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Old 02-14-2013, 01:14 PM   #10
Ryne @ CMS
 
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Drives: 16 Camaro SS, 06 C6 Z06, 15 Sierra
Join Date: Nov 2009
Location: Murrieta, CA
Posts: 778
Quote:
Originally Posted by BullF-16 View Post
I didnt either but Pat G is the man in the LS tuning world. Here are his exact words in an email. I had a question about removing a check valve from my
RX Monster can and an SD tune would not be affected by this. Here is what he said:

I did an independent speed density tune to where it had perfect fueling without the MAF. Then I did an independent MAF-only tune where it had perfect fueling without the VE tables. Then I turned them both back on so now you have the benefit of both.
What Pat G means is the computer uses both systems during normal operations, its called a dynamic airflow system. This has been in place since the 90's on gm cars, but is really trick in the newer cars. How the system works is the system primarily runs off the maf, but for startup and quick throttle transitions etc. etc, the computer will reference the VE for airflow calulations. This is why a proper tuner will always dial in the VE in addition to the MAF. On the newer cars (vettes, camaros,trucks etc etc) that dont have "actual" ve table rather VE co-efficients (not as easily calibrated) and a lot of tuners simply disable Dynamic airflow which in all honesty works for the most part, but in rather more aggressive combinations i see startup issues, and simply not so crisp throttle response on quick throttle transitions IMO. I feel a proper tune should still utilize the dynamic airflow system if at all possible, its takes more time to dial in, but i feel its a better tune overall. the way you dial in each system is to isolate each system from each other, for example while dialing in VE only you set your maf fail to 0 hz, and to dial in your MAF only you disable Dynamic airflow, once done you set your dynamic airflow shut off point to your desired RPM.
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