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Discussion Starter · #1 ·
I have the Compucar Nitrous in a Bag kit. I installed it in the end of the filter as suggested. Compucar says it will allow the MAF sensor to richen up the A/F to compensate for the spray. I dynoed it Monday afternoon. My first run resulted in a the engine cutting out and I aborted before I even got to 4000 rpm. We moved the nozzle to just in front of the TOB. It ran a lot better but it was rough so I aborted that run. I drive the car pretty easily on the road. I didn't notice any problem until yesterday when I passed a car in sixth gear. I had plenty of room without the need to down shift. I noticed the car was skipping quite a bit when i mashed it tot he floor. I slowed and it would do it in fifth and you could barley feel it in fourth. The engine had to be at WOT to notice this symptom. It seems in higher gears like fourth and higher where the engine lugs is where it is most noticeable although I can barely feel it in lower gears. I pulled the chip and ran it on the stock computer and it still does it. I checked for leaks and corrected my one small vacuum leak with no change. I looked at my plugs and they are a little black.

I'm wondering if I contaminated my MAF sensor when I shot some spray through it. It's a dry system with no purge. Maybe there was condensation or something in the line. I think the second pull was rough because the sensor was contaminated and not the juice. I think if I had made one more pull off the bottle it would have still skipped.

I'm ordering a set of plugs today from Advance. They say teh NGK TR6's have been changed to a new number. I'm going to NGK's website to find any info. I also did a search on MAF cleaning and read that you can get a new MAF from Pep Boys for $70. I'm not sure if this applies to an 03. I'm sure it's fuel or ignition.

Is it pssible the spray itself could contaminate the MAF sensor?
 

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I'm going through something very similar right now. I have some comments for you:

1. Don't spray into the MAF.....period.
2. Get the system tuned using a wideband and scan tool.
3. Make sure you have enough fuel system overhead to support the extra HP. Make sure your fuel filter is clean, your fuel pump is not malfunctioning, you are running good gas, injectors not clogged, etc.
4. Run copper plugs with recessed insulator and gap them down.

My car runs awesome now with 17psi of boost from the heaton. Air/fuel is perfect as measured on my FJO wideband, I'm running a BAP as well as 50lb/hr injectors so I have plenty of fuel system overhead, I just replaced a failing fuel pump (actually leaks in the corrugated tubing connecting the two otherwise healthy pumps). I'm not running a chip so my WOT timing curve is stock (very conservative).

Now, here's my problem. If I hammer it in a low gear and the nitrous kicks in, the car shuts down. I need to datalog this tonight to verify that the PCM is pulling mucho timing to cut power. I can tell you that the air/fuel is perfect around 11:1 on the spray, fuel pressure is stable at around 65-70psi. Right now I use the MAFterburner STAGE2 for solenoid control and fuel enrichment. I have the window switch set to open at 3000rpm and turn off at 6200rpm. If I nail it below 3000rpm, when the solenoid fires at 3k, the car falls on it's face. However, if I raise the on RPM to around 3500rpm, the problem does not exist.

When I pull the codes from the PCM, all I see is:

1. Supercharger bypass solenoid malfunction (i.e. I have the boost cut solenoid unplugged)
2. Supercharger overboost condition

The plugs look perfect, no signs of detonation, perfect coloring, etc. My *fan-spray* nozzles are within a couple of inches behind the MAF.....I think this is MUCH too close.

So, I'm have the following theories:

Either:

1. spray at low flow rates is screwing up the MAF signal (moving the nozzles should fix this)

2. the PCM is seeing too much boost and since it can't yank boost, it's yanking timining (maybe torque modeling is kicking in?)

3. still having spark blowout despite running AWSFA-12C plugs gapped down to 0.032" (I've also run NGK BR7EFs)

Well, hopefully someone who is running the spray with similar configurations to ours will chime in here and give their two cents. I'm starting to lose patience. :evil

MJ
 

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Snake Charmer
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mjchip said:
Now, here's my problem. If I hammer it in a low gear and the nitrous kicks in, the car shuts down. I need to datalog this tonight to verify that the PCM is pulling mucho timing to cut power. I can tell you that the air/fuel is perfect around 11:1 on the spray, fuel pressure is stable at around 65-70psi. Right now I use the MAFterburner STAGE2 for solenoid control and fuel enrichment. I have the window switch set to open at 3000rpm and turn off at 6200rpm. If I nail it below 3000rpm, when the solenoid fires at 3k, the car falls on it's face. However, if I raise the on RPM to around 3500rpm, the problem does not exist.
This is a bit off the subject but your into this kind of stuff so I figured I would toss it out. I have been contimplating a small wet shot but having it kick in at WOT in 1st or even second gear would shred the tires. With that in mind, would it be feasable to not only have a WOT switch but a couple more switches so the NOS would only fire under WOT in 3rd and 4th gear?
 

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Shadowgray03 said:
This is a bit off the subject but your into this kind of stuff so I figured I would toss it out. I have been contimplating a small wet shot but having it kick in at WOT in 1st or even second gear would shred the tires. With that in mind, would it be feasable to not only have a WOT switch but a couple more switches so the NOS would only fire under WOT in 3rd and 4th gear?
Yes, I've done just that.

MJ
 

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Snake Charmer
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mjchip said:
Yes, I've done just that.

MJ
Did you ohysically mount the switches on the tranny so they would be activated by the shifter itself?
 

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Shadowgray03 said:
Did you ohysically mount the switches on the tranny so they would be activated by the shifter itself?
No, I used a manual lockout. I held the button so that it wouldn't allow the solenoids to fire during 1st gear (broke the circuit while activated). It was mounted to my shifter handle.

MJ
 

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Discussion Starter · #7 ·
Thanks MJ. You are one of the "few" willing to help someone. I thought that's what these boards were all about.

I have the skipping problem at WOT without spray. Thsi problem occurred after I sprayed it on the dyno and noticed it over a day later when I mashed on it. When you drive the car around you don't notice it at all and it idles perfectly. But at WOT from 2.5-5k rpm it will skip.

After working on it Friday I found the problem. Looks like my chiller is going to make some good power. I made 10 more rwhp with this problem. I'd bet a months pay it will produce 30-40 rwhp as soon as I get this problem fixed.
 

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Silver03Snake said:
Thanks MJ. You are one of the "few" willing to help someone. I thought that's what these boards were all about.

I have the skipping problem at WOT without spray. Thsi problem occurred after I sprayed it on the dyno and noticed it over a day later when I mashed on it. When you drive the car around you don't notice it at all and it idles perfectly. But at WOT from 2.5-5k rpm it will skip.

After working on it Friday I found the problem. Looks like my chiller is going to make some good power. I made 10 more rwhp with this problem. I'd bet a months pay it will produce 30-40 rwhp as soon as I get this problem fixed.
Thanks, that's why I'm on these boards.....to share information. I gain as much knowledge as I put out so it's a good relationship.

So, what was your problem?

MJ
 

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Vendors on this board who sell the Compucar bottle in a bag setup?

I am looking to purchase the compucar bottle in a bag setup ASAP....Any vendors who would like my buisness please chime in.I would also like to get any info on install tips if anyone has any. I've seen the kit installed on Xplicits car,very sweet setup and simple. Jay
 

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Bluesmobile
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Mark,
Well, I finally tried out the Nitrous set up last weekend. It was from a roll though. No point in burning up the tires to see if it worked ok.
Boy did it work ok!!!
The settings I have are very similar to yours.
The solenoid opens at 3000 and closes at 6300.
No miss, no cutting out, no problems at all.
I am only running a # 35 jet, supposed to be a 50 HP shot on these motors.
And I only used one of the 2 solenoids so far.
I also have a manual toggle switch mounted on the dash, next to the radio that I turn on when I am either in second or when I am going into 3rd. Still experimenting here for now.

I have the BR7EF's gapped at .035. No high speed missing or blow out.
Running around 16 -17 #'s boost until the very top, where it drops a little.
I don't know if I have the issue that you do though, since I didn't hammer it until I was beyond the cut in point (4000) of the solenoid. This is most likely the way I would drive it at the track too, though.
A/F was mid 11's most of the time.
Dan
 

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Bluesmobile
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BTW,
I guess I should add that the graph shows 2nd, 3rd & 4th gear.
I also lowered the WOT position to 3.6 volts on the MAfterburner so it goes into open loop a little sooner. The chip is also programmed for the Nitrous to add a little extra fuel too.
Could it be that you a going just a little lean for a split second and causing the hesitation?
The nozzle is mounted ahead of the T/B, but after the MAF.

Dan
 

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Dana said:
BTW,
I guess I should add that the graph shows 2nd, 3rd & 4th gear.
I also lowered the WOT position to 3.6 volts on the MAfterburner so it goes into open loop a little sooner. The chip is also programmed for the Nitrous to add a little extra fuel too.
Could it be that you a going just a little lean for a split second and causing the hesitation?
The nozzle is mounted ahead of the T/B, but after the MAF.

Dan
My car isn't going lean at all. The problem only occurs when I spray below around 3500rpm. Unlike you, I have no chip so my PCM may be killing timing/fuel to shut down the motor as torque prediction detects values over those programmed in the max. torque tables.

I'm running AWSFA-12C plugs gapped at 0.032". I think it's time to get a chip to disable some of the torque modelling.

MJ
 
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