Unbaffled exhaust tuning tip from nightrider

[76shuvlinoff]

Shovels and drag pipes just seem to go together or at least end up together. I thought I'd sticky this here for a while.

http://www.nightrider.com/biketech/exhaust.htm

[sparkey]

Thanks-Great link

[fx4me2]

I got a tech tip awhile ago that was sort of the same,It was 1 1/4 bolt with 4-5 nuts inside,witch makes it about 1 in.This artical say about 1/2 in.Witch is better? Also on a slash cut pipe wheres the 1 in. from the very end or begining of the slash, mine is about five from the very end ,any difference?

[76shuvlinoff]

As far as bolt placement there might be a difference on a dyno sheet but I am wondering if anyone would actually feel it.

[fx4me2]

thanks. that was a good link

[smoldrn]

Hey, I just went to the link and it said that the domain name for Nightrider is expired.

[FSG]

It's good from here in Oz.  Try  http://www.nightrider.com   

[76shuvlinoff]

both links are working for me at the moment..

[smoldrn]

Ah sooo...so solly, sank you berry much.

[drinner-okc]

In 76 I was working at a H-D dealer, riding a 74 XLCH. 38MM Mikuni, 1-3/4 drag pipes & a 16 laced on the rear.
WFO the bike ran great, but around town was bloated & fat. Some of our older mechanics were drag racers, and one offered to wake-up the CH. He basically did exactly what that site recommends. but mad his with a bolt & a larger OD shim or spacer. almost snug to the pipe ID, but with a larger hole. He also slotted the threaded end so you could hold it where you wanted with a screwdriver to fine tune. When I sold the bike, people would test ride it and say the clutch slipped. I'd take
them back and show them they were spinning the tire @ each shift.
So, yes it will make a difference you can feel.

PS: just like a baffle, it will hold heat and cause the pipes to discolor/blue at the washer.
drinner-okc

[MBSKEAM]

like this....




mbskeam

[ricochet]

Looking at that last pic makes me think why not just use a 1/4-20 or larger eye bolt?  It effectively does the same thing and allows some flow because the profile is round stock.  No welding required.  Probably been mentioned before.

ricochet

[JamLazyAss]

Hard to imagine that little bit of restriction can make such a big change in performance.

[76shuvlinoff]

 Just about anything breaks up the reversion wave, back pressure is a different matter.

When I did this the washers I used filled the drag pipe to about 75% and I turned it back and forth looking for a sweet spot.

[hbkeith]

been doin that for 25 years, it works, that idea came from the old honda 305

[FLTRI]

.... that idea came from the old honda 305

God, I hate to admit I remember that.
Bob

[Old Crow]

I remember the ones with the knob on them that you could open or close...Snuff-or-not's was what we called them.
Had them on a 175 Honda before I ever got the 305. 

[Reddog74usa]

Yep a thumb screw also works very well as you can twist it to tune. Yep you will feel the difference.

[Hillside Motorcycle]

Back when every mother's son in 8 county's, was into throwing the biggest pipe on their bike, when those first came to market,(IE 2 1/4", and larger), we manufactured "torque nozzles" from 6061 aluminum bar here.
Slip-fit on the O.D., 1" long, and 1.600" thru hole, with a 10* taper, which faced the front of the pipe, and then, with a 1/4-20 drilled/tapped hole thru, to attach to the pipe.
On the dyno, you could make pulls, and increase the I.D. by .060" at a time, 'till the bottom of the torque curve would just start to fade. Done.
Tried to get Drag to take them on, but they said they'd have 'em made offshore if they were interested. Thank's!!
Submitted them to Zippy's as well. Never heard a peep, as I believe both, probably thought that something that simple, couldn't possibly work.
The bolt/nut works well in 1 3/4" drag pipes, and another thing we had witnessed, is to cut them straight, not a baloney cut.
Scott

[Old Crow]

I just a couple of weeks ago cut the baloney ends off the drag pipes on my shovel.  You can definitly tell the difference even without changing anything else(including the washers).  Makes it sound a whole lot nicer too.

[ironman2]

Why bolt on open pipes just to baffle them w/ a bolt and loose ALL the sound of drag pipes,??

[76shuvlinoff]

I think you have to choose between the sound of drag pipes and low end /midrange performance.

[HotRodShovel]

Crow...absolutely man. I don't dig the baloney cut and I don't know why they don't make more straight cuts.

[Old Crow]

I don't think the washer really cuts down on the sound of the pipes.  I think it just changes the tone a bit.
Sure helps the torque curve, though.
Besides, ever try and find pipes for a rubber mount shovel?  You get 3 choices. 
2 into one(old style, not T-header style),about $200 plus a muffler, true duals, about $300 plus 2 mufflers, or drags, about $100 and done.
I've said it before and I'll say it again, I'm a cheap bastich.

[Dangit_Dave]

I have to agree... I run a '80-80" FXWG with 1 7/8" drags, The previous owner replaced the cam with a "top end" cam that I assumed was why it lacked low and mid range torque. I made a set of the washer baffles and was amazed at the difference it made! I now have good low RPM torque even when riddin' two up. Still sounds sweet, too. 

LOUD PIPES SAVE LIVES!