dyno run w/o SET valve

[mikeinwi.]

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.
http://media.putfile.com/dyno-run-2

[eli750k6]

Good work! Great to see some free horsepower!!
Your bike sounds like a freaking jet fighter in that video!!!

[Plarp]

Haven't tried it myself, but know tuners that have noticed similar results. I canned the ~2lbs that whole contraption weighs before my first ride on the bike.

[mikeinwi.]

Originally Posted by Plarposaurus

Haven't tried it myself, but know tuners that have noticed similar results. I canned the ~2lbs that whole contraption weighs before my first ride on the bike.

so you pulled the servo motor and the loooong ass cables off the bike? i was going to keep them umtil i was sure it did not do anything bizarre at speed but i'm just being cautious. any issues/tips on getting that crap off the bike? did you do anything about the FI light coming on? i have a roll of faux carbon fibre decal and i was going to cut a small square and cover the lite until i could extinguish it. i hate seeing that red lite staring at me.

[TLO03]

useful and interesting info ...thanks

[tahoe916]

Nice work, I thought that valve and its beneficial properties were always fishy.

[nakato]

o after taking out the SET valve, the red light will be on all the time?

[soysauce021]

Any scans of the dyno printouts?

[TheCunningMan]

I'm going to find every one of the buttheads who didn't believe it into this thread. Poor mike is wringing the piss out of his bike to share some info. THANKS for the info. "I been a rider for 30 years, that thar valve boosts bottom end, racers don't need that thar"

[ninjanwong]

Someone said pin #30 on the ECU should be pulled out to get rid of the FI light when removing the SET valve control feature.

[racedgsxr600]

I removed the valve on my 636 and noticed a difference

[ZaXoS]

hhhmmm, so Yamaha uses the EXUP for almost 20 years, and it is not a performance enhancer?
Besides the mid range HP, any other reasons one can think off? besides noise?
maybe smoother acceleration or better MPG?

[NevilleJnr]

I can check which pin it is, it's the same one you'll find in Yoshimura's fitment instructions for a full system. It is a Brown Wire with black tracer. It's on the larger of the two connectors, along the top row. Near the middle there is a blank. it's two away from the blank.

Disconnect it with a sharp pin-like screwdriver and pull the wire out. Then tape it up.

Ride happy without the Fi light blinking away.

[ZaXoS]

if you just pull that does the SET stops working?

[CSiJason]

Originally Posted by ZaXoS

if you just pull that does the SET stops working?

I was just about to ask that as well. IIRC, the valve is spring loaded to stay fully open until the servo closes it. Unless of course i'm mistaken.

I'd like to kill the servo on mine since I like the sound of it wide open.

[mikeinwi.]

releasing the cables allows the valve to go wide open. right now i have themremoved from the SET valve, zip tied together and tucked in the fairing. once i'm certain nothing goofy is going to happen i'll remove them from the bike.
Jamie at Fuel thought the brown wire w/black tracer was the one to pull also but with limited time and not being positive we left it. if someone can verify that i'll pull it.
the bike does seem to accelerate smother and rev faster at partial to mid throttle openings. did not go wide open for long but the dyno did not show that there would be a huge gain there.
so with all the mods (M4 slip-on, BMC race filter, PCIII w/custom map and the SET valve deactivated) i went from 123RWHP to what shoul be 137.5RWHP on a decent low humidity day. i'll probably have to wait until Oct for a day like that but that's about where it is now. 14.5 hp and 4.5 ft lbs of torque for about $800.00 worth of hardware and programming.
not a bad deal.

[Plarp]

Cunningly enough, when all the SET-associated hardware is removed, the valve is sprung in a full open position.

Originally Posted by ninjanwong

Someone said pin #30 on the ECU should be pulled out to get rid of the FI light when removing the SET valve control feature.

That is correct, #30 wire. Remove it and tape it off, no need for cutting. It is brown with yellow striping if memory serves correct.

[mikeinwi.]

Originally Posted by ZaXoS

hhhmmm, so Yamaha uses the EXUP for almost 20 years, and it is not a performance enhancer?
Besides the mid range HP, any other reasons one can think off? besides noise?
maybe smoother acceleration or better MPG?

not sure about the Yam but the dyno does not lie. we gained power up top without a loss of midrange. i can't absolutely positively prove it revs quicker in the 4-8K RPM range but it sure feels like it does. it also accelerates smoother now. again i rode the bike there and hopped right back on it and rode again. i could feel a difference.
i'll be going for a longer ride tomorrow and we'll see how it effects fuel mileage. next trackday is 6/12 at Black Hawk Farms. that will be the real test.

[03'Gixx600]

Nice... good to know for everyone not interested in the aftermarket exhaust +1 Man!

[mikeinwi.]

Originally Posted by 03'Gixx600

Nice... good to know for everyone not interested in the aftermarket exhaust +1 Man!

the few people i've talked with that would actually know what they are talking about say unless you are racing the full sys is probably not worth the $. the stock header is so good and lite and with the SET deactivated the gains are small and up high in the rev range. i'll keep the stocker unless something comes along that i have to have.