One-Off Exhaust Tip: From Concept to Installation

[Kevan]

PREFACE:
Though it's lacking a pair of cylinders and a couple of hundred horsepower, I thought many of you would appreciate the latest addition to my friend Keith's Rumble Bee.
Enjoy!

Late last year, Keith want to do something cool with his exhaust tip. OEM routing had it coming out behind the pass. rear wheel. Cool, but not cool enough. So, we came up with a plan.....(*insert Vincent Price laugh here*)

We took initial measurements of where we wanted it to go, and I whipped out the CAD and drew up a few quick designs:






As you can see, the original plan was to run a single pipe to the tip.
That didn't last. :grin:

Keith's truck has a roll pan instead of a rear bumper, and the RumbleBee ground effects attach to that pan. We removed the GFX and trimmed away the section where the new exhaust tip was going.

We took his truck to Midas to have the new (non-weld failing Magnaflow) muffler put on, and some new pipes run to the center of the back. I even drew up a quick diagram to help the tech get the pipes positioned correctly:


Yep.
Even with an insanely simple drawing that perfectly matched the vehicle, we arrived back at Midas to find this:

Oops.
Now re-do it.

They eventually got the pipes coming out the center of the GFX section. The rest of the exhaust was questionable, but....it's what we had to work with (warranty job).

So, now on to cardboard testing. I like to use foam core for this stuff. It's a little more solid than regular cardboard.
Here's the basic box:



(note the center support. More on that later)

Test fitting the foam core tip:


...and it'll go deep enough that you won't be able to see the 'back' of the tip unless you bend down and look almost directly into it:

(I think we took another 1" off it's overall depth)

Think foam core is all glamorous?

Think again. :grin:

After some minor tweaks, we settled on this:




Another test fit session (with level check):


Pipe attachment locations were sketched out and cut as well using left-over pipe chunks from the...ahem..."custom exhaust" job:


The foam core unit was taken to Flood Heliarc for it to be cut and welded together.
I opted for .125" 6061 T-6 aluminum for several reasons:
- Nice and light. Since this isn't load bearing, aluminum will work fine.
- Cheap....and plentiful. Most pieces could be found in the scrap pile from other jobs!
- Easy to form/bend. The side panels actually 'twist' slightly in order to shape correctly.

The pieces got cut, and then welded together:



(not bad for his first time welding, eh?)


The slots on the back face serve several purposes:
- They reduce drag on the back face of the tip.
- They allow air flow into the tip to keep it slightly cooler, and prevent it from melting the GFX.
- They look saweet! LOL

The original plan was to have them in a "V" shape; one on either side, but the shop did them vertical on both sides, then a small section in the center. I wasn't diggin' it at first, but it's grown on me.

Notice that there's no center support plate. The aluminum was thick enough that a center support plate was not necessary at all. It really is a heavy duty piece. You could stand on it, and it probably wouldn't bend.

The only difficulty would be how to attach the aluminum tip to the galvanized steel pipe. My welding guy is good, but he's not THAT good. LOL
So, I came up with another idea.
My welder told me about the possibility of some leftover aluminum pipe at the machine shop that I use (they do projects together). I called the machine shop and scored about 2' of GORGEOUS 6061 billet piping. With a quick reaming job, the aluminum pipes fit over the steel exhaust pipes, and would weld up to the tip without issue:



Another test fit session:


The fun part was getting the attachment tubes at the correct angle. When JimmyExhaustPro at Midas did the pipes, he didn't do them at the same angle, so we had to get the attachments tacked on, then angle them on the truck....hold it.....then have them welded into position:



Try that at home kids. I dare ya. LOL

It's odd, but the tip won't sit level or center until it's completely in position.
:grin:

Now comes one of my favorite ideas.
Instead of using standard pipe clamps (ugly), I talked to Keith about doing (3) set screws per pipe! The billet pieces were certainly thick enough to drill and tap, and set screws are way cheaper than pipe clamps, and smaller, and easier to maintain (on/off). Plus, it's pretty original for attaching an exhaust tip:

The one side looks 'off' because of the angle of that attachment tube. The set screw location had to be adjusted as well.

The last test fit session before being sent to JMB Performance for some powdercoating:

(the roll pan was being worked on at the time of the photo)

CONTINUED IN NEXT POST....(25 pics per post limit...sorry)
©2008 Kevan J. Geier
All Rights Reserved

[Kevan]

CONTINUED FROM PREVIOUS POST....

Less than a week later, the tip is back:



Damn JMB does some nice work!

Exhaust is on, and set screws are tightened:

(red loctite, of course...heh heh)

Finally installed:

DONE.

The truck sounds a *little* different. Slightly more 'focused' than just those two "machine gun barrels" that were on there before. It's nice and smooth though, without being top fuel offensive.

Plus it looks kickass!




GIGANTIC thanks to Robin and Brian at Flood Heliarc (Columbus, OH), and to Rich at Exact Machine (Sunbury, OH). The deals they cut us for this project were the best I've ever come across doing custom work.
THANKS FOLKS!

©2008 Kevan J. Geier
All Rights Reserved

[Malu59RT]

I enjoyed reading this. I'm guessing you are a ME what kind of work do you do (I'm a design engineer at an energy services company and use Solidworks at my job all day).

[Kevan]

Actually, I used to work on motion picture and video equipment.
A few years ago I invented a device for electric guitars that's turned out to be extremely popular. That's my full-time job now.

I don't have any formal ME training; just scars and burn marks.
I do, however, LOVE SolidWorks.

I'm glad you liked the pic-story of the project.
I'll do more in the future, but try to stick to Viper-powered stuff.

[Kevan]

Keith took some daylight pics today (in the rain):











The roll pan with the 'stripe' is completely temporary. SirMichaels is sending out a rust-free replacement. It will soon be all yellow again.

With the new roll pan, the GFX can be installed properly (no gaps on the outside edges).
That will also bring the GFX pieces out to the same level, and approximate angle, as the new tip. New paint on those too.

I'll post completed photos once everything is back from the painter and installed.

[plumcrazy]

i like it.

on my old 98 ram i used tips from a 70 challenger and did the cutouts, it looked like it should have from the factory

[DrDJ]

What a waste of time and effort.

DrDJ

[Kevan]

Originally Posted by DrDJ

What a waste of time and effort.

DrDJ

Why do you say that?

[dave6666]

Originally Posted by DrDJ

What a waste of time and effort.

DrDJ

Originally Posted by Kevan

Why do you say that?

Really. Just because you don't like it or wouldn't spend your time doing it that isn't a green light to be a Tracy. One could say, "Looks sweet, but it's not for me."

[propsail]

Makes me wish I had talent. Nicely done.

~Craig

[plumcrazy]

its a lot of fun doing these kinda projects for yourself

[RobZilla]

Fantastic work. Enjoyed the write up and all the pic along the way. I always like to see what other people can custom create. I agree it looks better than stock.

DrDJ