nitrous on a 4.2

[built2drag]

My wife has a 03 4.2 envoy.I pull my race car with it a good bit and one day at the track I tore my car up so said what the hell,and made a couple of passes in the envoy.I have to say I was impressed.I wasnt expecting it to be as quick as it is.
I was wondering if anybody else is spraying a 4.2?:undecided I have several kits laying around and plan on installing one this weekend.I was planning on starting out with a 75 shot and working my way up.

[Jman423]

:undecided Good luck with that... ;)

[Fishhunter911]

:undecided Good luck with that... ;)



Thats what I am saying.... not so sure I would just throw NOS on a 4.2. Not so sure it would like it to much.

[Toolman]

It will love it, just make sure you dont go lean..

[envoykicker86]

I havent yet but am buying a kit this weekend. I have looked around and did a little research and it looks like a dry shot of 75 is what is recomended at the higher end. People ive talked to said that 75 is plenty and not to go over so as not to damage the stock interior engine parts. ZEX makes a good dry kit that i am gunna get, they also have a nice air filter with the nozzle attached so you dont have to do anything to the intake. I am still waiting for ZEX to get back to me though becasue i have heard that the nitrous might be bad knews with and ignition advance like the jet chips. Got any ideas if that will mess with the nitrous?

[Laloosh]

what did u run?

[built2drag]

As long as the a/f stays safe and it gets enough spark I think it'll be ok.All it can do is blow or go;)

[Cmdrrjc]

This would be kind of interesting. Keep us posted on your progress and a few pictures wouldn't hurt. ;)

[Envoy Fan]

All it can do is blow or go;)

:laugh: Keep us posted on your project.

What kind of results did you get on the Envoy when you ran it stock at the track?

[UpAndComing2k2]

advanced timing+nitrous=KABOOM! (to an extent).
Thats why when building a race car, you have to decide, forced induction or n/a. With advanced timing (im not sure how many º's its advanced) you must run at least 93 octane so you do not get pre-detination and end up causing a rod bolt or something to break. I wouldnt us the chip while using nitrous. Also, im not sure what size injectors these trucks have, but you will want to find out what they max out at. If you need bigger injectors, get them, but remember, you will also need to get your maf, map, or whatever the sensor in here is called recalibrated to the new, bigger injectors. Reason is, bigger injectors advance timing as well, which is a BIG NO NO with f/i.

And someone said they wanted a dry kit, and figured i would give my opinion on this. First ill state the difference between the 2.

Dry kit: Sprays in the intake track, once through the intake manifold, mixes with fuel right befor combustion. This can cause smaller injectors to lean out and not be able to keep up with the spray, which will grenade a motor. The dry kit is normally cheaper and easier to install, but will not see as good of gains as a wet kit. On the dyno, a 75 shot will probably give you around 55-60 hp, when a wet kit will give you between 65-75. Installation and of course tuning plays a big role in the gains.


Wet kit: Taps into the fuel rail (most of the time) and in my opinion is a better choice. Since nitrous and fuel is mixed befor it even goes though the injectors, its a lot easier to control the a/f ratio in my opinion.

With my old 4cyl cars that i put nitrous on, i would run a 50shot dry kit, being sure not to overspray my injectors, but would run a 75shot wet kit.

this is all being said with me not knowing the weak spots in these motors, but I have raced a few 4.3 s10s that had spray and they seemed to do well, in my rearview:) If im wrong, let me know, cuz its late, im hungry and tired. But if im right, I would go with a wet kit for a 75shot.

-Kevin

and a big P.S. Be sure you get a bottle warmer with your kit, some people dont realize how important it is to have good pressure from their tank.:undecided I dont know what the stock c/r (compression ratio) is, but if its not high at all, you could get by with the chip and high octane fuel. Since i hear the TB has a good amount of factory HP, i would think the compression ratio is high, which wouldnt be good for a nitrous setup on a stock motor either. A thicker headgasket can lower the compression ratio some, but id just take the Jet chip out.

[OurZoo]

Would be interested in some pics of how ya do it and what not.

[ScarabEpic22]

If you wanted to run a chip while spraying, get a Westers as they can probably adjust it for you.

Also, just FYI the compression ratio is 10:1, and I think 10.1:1 for 06s with 291hp.

[built2drag]

Im going with a wet kit.Ive never been a big fan of dry.I'll take some pics and maybe a video outrunning my know it all brother in laws Porsche Cayenne.:yes: Ive made a few passes in it on motor and they all are mid 15's.
Only probelm Im having is finding plugs.I called the parts store and they didnt show having any colder plugs listed for a 4.2.Im going to try to cross reference and find some tonight.
I had a 03 S10 Xtreme I lost in hurricane Katrina.It had a stock short block and I was shooting it 150,so Im pretty sure the 4.2 will hold 75-100.

[Turbo4200]

Kevin-
Bigger injectors do not change the timing, much less advance it! The PCM controls timing via the crank and cam position sensors. As for cold plugs, Denso has them...

You can run a dry 75 shot w/o running bigger injectors on the 4.2. I would recommend a wet shot, but the dry is easy to plumb.

[z-ya]

If your going to spray it dry pull the screen from the mas air sensor so
you don't freeze it.

[built2drag]

I put it on last night.I dropped my 75 jet and lost it so I said what the hell,and put 100 shot on it.:yes:
It seems to like it and will run pretty good.Im going to post some pics pretty soon,going to do a little cleaning first.Kinda embaressed how dirty the motor is right now:worried:

[ieatglue]

Sounds good, but i still think i can get under 14 seconds w. my 03 LT EXT, anyway hurry with those pics, we wanna see :D

[Dacomputernerd]

I put it on last night.I dropped my 75 jet and lost it so I said what the hell,and put 100 shot on it.:yes:
It seems to like it and will run pretty good.Im going to post some pics pretty soon,going to do a little cleaning first.Kinda embaressed how dirty the motor is right now:worried:

100shot :eek: Cant wait to see some pics!

Will you be dynoing it if you get a tune+other mods in addition to the spray?