I went back to the dyno and ran a few different programs. The one that made the most power had an A/F ratio of 12.7 all the way through. Is that too lean? The other program made 20 less hp and 30 less tq but the A/F at 5300RPM is 12.2. That second program with the 12.2 ending A/F is rich before redline. Its about 11.6. The A/F graph is in the shape of U whereas the other program is straight. Ill try and scan the graphs soon....

 

Hell yeah thats lean! Switch to the other program. 11.6 is about as max as you want to go on the street.

 

I'd think you'd be more careful since you're already on your second motor.

But i guess as long as mommy is still paying the bills ...

 

Hey Gordo, i think that comment was completely out of line,. Grow up. Were getting tired of the senseless bashing of members around here.

 

BadDog,
unnecessay comment IMO. Joes been beat up about that enough and seems to have grown up.......JR

 

Very lean. Low to mid 11's is safe. Don't worry about the h/p at 12.7, it won't be there long. How was your timing? That is the other important factor in heading off detonation. Just remember that just because you have a built bottom end does not mean that it is bullet proof. Play it safe.

 

yes yes too lean, no doubt about it.
I agree about mid 11's for a street program and maybe just kiss 12 for a track program

 

Joe,

Better safe than sorry man. Im gonna be getting my truck dyno tuned at REM soon, and im gonna have it tuned quite rich... (I think its quite rich as it is, so im gonna have it leaned out a tad... but still very rich) that way im on the safe side!

-Mike

 

I was thinking too lean as well. We are still having problems wiith the computer. Im going to change over to a 2000 PCM and have sal tune me a very safe program. I hope my computer is the problem. We seem to be running out of fuel at the top end and the computer doesnt respond to changes. After about 4600 rpm the truck starts to lean out, its acting like the fuel pumps arent enough. I find that hard to believe though considering there are a lot of people on here running 6lb pulleys w/ a stock fuel system and still being able to run rich if desred. Maybe inistead of changing pcms i could try upgraded fuel pumps?

 

My 00' does the same thing, at 4800 rpm the A/F breaks and heads up into the 12's, up until that point it stays in the mid to low 11's. Also it does this with to different tuners chips....JDM and PSP. My next adventure will be fuel pumps but I'm not thinkin thats the problem.
Dale

 

It happen to me each and every run I made when running my upper and lower (6-7lbs of pulley) I talked about it in many post,
running out of gas, cutting in and out, or off and on @ 7/8 of the way down the track. Everyone thought I was crazy. The problem is, it only seems to do it with some Lightnings and not all ???
I would reccomend changing the fuel filter the day you Dyno for starters. Then I would make sure your injectors are flowing correctly.

The bottom line is, NO MATTER WHAT ANYONE TELLS YOU, our Fuel system is just good enough when it's stock. Once you add a chip, filter, big pulleys, etc... SOME are pushing their luck. AND BE CAREFUL CHANGING TO HIGH FLOW PUMPS, ""SOME"" have actually seen less fuel pressure, AND THATS A FACT JACK. You can read about it right here, something about not having the correct volts or amps and the pumps turn slower making less pressure.

I'm going with an adjustable Fuel regulator and guage so I can increase and monitor the pressure at all times (plus you'll know when it's time to change the filter)

 

I guess it depends on what method you use to measure A/F?
On my last trip to the Dyno my 1st and 2nd pulls were all in the high 11's,then I got a 12.9 on my 3rd run!
Talked with Jim @ JDM and he says not to worry as it was a result of the A/F probe sitting in my Hot Magnaflow muffler.
He recommends using a Wideband A/F Meter.I gotta find someone out here that has one!
Hope this helps!

 

it sounds like sumone is a little jelous!!!!!!

hell I say take advantage of it while you can!!!!!

 

Rob
I been readin your stuff and payin attention. My injectors have been cleaned and flowed at RC Engineering recently and believe it or not I did put a new fuel filter in the truck the night before the dyno and I have also been paying attention to the fuel pump thing. When I do the pumps, I was thinkin of not going to the 255's. I think Don's Bolt put 190's in his truck or JDM did anyway, and his truck isn't at a loss for power .

Anyway this is all good info, keep it up you guys.
Dale

PS. I also had 2 new 02 sensor bungs welded into the JDM headers just before those went in, so the truck was checked with a wide band.

 

Cool Bad as L

Sounds like you surly are on top of this fuel situation.
Do me a favor Bad, and post or drop me a line when you figure it out. I've only had one run out of an entire season that my L didn't cut in and out 7/8 down the track. That was when I changed my fuel filter and switched to my winter tune (I removed my upper pulley and put colder plugs in it) (Denso IT-22's)
Son-of-bitch ran the best ET, best 1/8, best 1/4, and best MPH I'VE EVER HAD, Go Figure Wish I had the upper on that day

I'm hoping the adjustable fuel regulator helps me out next season, I now have an Accu-Fab, Plasma Booster, Slicks, Bars, and of course the 2-3 Upper I had off during the 12.8.
So between the better Power, better Torque, better Spark, better Traction, and better launch, I expect at least 3 - 5 tenths taken off that 12.8 next time out
"IF" it doesn't die on me 7/8 down the track