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Discussion Starter #1
I'm currently straight BPU...What items are 100% necessary to run NOS?

From my research a Wet kit is the way to go..is the plain $500 kit all i need? Please anyone with NOS advise me on what i MUST have. Is NOS ran at full throttle or should i have a switch (automatic)?THANKS -TIM
 

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If you are straight BPU (ie, no fuel system upgrades, not already maxing the stock fuel system) putting on a wet kit of a mild shot (100 and below) would work fine. Nothing special is required on your part, other then normal tuning and preparation.

Proper plugs (colder range, perhaps), smaller gap, proper tune up, etc.

You can choose pretty much any wet kit you desire and make it work. Kits designed specifically for a certain model of car are usually easier to make work, but anything can be made to work.
 

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what about the extra fuel pump...

don't you need to buy another fuel pump? Let's say for the BPU++++ cars? Some run another intake stocker but what are some alternatives....
 

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Well, the fact that some people upgrade their fuel pumps/fuel systems when they go with NOS doesnt mean that NOS itself requires it.

Your fuel pump can only flow so much fuel, the stock fuel system/injectors, etc. can only deliver so much fuel. When you are maxing out fuel delivery because you are injecting so much air (ie, making alot of hp) then you will obviously need to upgrade the fuel system.

NOS might even be easier on the fuel system, as it doesnt require the pump to put out so much pressure, as raised boost. (ie, a fuel pump has to work hard to overcome 30+ PSI)

However, on a BPU++++ car that is already near maxing out the stock fuel, yes.. a fuel system is in order.

Now, if you ran the NOS fuel off a seperate fuel system of its own, then you can get by with running a good sized shot of NOS and not have to worry about fuel delivery.

There are many options. One option I'm currently looking at is NOS+Propane (both in gas form) for easy setup, and installation. Both are in the form of gas, plus upped octane of the propane make this a nice idea. Some viper guys run this, and I hear (not positive) that this setup is becoming known in the vette world as well. No need to worry about adding additional fuel capacity for the NOS+Propane, because its right there already.
 

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How big of a shot is safe?

My car is BPU++++, I wanted to dyno it at the end of this week but due to clutch slipage(sp) this is not possible. I'm going to run 19-20psi on race gas for street races so I'm expecting 430-440rwhp. My car has 55k miles on it. I'm thinking along the lines of a 75shot. What fuel pump should I buy? Is it true that 100shot foggers get clogged? I heard this from a few MKIV owners.
 

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I would definitely get a RPM window switch. This will keep you from hitting the spray at too low RPM, and will keep you from hitting the rev limiter while on the Spray. I have the pills set at 3000 and 6500. You just wire the window switch inline with the WOT switch. Also be sure to get a inline filter for the NOS.

Not necessary, but nice to have's include a bottle warmer and a remote bottle valve.
 

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Here is a link to the kit that got me thinking.

http://www.btrviper.com/prod_nitrous.php3

Tom Welch, the proprietor of BTR Viper, has run this on his viper for at least 3 years that I know of, and has run many 10.40 passes, with minimal (if any) breakage.

As for the size of nitrous shot that you can run. No one can answer that. It is said that the stock fuel system can put down 550hp to the wheels with a few tweaks (BD's fuel dampener bypass, hotwired fuel pump, etc) and this is roughly where the stock injectors max out as well. If you were truly brave and wanted to push the stock fuel system to its limits you would need:

If possible, wide band O2... EGT, fuel pressure gauge.. and other niceities would be an inj. pulsewidth monitor, O2 voltage perhaps as well (buick guys use this alot)
 
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My buddy Ben has it on his yellow viper............very nice system.......and smells like propane when he purges.......
"Hey Ben........you cooking something......"
hahahaha
 
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Ran NOS on twins for 8 months and then threw the turbos away. NOS on twins is a good way to make extra hit for a while then the tturbos fail-- thin shafts. It is a great excuse to go single. Dave H is right a window switch prevents NOS backfires with all their associated destruction and the bottle warmer makes it like Maxwell house coffee "good to the last drop!"
Seriously you must remember to only run 14 psi!!!! The NOS will show on your boost gauge as about 20psi when your boost is at the 14. Anymore boost and the plugs will foul instantly.
NGK 3330's at .026 to a max of .030 and you should be fine.
Major item is coil paks poop out at 30,000 miles and so does the flame. Nos loves a cold plug and a very hot flame.
New coil paks are around $370.00 from none other than Jeff Watson who BTW wanted me to do a bolt in cage for my bad boy. I don't think so!;)
PS the Nitrous Express package comes 50& 70 that is about max with twins for any amount of time for the turbos to last. 100 and you change plugs after almost every run. It is unlikely that you will surpass the 500RWHP so the stock fuel system is fine--if your afraid add another stock fuel pump in series---double the volume at the same pressure--up to 575RW--don't forget you dropped the boost so you don't get 425+70 you get 430 plus or minus:cool:
 

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I have been told that when you put the bottle on stock twins the manifold is too restrictive to move all the air out of the motor efficiently, and then you begin running some really high EGTs... Which, from what I was told, will eventually lead to two things: turbos going bad, and melted pistons/warped head/eventually basically needing a motor rebuild.:)

I have it on my car with a single turbo, so I can't really say anything from personal experience, but this info was coming from someone who has delt with it on a LOT of stock twin cars.

-Ethan
 

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Discussion Starter #16
I'm running 18-19psi with the bleeder T mod right now...are you saying i can't run 18psi...and spray? Do i need to turn down the boost to spray? does spraying affect your boost levels?
 
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NOS

On stock twins the NOS and fuel enter just ahead of the throttle body and the same is true with a single turbo.
When nos hits the hot air from the turbo headed to the motor it instantly cools and contracts and then expands from the heat it absorbs there by showing an increase in "boost." That is why starting at 14 psi max ends you up at 19+.
This is sort of like running twins without a BOV.
Acually my HP numbers above are closer to 450+- so there is more hit with NOS and it makes for a great launch with a six speed rather than launching at 4 to 5K you can launch at 3K or less.
The shock after a while, and that varies, causes the turbos to smoke since the bearings and shaft now permit oil into the turbo discharge.
I still run it with my single and I am sure that it isn't the best but at 15 psi and a 70 shot I got 569RWHP and [email protected]+ Now launches must be slip the clutch.
Hopefully this is helpful and BTW I generally get 8 solid runs a 10# bottle.;)
 
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I like the Profec B the best the HKS ez has been a pain in the ass and EVCIV was junk!
At 14 psi plus a 50 shot and you should 12.0s or better.
Tough for stock twins to get deep into the 11s.
I always have a tough time talking times since I run 5000 foot
elevation. cj;)
BTW are you from mass. I grew up in Tewksbury and moved to NM later?
I used to run a 68 Hemi Cuda in the late 60s at beautiful New England Dragway. Those were the days torque up the ass!!:D
 

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Discussion Starter #20
So i assumed the bulk of my current Hp was from raising my boost to approx 19psi. what sense does it make to lower your boost down to 14psi just to gain 50hp from the NOS? isn't raising your boost to 19psi give you close to as much? i dynoed at [email protected] i dyno higher with 14psi and a 70 shot? -TIM
 
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