Modifying Stock Exhausts

[Rio Wil]

I think one of the best mods to increase the exhaust note and make this beast scream like a banshee at hi rpm is the one pictured below.  The stock tips and chrome stacks are replaced with a 36 inch truck stack with a 4 inch id as I remember. The muffler is carefully sawed off at  7 1/4 inches and you can see what the internals of the exhausts are.  It is best to remove the exhausts from the bike and use a metal cutting band saw to get a nice square cut ......when you reinsert the piggies/canister into the truck stack, it helps seal the joint if the cut is nice and even.   You will get a bit of exhaust leakage noise with this method but because of the ease of removing or reinstalling the piggie/canister section....I don't mind. I get a drone because of my helmet but use a 27 db ear plug and its ok and I can still enjoy the exhaust note. The left canister slid into the 36 inch stack nice and snug like, but the right one required a bit of filing and gentle hammering to shrink some high spots so it would slide in by hand.   It might be my imagination but my butt dyno says I get a few more hp and there is no need to change the stock jets......

[John Schmidt]

That's pretty much what I've been running for the last 8-9 years, they do have a nice low and powerful note. One neighbor says my bike exudes power simply from the exhaust sound, unlike the two HD owners in the 'hood. He says they're just plain noisy.

Viper Creations, Mike Townsend owner/operator, out of Belmont, NH made them, but without the piggies still intact. I don't recall for certain but I believe he welds the two pieces back together, then grinds/polishes it down so the 4" stack will slip on. I had him mount some 38" stacks while he was at it. I first met Mike at one of the early InZane's held in Zanesville, OH....hence the name InZane. He's an old fashioned gear head and as I recall a machinist by trade. Did a great job on my pipes, I opted for the "louder" version and found I wanted to silence them a bit on the road due to the drone. So, installed a set of MarkT's silencers, makes it just right for me. But they still bark when you twist it hard.

I agree, they do have a great sound and I did pick up a few HP in the process. No rejetting was required although my mileage did suffer some for a while. Seems the right wrist kept getting that little twitch. 

[Gavin_Sons]

i just got done doing mine. I used 4 inch OD stacks. I went a little further and cut more can off, more like 10 1/2 inches and tig welded my stacks in place so they will never move.

[BF]

I've never seen anyone do the Ragnar Cut with a band saw before,    but I guess it accomplishes the same effect. 

Just with yours, you can slip the rear baffle section back in if wanted.  Pretty cool.   

Are you securing the rear baffle/piggie section somehow, or is it just slipped into place and left there while riding?  Any problems with them moving around any?

[Rio Wil]

Yeah, one of the piggies has a mounting bracket welded on it .... just drill a hole in the stack to line up with that bracket and use a screw to secure the baffle.

What else would one use to get a nice straight cut on the baffle, especially to cut through the inside section separators.....or are you thinking a wood cutting band saw that stands vertically, vs a metal cutting band saw that lays down horizontally?

[BF]

Yeah, one of the piggies has a mounting bracket welded on it .... just drill a hole in the stack to line up with that bracket and use a screw to secure the baffle.

What else would one use to get a nice straight cut on the baffle, especially to cut through the inside section separators.....or are you thinking a wood cutting band saw that stands vertically, vs a metal cutting band saw that lays down horizontally?

I like your idea.  You done good with the band saw.    

Perhaps you're not aware of the Ragnar Cut.  It eliminates the rear baffles by using a hole saw.

http://luiscajiga.com/Exhaustm.htm

http://luiscajiga.com/Exhaustm2.htm

The Ragnar Cut is a one time deal that guts the can.....no going back after that.  With your idea of cutting the section out with the band saw, there's a going back possiblity if one wants. 

I've seen people cut their cans up before, but I've never seen anyone do exactly what you did with the idea of being able to use/re-use the rear baffle section before.  Pretty cool IMHO.   

[Rio Wil]

Yeah the Ragnar cut is pretty brutal......this way you can weld the baffle back together and be virtually back to stock.

[MarkT]

I've seen people cut their cans up before, but I've never seen anyone do exactly what you did with the idea of being able to use/re-use the rear baffle section before.  Pretty cool IMHO.  

Really?  This is pretty much exactly the silencers I invented in 2001.  I've sold 241 sets of 4" silencers, and 52 - 5" sets.  Where ya been?





http://www.horseapple.com/Valkyrie/Valk_Products/M2W_Exhaust__System/m2w_exhaust__system.html#SilencersTxT

[Rio Wil]

Mark....what is the reason for removing the sheet metal from the baffle.

Wil

[MarkT]

It's not needed as the stacks replace their function - the gas is still confined.  So you can reduce the weight.  More importantly - no drag inserting/removing.  Before I skinned them, the entire walls had to be OD reduced as there was too much drag.  I even made a special tool to make it easier to get them in/out.  Now I only have to reduce the OD of the lands on both ends - goes pretty fast on the lathe.

[Rio Wil]

I got it.....still like the idea I can still weld them back together if desired and both can be inserted and removed by hand ......like I said, only the right side needed a bit of filing and tweaking to remove some minor high spots and not worth the effort to chuck up in the lathe, I can see doing it on the large numbers like you do, you have to make fitment  easy on the consumer....

[BF]

I've seen people cut their cans up before, but I've never seen anyone do exactly what you did with the idea of being able to use/re-use the rear baffle section before.  Pretty cool IMHO.  

Really?  This is pretty much exactly the silencers I invented in 2001.  I've sold 241 sets of 4" silencers, and 52 - 5" sets.  Where ya been?





http://www.horseapple.com/Valkyrie/Valk_Products/M2W_Exhaust__System/m2w_exhaust__system.html#SilencersTxT

Been right here.     I have a set of your silencers btw.   I have a set of your interstate piggie plates too. 

He left the piggies and the entire baffle section intact.  I haven't seen that done exactly like he's done before. 

[Rio Wil]

Just to be clear, this is not my invention.....I got the idea from some one on this site a few years ago....

[jdp]

Do you have to cut the baffle? Or can you just slide the 36 inch stack over the stock baffle? What is the advantage of cutting the tail end off and mounting it on the end of the stack?

[Rio Wil]

The idea is to increase the sound level of the exhaust, a quick and easy way is to modify the stock exhaust as shown.

The stock exhaust comes from the manifold as three pipes and to a collector where the three pipes enter about a 22 inch muffler which is covered by a chrome stack and terminates in the 3 piggies.
Just as a side note, the 3 exhausts are confined to their own route through the muffler and they do not mix anywhere in the muffler, all individual all the way out the piggies. There are three longitudinal sections to the muffler each roughly 7 inches long.

This mod cuts off the "rear most 7 inches"  (excluding piggies) and removes over one third of the muffling capability....ie, considerably higher volume.

The rear 7 inches and the front 7 inches are basically identical, the middle 7 inches is simply 3 chambers the exhaust travels through to get to the rear chamber. The little fins you see in my second photo actually extend about 7 inches to the front of the muffler.

So the mod is, cut the rear 7 1/4 inches off the 22' muffler (with piggies intact) slide the new stack up over the remaining 14 inches of muffler and you have louder exhaust.  If you want quieter exhausts, simply insert the cut off section (with piggies) back into the stack and secure with a small screw....now you are quiet again, just like stock.... when reinserted into the 36 inch stack the piggies will terminate right at the rear opening of the stack, ie, they are inside the stack not added on  to the end of the stack.

The picture of the cut off section sitting on the plastic bottle just shows about how far the cut off section will go when reinserted into the stack.

Way wordy.....hope this helps.....

Oh, and yes you can just remove the stock tip and stack and slide the 36 or longer stack over the entire unmolested muffler.  It might be tight and need some gentle persuasion with a mallet, it will also need a slot cut in stack the same as the stack you take off.....this is where the muffler mounting bracket is....

[BF]

Do you have to cut the baffle? Or can you just slide the 36 inch stack over the stock baffle? What is the advantage of cutting the tail end off and mounting it on the end of the stack?

ShopTalk is your friend......

http://www.valkyrieriders.com/shoptalk/truckstackinstall.htm

To answer your first question, no, you do not have to remove the rear baffle section to install truck stacks.  

The basic idea behind cutting off the rear of the exhaust can, ie, rear baffle section, is so that one can have a louder exhaust.  

As in Rio's idea, you can reinstall the baffle section when one wants a quieter exhaust.

It's the same idea behind MarkT's silencers.  Take 'em out when you want loud, put 'em back in when you don't.  

Alot of folks gut or take out the rear baffle section only to find out that the newly induced drone drives 'em nuts. 

That's the idea behind putting the baffles back in. 

[jdp]

Thanks for the help,I understand now,thanks

[dave011182]

Did you remove the separators in the center section of the stock muffler can to get a different sound, or just cut the rear baffle/silencer sections for ease of installation when you want it quieter?

I've been thinking about cutting mine to remove the dividers, then putting it back together to see what kind of sound I get. I'm going to try doing this with all the stock covers. We have some 4"od exhaust poor at work I can use to splice it back together for testing purposes. it looks like it will work with the stock covers, but won't know for sure until I try.

[salty1]

I'm enjoying this discussion, getting lots of ideas. One thing that struck me was the length of the piggies in Rio Wil's photos. Are those from an Interstate muffler system? My Stanard exhaust has shorter ones and they have not been modified.  ???

[Gavin_Sons]

the stock exhaust i turned into truck stacks had piggies that long, and they came off a standard.

[MarkT]

I'm enjoying this discussion, getting lots of ideas. One thing that struck me was the length of the piggies in Rio Wil's photos. Are those from an Interstate muffler system? My Stanard exhaust has shorter ones and they have not been modified.  ???

The piggies shown in that photo are off an Interstate.

[salty1]

I'm enjoying this discussion, getting lots of ideas. One thing that struck me was the length of the piggies in Rio Wil's photos. Are those from an Interstate muffler system? My Stanard exhaust has shorter ones and they have not been modified.  ???

The piggies shown in that photo are off an Interstate.

Thanks MarkT, I thought that was the case. Does the OEM Interstate have more "growl than the OEM Standard exhaust?

[Rio Wil]

Did you remove the separators in the center section of the stock muffler can to get a different sound, or just cut the rear baffle/silencer sections for ease of installation when you want it quieter?

I've been thinking about cutting mine to remove the dividers, then putting it back together to see what kind of sound I get. I'm going to try doing this with all the stock covers. We have some 4"od exhaust poor at work I can use to splice it back together for testing purposes. it looks like it will work with the stock covers, but won't know for sure until I try.

Dave, in the stock exhaust, each cylinder exhaust pulse travels all the way through the muffler in its own confined series of chambers and out its own piggie.  If the center section baffles were removed (and the rear cut off section reinstalled) it would allow each exhaust pressure pulse to escape out all three piggies at once......that would have the effect of slowing the pressure pulses out the three piggies....maybe it would lower the tone of the exhaust?????..I don't really know..... I am not sure how having the center section hollow would effect the exhaust pulse scavenging effect especially if the rear section was reinstalled and creating back pressure in the other two exhausts paths.

Interesting thought though.

[Rio Wil]

the stock exhaust i turned into truck stacks had piggies that long, and they came off a standard.

Aren't the standard piggies aligned vertically and the interstate piggies are horizontal (viewed from the rear) as well as being different lengths.

[dave011182]

I was able to completely preserve my stock exhaust, and put it back on last weekend when I did my tires that I have yet had the chance to really out any miles on. I did this so I could take my time and tinker around with the other pipes I have that had the piggies cut and rear baffles drilled when I picked it up. I got the second set for I think $60 within a month of becoming the owner of my 03 standard. I was getting ready to order some stacks when my need for tires took priority for the money I had set aside. This is why I'm trying to do this and retain the stock covers for now.

The standard piggies are vertical, I thought the interstate had the longer horizontal ones to reduce noise to the rider by clearing the bags.
Mark T is the expert here from what I can tell, he makes a very nice exhaust from everything I've read. I think there a several things I can attempt on my own before I have to save up and send mine to him. If he's still doing it when I'm ready.

I'm going for a different/deeper sound and trying to do so without increasing the volume much, but also wonder if reducing the pressure to each rear baffle section would actually make it quieter again?

[Rio Wil]

Here is what you might try......since you have a set of already molested exhausts, (drilled and de-piggied), simply cut off the back 7 1/4 inches of the muffler, use the stock stacks and see what you think of the sound.  You should be able to reinsert the cut off section (again with the drilled piggies) and see if there is a desirable change either way. You keep your stock exhausts in case things don't work out to your liking. I personally would never do the cut piggies/drilled baffles because the cutting off the rear 7 1/4 inches and making them replaceable is such an elegant solution to providing a snarling beast or quiet comfort sound....its the way to go.....

I am not personally a fan of de-skinning the cut off section because it only takes a few minutes to individually fit the section so it is a slip fit and still makes a good seal for leakage  if you want to reinstall it......       

[dave011182]

Not much yo can do with the stock covers easily, they only go 2/3 if that sounds the can and require almost the entire can to be in place. the stock tips attach only attach at the end of the can that will be cut off to make the silencers. I have a couple short lengths of the standard non chromed stacks and think I'll be able to use them to hold the to pieces together and put the stock covers back on over them. Once I cut them off and they can be accessed I can put new plugs back into the rear baffles if I feel the need. it would be much easier to do without retaining the stock and just going to full length stacks. I'm trying to do a low budget/low tech mod just as an experiment. if it works I'll write it up in full detail.