3" Cat Back DIY (lots of pictures now)
 

I'd rate this as easier and less messy than changing the oil in our cars (but more time consuming). These pictures are before welding it all together obviously.
http://i170.photobucket.com/albums/u...t/100_0742.jpg
http://i170.photobucket.com/albums/u...t/100_0743.jpg
http://i170.photobucket.com/albums/u...t/100_0744.jpg

http://www.summitracing.com/
45* Bend P/N MPE-10739 $21.95 x 2 = $43.90
Magnaflow Muffler P/N MPE-14219 $101.95
12" long Exhaust Tip P/N MPE-35104 $35.95
Total Cost $181.80 + Shipping

*Note: I just reused the flange and hangers from the old beaten ANSA catback. My father welded it so if you can't weld, and don't know someone that can, it will cost more. Should still be way less than buying a catback though.....

Also, I wish I had bought a 14" long tip instead of a 12" long tip. We could have used some of the extra 3" pipe we had to extend it out but we opted for doing only the one weld to the muffler.

Looks like a good project and an excellent cost saver.
Let's see some pictures of it installed!

Wow thats and excellent DIY! Great prices too! now what about a straight pipe piece? :D

Instructions...

Tools Needed:
*Chop Saw w/ a metal cutting blade/ "wheel"
*Sawzall (or hacksaw)
*Welder
*Wrenches for disconnecting cat back. (I can't remember what sizes but I think my old ANSA was held on w/ 13mm and 15mm bolts)
*Jack and jack stands (we used 8, but then we never get under and fully lifted car that doesn't have alteast 6 jack stands under it)
*Sharpie or paint pen for marking where to cut

1, Disconnect battery (the most important step before welding on your car...)
2. Put car on jack stands
3. Remove old cat back
4. Cut off flange w/ chop saw
5. Cut off hangers w/ sawzall
6. Clean up parts for welding
7. Bolt flange to test pipe
8. Position new muffler under car and support (we used two jackstands)
9. Slide one of the 45* bends into the muffler and support (we used the hydraulic jack)
10. Hold up the remaining 45* bend to see where it needs cut to meet up with the test pipe and 45* angle.
11. Measure twice, cut once (using the chop saw)
12. Tack weld the just cut 45* bend to the flange such that it clears the rear suspension
13. Adjust the second 45*bend so it meets up nicely with the other bend and the muffler
14. Tack weld the second bend to the first and the muffler
15. Carefully remove from car
16. Weld
17. Install
18. Enjoy

After writing the instructions I guess it's probably harder than an oil change, but less messy and less frustrating (that oil filter is a bugger).
I'll go take some pictures.. On my car the wastegate dump pipe hung really low after installing a Tial 38mm so we shortened the wastegate dump and made the cat back longer (w/ another 3' of Stainless)
Btw: the popular Borla 40944 is #149.99 and part number BOR-40944

Here's a photo of it out on the lawn the evening we finished it.
http://i170.photobucket.com/albums/u...t/100_0758.jpg

Dad says his welds are embarrassing but I think they're pretty good for his first time welding stainless... These pictures are far worse quality!

http://i170.photobucket.com/albums/u...exhaust001.jpg
http://i170.photobucket.com/albums/u...exhaust006.jpg
http://i170.photobucket.com/albums/u...haust002-1.jpg
http://i170.photobucket.com/albums/u...haust003-1.jpg

The second shows that there is plenty of clearance around the sway bar (a little less than an inch, but I've pushed on it and there's no way it'll bounce into the sway bar and rattle)
They all show that underside of my car is filthy!

nice job!!

that looks really good! Those welds look good to me. I'd say learn everything you can from your dad :)

wow, that's brilliant especially considering the ridiculous prices of 951 exhausts!

how does it sound? how did you chose the muffler?

also curious how the ANSA sounded as i have one on one of my alfas and it sounds incredible.

Thanks guys!

It sounds much louder than before when you get on the throttle but not all that much louder if you're just putting around.

I chose the muffler based on recommendations here on Rennlist.

You can see the ANSA was quite beat up and leaking at the front of the muffler. It was also a straight through design like this Magnaflow is but it was WAY quieter. Boring even! I was worried that the change to 3" from only the wastegate back would be insignificant (especially considering the old muffler was straight through as well). Not the case! Now it sounds deeper and it really howls under boost :) Also, I have to richen up my tune now..
What I can't understand is why the Catback typically costs MORE than the test pipe. If your were to build the test pipe you'd have to buy tons of (expensive) mandrel bends and it would be an absolute pain to get it to fit perfectly. This was $180 of parts that took nearly no cutting to make a cat back out of!! (not that I'm complaining... I'll probably buy a 3" test pipe someday and I'm glad it's cheaper than the catbacks!!)

lol I was just thinking about this yesterday, get a muffler and some piping, how hard could it be ... if only I could weld

LOL

looks good though, sound clips?

Nice Job, I'll might be doing the same since some tuners want $600.:evilgrin:

Nice! Glad to see more DIY for cat back. No need to spend those prices on cat back.

I did the same years back with a 180 curve piece and straight pipe from Summit and a flowmaster from ebay and was about 100$ in parts and $100 for an exhaust shopt to fit it and weld for me.

Tell your dad his welds look just fine! :)

Whats great is how the two 45 degree bends work perfectly together without hardly cutting any off the long side! That's awesome.

I'd Better get some pics of mine posted .
I''m using the gutted cat as kind of a empty resonator expansion chamber style thing .. I'm also using the standard down pipe with the inside cut out so its like 2.8"