dyno'd the bike without the Suzuki SET valve in the header tonite. this valve is supposed to add midrange power per Suzuki right but many believe it's simply a noise emissions tool that robs power.
i was seeking the truth and found it at Fuel Moto with Jamie's DynoJet dyno.
conditions are crappy tonite as it's high humidity (52%) but we did it anyway. we ran the bike 1st with the valve in place and got 134RWHP. down 1.5 from where it was last time due to the humidity. anyway we had a baseline.
we then removed the 2 cables controlling the SET valve and unplugged the servo motor connections way in the back on the right side of the tailsection.
fire the bike up and the 1st thing we noticed was the sound. it was louder but not by alot. it was deeper though at idle. we could manually close the SET valve with a pliers (it's spring loaded) and make it really quiet.
so we strapped it to the dyno. it made 136RWHP without sacraficing any midrange. it did not need any tweaking to the custom map that Jamie programmed last time.
my FI light came on though so i'll have to determine which lead to the servo is causing that.
so for no $ it gained 2RWHP and a little volume. i thought that's cool and we pulled it off the dyno.
we were surprised that something that seemed so restrictive could net such a small gain. but after thinking about it we came to this conclusion: the valve is nearly wide open at higher revs so a gain up top would not be huge. at lower revs and partial throttle is where the valve is doing it's job
. so i take it for a ride. sure enough the midrange is stronger without the valve restricting the exhaust. i was on the street and you know i'm a law abiding citizen so i was not going real fast but from 4-8K RPM the bike revs faster and feels more lively. i'll have a better feel once i get back to the track.
so this is more a seat of the pants type thing than a hard #'s conclusion. i know you can't feel the diff with 2 added HP at 14,5K RPM but i rode the bike to Fuel Moto and less than 45 mins later rode it without the valve and could feel a difference. i don't think i'm imagining it.
has anyone else here tried this?
here is a video clip of the bike on the dyno.