Nitrous Oxide Advice Options

[Killswitch]

First off I need opinions on what is the best Nitrous setup on my car. After a complete motor rebuild what is the limit off the nitrous I can push? Anyone have some setups they can show me?

[NuclearHappineS]

How much do you want to spend...if you want to spend like 500usd you're gonna limit yourself to a 50% shot (75 shot or so)...

if you're willing to spend 1000-1500usd you can spray a 100% shot and be rather safe... so a 130shot of n2o

For a 75 shot, get yourself a basic wet kit (NX is the most commonly used kit but NOS is good too). Follow up with a WOT switch, an rpm window switch, a good fuel filter, 1 step colder copper plugs and you should be good to go.

If you're willing to spend 1000-1500

Direct port kit
255lph pump
progressive controller
window switch
WOT switch
2 steps colder plugs ... and gap them down
stock intake, manifold, throttle body
upgraded header
cutout or 2.5" exhaust
some form of timing retard
High octane

[6th_celi_vert]

I dont suggest nitrous on ANY motor. Ive seen the consequences one too many times.

This post has been edited by 6th_celi_vert: Oct 11, 2006 - 1:12 PM

[playr158]

this is all i have to say....


look at the A/F graph those 2 flat runs are w/o nitrous the two F$%ked up ones are with nitrous...thats dangerously lean and motor goes boom...and that is on a celica

This post has been edited by playr158: Oct 11, 2006 - 1:22 PM

[Bitter]

nitrous can be safe, but you cant just slap it on, spray 75shot and go. theres more to it than that.

[NuclearHappineS]

that dyno is of a person who is spraying a 75 shot on a 100hp motor, that's more than 50% non progressive. That is also a dry kit which will start out lean for sure (the way dry kits are designed unless you're spraying through a MAF/MAS/AFM.

the problem is, you guys don't understand how nitrous works. and thus you dont understand that the setup i recommended would perform and last completely differently than that of the setup you have posted about.

A dry kit will raise fuel pressure by about 100-120%, which is an increase in fuel flow of about 45-50% ...

a motor that makes 100 at 6000 rpms (the dyno you posted) , makes about 50hp at 3000rpms and 100hp at 6000 rpms roughly

50% of 50 hp is a 25shot at 3000 rpms
50% of 100hp is a 50shot at 6000 rpms

The person is spraying a 75shot on a 100hp motor... that means they will be about moving about :

50+75= 100hp worth of air at 3000 rpms
50*1.5 = 75hp worth of fuel at 3000 rpms
and
100+75 = 175hp worth of air at 6000 rpms
100*1.5 = 150hp worth of fuel at 6000 rpms

assuming the air fuel ratio was a safe adn rich 10:1 on that motor before beying sprayed

that means the a/f ratio will be
100/75*10 = 13.3:1 at 3000 rpms
175/150*10= 11.6:1 at 6000 rpms

oh darn, look at the graph, looks like the a/f ratio is a bit leaner than 14:1 at low rpms, and ramps up to 11.5:1 at higher rpms...so maybe i have a clue what i'm talking about...

To make a dry kit like this effective it would be best to:

1- use it on a big motor, where a 50% shot comes out to something nice like 75,100 or 150 hp (ie starting with a 150,200 , or 300hp v6 motor)
2- use it with a progressive controller to where you get a shot equal to half of what you're jetted at (which is half fo the motor's peak hp) ...and ram up to 100% of your jetting ( which is half of the motor's peak hp)

then you will find that it will give a nice turbo like bump in hp, and your a/f will be a nice flat 11.5:1 throughout the whole rpm range (and this is on a dry kit) and that makes this really safe.

The wet kit injects fuel through the nozzle

so at 3000rpms

you get :
50hp + 75hp worth of air =125hp
50hp + 75hp worth of fuel = 125hp worth of fuel

at 6000 rpms
you get
100+75hp worth of air = 175hp
100+75hp woirth of fuel = 175hp

if u started with a 10:1 a/f ratio

you will end up with
125/125*10=10:1 A/F ratio
175/175*10=10:1 A/F ratio

see , for most people that don't understand howi nitrous works, a wet kit is safer because it is independant of injector duty cycle ...just adds xhp worth of air and x hp worth of fuel and you're good to go.

Dry kits are good too but you have to have a clue...and sorry to say, the person taht owns that ST with the zex kit edoes NOT have a clue

[NuclearHappineS]

let me redo the numberfs to be 100% exact
stock:
3500 rpms, 75hp, 75shot, 13.5 a/f ratio...75whp = 88 chp
5500 rpms, 90hp, 75shot, 11.5 a/f ratio...90whp = 105 chp

3500 rpms
88+75 = 163hp worth of air
88*1.5= 132hp worth of fuel
new a/f = 163/132*13.5 = 16.67:1 a/f ratio

5500 rpms
105+75=175hp worth of air
105*1.5=157.5hp worth of fuel
new a/f = 175/157*11.5=12:8:1 A/F RATIO

check the dyno

does this look familiar ?

[Killswitch]

Yea im down . Now about the progressive controller,
window switch, WOT switch. Where do I get those?
And about the 2 step colder plugs.... What kind, and to what gap do they need to be? Also where would you reccomend getting one from? Direct Port or Wet?

This post has been edited by Killswitch: Oct 11, 2006 - 6:29 PM

[Bitter]

Zex makes plugs for Nitrous/FI that work well. im not sure if they carry them for your motor tho. i know that the FI mitsu guys like them.

[NuclearHappineS]

http://www.fjoracing.com
2-STAGE PROGRESSIVE MINICONTROLLER
(INTEGRATED HIGH CURRENT DRIVER)
Activates 2 independent outputs based on TPS input and
RPM (includes cables and software). PC configuration
via USB connection. Includes integrated PROGRESSIVE
driver.
KWS0022 $206.25


Nitrous Oxide System, Sportsman Fogger, Wet, 50-250 hp, 15 lb. Bottle, Blue, Direct Port, EFI, 4-Cylinder, Kit
http://store.summitracing.com/partdetail.a...mp;autoview=sku
680usd


Fuel Pressure Safety Switch, Adjustable, 25-50 psi, 1/8 in. NPT, Each
37usd

...etc

you can shop around

however, if you want a 1 man/1 store solution to all of this

dave from http://www.nitrousoutlet.com/
and dean from http://www.phasechangeracing.com/

This post has been edited by NuclearHappineS: Oct 12, 2006 - 3:58 AM