Exhaust back pressure

[skiman]

Spent some time this weekend talking to a vee twin dyno tuner and learned a lot about how open pipes kill low and mid range power, so I started adding some restriction to my V&H bagger and was amazed at the improvement I got and it sounds much much better also,
going to do more work with the controller now that I changed to exhaust back pressure.

[ringadingh]

A couple years ago I had the baffles out of my bike and decided to run around the block, It was way down on bottom end power compared to leaving the baffles in.
If you are looking for top end power only, open pipes are the way to go, as well as deaf. ;)

[ndbigfish]

Ski,
How are you restricting the V&H?

[classic1]

I did the "lolly-pop" thing to the forward end of my V&h baffles. I drilled a 1/4+ sized hole and welded a 1/4-20 nut on the outside of the hole on the baffles before the perforated part. Then I used a hack saw to slot the end of a 1/4-20 x 1" set screw and welded a 3/4" dia washer with a 1/4" hole in the slot. I put a nut on the set screw and screwed it into the welded on nut and used the other nut as a jam nut to hold the set screw in place. I used an allen wrench to rotate the washer into position as I tightened the jam nut.

[poppy]

Hey Classic1,

Got a picture of the finished modification? Or a link to the information?

[classic1]

I'll have to find the pics. I might not get that done today though. The 'lollipop" info was on some Harley site and is used by "bigcitythunder.com" with all of their baffles. It's a simple design but you can tell a difference in the throttle response. Big City Thunders performance comparisons are without baffles and with their baffles. I just searched the net and there's info on it.

[skiman]

You can find many baffles to use with the V&H bagger, look for the ones that go in the 2 inch pipes they are 1 7/8' OD and slide into the front end of the V&H baffle just make sure you put it in direction of exhaust flow.

[redjay]

I noticed after I gutted the goatbelly the performance was flatter. Just debaffled mufflers works for me, sound and performance.

[wompus]

Here's a good place to start if you want to increase back pressure and quiet the bike down a bit.
http://www.gadgetjq.com/vhbagger_shhh.htm



.

[skiman]

I noticed after I gutted the goatbelly the performance was flatter. Just debaffled mufflers works for me, sound and performance.

Is flatter north talk for better. down here flatter is along the lines of a flat tire as in poor performance http://s2.images.proboards.com/grin.gif

[skiman]

On another note I won a brand new set of HD mufflers now I can be Nomad tough with Harley stuff

[Loafer]

On another note I won a brand new set of HD mufflers now I can be Nomad tough with Harley stuff
http://s2.images.proboards.com/cool.gif

[redjay]

The performance was worse than before the goatbelly was gutted, thats what I mean by flatter. Less ooooomph.

[skiman]

The performance was worse than before the goatbelly was gutted, thats what I mean by flatter. Less ooooomph.

Ok I miss read the post
I really stumbled onto the back pressure thing because I was asking the guy at the shop what he had for baffles and he mentioned if I was looking to get the low and mid range back, I was really looking to quiet the bagger duels down. I must be getting old because the noise just gets on my nerves after a few hours like riding in the back of a C-130
I rode my friends HD ultra with a 103 kit and stock pipes it sounded great to me so that's why I got the muffles still going to work on a good set of baffles for the V&H cans too

[Dave]

I rode my friends HD ultra with a 103 kit and stock pipes it sounded great to me.....


Is that not what everyone here's trying to be like. Mini-Me's ?

[skiman]

Well sadly nomads are not supported well for aftermarket so you gotta do what ya gotta do.

[rewindgy]

And that's why I put Supertrapp SE's on the V&H front pipes. Theyare designed to make power from around 2000 - 4500 RPM. They do not have removable baffles and do have some back pressure as they are not straight thru! A friend put them on his Harley ( which they are actually designed for) and he is quite pleased with the performance - they are not loud but they will bark if you roll on it. With the trailer they appear to give better torque in the RPM range I run at.

[macmac]

Flatter, or flat spots are pretty much unviersal, a place in rpm where air mix and fuel don't match, usually so lean not much happens, and frequently right smack in the middle of a power band where there was power before.

[classic1]

Hey Poppy, here's some pics of the "lollipop" that I added.

http://s620.photobucket.com/albums/tt285/nomad-1/nomad-1%20baffles/