Need to lean out a wet kit. How?

[Diabolic]

I have a Zex UNiversal EFI kit on my 93 Lightning. I have been running the kit for the past 7-8 bottles with 100 jets for the nitrous and adding the fuel through my tune via the injectors. Basically I'm not spiking the fp like a tradional dry kit, but just asking the computer for extra fuel at standard wot fuel pressure. Long story short, I wanted to try a 125 and 150 shot, but my 30# injectors wouldn't handle the extra fuel without spiking the fp because my engine makes about 360 fwhp without the nitrous.



I decided to go ahead hand use it as a wet kit so I installed the fuel line to the fuel rail and then to the nozzle. I'm running a 34 fuel and a 46 nitrous jet for the 125 setting. When I spray it this way the AFR drops to 10.6! I had my afr showing 11.8-12.2 when it was dry and the plugs looked clean. Heat strap in the correct place, no speckles or diamonds on the porcelain. Slight black fuel ring, but nohing too severe. I havent checked the plugs yet swince switching to a wet kit but the 10.6 AFR is way rich compared to my dry AFR readings.



Should I drop the fuel jet down to a 30 that's reccomended for a 100 shot? I believe that's about an 8.5% reductin in fuel if going off the jet numbers and 34 is 100% fuel. Am I looking at this the wrong way or on the right track?

[turbostang]

I'd say that you are in the ballpark with the 30 jet, but only a trip down the test track and logging it would confirm. Did you pull the timing back accordingly?

You have to watch using the jet size as a percentage increase/decrease - some manufacturers jet sizes don't correlate to the actual hole size. So, a "70" doesn't mean .070, it could mean .065

So the surface area of a .070 jet would be 0.0038484510006474973 and the surface area of a .065 jet would be 0.003318307240354219

So, that's something like a 14% decrease in flow.

just some food for thought, maybe Jet will chime in - he can better answer the question.

[Diabolic]

The stock tune ramps up the timing from a low of 8º just off idle to a total of 24º by 5000 rpm under wot. I changed the timing curve so that I see 32º up until 2400 rpm and then I pull it down to a flat 20º across the board. My heat line across the strap is just past the curve towards the tip. Now that's with the dry kit at 100hp and AFr of about 11.8-12.2. I'm sure as rich as it is righ now I could throw some more timing at it, but I'd rather get the AFR back to where it was happy with the dry kit.

[turbostang]

agreed, I'd rather get the a/f in check first as well.

[1fast4]

agreed, I'd rather get the a/f in check first as well.

Agreed with the agreed.

[Diabolic]

Stepped up the nitrous jet and got the AFR in the mid 11's. Pulled # 1 & 2 plug. They both looked great. I installed them new at the city park, rolled out about 50 feet then got 1-3rd gear. Shut it off and pulled the plugs. Still slightly rich and I could use another degree or 2 of timing. Pretty safe and fun little setup. I may just head out to the cruise Sat.

[turbostang]

Do it!

Come up and say hi if you make it out there.

[Diabolic]

Will you be the only guy with a mustang out there? What's it look like? What's your name? I'll probalbly be the only guy with a Gen1 in black with a child seat! Ha ha ha! Stealth!

[turbostang]

Nope, not in my Mustang this time around. I HOPE to be running my S10 though. It's ugly black primer, cant miss it. If I'm not running it, just ask around - most everyone knows who I am. I'm almost always by the starting line.

(FWIW, it's possible that Mike McGee will be driving my truck too)

[Diabolic]

I'm curious to see what the Farm Truck will run with a little giggle gas.

[JETFAST]

Thats really only an issue with carb jets. Not so much nitrous jets. There are some difference from one jet to another, but it's not .005, more like +/-.0005

Depends on the fuel pressure and how much fuel you are trying to flow and burn. With out knowing your fuel pressure or bottle pressure, or the actual flow of the system and jets, it's hard for me to know where you are.

You made a step in the right direction. Give it what it wants.

[Diabolic]

I'm running a stock fp regulator, but with the 255 inline activated I see 41#'s of fp at wot. My bottle heater shuts off at 950 and the highest I've tried is 1000 PSI. At 1000 PSI the truck seems to fizzle out more by the time it gets half way through 3rd gear. It seems to pull harder around 900 or so. Just but o meter and that might be because it feels like it comes on stronger at 1000 PSI.

[JETFAST]

i would start with 58n 34f and go from there.

[Diabolic]

To be 100% honest I want to go ahead and upgrade to some 42# injectors. Get my SD tune back in line with the new injectors, then go back and try a 125 and 150 dry shot. Just add the fuel through the tune. I like that idea much better than spraying fuel through my GT40 intake.

[Diabolic]

i would start with 58n 34f and go from there.

I don't currently have a 58 jet but I do have a 67. Think that paired with the 34 would be asking for trouble? 9.0 Compression Ratio with aluminum heads and factory Hyper pistons.