HarleyTechTalk

I don't have any specific measurements for that, but the "lollipop" trick has been around for a long, long time and is not specific to the Pro pipe. When I've done it, the exact location of the lollipop isn't critical, the size of the washer and the hole in the washer is what does the tuning. Basically, weld a washer on a bolt, insert the lollipop in the rear end of the pipe and turn the lollipop until you get the result you are trying to achieve. You can get an idea of what will happen if you have someone stick a large flat screwdriver or putty knife in the exhaust stream and turn it while holding a steady RPM on the dyno :>) The poor man's Supertrapp? Laugh all you want, it can help to tune out flat spots and dips in some instances.

Ederdelyi
I have heard of doing that with drag pipes. The article I am talking about is a guy that tried all different set backs of the washer on the bolt & came up with a dia & distance that worked for low,mid & topend range? I don't recall the persons name on this site. I do think he was an engineer?
Topend

Well, I've designed and built more than just a few exhaust systems in my time. Mind you, I won't say it's not "possible", but saying it "worked" at low, mid, and high RPM sets off warning bells in my head. That's gotta be one hell of a washer!
What exactly did this thing do at all the RPM ranges? The principle is the same, whether it be drag pipes, megaphone, or collector exit. Exhaust tune over that broad of a range is extremely difficult to attain without some sort of active control, IME.

<<The article I am talking about is a guy that tried all different set backs of the washer on the bolt & came up with a dia & distance that worked >>

I think the guys screenname was Coach, don't think he was an engineer.  He was always in the process of marketing this invention so he was short on specifics...but eventually I think he posted pics.  The main thing it did is eliminate the typical pro-pipe low end tq dip with little or no decrease in top end.

Is this what you were looking for?

QuoteExhaust tune over that broad of a range is extremely difficult to attain without some sort of active control, IME.

How about reactive control?

http://www.rocky-mountain-performance.com/

Talk amongst yourselves...   

Do they happen to make lifters as well?

I'm getting a f'n headache ... no wait, it's slipping much lower. It's been degraded to a lowly pain in the a$$ ... I can deal with that :>)

Quote from: txtech on February 07, 2009, 01:44:58 PM
how much differrence between the bp and hs bob??? from looking at the pic, where would you modify the baffle? enlarge the side holes or drill the center plug thats halfway down the baffle??  i"am running a 95, 9.8 comp, 211s, pc3,in a 06 dyna,against shop built 103s i need all the help i can get.

As I mentioned before a couple hp/tq difference between 'em all. IMO, splitting hairs with these 2into1s is not justifiable. Choose the look and sound you want, then get it tuned for best performance.
The HS can be modified to help the low rpm loss whereas AFAIK the BP cannot.
PS - It is not opening up the holes, it is closing them down for better bottom end. And I have not seen a loss up top, at least till 6500rpms.
Bob

Quote from: fuzznut5197 on February 07, 2009, 04:46:45 PM

QuoteExhaust tune over that broad of a range is extremely difficult to attain without some sort of active control, IME.

How about reactive control?

http://www.rocky-mountain-performance.com/

Talk amongst yourselves...   

These may work, but you will need to maintain (read: clean) them regularly or they will bind up with exhaust/debris. Also I can just imagine what the "rattle" factor would be over time.

Quote from: FLTRI on February 07, 2009, 05:41:29 PM

Quote from: txtech on February 07, 2009, 01:44:58 PM
how much differrence between the bp and hs bob??? from looking at the pic, where would you modify the baffle? enlarge the side holes or drill the center plug thats halfway down the baffle??  i"am running a 95, 9.8 comp, 211s, pc3,in a 06 dyna,against shop built 103s i need all the help i can get.

As I mentioned before a couple hp/tq difference between 'em all. IMO, splitting hairs with these 2into1s is not justifiable. Choose the look and sound you want, then get it tuned for best performance.
The HS can be modified to help the low rpm loss whereas AFAIK the BP cannot.
PS - It is not opening up the holes, it is closing them down for better bottom end. And I have not seen a loss up top, at least till 6500rpms.
Bob

thanks for the info bob, 

A pressure/velocity sensitive exhaust cutout --- remember lake pipes or collector plates from your street racing days, anyone? It's the "automatic" equivalent of a cable operated cutout that JC Whitney and others used to sell. Most times it just made more noise, but it sure did give the illusion of making your vehicle go faster. Sounds nasty, must be fast, right? Excuse me while I go out to the shop and whip up an exhaust "Pet Rock" to augment my retirement income. I'll create my own "stimulus package", I don't need no steenking gooberment help. :>)

ederelyi
Vetteandharley hit it right on the head. That is the thread I was talking about but I did not recall all the facts & info correctly.  I have tried the hose clamp around the baffle & seemed to help the bottom end by the seat of the pants feel but seems just a bit lighter in the mid range. I thought I would try the bolt & washer setup this spring if I could find the specs. for the bolt & washer.
Larry

Quote from: ederdelyi on February 07, 2009, 06:11:30 PM
A pressure/velocity sensitive exhaust cutout --- remember lake pipes or collector plates from your street racing days, anyone? It's the "automatic" equivalent of a cable operated cutout that JC Whitney and others used to sell. Most times it just made more noise, but it sure did give the illusion of making your vehicle go faster. Sounds nasty, must be fast, right? Excuse me while I go out to the shop and whip up an exhaust "Pet Rock" to augment my retirement income. I'll create my own "stimulus package", I don't need no steenking gooberment help. :>)

a friend of mine bought a suzuki m109r ,it came with a spring loaded baffle bypass supposedly closes under 2500 for lowend and opens up 2500 up runs like sh.t and sound like it missing a cyl at idle,wouldnt get 30 mpg if you drop it out of a plane. i could outrun it when mine was still a 88 with 204s...

To be clear I was commenting on the "reactive control" device with my last post. The bolt and washer or "lollipop" does in fact work in some cases. As stated, it will only work over a limited range and may actually require a combination of fuel adjustment/timing and the lollipop position to achieve best results. Cam timing has a great deal to do with how a pipe will react to the overall combination of parts ... and no simple baffle or lollipop is going to completely fix a mismatch.

For the Pro Pipe HS, I covered 2 sets of holes in the baffle with hose clamps, made for much better throttle response below 3k rpm. Have not noticed any negative higher rpm performance.
AP

Quote from: apendejo on February 08, 2009, 08:26:04 AM
For the Pro Pipe HS, I covered 2 sets of holes in the baffle with hose clamps, made for much better throttle response below 3k rpm. Have not noticed any negative higher rpm performance.
AP

I really like my D&D FatCat with Jet Hot ceramic coated Sterling Extreme headers.  Don't get none of that blue/purple/gold discoloration reflection in the other shiney stuff like the cam chest cover and side door cover.  Supposedly it runs cooler, but I ain't gonna touch it.  Supposedly it flows better, but I like it anyway.  Good exhaust.

Thunderheader for me.  I've never tried the D&D, but I hear good things about it.  I like the V&H pro pipe also.  I dig my thunderheader because of the deep sound.  I don't care too much for the look though, but the sound is oh so sweeeet.   

  So Bob could you let us in on the number of discs you are running with your ST megaphones?   Are you running same on left and right?   Closed or open end caps?
Walt

<<How about reactive control?  http://www.rocky-mountain-performance.com/  >>

<<Do they happen to make lifters as well?  I'm getting a f'n headache ... no wait, it's slipping much lower. It's been degraded to a lowly pain in the a$$ ... I can deal with that :>)  >>

  I lurk on VTF and there is a guy over there whose answer to every pipe question is to on put this "quiet riot" goober and join the 21st century.  Pro-pipe, e-pipe, rb racing...take out the baffle and put in the QR.  Probably is the guy who makes it...LOL.  Just today he said all the knowledgeable pro's know the white bros e-pipe is a bad pipe.  Unbelievable.

Sean

Quote from: waltcentral on February 08, 2009, 05:00:56 PM
  So Bob could you let us in on the number of discs you are running with your ST megaphones?   Are you running same on left and right?   Closed or open end caps?
Walt

I run very few (10 each side) because I want quite power and personally don't care about power above 5000 rpms. But do care about bottom end torque which 8 discs each side doesn't hurt.
I tune for a living but don't care about the peak HP number just peak torque below 4000rpms.
Oh, of course closed end caps.
HTH,
Bob

Bob:  What pipes will v and h rechrome if they turn colors?  My propipe HS is gold about halfway back in the megaphone section.  Also if you cover the two sets of holes in the baffle will how much will it affect the tune?

Just got out my instruction sheet from the HS and it clearly states  "Warning!  Vance and Hines does not warranty any chrome products against discoloration."

Quote from: vetteandharley on February 08, 2009, 06:41:32 PM
Bob:  What pipes will v and h rechrome if they turn colors?  My propipe HS is gold about halfway back in the megaphone section.  Also if you cover the two sets of holes in the baffle will how much will it affect the tune?

Assuming it is EFI, it should not do anything but increase low end power and throttle response. If it affects tune it will be minor and probably not noticeable.

QuoteJust got out my instruction sheet from the HS and it clearly states  "Warning!  Vance and Hines does not warranty any chrome products against discoloration."

Yep, that's what they ended up doing. First they blamed the tuner/dyno for the yellowing but after so many returns from non-dynoed bikes they started the disclaimer you got/have to keep from replacing hundreds of yellowed/blued pipes, which is, IMO, why they eventually came out with the "Blue Proof" redesign.
Bob

Quote from: sean fxd on February 08, 2009, 05:19:11 PM
<<How about reactive control?  http://www.rocky-mountain-performance.com/  >>

<<Do they happen to make lifters as well?  I'm getting a f'n headache ... no wait, it's slipping much lower. It's been degraded to a lowly pain in the a$$ ... I can deal with that :>)  >>

  I lurk on VTF and there is a guy over there whose answer to every pipe question is to on put this "quiet riot" goober and join the 21st century.  Pro-pipe, e-pipe, rb racing...take out the baffle and put in the QR.  Probably is the guy who makes it...LOL.  Just today he said all the knowledgeable pro's know the white bros e-pipe is a bad pipe.  Unbelievable.

Sean

I wish he would come over to real tech site and say that.

Quote from: GoFast..... on February 09, 2009, 06:40:06 AM

Quote from: sean fxd on February 08, 2009, 05:19:11 PM
<<How about reactive control?  http://www.rocky-mountain-performance.com/  >>

<<Do they happen to make lifters as well?  I'm getting a f'n headache ... no wait, it's slipping much lower. It's been degraded to a lowly pain in the a$$ ... I can deal with that :>)  >>

  I lurk on VTF and there is a guy over there whose answer to every pipe question is to on put this "quiet riot" goober and join the 21st century.  Pro-pipe, e-pipe, rb racing...take out the baffle and put in the QR.  Probably is the guy who makes it...LOL.  Just today he said all the knowledgeable pro's know the white bros e-pipe is a bad pipe.  Unbelievable.

Sean

I wish he would come over to real tech site and say that.

Actually the thing should/will work, and the concept is not new. There have been all kinds it dynamically adjustable intake tracts, exhaust systems, cam timing, aerodynamic influences. The problem, especially as applied to our high vibrating rockcrushers, is anything stuffed into the exhaust flow, will not live for long at least without making some real junk noises after a given time period, especially after "racing" the engine @ higher rpms for extended periods of time.
As always, JMHO, Bob