Hello all - TL;DR? Skip to the bottom bolded and underlined part before the pics for my main concern

I hesitated to make this thread but if mods need to shut it down because it's not an LS engine, no worries. I'm also not sure how much traffic is in this section nowadays but would like to try to get some insight, as this group seems to know their stuff involving nitrous. I am not 100% set on this but have really enjoyed the journey of solving the puzzle of putting together a kit when there is not one available for these cars. There used to be a kit (Holley NOS 5172) but those are long gone. 5172 was deemed a "safe" kit back in the day and I have been intrigued by it for years. Holley doesn't even have the old instructions archived anymore for it after I called them. I have done a few things but mainly still in the research phase for nitrous use on the LT5 and wanted to ask primarily about the fuel enrichment aspect. Wet shot is out of the equation as these plenums can puddle fuel. So the nitrous would be dry through the plenum with supplemental fuel injector increased output at WOT

My only other option I am aware of for upping fuel to match the very light 75 shot I may one day work up to running was a boost a pump. The more I read about the BAP and the hotwire kit, the more it sounds like they both do the same thing. I'm not opposed to installing both. I recently picked up a new fuel sending unit converted for single pump use with a Walbro 255 pump versus the factory two pump style unit it will be replacing. What I would like is to have the BAP set up to only be "on" when the nitrous system is armed. This way the WOT vaccuum signal triggers the amplified fuel pump output only when nitrous is on. So this could be triggered off a relay, correct? If so, I am wondering if anyone has a picture or diagram of how they did this to come on when the system is armed. My initial thought are tying the BAP relay trigger wire into the nitrous switch arming trigger wire. Looking at the pictures for the universal splice option, looks like I could use a relay to complete the circuit off the BAP ground wire so it's on when the arm switch is flipped. I did not see any other type of wire coming off this that can assist. I caught myself looking through the diagrams in the sticky but did not see this specific diagram.

What I have so far:

• Window Switch set up to look for 97% WOT and activate nitrous relay at 4,000 rpm and off at 6,000 rpm. 4-6K is the rpm range factory cams create peak power, so I figured this is where the hit can also take place. That leaves plenty of room before the 7K rpm redline or the 7200 rpm rev limit. I wouldn't be shifting at 7K while spraying. I could bump cutoff to 6500 I suppose. The LT5 uses a waste spark ignition system but the tech is from the 80s. The window switch was reading 1500 rpm at an actual 750 rpm idle. I had to set the parameters to monitor like it was an old school distributor on 8 cylinders and the switch has no problems monitoring proper rpm now.
• PSN-1 nitrous gauge displaying AFR and bottle pressure
• Mini switch panel mounted and wired up to arm the system, open the bottle, turn on/off the bottle heater and purge - will be looking to use a bottle pressure switch to tie in with heater
• 4AN Line plumbed to solenoids with inline filter
• Fabbed bracket with nitrous and purge solenoid mounted and plumbed together via manifold

Things still to be done

• Kenne Bell Boost-A-Pump install - the universal option is my assumption per their website
• Plumb passenger side fuel rail to accept fuel pressure safety shut off switch and adapter to monitor fuel pressure
• New injectors and new fuel tank install with Walbro 255
• Colder spark plugs and a DIY jig for cutting plugs to read them after using the nitrous

My primary focus is as many safety nets in place as possible with this project. One of the nice things about the PSN-1 gauge is it is a window switch itself containing a nitrous kill feature for AFR monitoring if it's not optimal. Unfortunately, I put the cart before the horse on this purchase. In a perfect world, I would like to have the sum of all parts integrated and working together. Unfortunately, I don't think there is a way to tie the PSN-1 gauge in to kill the system if needed. The Nitrous Outlet window switch is currently occupying that spot monitoring WOT and rpm window while tied to the nitrous relay and I don't think I can work the PSN-1 into that circuit to override if the switch sees WOT and 4K minimum rpm but the AFR is not good. I'm sure there are a few gurus in this area, maybe someone could shed some light on if this would be possible or has done something similar.


Primarily, I would like to know how others have wired in a universal BAP to only be on when the nitrous system is armed and IF it may be possible to have the PSN-1 override an existing window switch if the PSN-1 reads less than ideal AFR while using nitrous.

A few pictures of what I have so far:



Despite the poor picture I took with the vent on, this gauge is very legible from the driver seat through the vent

. I wanted to keep the interior as visually clutter free as possible. And if I don't want to look at it, I can thumb the vent direction wheel down and it disappears, day or night. A shift light is also built into this gauge and visible no problem.


Micro switch panel originally for the pop up C7 power outlet tray. I picked up a spare door trim piece and fit this switch panel into it. Harness run through the door with plenty of slack so I can remove the panel and service anything if needed. Refinishing the door pull trim piece and cleaning it all up later.




The idea in my head is when I replace the fuel injectors with a new set, I will remove the valve core out of the factory schrader valve on the passenger side fuel rail and install this adapter block. This is originally meant for gen 2 sbc LT1/LT4 fuel rail adapting but it appears to work placed in this orientation. I wanted to mount a schrader valve adapter on the top port to still have access to monitor fuel psi with a diagnostic gauge if needed and the port facing out toward the wheel would be where I threaded in a fuel psi safety shut off switch for nitrous if psi is not where it should be.


Just an aluminum bracket I made to mount the solenoids so I could route the purge line and get orientation of the solenoids plumbed to the manifold so the feed line clears the coolant tube going to the intake ductwork


Window switch, relays, power supply, fuses and most of the wiring in the rear storage compartment behind the driver seat that I never used anyway. I will relabel these with a more professional labeling in time. Just to keep track of what is what for relays and wiring for now.


All I have for now. Any info or help is greatly appreciated!

 

Nice spot for that PSN-1, you'll be able to see the shift light no problem. I have nearly an identical system in my 98SS. From what I can tell, there isn't a convenient way to send the cut signal from the PSN-1 to the N/O window switch. However you could just let the PSN-1 run the system and remove the N/O window switch.

 

Thanks! With your wideband connected to your system, do you have to crank the car immediately to avoid shocking the sensor? I was reading the instructions on wideband prep and it said not to prewarm the sensor if cold starting. Intentionally prewarming isn't something I would do but if for example I were to sit in my vehicle with the key on for the accessories without starting the vehicle how does that work? Is there a "cool down" on the sensor to avoid shocking it when cold starting? I've been meaning to call Innovate about this issue.

The gauge in the vent was a little bit of a pain, as you know about all the wiring running off the back of the PSN-1 and snaking it down into place. I ran the bottle pressure sensor wiring down the passenger side of the trans tunnel to the back hatch area. The manufacturer is very generous with the length of line provided. It all tucks neatly behind the carpeting back there so you don't see it if not in use. I appreciate what the PSN-1 offers as a total package but one thing I love about the NO window switch is it looks for WOT percentage set along with the rpm. I also like the timing retard trigger feature for a stage 1 and stage 2. Although I'm never touching a stage 2 or possibly even the timing retard at a 75 shot area. I wouldn't expect to need any timing retard but ignition timing on this waste spark system is an area I need to research. The PSN-1 was more of a consolidated gauge showing me AFR, bottle PSI and shift light but it would've been nice if the AFR kill function could be integrated in but not a deal breaker. I think if I had bought an AFR gauge and PSI gauge separately, the cost would've evened out anyway, at least I keep lying to myself about that.

 

I have never had an issue with the shocking the sensor or not letting it cool down. I pretty much always start the car right up so it's just not an issue for me. The sensor delivers consistent data regardless of the condition or heat status.

If you figure out a way to deliver a kill signal from the PSN to the NO Win Switch, please post it up as I would be interested in it as well.

Have you data logged yet with the PSN-1?

 

Sorry for the extremely late reply on this. Unfortunately, the cables provided with the PSN don't hook up to the laptop I have, so I will have to see what I can find that can connect. I am finally getting around to having a bung welded onto the passenger side pipe, after the header collector and catalytic converter. I think in this case, I really need to follow the instructions, but I was curious about the O2 sensor depth. According to the instructions I have, "The provided 1 inch bung will best protect the sensor. When fully threaded, the sensor's tip will sit flush with the exhaust pipe, this does not adversely affect the readings." Bold part is theirs not mine. I picked up a stainless bung as the bung in the kit appears to be mild steel. The exhaust is a full length Corsa stainless steel and I know the two types of steel can be welded, but not sure how well they get along. I suppose I can coat the location to prevent rusting afterwards. I am not an O2 guru, just wondering what other's thoughts might be on this. The easiest solution is just pick up a stainless bung that looks like the mild steel piece.


Stainless steel

Mild steel

 

I would want at least the tip in the exhaust stream. That's how my setup is configured and I trust my AFR's.

 

Another extremely late response, but I got the bung welded onto the exhaust a few weeks ago. Don't trust anyone with the car, so I brought the passenger side part of the Y to the shop. The installation appears to be successful. There was one drive where the gauge got stuck at 13.6 no matter what the engine was doing, but since then the readings have been great. I need to study up on where the readouts should be on idle/cruise/WOT.

I would like to datalog, however I do not have a device that can interface with the connection used by the PSN-1. I'll look into any options to access the PSN-1 for datalog. Readings are consistent during cruise and idle. I haven't done much else other than clean up the switches. I wanted the interior to be as stock looking as possible. I relocated the switch panel to one of the cup holders so it's out of sight with the lid flipped up. I have full power mode enabled all the time in the chip, so it doesn't matter if the valet key is switched to "normal" or "full". I ended up converting it to arm the nitrous when the key is inserted and turned to "Full". I will continue pecking away at stuff. The next thing will be the BAP installation and tying it into the system to only turn on when the system is armed.

 

Very cool out here just spraying the holy ZR1.
I would guess even though I have no experience with the ZR platform that the stock fuel system will support a 75hp shot.
Keep us updated.

 

At the very least, I hope the pics were worth a look. This has been one big exercise in idle hands and boredom. I think by the time I'm done installing everything, I'll have enough play money for a 391 stroker LT5 build. I would agree that the stock fuel system should be adequate, but I was already planning to change over from the factory dual pumps to a single unit when I installed a new tank. I still don't know what was in the original NOS ZR-1 kit that increased the fuel pressure. I'll take a wild *** guess that it was something like a BAP that referenced a vacuum signal and increased the current to the pumps to ramp up the fuel psi while spraying in full power mode.

I'm just pecking away at things here and there when I feel up for it. I haven't done much, just some small stuff. Picked up a bottle bracket and mounted it with a bottle I already had on hand. I now have a bottle heater and remote bottle opener. All I would have to do is reach back behind me and turn a valve wheel, but the switch panel has an "opener" toggle switch and I want the whole panel functional. I picked up a bottle pressure switch for the heater circuit, but I need to read up on it. If anyone using one of these is reading this, how was your experience using this pressure switch? It appears to be the exact same one NO, NE and various other suppliers offer. One site stated it comes preset at 1050 psi.

 

I never forgot about this request, if I figured this out, I just hadn't sat down to think about it. But this SHOULD do the trick. It's called an "AND circuit" and I take no credit for it, as that belongs to others on an electronics forum I was lurking around for this idea. The idea is to get two separate systems to each provide input for the end result to occur. Both systems have to input or the circuit will not complete. In my case, I wanted the Nitrous Outlet Window Switch and PSN-1 to both work together to allow the nitrous to spray. If either one was not happy, or did not see the specified condition, no relay trigger for that system and no current to the solenoid. The below is what I came up with and if this works as is, I've got monitoring and kill switches for the following now: RPM, WOT, AFR and bottle pressure. I also got an adapter cable to usb to hook up to the PSN-1 for data logging.



So based on this, some examples of a few conditions that could occur:

1) The Window Switch sees RPM and WOT and sends signal to its relay to trigger, but the PSN-1 does not see expected AFR, so no signal from the PSN-1 to its relay to trigger and complete the circuit to the solenoid
2) PSN-1 sees AFR and bottle pressure but the window switch only sees WOT, PSN-1 completes the circuit on its side but the window switch will not triggers its relay, so no completed circuit on its side to allow the 12 volt supply source to energize the solenoid
3) PSN-1 sees AFR and bottle pressure, the window switch sees RPM and WOT. Both trigger their relays, completing the circuit for the 12V to activate the solenoid

As far as I know, this type of circuit can be daisy chained indefinitely with other systems, using relays as the "door" to the next part of the circuit.

 

Nice write up! I don't see why this wouldn't work. I have both system on my car and will eventually try this.

 

do you think that it would be ok if i put nos in my 2018 audi a4 sline

 

Why are you asking this in a GM LS engine forum?
There has to be an Audi forum out there that can help you on this....
Google is only your friend IF you ask the right questions.
Unless, of course, you're a troll....