3785 Gets a 400 swap, fabbed 180's and fabbed mufflers

quote:

Originally posted by tajon:
that is amazing. WOW!

What would be the advantages to using the 180s vs. the undercar or longtube type design?


On a side note, after all this work is 375 HP going to be enough?

Tajon that is a very good question.

The advantages and disadvantages of the 180 design was discussed here. I think you will find it interesting.

http://pantera.infopop.cc/eve/forums/a/tpc/f/5650045562/m/7540041375

I am going to start pretty tame on the engine and work up from there. Initially I think it will be fine to get the rest of the car sorted and get the thing on the road. This will also give me a good chassis dyno baseline to decide if I need to make a header change and or what engine changes I might need to make.

So I guess the answer is, initally yes it will be enough but later on probably not.

Brooke, thanks for the link. It was a great read with lots of youtube in between. The 180s sound sweet. Are you going to video your dyno testing with the different headers?

I'm wondering how much louder are the 180s?

quote:

Originally posted by tajon:
Brooke, thanks for the link. It was a great read with lots of youtube in between. The 180s sound sweet. Are you going to video your dyno testing with the different headers?

I'm wondering how much louder are the 180s?

I hadn't thought of shooting video but that might be a idea...

I have no idea how much louder or not the 180's will be.
Most people I have talked to just mention that the 180's are a completely different type of sound.

i'm still waiting for some video.

Me Too!
Seriously though, it will be a year or so until my car spins the dyno rollers.
Lots of work yet to do.

The pipe did come in the other day for the 4-1's
so I can start fabbing those as time permits.
Then its on to further adapting /fitting the 400.

It looks like my other winter projects are going to turn into early spring. Then I should be able to get back to work on the Pantera.

quote:

Originally posted by Pittcrew:

It looks like my other winter projects are going to turn into early spring. Then I should be able to get back to work on the Pantera.

Amazing how fast the clock tends to spin some times!

It’s been a long time since I added to my thread, thing always seem to get in the way
of working on the P car. I have been working on this current project since February.

I want to thank Gary Walker and Johnny Woods for their advice and support so far during this segment of the build.
I haven't ever built anything like this before and it was nice to have their input.

While working on non P car related projects this winter I had been thinking a lot about the exhaust system to hook to the 180's.
The obvious choice was to hook up some short glass packs and exit out in the side of the engine compartment then out the factory opening in the back of the body. This is what most people have done in my situation where they want to keep the A/C

I just wasn't “feelin” it.

I did a search on the PIBB for "exhaust" and had over 150 hits! Pantera people care about exhaust for sure.

I love the look of the ANSA's out the back of the car. IMO They work with the styling of the car so well they almost qualify as a styling que.

I decided to route the exhaust differently than was usually done with 180’s. I decided to hook them to some used L model ANSA's that I bought to modify. I have a brand new set of Ansa GTS mufflers but having paid Hall over $800 for them I'm not about to cut them up.

After all the talk of how badly the ANSA's rob power I decided to mod the inside of my used ANSA’s

Then I would take and hook them to my 180's in a way that I can also use them with the 4-1's.

After making the decision to go with the ANSA's I felt better.

Now I was “feelin” it.

I also realized a mistake I made with the collectors on the 180's.
Having the collectors attach the way I did with the bolts won't allow them to hook up the same every time. This will make the exhaust system angles subject to changing and requiring a lot of tweaking to get them in the right place again. As any movement in the collector will affect how the exit pipe and muffler sits.

I decided to cut off the existing collector mounts and go to the commonly used collector tabs to be able to mount the collector with better orientation repeatability.

I could have welded stops on the tubes to locate for the bolts but I liked this idea better.

Then my imagination started working(uh oh..) and I thought if I am changing the inlet pipe, gutting and changing the internal ducting and changing the rusted resonator tips the only thing I am using is the can body.

Hmmm with some simple forms I could make my own can bodies I have a bead roller so I can put ribs in them for strength build internal ducting weld on some tips………(insert snowball getting larger and larger here)

I realize this would add a bunch of work to the project. Maybe it would be better just to use the existing cans to keep it simple.

Since when has any part of my project been kept simple?.......

I believe there are two problems with the typical ANSA system, the Inlet tube diameter and internal baffle architecture and sizing.

I have both a New GTS set and the used US based L model set for comparison.

The U.S based L model system is a joke. It has a 1 3/4 tailpipe entering the can and exiting through two 1 1/2 I.D. resonators.
Probably not a very good flowing system.

The GTS system is a little better. The inlet pipe is actually a odd size and measures 2 3/8 O.D. The resonators are a slightly different design than the L system and have a ID of 1 9/16.

Johnny Woods did some work on a GTS ANSA system.
Here is that thread.Great work here.

http://pantera.infopop.cc/eve/...0045562/m/4600039074

I had been PMing Johnny questions about the internal baffling dimensions.

It was interesting, he told me that at the inlet entrance the 2 3/8 tube is actually necked down to 2 inches through the inlet perforated tube.

In his opinion the exhaust exiting through the necked down perforated tube into the small perforated inlet tube of the resonators was the largest restriction. He felt that the area of the two resonators was sufficient to the inlet size but the perforated tubing was by size and routing the restriction in that design

I did some area comparisons out of curiosity.

On the US made ANSA the areas are:
Inlet of 1 3/4 has a square inch area of 2.142
The two 1 1/2 resonators have a combined area of 3.086.
The statement can be made that the mufflers capacity to exit exhaust is greater than the tailpipe can introduce based on in/out areas alone.

GTS Muffler
Inlet of 2 3/8 has a area of 4.070
Necked down to two inches the area is 2.840
The combined resonator outlet has a area of 3.354
The same statement can be made again that the exiting area is greater than the inlet area.

What I am thinking of building is this configuration.
Inlet 2.5 inches area 4.529
Internal V shaped baffling out of two 2 inch od perforated tubes area 5.68
exiting into 2 ¼ inlet 3 inch outlet tips
I feel that the ability of this design to exit is greater than the inlet area

I believe using ANSA resonator tips might be a restriction.

*All areas were calculated as .049 wall tubing.

Normally I would sit down and list the criteria I wanted the mufflers to meet. Since I have no idea what I am doing I didn't know what to list!
I figured I would make it up as I go.

To get started I wanted the mufflers I was making to be a similar style to the ANSA’s
I made a generic muffler shape and traced it on to a 2X4.



I did this to six of them then cut out the shape on my band saw. I then glued and screwed them together. Because my bandsaw skills aren’t the best I used some body filler to make the shape uniform on the sides and marked a center line.





I cut out four pieces of 18ga cold rolled sheetmetal measuring 12X8 for the top and bottom of the muffler can.
I marked out where I wanted to put the beads for added strength and rolled them with my bead roller. I used a 3/8 roll set and at the tension I was using the beads are ½ inch wide.





I marked the center of the sheet and used a piece of angle iron to clamp the part to the forming block and work table.



I used a plastic hammer and bent down the side until it matched the shape of the form.



Because the metal has spring in it I inserted a steel ruler under it to over bend it so when it sprung back it would be the right shape. I did this to both sides until the shape matched the form.



Then the part was put in my brake and the edge bent up.





Here is a finished part next to a blank sheet that will be the top to the other muffler.

Awesome!!!
I am not sure if I helped you but I have always been inspired by you welding and fabrication!

After making the other top I put the two together to check aligment and overall shape. I was very happy with the result.



The reason those parts were the tops is because I wanted to incorporate a different design feature into the bottoms.
I started by reversing the Isis logo and cutting out a stencil and marking it with a sharpie on what would be the inside of the can.



I rolled the long side beads into the part then installed a 1/8 inch roll set and rolled the Isis emblem. I traced the emblem reversed so I could track it with the small round part of the roll set making it easier to follow the shape. At the tension I was using the bead is ¼ inch wide.

I realize only road kill or very small animals will ever see it on the bottom of the muffler but it was a touch I wanted to add.

I started building the form for the end caps out of a 1X6 piece of Maple. I cut two pieces and glued them together in the press using Gorilla brand hard wood glue.



I cut out the shape and used a ½ radius bit in the router to make rounded edges. This gives it the same curve as a 1inch diameter circle.





I made a 1/4 inch thick steel plate to act as a retainer for the ends while forming them.



Next was to try a experiment to see if I could flare the holes for the opening and exits in the ends. I bead rolled some circles in a piece of scrap and hole sawed one of them and it fit the tube perfectly and had the effect I wanted.



I cut out the four pieces that were to be the ends and bead rolled the appropriate circles in them.



I cut the reliefs into them and tapped them over with a small hammer. Then I bolted the form plate to the backside.







The top and bottom halves were clamped together and the end tapped in backwards from the top for welding up the relief cuts. This insured it would have a nice fit after welding.



Here are the ends after welding and grinding.



I built a fixture to hold the ends square and then screwed on the tops and bottoms.

I took them back apart and hole sawed the ends I used a 2 ½ hole saw for the inlet side and a 2 3/8 for the outlet side.



The tips I used are Hooker they are 2 ¼ inlet and 3 inch outlet.





These are the same tips midenginemike used in his muffler thread here.
http://pantera.infopop.cc/eve/...562/m/4850059725/p/1

The tips are slash cut but the angle is very shallow so I measured the original Ansa tip slash cut to see what the difference was.
I liked the steeper angle of the Ansa’s better so I decided to match it.





I marked the tips for the new angle and cut out the metal with a cut off wheel. I put them on a belt sander to clean up the edges. Here is a before and after comparison.





Here are all the parts lined up ready to begin building the fixture to weld the tips to the ends.

The GTS Ansa mufflers have the tips exiting at an angle. I like the look of this so I decided to match the angle with my tips.



I screwed the bottom on to the ends and mounted them into the same fixture I used to square them and welded the jig to locate the tips.





The reason I used a 2 3/8 hole saw on the tip ends of the can is because of the angle the tips.It could not be angled up with a smaller hole. I taped the tips to prevent weld spatter from getting on the chrome and welded them to the ends.

Next was to build the internal piping. I bought a 4ft long piece of stainless 2 inch dia perforated tube. It is a magnetic alloy so it can be welded conventionally using ER70S2 rod or wire.

I purchased it from here:
http://lachoppers.com/perf.php

I constructed a V similar to what Johnny Woods did in his thread.





In order to get a good fit from the perforated tubing to the 2 ½ inch inlet pipe and get a good surface to weld to the end cap I welded a ½ wide piece of tubing to the end. This piece was a 3 inch piece that I cut down to fit snugly to the outside of 2 ½ tube.



For the tip ends I made a simple offset reducer cone to go from the 2 ¼ tip to the 2 inch perf tube. The offset was for the angle the tube enters the tip.





Here is a view from the end of the tip showing the fit at the entrance



Here are the pieces all done and ready to be welded in. After welding into the muffler can I will wrap them in fiberglass muffler packing.

Before welding the baffling I assembled the cans. I want to fit them to the car and build the hanger brackets, route the exhaust pipe to them and build the inlet tubes.
Here they are as they sit now compared to my new Ansa GTS system.

I will post more as progress continues.

Brooke,
I have to tell you something, wait a minute while I wipe the drool off! Awesome! Seeing all of this makes me feel so useless. I truely admire your talent! Great job and thanks for sharing with us!

quote:

Originally posted by Rapid:
Brooke,
I have to tell you something, wait a minute while I wipe the drool off! Awesome! Seeing all of this makes me feel so useless. I truely admire your talent! Great job and thanks for sharing with us!

Rapid, you are hardly useless, your car has been an inspiration to me and I am sure others in many many ways.
Thank you for your kind comments.

quote:

Originally posted by comp2:
Awesome!!!
I am not sure if I helped you but I have always been inspired by you welding and fabrication!

Gary you have been a big help.
Its nice to bounce ideas off of someone who is like minded.
I was definately in the dark on this one having never built a muffler in my life.
It was nice to get yours and Johnny's input.

Damn, I will EASILY pay up 50 bucks to get a pair of those Isis silencers!!