Quote:
Originally Posted by Diesel_Dave
Correct, a non-lean burn fuel injected gasoline engine will adjust the fueling based on the O2 sensor readings, so as to keep the AFR right near 14.7:1.
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So lean burn does not do this? If that is the case then why do WAI on the VX give us better FE? I would think the O2 is seeing "less" oxygen, thus reducing fuel... I am new to alot of the theory tho.
Quote:
Originally Posted by hackish
I spent 10 years tuning vehicles, everything from hyundai accents up to exotics any everything in between. I only skimmed the thread but I'll add a few details in here that will hopefully correct a few things and add in a bit of info.
Reducing the backpressure will improve fuel economy significantly while accelerating. Steady state operation will make more gains on some vehicles - especially the EGR equipped ones. If the engine wastes less energy pushing the exhaust down a restrictive pipe through a restrictive muffler then more energy is left to turn the wheels.
I had a 1993 Civic VX with a crappy restrictive 1.25" crush bent pipe. Finally it rotted off so I bought the cheapest stainless setup I could ($150 at shop cost). With no other changes in driving habits I picked up 7% and that was with at least 5000km of test data on either side.
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What is steady state? Remaining at a constant RPM/ lean burn? I also own a VX, bought recently. It has a newish stainless pipe from the cat back. Just measured diameter from outer circumferance. Got a nice 2" pipe.
I'm getting mixed signals about pipe diameter. Not sure if it will throw my O2 readings off, while creating less backpressure...