when they say 21 hp, they fool you by converting that to "estimated crank horsepower"
which means... the dyno shows rwhp. divide that number by .825 (for our cars) and you get crank horsepower.
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340(our cars rated HP) multiplied by .825 = 280(the general rwhp of our car stock when dyno'd)
thusly
280/.825=340
.825 becomes the constant for all rwhp numbers to convert to crank and vice versa.
this is the same as 17.5% loss of hp to the drivetrain
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now. that is all subjective as to what number they believe to be the calculated percentage loss of hp thru our drivetrain. and what dyno they test it on.
secondly a lot of people ive dyno'ing CAI's a lot of trouble, because the whole idea behind a cai is that you have to have the car moving forward in order for it to actually show its true numbers.
a car standing still on a dyno, even with a giant fan blowing at it still wont give "true" results.
goto
www.lxforums.com and find the section in the forum called
MFO(Mods Face Off). they have a bunch of different mods, with extensive research, as was previously mentioned in this thread, on CAI's. and comparisons between them all. with dyno charts. all done on the same car and same dyno.
to give you quick overview.
the Airhammer(custom fabbed by a member on the lxforums) netted the most hp, but isnt a "brand name" and may not filter the best.
the AFE stage 2 netted the second most HP. and is a trusted brand.
i advise reading those. and forming your own opinion as everyone elses will vary. the short of it, to me, is that it filters better, and lets your car breath better, and adds a little extra throttle response, helps to make gains from other modifications more noticeable.
and if nothing else, if none of this is really true. atleast you know it will make your exhaust note sound quite a bit better
best of luck and...... *get an afe stage 2

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:rockon: