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Old 02-08-2022, 09:55 AM   #19
KingLT1


 
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Drives: 2016 1SS NFG A8
Join Date: Aug 2017
Location: 46804
Posts: 6,797
Quote:
Originally Posted by Joshinator99 View Post
Yeah, it needs from approx 5 degrees before IVO to 5 degrees before ignition. That’s your window and why we keep IPW under ~6 ms or so.
True but advancing SOI allows for longer IPW's. For example, My brother's C7Z seems to tolerate IPW's up to 7.5ms before things start to get wacky. Now I didn't leave it that way of course, but it seems custom cams with advanced SOI can tolerate longer pulse widths. First thing I notice when fueling goes south is the wideband will start to show rich when it's really not. Bring the IPW's down and the AFR reading will show leaner even though the engine really richened up. What you are seeing is wasted fuel going out the exhaust causing a false rich reading. Also can cause "fuel knock". My car with stock cam doesn't like anything over 6.5ms. And if you leave the SOI stock values you could likely start to see some issues above 5.8-6.0ms.

SOI main purpose is to get the fuel injected on time for complete combustion. I do believe there are some gains in power to be had but it's not huge. Interested in your results this coming Spring.
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2016 NFG 1SS A8
Options-2SS Leather/NPP
Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP
Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA
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