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Interesting info about backpressure and the flapper
Bolting the flapper open does little to nothing compared to removing it. I noticed a big change going from it bolted open to removed, now here is some data that shows it
Maybe I missed it but I didn't see any actual results of power gained or anything else. Just a bunch of grown men bickering and postulating theories.
Saw that. But what's that mean for power? To many variables. We can all agree it's not good but by how much? I won't get a chance to cut mine out before I redo the entire exhaust and upgrade everything so I'm going to have to go on y'all's word here.
Less backpressure is better for power obviously, but im not exactly sure of the correlation. For comparison, most common turbo setups have 2.0-3.0:1 backpressure ratio, so 15psi of boost is 30-45psi in the exhaust. Not really relevant to this discussion except to say some backpressure isnt the end of the world.
Thought I recalled something like that on turbo's (gotta love 'em) but I remember blowers aren't as forgiving. I think Pat had some info on that at one time.
That's the problem. No one has bothered to do the research on what 5psi of back pressure does to performance so it's all speculation and theory at this point. There are so many variables here it's hard to even guesstimate what it does on these trucks.
Observations I can pass on about the flapper having been the first thing I did on the truck. Initial start up is more throaty. Power feels more linear but that can vary as spring tension from truck to truck vary, mine was disturbingly stiff. WOT rumble is more glorious with a hint more top but that can be subjective. Either way- and per the linked article above it's all benefit to get the flapper outta there. Even if your flapper has a lighter spring pressure, even with it open there's still a good amount of blockage...…….
02-19-2019, 05:35 PM
Interesting info about backpressure and the flapper
