Printable Version of Topic

Click here to view this topic in its original format

914World.com _ 914World Garage _ 2.0 muffler hacking

Posted by: scooter311 Nov 11 2004, 11:07 AM

So who here has hacked up a muffler for their car? I have the strange desire to make something custom for my car, and toss the monza that's on it now. I remember seeing a couple posts fromma while ago about someone taking a banana-type (don't recall if it was Bursch or whatzitwas) but the guy cut 2 holes in it and welded on some tips from like Pep boys or something. He actually did a nice job of it too - looked like a 911 style.

I would like to try something similar, maybe like a boxter style (with the tips closer together)- I'll be bored this winter, and seein's how all the big projects are done, I'll have time to sit around and really ruin something up good.

Anyone remember or have pics/links? Or recommendations? Laugh at me? Cheer me on? Send me cash?

Posted by: ClayPerrine Nov 11 2004, 11:30 AM

I don't have it here, but in an old copy of Upfixin Der Porsche there is an article that tells how to make a stock 911 muffler into a sport muffler. You open it up, remove some of the baffling, and add 2 new tips straight out the back.

I thought about doing that , but decided to just use a burscht on my car.

Posted by: scooter311 Nov 11 2004, 12:50 PM

Yeah, that's what I thought this guy did - thee was also a post where another guy fabbed his own for a six that had 2 smal, round mufflers and a balance tube.
What would be a good muffler choice for a hackup ?

Posted by: Eric_Shea Nov 11 2004, 01:47 PM

I just finished the Up-fixn Mod on my 911 muffler. Relatively easy. Went to Midas and they "gave" me a 12"x2" scrap from their trash bin. (2 6" pieces needed).

I used a 2" hole saw and carefully cut the holes. It's double layer stainless... PITA to cut. I used a cutting wheel on the original single outlet and took that material and flattened it to make a patch. Took it to a friends shop who had a cutting torch for the internal baffles. We then welded on the pipes and painted with POR-20 "Manifold Grey"

Pics later...

I would imagine a 2.0 muffler might be a good candidate for this. If you've got a 911 or 914-6 then buy Z's in the classified section. At $150 it's a good deal.

Posted by: scooter311 Nov 11 2004, 02:26 PM

Ahh great tips - they what I be lookin' fer.
Eric, how much of the baffle did you remove? ie. just the portions where the new holes are cut? That sounds like what I have in mind.
I don't know what these look like inside, so pleeze forgive all the ????s

Posted by: Eric_Shea Nov 11 2004, 03:15 PM

It would probably be best to wait for Clay to find that Up-Fixn pic. (I have it on my other computer) but...

Looking at it from the rear of the car, you go in the left hole and torch a (roughly) 2" hole in the baffle (it's horizontal across the center so, in and up). The you take a left turn once your up and inside the baffle and torch another hole in the end of the baffle. All this is done on the top 1/2 of the muffler internales (does this make sense?)

Posted by: ClayPerrine Nov 12 2004, 06:59 AM

Sorry.. I don't have an electronic copy, just the paper one. Eric, if you have one on the computer already it would be better than the scanned version.

Posted by: Eric_Shea Nov 12 2004, 10:23 AM

I tried posting a Word doc. but that got a little funky. I made a PDF of it. Try this...

Attached File(s)
Modified_911_Muffler.pdf ( 71.25k ) Number of downloads: 109

Posted by: Eric_Shea Nov 12 2004, 10:23 AM

Same deal... I guess you'll have to right mouse click and "Save Target As"

Posted by: Eric_Shea Nov 12 2004, 10:36 AM

I would make one other "crucial" suggestion before slicing away on a good 2.0 muffler.

Get Brad involved in this thread.

I believe he's had some experience working at SSI and they've had each and every one of these things taken apart. He can probably tell you if the guts of the 2.0 muffler match the ones in te 911 muffler in the drawing.

My Camera took a dump on me mid-way through the project so we miss the torch work and the welding of the tubes back on...

Attached image(s)

Posted by: Eric_Shea Nov 12 2004, 10:36 AM

Close up of the hole

Attached image(s)

Posted by: Eric_Shea Nov 12 2004, 10:37 AM

Next to go...

Attached image(s)

Posted by: Eric_Shea Nov 12 2004, 10:38 AM

Lopping off my member...

Attached image(s)

Posted by: Eric_Shea Nov 12 2004, 10:39 AM

Post-Op

Attached image(s)

Posted by: Eric_Shea Nov 12 2004, 10:40 AM

New tubes... this is where the camera started to go south on me (could be because it fell off the trunk of the GT project... )

Attached image(s)

Posted by: Eric_Shea Nov 12 2004, 10:43 AM

Remember... those tubes (with the nice green hue) in the previous shot were "f-r-e-e" (a favorite word amongst listers here). Go to your local muffler shop and ask them if they have a 12" or longer piece of 2" pipe.

Attached image(s)

Posted by: Eric_Shea Nov 12 2004, 10:44 AM

Final product. Shot with the new camera a few minutes ago...

Attached image(s)

Posted by: Brad Roberts Nov 13 2004, 01:02 AM

They are different on the inside.. but only the size of the holes in the baffle plates (911 is larger) All you are doing is allowing the exhaust to exit prior to entering the last chamber when you do the "sport" mod. They have a "Rallye" mod also where the tips are farther out and access the chamber later than the sport. This is typically a tad quieter than the sport. You can see in Eric's pics where the vertical baffle plates are located (see spot welds)...

Pretty easy mod. The 2.0 4 cyl sounds "ok" at best when that lower chamber is opened up.

B

Posted by: tracks914 Nov 13 2004, 08:42 AM

I'm in the process of trying something else.
I took a spare 1.7 muffler and cut the back half off of it. I looked at how small the holes in the baffle pipes were so I drilled them bigger and also added a few holes in the dividing baffles to release backpressure from the ends.
I have now made a new back half out of SS and I am looking for a nice piece of 2" SS pipe to replace the 1 1/2" exhaust pipe.
When I find that I am going to weld on an oval cadillac exhaust tip to exit in the stock position.
Pictures to follow as I progress.

Attached image(s)

Posted by: tracks914 Nov 13 2004, 08:42 AM

See how small the holes were?
The entire engine exhaust has to go through these small holes + one more row on the other side. No wonder they say thses exhausts don't breath very well.

Attached image(s)

Posted by: Eric_Shea Nov 13 2004, 09:43 AM

Insane Doug

Keep us posted...