porsche 928 RI

Just wondering if a 50 dry shot of nitrous would be safe on an 82 with 163k miles on the motor, i was just looking for an occosional extra punch mabie just a 10 ounce bottle and would not be using it reagulary

mark kibort

wet would be much safer and probably better. you have to meter the air, and it would be hard for the AFM to accurately measure 50shot. It might, just be risky.

I used a 50 shot for a couple of years. it worked great! Put the wet nosile in the plennum using the aux air hole for the A/c system. I used the plate and threaded the Nitros express nosile into that. It was a tight fit as fuel and NOS had to straddle the oil breather line, but it worked.

mk

AO

I ran with Mark's kit and I tried it dry for a week or so while I was waiting on a fitting. It goes WAY lean with a 50-shot dry. Plumbing for the wet isn't hard.

Here's a thread from my old NOS days.

https://rennlist.com/forums/928-forum/200769-nitrous-install-update.html

porsche 928 RI

do you guys know where i can get the adapter for the ac fitting or should i just make one?

Jfrahm

Why would it go lean if you had the fuel pressure bump set up right? Might be better than blowing gasoline through a dry manifold.

AO

Just make it.

AO

The problem is that you only run NOS a few times. All the other times, you'd be way rich.

porsche 928 RI

is there a fromula for Fuel Pressure vs Nos shot?? also i would only be spraying at ummm friday night street drags so i could just richen it before i run no big deal

mark kibort

The only way to go "dry" woud be to spray the NOS infront of the AFM. It would be chancey. dry with bumping the fuel pressure wouldnt work, as you cant get that kind of fuel bump very easily and consistantly.

shooting dry in to the plennum is just unmetered air and you will go lean immediately, so that doesnt work. that kind of dry system is tied to the fuel injectors and fuel pressure to do a 50hp adjustment with pressure and fuel injector duration. not that easy on an Ljet system.

the fiting is just threading the already ready to go plate that the aux air valve uses at it mounts to the plennum. a machine shop will drill and tap a hole. the nosil is tappered so that as it screws in, it gets tighter. Have them drill the hole so that the nosil is pointed up at a 45 degree angle if possible. not just straight in, as the fuel and air would be shot to the #1-5 intake runners. you want it to fire into the plennum, not straight up.

the fuel and air are atomized at the nosil, so it is not really that fuel wet as you might think. its a fogger.

mk

Brett928S2

Hi

I would NEVER EVER run a dry Nitrous system on a 928 !!!!!!!!!!

Wet is fine but the 928 fuel system/electronics CANNOT cope with a dry system....

You WILL burn out plugs and probably big holes in your pistons....

PLEASE do not try it....

All the best Brett

mark kibort

I was trying to say it nicely.

Brett928S2

Hi Mark

Lol, I thought I did say it nicely hehe.

I have a thing about "dry" systems...over the years I have seen a lot of them cause blown engines and holed cylinders, as you know there is NOTHING worse than a Nitrous engine that runs lean....usual result...BOOM....

Its not the Nitrous fault.....its fine with WET systems,,, as long as enough fuel is supplied to match the Nitrous....the problem being the Nitrous system NEEDS to PROVIDE that extra fuel as the 928 System CANNOT....

It would have made my life a LOT easier if it could lol

All the best Brett

Jfrahm

I've run a dry system on a Ford with EFI, bumping the fuel pressure at the FPR worked quite well using the supplied gas regulator and plumbing. I had a fuel pressure gauge and took note of the fuel pressure during delivery. If there is no way to bump the fuel pressure on an L jet during nitrous delivery, I would agree that a dry system would not work.

For a dry kit to be safe you do want fuel pressure monitoring and a safety switch, but that's no big deal. The injectors have to lift reliably under the higher fuel pressure, and the pump has to deliver the required fuel at the higher pressure. I do not suggest a dry kit for high HP shots but for modest applications it works great (assuming it's compatible with whatever you are putting it on.)

I do not know a lot about the L jet but... I think it would work. It's not CIS.
-Joel.

mark kibort

I guess It might. If you can find a way to bump the fuel enough without exceeding the limits of the injectors, I guess it would be possible. tuning might be a big tricky. special regulator, etc. a simple tap on the fuel rail with a solenoid to the NOS nosil is an easy solution.

mk

Jfrahm

Tuning is not so hard, just run it fat and turn it back until you don't have to wipe soot off the back of the car anymore. You can also use math to get in the ballpark but I like to start with a little black smoke and work from there.

-Joel.