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View Full Version : Nitrous Gurus, I Need Advice



Boostaddct
01-19-2007, 10:15 PM
When installing a Single nozzle wet kit, if you use the jets supplied by NOS for the 75hp or 100hp setup do you still have to worry about tuning or can you count on their jets to not affect the a/f much if at all? I am looking to spray my car with a 75-100 wet shot and want to know if I should just plan on throwing the kit on and calling it a day or if I need to consider tuning it via an SAFC. I am hoping it will be fine on its own because I was hoping to tune the SAFC on just the motor. If I get a perfect tune on the motor alone, I'd like to be able to install a nitrous kit that will not affect the a/f. Thanks for any help/advice anyone can give me.

HITMAN
01-19-2007, 11:17 PM
When installing a Single nozzle wet kit, if you use the jets supplied by NOS for the 75hp or 100hp setup do you still have to worry about tuning or can you count on their jets to not affect the a/f much if at all? I am looking to spray my car with a 75-100 wet shot and want to know if I should just plan on throwing the kit on and calling it a day or if I need to consider tuning it via an SAFC. I am hoping it will be fine on its own because I was hoping to tune the SAFC on just the motor. If I get a perfect tune on the motor alone, I'd like to be able to install a nitrous kit that will not affect the a/f. Thanks for any help/advice anyone can give me.


You're still going to have a bit of tuning to do. Following NOS's instruction will get you in the ball park, but you should still have some way to retard the timing when spraying, and you should be running a separate fuel pressure regulator to adjust your A/F ratio up or down. Get these things, get yourself to a Dynojet, hook up a wide-band O2 sensor, and tune this thing. Start with pulling about 2° of timing. Shoot for an A/F ratio of no leaner than 11.5:1 to keep it on the safe side. A hole in a piston will remove the smile from your face as fast as the juice will put one there. :wow

Boostaddct
01-20-2007, 10:19 AM
The problem is that there are really no engine mangement systems that allow you to pull timing. My plan was to add the wet kit along with a fuel pump and then attempt to tune it via playing with the jets. Is that also a possibility? And speaking of dynos, who has the best rates on dyno time around here.

juicedimpss
01-20-2007, 10:43 AM
you need a way to pull timing.

Boostaddct
01-20-2007, 10:46 AM
Ok, I will look into my options for that. Thanks for the advice.

Crawlin
01-20-2007, 10:59 AM
does your stock computer management have an air intake temperature sensor?

EVIL AWD
01-20-2007, 11:17 AM
The problem is that there are really no engine mangement systems that allow you to pull timing. My plan was to add the wet kit along with a fuel pump and then attempt to tune it via playing with the jets. Is that also a possibility? And speaking of dynos, who has the best rates on dyno time around here.

You don't need a fully programmable EMS to pull timing. For a 75-100hp all you need is a MSD Start/Retard control box and an MSD ignition. The amount of retard is adjustable using plug-in modules and is activated by a single wire that is connected to your nitrous solenoid. The part number is MSD-8982. The recommended jets from the manufacturer will get you pretty close. I'd definitely get a wide-band on there though just to make sure.

BAD LS1
01-20-2007, 11:43 AM
OK first off what kinda car is this? This can be done pretty simple. But i reccomend you have some way of logging timing and AFR whether it be via a wideband or "close enough" Narrow band o2 sensor Mv output at WOT, an no not one of them USELESS autometer AFR guages.

And with a mild 100 wet shot, on 93 octane timing can usually stay stockish as long as its not like 30* advance at WOT.

But if your car is like most others, they see the colder temps at the IAT and ADDS timing (3-4*). But i can only speak from experience on GM vehicles when it comes to that.

Crawlin
01-20-2007, 11:49 AM
Like Tom said, need mroe specifics,

for the GM guys, since we can't just bolt up an MSD timing retard to the LS1cars, alot of the guys are putting a resistor inline of the AIT sensor to make it think i's 150* so the computer is pulling timing.

it's kind of ghetto

Boostaddct
01-20-2007, 05:12 PM
CrawlinZ, it does have a factory IAT.

The car this is in regards to is a Lexus GS400. I cannot do the MSD method because it is a coil on plug ignition system.
So far I have found two possible engine management systems that also compensate for timing; one is the SplitSecond FTC1 and the other is the new Greddy V-Manage which is designed for cars with variable timing such as the Lexus with VVTi. I ruled out the AEM EMS due to the high cost. Thanks for all of your feedback guys, hopefully I can get this figured out. I definitely do not want to be popping motors in my daily driver.

BAD LS1
01-20-2007, 05:48 PM
LOL isnt this the type of car williamz has? Im sure he has a bottle on that thing by now!

I would deffinatley not whack it with anything more than a 100 wet shot.

Boostaddct
01-20-2007, 08:31 PM
Yep that is what Williamz has also. He does not have spray on it yet, or so he says ;)

MurphysLaw88GT
01-21-2007, 10:53 AM
that motor might be expensive to replace when it grenades

Boostaddct
01-21-2007, 11:10 AM
It definitely can be. I'm more concerned about ruining a good daily driver and having that down time.

Bee
01-27-2007, 12:39 PM
seems like this setup my be a smaller type engine in the vicinity of a 4cyl or 6cyl. 75-100 sounds a bit small...for monster v8s.

anyhow, using your SAFC is definite. A/Fs will change dramatically. n2o is very inconsistant when compared to a blower/turbo(considering if your plumbing is tight). bottle temps and extra T fittings require more burst of fuel.. that instant activation of n2o can instantly lean your a/f mixture. Keep your eyes carefully on your wideband or better yet if dynoing spot the lean areas and fix them w/ your SAFC.... good luck :thumbsup