4" Airflow stack installation

[Sonny]

I have just purchased a set of 36" Slash cut Airflow stacks. Very nice, excellent chrome, heavily made. 
Problem is they will not slide up over my stock mufflers.  I have removed the small piece of metal on the back side.
Ground down the two muffler tach welds along with left over tach weld from removing the small piece of metal. 

I was wanting to slide them up on the mufflers so they could be lined up properly, mark where they need to have the slot cut out pull them off and get to cutting.  If they are this tight once they are on they are on for good.

Has anyone else ran into this?

[humshark]

My slash cuts were very tight going on.  They had been cut by "horse apples" so I wasn't needing to take them back off.  Good thing, cause they aren't coming off!

[Six Packer]

As I recall, there are some istructions for installation of stacks in the Shop Talk pages.  In any event, you have to make a cut in each of the stacks to slide over the hanger support on each side of the bike.
(See the instruction for the proper size cut area)  I did this with a side cutter after taping of the cut area.   After that is done you should soap up the cans and the inside of the stacks with dish soap which makes it easy for the stacks to slide in position.  The soap will quickly dry so don't worry on this.   I used this method and didn't have a problem except for using a piece of 2X4 at the back end to persuade the AirFlo stacks when they held up a little.  Good luck with the install.

[Udo]

I have used a long ratchet strap as a "press" and a piece of wood at the end of the stack.

[Sonny]

Thanks for the information.  I'll give it a try.  Don't know why I didn't think about the soap.

[fstsix]

Back when i did the Not so easy Glass pack Mod I remember spraying W-D 40 in the cans with wood over to tap on or was that hammer on. Dont try to install unless you have done your cut first not going to come off without damage.

[LL]

If you use any kind of lube, make darn sure it's all gone before heating the pipes up. Wanna know how I know?

[Trynt]

You'll find the stacks are very hard metal. I had to use a cut off wheel to notch them because a hacksaw would hardly scratch them.  Soak a rag with WD40 and liberally coat the mufflers.  The WD40 may smoke a tiny bit when the exhaust is hot for the first time, but otherwise will not be a problem.  Get a 8-12 inch  section of a round 4" wooden post.  The round post will fit nicely (at 90 degrees)  into the mouth of the slash cut and allow you to drive the stack onto the muffler ( by striking the post with a heavy hammer) without fear of bending the tip of the slash cut.

[PharmBoy]

I'll try to post pictures of how I installed my slash cut truck stacks for myself and another set for a friend.  First I made a block to fit over the slash cut end to protect it while I bounced the block on the floor.



Then I measured carefully and made the cuts.




Next, I attached a cord to both sides of the block making it long enough so I could put my hand through the loop, grab the stack and keep enough upward pressure on the block with my wrist to keep it tightly in the slash cut end while I bounced the block on the floor, driving the muffler down into the stack.  I used dish washing liquid and water in a 50/50 mix as a lubricant.  Make sure that the cut in the stack is aligned with the bolt attachment assembly on the muffler because once you drive it on there will be no moving it.  Also, put the front chrome piece back on the exhaust so it will act as a stop for the truck stack as it is driven onto the muffler.



And the finished product...JTL

[R J]

Seems like Mark T runs them through his lathe and trims some of the excess meat off for a easier fit.

[Sodbuster]

Is it possible to drive the "stack" on a little more and tuck it in behind the front chrome piece ??

[Sonny]

PharmBoy,   
More than thanks for the information and pictures.  Wish you were in town I'd be ask'n to borrow those blocks you made. Great idea!
I'm think'n I'll have a machine shop make the cut outs just to make sure they are centered perfect. I would'nt want to make that mistake. 

thanks to all for your input.....

[PharmBoy]

I forgot to tell you guys to be sure and grind or file down all the high spots on the muffler that would stick up higher than the outside can.  This can easily be determined with a straight edge.  I found a few of the factory welds that were supposed to have been ground down level with the outside can still needed some attention.

Sonny or anyone else within driving distance of Lawton, Ok;  I will be glad to help install the slash cut or other stacks on your stock muffler here in my garage.  Just let me know when you would like to show up and have Airflow ship the truck stacks here to my house. (My e-mail is in my profile or send a message through this board)  I find that a little time wrenching together is a good way to really get to know someone.  It really doesn't take long when you have all the tools ready...JTL

[PharmBoy]

Sodbuster, the front chrome piece and the truck stacks are very close to the same thickness and they do have the same curvature, so having the front chrome piece installed while installing the truck stack makes the front chrome piece a "stop" for the truck stack.  The gap between the two is almost non-existent and that long, shiny truck stack sure looks good when installed.  The quality of Airflow's chrome is outstanding...JTL

[Sodbuster]

Sodbuster, the front chrome piece and the truck stacks are very close to the same thickness and they do have the same curvature, so having the front chrome piece installed while installing the truck stack makes the front chrome piece a "stop" for the truck stack.  The gap between the two is almost non-existent and that long, shiny truck stack sure looks good when installed.  The quality of Airflow's chrome is outstanding...JTL

How successful were you in being able to keep the angled ends to be in-line or coplanar with each other ??

Also, how hard is it to sneak up on that last quarter inch to mate with the front chrome piece ??

Thanks for the great tips on install 

[Black Sled]

I forgot to tell you guys to be sure and grind or file down all the high spots on the muffler that would stick up higher than the outside can.  This can easily be determined with a straight edge.  I found a few of the factory welds that were supposed to have been ground down level with the outside can still needed some attention.

Sonny or anyone else within driving distance of Lawton, Ok;  I will be glad to help install the slash cut or other stacks on your stock muffler here in my garage.  Just let me know when you would like to show up and have Airflow ship the truck stacks here to my house. (My e-mail is in my profile or send a message through this board)  I find that a little time wrenching together is a good way to really get to know someone.  It really doesn't take long when you have all the tools ready...JTL

Pharmboy - how long are your stacks?  36"  They look great...

[PharmBoy]

The stacks are 36" from Airflow(made for the Valkyrie).  Mine aren't perfect, but you have to look pretty hard to see it.  The second one that I did came out perfect.  I had a little help keeping things straight while marking and installing over the mufflers on that one.  The stacks just slide right down to the front piece of chrome with a soft little clang.  The front piece of chrome acts as a stop and there is virtually no space between it and the front of the stacks....JTL

[Sonny]

Done !

Worked on them Saturday morning. Took a couple hours start to finish. PharmBoy your instruction worked great.  The only thing I did different was install them with exuast system still on bike and used the block to drive them on. I can put a straight edge side to side and they are lined up perfect.

Thanks again for the instructions....

Ride safe...

[PharmBoy]

Sonny, congratulations on such a successful install of your truck stacks.  I had never thought of installing them without removing the exhausts.  That is a great labor saving idea.  It should cut the install time down considerably.  That bike of yours sure does look nice.  How about some pictures?  I'd really like to see it with those long, shiny stacks on it...JTL

[Sodbuster]

pictures .... we need pictures !!

[Sonny]

I would be happy to add a few pick's to this post. Still trying to figure out how to do that

[PharmBoy]

Sonny,
I use photostash here on the VRCC Board.  Most of the time you have to down-size your photo to make it an acceptable size for photostash.  I have used the step by step illustrated tutorial on the VRCC Oklahoma Board.  From the main VRCC page, click on regional boards on the left side of the main page, then click on VRCC Oklahoma Chapter.  On their main page on the left side under Pictures, click on Photo Resizing Tutorial.  It is a step by step "How To Do It" lesson on changing the size of your photographs.  It took this old country boy a good while to pick it up, but it works very well to enlarge as well reducing the size of your photos as well as a section on cropping of photos....JTL     (We still want to see pictures of that good looking bike)

[Sodbuster]

Hey Sonny - If you want you can sent me a jpeg and and I can download it for ya.  Also, did you end up having a machinist cut slots for you.  Curious to know if they are centered on the stacks ??

[fstsix]

Posting pictures dont feel bad  I thought it was easier to install a supercharger  .  .

[Sonny]

No I used PharmBoys instructions when I cut out for the mounting brackets. Used a surface gauge to find the center line of the pipe and masked the pipe just like PharmBoy did. Made the cut with a jig saw and cut the back piece with die grinder. Made a driver out of cut 2x4's and drove'm home.

I will try to get some pic's as quick as possible and get them posted...

[Sonny]

Trying one more time to load pictures of the stack installation results in Just picks last uploads.