrous backfire that I have seen on a WRX.

-Pace
 

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I'll second Pace's comment - I have run nitrous on a variety of vehicle for years, and the only problems I have seen with it were due to poor tuning. Don't fall for all the hype, it's perfectly safe as long as you tune - just like every other form of "forced" induction.
 

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Just for my education

Do you "spray" throughout the rmp range including while the tubo is spooled or do you spray until the turbo reaches a predetermined point of boost?
 

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You don't have to convince me guys, I've been thinking long and hard about using the STI TGV spacers as a very nice place to mount a direct port setup... :)

jb
 

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DRIVER said:
Just for my education

Do you "spray" throughout the rmp range including while the tubo is spooled or do you spray until the turbo reaches a predetermined point of boost?
Automatic Tranny guys spray from the get go. IF I ever get N2O, I won't spray until 2nd gear and the rest of the way down the track.

-Jim
 

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DRIVER said:
Just for my education

Do you "spray" throughout the rmp range including while the tubo is spooled or do you spray until the turbo reaches a predetermined point of boost?
At the drag strip; once you start spraying, you usually want keep spraying. Many systems are activated with a WOT switch, so that should give you some idea.

It's probably not a good idea to spray below a certain RPM point, say 3000 on the WRX, unless you like watching con-rods exiting your block. Nitrous = instant torque.

-Pace
 

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I am also new to nitrous and have recently installed the NOS wet kit. I have a 5spd and a primary activation switch that works at WOT and also a button I hold in my hand to spray. My question is when changing gears do I need to let off the nitrous and then spray again after I've changed gears or can I spray while switching gears? Also, after I'm done using the nitrous and I turn the bottle off, do I need to manually purge the system or can I just leave it connected. After I used it the first time I turned the car off and unscrewed the nitrous line letting the excess gas out, but the next time I tried to start the car it wouldn't start so I tried again and it started but it took a second and my friend said I shot out some black smoke out of the exhaust.:confused: So, are you suppose to manually purge the line with car still on or what?
 
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