Where to inject my nitrous

[Phantomus]

I have a question. I'm putting in a wet shot of nitrous and wanted to know if it matters if I put it before the mass air meter (which I can't seem to find on my 2000 2.4) or after this elusive sensor. Remember, this is a wet shot so I will be able to tune how much extra fuel I can shoot with my nitrous.

[MagusXIII]

Since you are bduilding a wet kit, put the nozzle AFTER the MAF sensor. The fuel is being added independently of the computer control. Also, you will mess up the MAF sensor if you locate the nozzle before the MAF by it being covered in gasoline.

An easy to remember what goes where is to remember that in the alphabet, D(ry) comes before M(AF) but W(et) comes after M(AF).


Don

[Phantomus]

Where exactly is the mass air meter on this car. I'l later upgrade to log style H.O. intake with a custom set up, but for now I have no clue where this sensor is on the LD9.:???:

[Phantomus]

Is it underneath the throttle body or somewhere in that "Made by tonka" plastic intake I have?

[MagusXIII]

Sorry I have not replied sooner as I was looking for a pic of an LD9 with the intake in place so I could point out the MAF sensor. But the MAF sensor will be between the filter and the throttle body.


Don

[Phantomus]

Try this pic of my engine long ago....

[Phantomus]

Try this...

[Phantomus]

I took out the stock intake box and systematically removed every elbow and plastic piece one by one until I got to the throttle body. Did I miss it some how? On my camaro, it is right in front of the throttle body. All I found here is the IAT sensor.

[Yeahdoug]

The 2.4L doesn't have a MAF. Its speed density.

[MagusXIII]

Originally posted by Yeahdoug
The 2.4L doesn't have a MAF. Its speed density.
Then that kinda throws a small wrench into the equation here... That means you have a MAP (Manifold Absolute Pressure) sensor. Now...will a wet kit harm the MAP sensor with the fuel running thru the intake?

I thought by the time the LD9 came out, all GM vehicles were Mass Airflow. And...I take it ALL Ld9's were Speed Density?


Don

[Yeahdoug]

Should be fine. Just tap the jet somewhere before the tb. Not to close and not to far away though.

[MagusXIII]

Originally posted by Yeahdoug
Should be fine. Just tap the jet somewhere before the tb. Not to close and not to far away though.
6 to 8 inches away from the TB...or any bends before it is considered ideal. You want around 6 to eight inches of straight line for the mix to properly blend.

Yeahdoug, thanks for the info. I am still surprised GM did not abandon SD systems, but appreciate learning something new and getting correct info.


Don

[Yeahdoug]

I'd rather have SD then Mass air for my car anyway. Easier to trick the computer.

[TA^Guy]

Originally posted by Yeahdoug
I'd rather have SD then Mass air for my car anyway. Easier to trick the computer.
It is.
Funny how Mustang went from Speed Density to MAF.
Then FBodies and Vettes go from Maf to Speed Density and back to MAF.
In some cases the speed density does actually flow better. But I just loved how my intake looked with out it on my '92 as opposed to my friends who had '89 IROCs.

[MagusXIII]

John and yeahdoug, dont OEM SD systems though start to act fussy when one takes a n/a engine and turbocharges or supercharges it? I myself have long felt that this is where the MAF systems do work out better. Now...when one talks about aftermarket SD systems like Simple Digital Systems, then that is a different story.

Btw, with SD systems, nitrous oxide is not even fussy like forced induction. Your manifold pressures are not not even going to change that much, if at all. My question was would a wet kit damage a MAP sensor in an EFI engine that is a multipoint unit and not TBI? To which I owe Yeahdoug thanks for clearing that up for me. After all, we all know what gasoline will do to a MAF sensor.


Don

[Yeahdoug]

OEM SD will act funny inder boost. On a 1 BAR MAP sensor you have to trick the computer. Or get a reprogram and get a 2-3 BAR sensor. I have a check valve in my system that doesn't let the MAP sensor see boost and it thinks things are just fine a dandy :)


MAF sensors are better for bolts ons and simple mods. But when going all out SD systems CAN be better. All depends on the car. The 3.4L RSM kit converts to SD. Easier to work with. Mass air cars are more touchy when running boost too. Any leaks and the car will run very poorly. Venting your BOV to the atmosphere will cause problems on MAF cars too.

Oh and the N20 should not ruin the MAP sensor.

[TA^Guy]

Don I don't know about forced induction on a SD unit as I've never dabbled with that on my Z28. But as far as I know and hear that the MAF sensors are more accurate and better for FI setups.
I don't think N2O would bother readings from a speed density unit for reasons as you stated, but I can't say how fuel could/would effect it either.

Best thing is MAF units aren't as bulky or finiky as they used to be but are still as accurate or more accurate.

[T3rry]

the safest place to inject your nitrous would be near the end of your tailpipe :D

[Phantomus]

I doubt that nitrous in the tailpipe would give me as much horespower as the manifold.:D

[Phantomus]

As for the nitrous itself, Ihave a few left over parts from previous nitrous kits. I had planned to use a fogger nozzle to tap into the plastic intake before the TB, but I was wondering if I should use individual runner injection for the nitrous. Would it be bettter?

[Phantomus]

It would be more expensive but I am running a wet kit here so I thought that may be individual runner injection could keep that fuel off of my MAP sensor.

:)

[MagusXIII]

Originally posted by Phantomus
As for the nitrous itself, Ihave a few left over parts from previous nitrous kits. I had planned to use a fogger nozzle to tap into the plastic intake before the TB, but I was wondering if I should use individual runner injection for the nitrous. Would it be bettter?
It will be better, but not by leaps and bounds. You will definitely gain more uniform mixtures across every cylinder. While this is not a problem with the 2.4, some engines, most notably the V6 SHO, have long runners that, with some wet kits, can cause the fuel to begin to fall out of suspension. Individual runner nozzles solve that. Dont worry though about fuel falling out of suspension in your engine if you do run a single nozzle. My 2.0L Zetec in the ZX2 has a twister intake manifold than the 2.4 and I have not had that problem ever.

Now, as for your other post about keeping gas off the MAP sensor. I dont think that would be too much of an issue after reading what others have said. Besides, back in the days of throttle body injection, you surely would get a wet MAP sensor and I dont think those MAP units are much different than today's units.

Now sadly, I am having a brain fart here, but with individual runner nozzles, dont you wanna run, say, 20shot per cylinder/nozzle to get close to the 75shot single fogger nozzle output? I am certain you should do that, but not positive.


Don

[Yeahdoug]

Dude just spray it before the tb.

[Phantomus]

Sound like a much better idea. It'll also save me from have to by more line and I.R. nozzles. Easier to hide too.:D