Supercharged111
December 15th, 2015, 06:45 PM
When comparing the 3D shape of the factory timing map's shape I noticed that it appeared to be more exponential than my most recent map (at least the areas I addressed). My previous map was focused more on smaller RPM and load regions (high load/lowish RPM representing me dragging a trailer and holding OD) whereas my most recent iteration is theoretically more ideal across a broader range based on datalogs where I capture brief periods of substantial knock activity. Only a road test and datalogging will tell where I went right and wrong, but I am wondering mostly with respect to load increase/decrease is the engine's desire more linear or exponential and perhaps where is that threshold? It seems the areas I was closest to correct according to the knock sensor were areas where I was closer to the optimal timing, but clearly there were areas where both me and the tune were lazy so I had to combine the 2 to get what I believe in this moment is superior to what I currently have. For shits and grins here's the before and after. Truck's mods are as follows:
98 Sierra L31 350 Vortec with Marine cam, 1.6:1 Comp Pro Magnum roller rockers, 1 5/8" long tube headers, dual 2 1/2" to single 3" exhaust with Magnaflow muffler, unknown underdrive pulley, and these tunes:
And for some gay ass reason I can't add my newest tune to the list? POS won't upload without a red X?
98 Sierra L31 350 Vortec with Marine cam, 1.6:1 Comp Pro Magnum roller rockers, 1 5/8" long tube headers, dual 2 1/2" to single 3" exhaust with Magnaflow muffler, unknown underdrive pulley, and these tunes:
And for some gay ass reason I can't add my newest tune to the list? POS won't upload without a red X?