How do YOU tune the spark tables?
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How do YOU tune the spark tables? Just what the title says, how do you personally tune spark tables (Rick@synergy, you and your damn steady state dyno aren't allowed to participate 
)? More specifically for the low MAP/RPM cells. Do you drive the car and adjust the delta spark using bi-directional controls until it sounds/pulls smoother? Do you add timing to all the cells until you hit KR and then back off? Do you create a log of Dynamic Air and RPM, and only add spark to those cells where the car bucks?
When I first started tuning my car for the cam, I got real real bad bucking, to the point I was scared the car was going to tear itself apart. I used a wideband to tune the VE table and now the wideband says its within 1-2% of being perfect. The car still bucked (though it was leaps and bounds better), so I started increasing the timing in the low MAP/low RPM cells. I got the bucking to go away, but some of my cells are up to 48*. I didn't really think anything of it because I wasn't getting KR, and I know big cams can handle it, but now I'm that I might have gone too far, and I might be loosing power/burning the mixture in my exhaust system.
)? More specifically for the low MAP/RPM cells. Do you drive the car and adjust the delta spark using bi-directional controls until it sounds/pulls smoother? Do you add timing to all the cells until you hit KR and then back off? Do you create a log of Dynamic Air and RPM, and only add spark to those cells where the car bucks?When I first started tuning my car for the cam, I got real real bad bucking, to the point I was scared the car was going to tear itself apart. I used a wideband to tune the VE table and now the wideband says its within 1-2% of being perfect. The car still bucked (though it was leaps and bounds better), so I started increasing the timing in the low MAP/low RPM cells. I got the bucking to go away, but some of my cells are up to 48*. I didn't really think anything of it because I wasn't getting KR, and I know big cams can handle it, but now I'm that I might have gone too far, and I might be loosing power/burning the mixture in my exhaust system.
For the stock cam, I smoothed out the ridges in the factory table by hand and took a little out where there was knock (the factory seems to have too much advance for the .56~.64 cells where the motor sees higher loads while still commanding a 14.63 AFR). Then, starting at redline and working my way down, I increased the WOT cells by ~2.5* up top down to about 4800rpm. After that, I increased the WOT cells by a decreasing amount (i.e. +2*, +1.5*, +1*, etc.) so the extra spark was blended in as the RPM's rose. This combined with a 12.2 peak tq AFR and 12.6~12.8 peak hp AFR netted nearly 2 tenths and 2 mph in the 1/4 for me. That's why I suggest this tune to anyone with an '01-'02 f-body and stock cam.
Thread Starter
TECH Regular
Joined: Aug 2005
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Originally Posted by SSpdDmon
For the stock cam, I smoothed out the ridges in the factory table by hand and took a little out where there was knock (the factory seems to have too much advance for the .56~.64 cells where the motor sees higher loads while still commanding a 14.63 AFR). Then, starting at redline and working my way down, I increased the WOT cells by ~2.5* up top down to about 4800rpm. After that, I increased the WOT cells by a decreasing amount (i.e. +2*, +1.5*, +1*, etc.) so the extra spark was blended in as the RPM's rose. This combined with a 12.2 peak tq AFR and 12.6~12.8 peak hp AFR netted nearly 2 tenths and 2 mph in the 1/4 for me. That's why I suggest this tune to anyone with an '01-'02 f-body and stock cam.
i started with the max torque timing table and then backed off a little and then fine tuned it from there. Got this method from soundengineer who has been answering most of my questions. I bet he's tired of me.
