Originally Posted by Farnsworth
Originally Posted by ZeeOSix
Any flow restriction reduces the absolute air pressure at the intake of the throttle body and results in less CFM of air being ingested, so any air flow restriction means less HP. It's that simple. Go do some research on the internet ... there's tons of info on intake systems and how less intake restriction give NA engines more HP at WOT.
The bottom line is that EVERY air filter and air intake system has flow restriction - some being more restrictive than others. Why do you think some aftermarket air intake & filtering systems make an engine develop more HP than a stock OEM system? When you increase the HP output by 3~5% on a 450 HP engine, you're talking about a 13~22 HP gain. Halltech intake systems on Corvettes showed that proof over and over on dyno testing. Plenty of info on the 'net about it - Google it.
So yeah, some people know more about intake systems than the OEM engineers. But keep in mind that those OEM systems have other design requirements around them, such as intake noise levels, etc, so the OEM systems are not optimized for breathing and max potential HP. Some are good, but still not ideal from what is could be. And yes, there are even aftermarket intake system for the Tacos, which increase HP output. Basically about any OEM intake system can be improved for more engine HP, because less restiction in the intake system results in less delta-p which results in more CFM going into the engine at WOT. It's pretty basic physics.
You may know more than Toyota engineers , or quote people you think know more, about everything, but you said nothing about the graph showing you are wrong. By a company specializing in restriction gauges. There it is no hp loss, in fact it shows a little increase. Go study more on the internet. Seems sort of latched on. Go right ahead and talk more. In real life it takes about 25 inches of water for the pores to be restricted enough to matter. That's all I need to know about maintaining our cars in real life. I may buy one, but actually at 50k my filters look good still, no restriction that would change anything.
Bickering over before the lock. Talk more all you want.
... sure, a more restrictive air filter INCREASES horsepower. Nice cherry pick attempt, but more going on there than what it appears (diesel held at constant RPM, not at WOT). Now go do some more research about all the dyno tests that show noticeable HP increases on gasoline engines at WOT with less restrictive filters and intake systems.
Start here, and that's improving an already good OEM intake system on high performance engines:
https://www.halltechsystems.com/default.asp
Maybe you should email Halltech and tell them they can get more HP if they make their filters and intake systems more restrictive.