[chiphead]

Originally Posted by JLMounce

Based on the peppering you are seeing on the plugs, my recommendation is to pull 2* out in the entire loaded range from 50kPa to 100kPa. If you have a good idea where you're peak torque is in the RPM range, you can build a trough around that rpm as well, then ramp in a bit more timing later in the rpm range where propensity for ping is less.

Your cruise AFR may be too rich to support the timing you have in it. You may want to pull 2-4 degrees of timing in the cruise range below 40kPa. That may help slightly with highway cooling. Realistically though I'd try to get your cruise AFR leaned out to the upper 13 territory if possible. That would better support the timing you have for the cruise range.

Thanks, that's really in line with the tuning approach I was going to use. I just wanted some confirmation it was valid. I pulled 1-2 degrees of timing above 50KPA (15" of vacuum and higher load) and pulled 1-4* of timing at lighter loads. I was adding a lot of vacuum timing at 15" of vacuum around 2600-3400 RPM, likely a bit too much.

I went down 1 jet size on the primary of the 4150, from 71 to 70. That should lean the cruise AFR about 7% above 2500 RPM when the mains start.

Where in RPM range does the 2802 cam make peak torque? I'm guessing 3200-3800 RPM in a 400? How much timing should I add back above 4000 RPM? Rev limiter is set at 5700.

[JLMounce]

Originally Posted by chiphead

Thanks, that's really in line with the tuning approach I was going to use. I just wanted some confirmation it was valid. I pulled 1-2 degrees of timing above 50KPA (15" of vacuum and higher load) and pulled 1-4* of timing at lighter loads. I was adding a lot of vacuum timing at 15" of vacuum around 2600-3400 RPM, likely a bit too much.

I went down 1 jet size on the primary of the 4150, from 71 to 70. That should lean the cruise AFR about 7% above 2500 RPM when the mains start.

Where in RPM range does the 2802 cam make peak torque? I'm guessing 3200-3800 RPM in a 400? How much timing should I add back above 4000 RPM? Rev limiter is set at 5700.

I like to move in 2* increments, and that's where I would start. I'd pull that out from 3500-4500 rpm if you think that's where you're peak torque might be. See how it feels. Because your converter flashes around there, you may not even notice it.