I recently picked up a NX Wet Kit for my 1995 Z28 (Stock motor only bolt-ons). I just got the basic kit for now no extras yet. I actually put the kit on a couple weeks ago. Install was a breeze, only minor prob was getting the lines to seal but I got them to seal after a bit of playing around with them.

After the install I set up my MSD digital 6 ignition to pull a bit of timing while I spray, also I raised the stock rev limiter as high as it goes with tunercat.

I decided to take it for a little ride with a 50 shot. I could feel it rev faster but was very unimpressed with the results so I pulled over and put in a 75 shot. A little better, I could feel the kick much more pronounced but I was still wanting more, but I decided to wait for copper plugs because I have herd the Platinum AC Delcos don't do very well to say the least.

Did the tune up this weekend. NGK TR6's gapped to .035 and MSD 8.5mm Super Conductor wires. It took me a while but I finally finished the install. It actually was my first LT1 tune up so now I can say I did it myself. I think I did a damn fine job too running the wires around the headers, and in that tight spot by the pulleys on the passenger's side. At least better than the last mechanic that I paid about 1000 dollars to do anyway.

Also, I installed a MSD Window Switch. My friend actually gave me the set of 3000 pills for nothing so I figured Since everything with the tune up went OK and the car runs good I would use a 3000 pill ON, and a 3800 OFF. At least I could see what a 100 shot of N2O is like.

So thats what I did took my car for a ride around the block and hit WOT spraying at about 30 mph. Tires spun from 3000 Revs up to 3800 Revs. Nice. I figured I would try it without N2O and compare, and that went fine. But I wanted the juice again so I hit it and POP! The car died and I saw I lost stuff so I pulled to the side of the road. I just thought to myself "OH F**K" as I looked under the hood. The whole bellow had popped off the throttle body, and the drainpipe in the bellow was blown off, that is what I lost. So I picked up the pipe. Then I tried to start the car, it did start but ran very rough from sucking air straight into the throttle body. Luckily I had some electrical tape in the car so I taped the pipe back on and started the car. The car ran very nice, smooth, just like nothing had happened so I drove it home.

And that is where it sits while I am here scratching my head trying to figure out what happened.

Did the N2O puddle on the intake? Too low of fuel pressure? I don't have a FPSS. Is 3000 RPMs too low to turn on the juice? Any idea what went wrong?

Phil

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'95 Z28 A4
13.599 @ 100.23MPH

[This message has been edited by Loonies (edited July 21, 2002).]

 

Let me get this straight - the rubber elbow bellow is what popped off? The same thing that takes 90 degree turn and into your MAF housing??

KASR

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94 Z28 Hardtop - (stock: 10.5:1, 5.7L, rated 275hp@5200, 325lb@2400, MFI - Current Rating: ???)
Throwing money at the hungry beast and moddin' away like a mad-man =) Holley CAI, !TB, !MAF, Flowmaster Catback, Monza Quad Tips, 3" cutout, 3.23 gears GU5/G80 perf. axle, QLC, 4L60-E, Spectre Breather and Filter, Autolite 103 plugs, wires, and filter, MSD 6A MODS TO COME: Jet-Hot Hooker Long Tubes, Yank 3000 TC, cc305 cam, 1.6 rockers, NX Gen II

 

Yes

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'95 Z28 A4
13.599 @ 100.23MPH

 

Sounds to me like you had a nitrous backfire. You really need to do some logging and see whats going on .

Make sure that the window switch is functioning properly because if it is working right it will usaually prevent backfires from stalls .Another thing that can cause a backfire are worn valve giudes. One other thing that may or may not be a problem is the small window you were running (3000-3800)...you should set the window to cut off the system at 5500-6000

------------------
Greg
95 Z28 conv M6
Georgia F-Body Association

Stage 1 heads, 1.6rr, Meziere WP
lt4 hot cam,lt4 timing chain kit,52mm TB,
Hooker Headers, Pro 5 shifter,3.73s,
NX 150 progressive,
Self-tuned via Tunercat

 

Oh...almost forgot...get a fpss on that thing.

 

That sounds like the usual nitrous backfire. Your window switch is working, correct? I'd scan it too, make sure the mix is good. Most folks have the low end of the window swich around 3K, so you should have been fine, but if there was tons of extra fuel, for example, you could have had a problem.

What's the nozzle setup like on that kit, and do you know that it's spraying nicely into the intake? Any chance it's pointed wrong?

Dave

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1997 LPE 383/n2o Camaro Z28 Convertible
12.39@112.2, 1.76 60' (na) 11.27@124.6, 1.76 60' (n2o)
LT1 Diagnostics, New to Nitrous? Northern California Racing Club

 

It has the NX "shark nozzle" in the bellow. It looks like a big Y you plug into the bellow. I put it in the inside corner of the 90 degree bend, and it is pointed the right way.

My car only has 65,000 miles and I don't think any valvetrain parts were ever replaced. Do you really think that valveguides would be a problem?

Before next time I spray I will:

-Get a higher Window switch OFF pill. (5600)
-Get a FPSS.
-Log the Run on TTS Datamaster.
-Run a lower shot. (50)

Thanks for your help.
Phil

------------------
'95 Z28 A4
13.599 @ 100.23MPH

 

If your car doesnt smoke when you start it up after it sits awhile your guides are probably ok....I only mentioned it because that was what caused a nitrous backfire on a friend of mines ss that blew his airbox off.

Makesure your window switch is working right. Make sure your jets are paired right for the shot you want. Make sure you have no leaks in the system. Log some NA runs and see ir they look ok. Then start with a 50 shot and log a run and check it out..

Since you allready had a problem it would be wise to do some wideband dyno runs to check your A\F ratio.

 

Hi. I’m new here and I’m already in trouble. My 1995 lt1 nitrous rpm window switch is due to be at my house on Tuesday. I’m trying to find out what wire does the rpm window switch tachometer lead connect to? It’s from JEGS and they say it goes to the negative side of the coil. I need to know which wire it is so I can go spray this trans am. Anyone else have this problem?
thank you!

Vettster

 

1995 LT1 ignition wiring diagram, courtesy of Shoebox:

http://shbox.com/1/95_ign_system_schematic.jpg

Interestingly, the 1993 ignition took the tach signal off the coil, but it required a “tach filter”:

http://shbox.com/1/93_ign_system_schematic.jpg

JEG's sells a lot of different window switches. Which one did you buy? And it doesn’t come with instructions?

 

JEGS 555-40826 is the window switch I ordered from JEGS.
The instructions say the following: Special Note: Most late model engines that don't have a distributor or have multiple coils will need a tach adapter for use with this RPM switch. We recommend MSD 121-8913

I really appreciate everyone who is willing to help.

If there is tachometer signal wire I need to know which one it is so I can get it done and test.

Thanks again!

 

The dash tach (1994-97) is driven by the PCM, pin A13.

You can see the tach wire on this page from the 1995 factory service manual:

http://shbox.com/1/1995_pcm4.jpg

The question would be does the window switch accept the specific signal from the PCM?

Look at the tach filter in the 1993 schematic. That takes the signal off pin "A" of the back connector on the coil. That is where the ICM supplies the ground to build the coil charge, and opens the ground to fire the coil. I suspect the window switch input would be compatible with that point. The uncertainty is "why does the factory tach require the filter?" I don't know the answer, but it suggests the factory tach is looking for something other than the direct signal off the coil ground.



Not applicable, because your engine has a distributor and a single coil.

The instruction manual for the window switch indicates:

Seems to suggest either way would work, but is not what I would call "crystal clear".......

Hopefully someone who has attached a window switch to the stock ignition will chime in with a definitive answer. Unfortunately, there are not many people using this site any more. I had an aftermarket engine management system controlling my engine/nitrous, and the programmable "window switch" was included of the the system.

 

Thank you all for the encouraging help.
I'm in the market for a service manual also.

Vettster

 

1995 F-Body factory service manual (free) download:

https://www.mediafire.com/?40mfgeoe4ctti

 

Thanks for the 1995 manual! What’s my chance on a manual for my 2002 trans am convertible LS1??
Thanks bud!