Working on my 2011 96" RG. A few weeks ago I put a 555 cam, S&S air filter behind my stock cover, MF 2-n-1 exhaust and PowerVision tune. Rolling on the throttle I here a heavy "clacking" noise coming from the air filter. I pulled the cover and put my ear to the filter and it's for sure coming from the fuel injection area. I didn't hear any thing with the stock backing plate, and I had cut larger holes in the back of the stock backing plate and put a K&N filter it in. I have heard it ever so slightly on other bikes, but this is loud. Can someone explain to me what's going on?
Increasing the overlap ( that's the time the intake valve is opening while the exhaust valve is still closing) increases the power, and also changes the sounds heard from the throttle body. Stock cam has negative 12° overlap, and the 555 has 40° to 44° (depending on which 555 you chose). The noise comes from the intake pulsing the extra 52-56 degrees of overlap presents to the throttle blade. More noticeable with some air cleaner/cam combos.
The reason I didn't go with SE TB..
harleytechtalk.com/htt/index.php?topic=86959.msg986374#msg986374
Adding to rigidthumper's reply, the exhaust plays into it too. Kinda like what happens with drag pipes on a shovel, the reversion wave from the end of the pipe returns through the engine during that overlap period, and out the intake. On the fly by wire throttle body the blade is able to flutter with the pulse, because you aren't holding it still with a cable.
I took off a Ness Big Sucker (open back) AC because I couldn't stand the KLACKING. I could hear it over the exhaust. Replaced it with a Ventilator, pretty much silent.
Throttle blade flutter is really pronounced with a Heavy Breather, but I like the way it performs so I live with it.
Thanks Guys, I do like the way it performs. I'm going to try a different intake and if it's not better, I guess I'll live with it. It is kind of freaky hearing it on my own bike thinking the motor is going to blow. I did a 200 mile ride yesterday and it didn't get any worse or louder.
Once modified they all do that :hyst:
But honestly,after changing cams and going to a more open A/C,that was the first thing I noticed when I went through this years ago.And since then I've noticed a lot of people talking about this same thing after upgrades.Just the nature of the beast I guess. Coff 06
Just be glad you don't have a mikuni carb :bike:
And a dry clutch.
What I did was cut a piece of flat copper about 2" wide and whatever the length of the football cover is and JB welded it to the inside of the top part of the cover kinda like a extension towards the tank,To mask that noise and keeps the rain out if you happen to be parked outside in the rain,And it helped a bunch,and I'm running a 3" deep filter behind the cover, (Just sayin)
Quote from: Skin on April 07, 2019, 10:48:11 AM
Thanks Guys, I do like the way it performs. I'm going to try a different intake and if it's not better, I guess I'll live with it. It is kind of freaky hearing it on my own bike thinking the motor is going to blow. I did a 200 mile ride yesterday and it didn't get any worse or louder.
A different intake will not make the sound go away..
Quote from: nosjunkie on April 08, 2019, 05:29:16 AM
Quote from: Skin on April 07, 2019, 10:48:11 AM
Thanks Guys, I do like the way it performs. I'm going to try a different intake and if it's not better, I guess I'll live with it. It is kind of freaky hearing it on my own bike thinking the motor is going to blow. I did a 200 mile ride yesterday and it didn't get any worse or louder.
A different intake will not make the sound go away..
Sure it will. Put the stock intake back on.
Quote from: Admiral Akbar on April 08, 2019, 07:21:44 PM
Quote from: nosjunkie on April 08, 2019, 05:29:16 AM
Quote from: Skin on April 07, 2019, 10:48:11 AM
Thanks Guys, I do like the way it performs. I'm going to try a different intake and if it's not better, I guess I'll live with it. It is kind of freaky hearing it on my own bike thinking the motor is going to blow. I did a 200 mile ride yesterday and it didn't get any worse or louder.
A different intake will not make the sound go away..
Sure it will. Put the stock intake back on.
Where does it say he changed the intake.. it is stock... You mean put the stock cams back in?... the sound is coming from the intake pulse..