View Single Post
Old 09-13-2013, 10:06 PM   #6
Rombinhood@OpenFlash
Senior Member
 
Join Date: Jul 2013
Drives: FRS
Location: SF, CA
Posts: 180
Thanks: 47
Thanked 436 Times in 99 Posts
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by mad_sb View Post
WOW, those are some enlightening results. I really didn't think th factory sensor was that far off. Has the factory sensor been compaired to a wideband on a catless car? I guess i will find out next week when i install my wideband,
Yes, the factory AFR sensor reads very optimistically. But of course, there are some variances in even the best aftermarket wideband AFR sensors so it's impossible to tell how accurate each is without actually measure the number of air molecules and fuel molecules going into the engine. So all sensors just give estimated AFR values. But the important thing to walk away with is that some of these vendor tunes seem to be almost arbitrarily tuned for a leaner-than-necessary AFR. If running air/fuel mixtures that lean actually had a performance benefit, I could see at least some kind of argument being made. But that's not the case. As you know from your tuning experience, you can (and should) run any high compression, knock/octane limited engine as rich as possible without seeing power loss. That's a basic tuning principle for street tuning for safety and power-- shiv
Rombinhood@OpenFlash is offline   Reply With Quote