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View Full Version : Flapper mod for CBRs?



baffa
13th December 2013, 15:32
For those of us with CBR1000RRs, 600RRs, and so forth.

Have you down the flapper mods, and what did you think?

Bike is an 07 thou with a full Yoshi, so there was no exhaust flapper, but finally got around to doing the front.
Definitely makes more noise at low revs, and seems to pull a little harder, but didnt make it any smoother (doesnt run rough, but not quite perfect).

Quite happy with it over-all, feels like the power delivery is a bit flatter.

SPP
13th December 2013, 20:42
08 thou.

I pulled the intake flappers, solenoids, plenum, hoses, and wiring. If nothing else at least a bunch of clutter is gone.

I didn’t notice any increase in intake noise but throttle does seem a little smoother down low. Still has the 3K stumble but its better.

AllanB
13th December 2013, 20:47
Heaps of chatter some time back about the intake flapper mod on the Hornet 900. General conclusion was it makes more intake noise without .....

Exhaust flappers can aid low end power I read somewhere then open fully to free flow at the top end

SPP
13th December 2013, 20:51
Exhaust flappers can aid low end power I read somewhere then open fully to free flow at the top end

I can believe that. Yoshi R77 with some back pressure (insert in) the bike feels a bit better down low.

Chrispy has a blade and took mine for a spin around HD. Compared with his my throttle was fat he reckoned, then I stumbled on this AFR chart:

Orange was stock
http://194.77.27.94/bilder/a2f.jpg

baffa
17th December 2013, 09:42
Pffft, science.

After a bit more open road riding, I can notice a difference.

Apparently removing the whole rig does save a kilo or two, but that sounds like work.

SPP
17th December 2013, 11:38
Apparently removing the whole rig does save a kilo or two, but that sounds like work.

Nah, you’d save more weight taking a shit.