I posted this on Innovate forum

Newly installed N20. 75HP shot. Nozzles are in air inlet about 10 icnhes from TB. WB 02 sensor about 20 inch from end of collector. Using Innovate stainless bung protector.

Seems when I use N20 as I did this morning WOT from a 55mph cruise in 3rd gear of 4 "on" at 3100 rpms my pillar gauge went to max 22.5/1. Yet on my datalogs I am seeing the NB02 at 970mV.

24-25 deg SA(4 deg pulled for N20) during use. No KC running 93 octane.

last season same 3rd gear pull with A/F richer N20 jetting I was seeing 10.5/1. I enleaned one step on jetting chart as the engine was breaking up as ignition could not light the mixture IMO.

Possibly ignition not up to task? Plugs 2 steps cooler at .035.

Possibly the unburned A/F being seen at WB sensor? Can i be filthy rich on N20?


Possibly ignition not up to task? Plugs 2 steps cooler at .035.

Possibly the unburned A/F being seen at WB sensor? Can i be filthy rich on N20?


Innovate member responded "When there is a misfire for any reason, such as ignition breakup or too rich AFR, the unburned air is detected and reported as infinitely lean. 22.5 is the limit of the gauge display. Find the reason for the misfire and the reading will be normal. "

Earlier in week I did what i have not done yet is a 1st gear shot and car responded well. I wasnt able to see the pillar gauge as car did a shimmy shake and tires did not hook up 335/17. I dont believe i had a misfire there but could have had partial burn. That was under less load that the 3rd gear pull. Load may affect the burn ?

I am leaning to getting a remote coil with a ignition box with the HEI in cap adapter from MSD. whay say you?

 

I think the ignition box will help some. Can you try to put a bung on the other bank of cylinders and see if those are missing? it could be one cylinder missing or a few but I thought you'd feel that effect.

Can you look at the plugs to verify mixture?

I ran my plugs around .032" or so, 2 steps colder with an ignition box and ran fine. Stock jetting for 150 shot was way pig rich so i went with 75 fuel jets and 150hp nitorus jetting. 11.5-12.0 to 1. car liked it.

 

To place a bung on other side I have to pull the pipes and they are one piece from collector to muffler with a crossover. duals. a pretty big job.

I guess I do a WOT run then pull a plug. the plugs are new this spring. the fact I have no KC may suggest still too rich on fuel vs n20.

 

970 narrow band reading is very rich so thats one thing that would confirm rich. Is that narrow band on the same side as the wideband?

You can still have knock counts being too rich but if you arent seeing any, that may be a good sign.

 

Your post is kind of rambling and hard to read- I think I'm seeing that when you spray your NB reads somewhat rich and the WB reads really lean. There is no N2O related reason why that should happen and both sensors measure the same thing to get a reading, one is just capable of doing it over a wider range, so I think you need to chase down a problem before spending time fixing other things.

My first question would be are the 2 sensors reading the same exhaust gas (are they mounted in the same pipe? How far apart? Are there any joints or other changes that could change readings that much? Do they read the same range when you're not spraying (when the WB is reading 14.7 the NB should be swinging past stoich and spending an equal amount of time above and below, or if you're looking at a gauge it should show stoich)?

If there is no physical reason why they should be showing different readings then I'd try to figure out which is right (do you have a FP gauage? is FP dropping when spraying, if it is you may actualy be running lean. Plug readings? Surging/popping out of the intake - lean, black smoke/feeling "fat" lazy can be rich...). That should point at which gauge you you need to figure out is messed up

 

WB is at passanger ext pipe and NB is in drivers side pipe. True duals with crossover. NB is right after collector. WB is about 15-20 inches further back. When not spraying sensors read as expected. NB swings as expected. WB I feel is spot on. My duty cycle is 75-80% not spraying so my fueling is adequate. My Aeromotive FPR feeds the injectors- N20 fuel jet (#20) and the FP gauge. Last season I was very rich with spray on(10.5/1). I just enleaned one step on N20 jetting this season as I came to understand NOS shows fat jetting in their charts. I upped the FP 15% as I was concerned seeing 85%DC w/o spray "on" . All my WOT logs this season were good on DC. I am using a TPI Delco FP with TBI 80 lbs injectors.


[QUOTEPlug readings? Surging/popping out of the intake - lean, black smoke/feeling "fat" lazy can be rich...). ][/QUOTE]

I just installed the plugs so have not yet pulled one to do a read but will soon. No surging, no popping. Feeling fat(?) I say yes but only in a 3rd gear pull. First gear pull in runs out nicely as does 2nd gear.

I will pull the log from last week and verify the switching. I dont believe it does "switch" in PE mode. I need to see if the mV change 800's to 900's. I dont think it did. For sure in CL it does switch as expected. I believe both NB and WB are running correctly.

 

Perhaps check the passenger side spark plugs for a missfiring cylinder? narrow band side confirms reach, yet wideband goes off the chart. Can you swap sides to check things on the drivers bank with the wideband?

 

Now you are onto something! This spring I oil fouled plug #2 only that had about 30K on them. All others were perfect. We put in new plugs about 2 months ago and I was going to pull #2 to see how it looked but have not yet done so. I may have a weak plug or plugs on passnger side where WB resides! I bet that is it.

 

Its worth a shot. After spraying my 383 for abit i tore it down to find i had one plug with a broken off ground strap!! May have ran that one abit too lean? Hard to say, but motor didnt seem to skip a beat, atleast when running all motor. Wideband was in the passenger side, but that plug was on the drivers side so I never saw a wideband reading.

 

a misfire should read rich, not lean...

 

Thought the o2's typically measure just o2 content, not fuel. So if it missfires and dumps in alot of unburned o2, then it reads lean?

 

O2 sensor will show lean because the air was not consumed. Misfire is lots of air and shows lean.

 

Here is commment from Innovate forum: Innovate member responds "When there is a misfire for any reason, such as ignition breakup or too rich AFR, the unburned air is detected and reported as infinitely lean. 22.5 is the limit of the gauge display. Find the reason for the misfire and the reading will be normal. "

 

Today did a second gear of four(3.07 gears) pull today WOT at 3000 rpms and car responded well. BUT was lean at 12.8/1. Engine responded well. DC went to 93% !

Did same in 3rd at 2600 and engine bogged badly. WB went to max rich 9.0/1 and went no where. Seems if engine loaded (3rd gear) it cannot handle the additional fuel. I think I need to set "on" at 3800 rpms vs 3200 and try that.... Need better spark management as well.