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View Full Version : New Cam = New Injector Timing?



PRAY
March 18th, 2014, 06:59 PM
I put a cam in my TBSS that has 10* of overlap and obviously different IVO ICP EVO EVP values from stock. It seems to me that Injector timing would need to be changed (earlier or later) to compensate so the fuel charge hits the back of the closed intake valve to atomize and not be shot out of the exhaust at low engine speeds and idle. From what I have been reading, this is how the factory does it. I have been reading up on this on HPT but it seems that they calculate their injector timing off of EOIT (End Of Injector Timing) unlike our EFI Live set up that calculates it off of injector opening time. I have not had the time to figure out exactly what the new timing values need to be. Is there a thread on here that describes how it needs to be adjusted in EFI Live? I really want to clean up idle and part throttle acceleration. The gas smell at idle is killing me. I understand that as RPM increases this issue becomes a moot point due to IPW being over 50% and over 4ms. I know there are a lot of very smart people on this site that have probably figured this out and I am probably way behind the times. Any help with this or a spread sheet would be greatly appreciated. Thanks.

statesman
March 19th, 2014, 02:07 AM
I don't think there's a spreadsheet for that. From what I've read, it looks like a case of just making adjustments until you get the best performance.

http://forum.efilive.com/showthread.php?11222-Interesting-info-on-B3702-Injection-timing

PRAY
March 19th, 2014, 03:37 AM
Thanks. I will look at the link and try to figure it out with the HPT spread sheets. With the way ours is set up in EFI Live. Which way do you go? Add or subtract?