Tonight after work I decided to make some changes to the WOT fuel. I burned 3 chips.

1. +1.5% increase on the % fuel change to A/F ratio at WOT vs RPM

2. +3.8% increase

3. +4.8% increase

I figured that I am safe going richer, rather than leaner until I get me WBO2 going.

As a result all 1/4 mile times were +- .02 sec. Most were around 12.87 at 109 MPH.

I was kinda figuring that the times would change more. Should I go even higher. What is the best method to finding performance without entering the danger zone. I will wait for the WB to go there.

Any advise would be very much appreciated. I will be going to the track for the first time this friday with the new setup wanted to dial it in a bit more.

Timing is tweaked pretty good and all cell are at 128 BLM except idle. Idle is at 131.

Grumpy thanks for your final answers that you provide. It really helped understanding the timing events. I have max timing at 29.2 at WOT. Very nice performance there. THanks again.

 

With your mods you'll probably find you need to increase it a lot more than that from the stock program-but yes, you need a wideband to see where you're at.
Just an example-on mine the original (PE % change to F/A ratio vs rpm) was -3.9 at 5600 and up-and I had to change it to 10.2 to get a 12.8:1 F/A ratio in that same rpm area.
I think you'll be suprised/worried about how lean you were! I started at over 14:1 at wot when I first hooked up my wideband!

 

Try 5% jumps, and you've got it right by trying rich first.

Without a WB you need to be looking at the plugs. Tuning blind can get real expensive. You just gotta see what's going on in the combustion chamber, GOTTA.

29d sounds like a respectable number to be at. I just wonder what these magazine experts have in their coffee in the morning.

 

WOW! I thought I was running pig rich. That is kinda scary. I should hurt too much other than performance by going richer right? Unless of course ash deposits on the valve seat. please let me know if I am entering ground I don't want to be standing on. The reason I thought I was really rich was I have been getting really black marks above the exhaust and a whole lot in the exhaust pipes themselves. Boy I wish the guy making my WB would hurry the hell up! I will plan on burning some more chips up around the 10% area. More exactly, taking the -3.9% up to and around +10.0%. Man that is way more than I thought I would have to. But I guess that is were I went wrong. I thought instead of following the golden rule. Give the car what it wants! You have to be proud of yourself everytime you hear that Grumpy.

My hooker super comp headers are a bit discolored on outside radius of the bends. Is this due to a lean condition?

I pulled some plugs. Keep in mind I am no expert. They were a light brown with black *soot* down in where the electrode originates. The plugs only have about 300-400 miles on them. No small specs or anything to cause histeria. Should I be concerned about a lean condition.

Also knock counts are very minimal now with the timing curve pretty well straightened out. It only indicates a few between shift, on occasion. I read a post that indicated that this could be due to a lean condition caused between shifts. Also exagerated by my stock converter only being 1300 RPM stall. When I go get counts its only 1-2 and pulls .3 -.5 degrees out. Perhaps more fuel will make it non-existant.

Thanks for the help and sorry about the long post. I just don't want to ruin something. Thanks.

 

It just depends on the car. A while back, I burned ~15 chips only changing the PE % change to F/A vs rpm table, then measuring performaqnce with a g-tech. I started with the base ARAP -3.9% values and stepped all the way to 10%. My best times by far were with negative numbers. The bin where I went all the way to -6.0% in the upper rpm yielded the fastest times. Was I lean? Not for sure. Shouldn't the performance start dropping off when you're getting too lean? I was doing plug chops also...I could never see much difference between any of them. I definately never saw an indication of a very lean combustion chamber. I have recently swapped to an LT1 intake, so I'm about to start tuning it from ground zero again. I've really got to get a WB.