gergstuff

I have been scouring the forums for ideas, since I am doing this at work and work keeps getting in the way it is taking awhile.

I was hoping someone could help me cut to the chase.

Seems like a Y pipe is a good idea to replace the catalytic converter but the only pre-fabricated y-pipe I have found thus far was over $700 which is a bit rich for my blood. Can someone suggest a source for such an item for the budget minded consumer (me)? Would it be cheaper to have a local shop fabricate one for me?

Second good option I have gleaned is for a rear muffler replacement with a set of straight pipes. I have found several vendors that offer such a thing but all seem to be geared for models much later than my '78. Again can someone steer me to a source for a rear muffler replacement for a '78 or is local fabrication the only way to go?

Thanks for the help!

Craig

linderpat

I have a full custom exhaust by Tom Cloutier of CA on my 78. It is cat delete, y pipe, into a magnaflow muffler. It is the best sounding 928 I have ever heard. I do not believe he does these any more, or if he is even still around. But here is an old thread that you may find helpful: https://rennlist.com/forums/928-foru...rk-of-art.html

Jadz928

Y-pipe from Dave Lomas @ Motorsport:
https://plus.google.com/108913758134...ut?gl=us&hl=en

Borla Cat-back from Summit (or any Borla distributor):
http://m.summitracing.com/parts/bor-14276

z driver 88t

The problem is the Borla setup is only a 2.5-inch exhaust. There have been a good number of exhaust dyno threads out there, but most suggest the 16V needs at least a 3 inch and up to a 3.5 to get the most out of it, assuming you are running a single exhaust . https://rennlist.com/forums/928-foru...aro-28whp.html

Unfortunately, there really aren't any off-the-shelf options other than the Borla. I believe most of the 16V owners are just cobbling together various pieces of 3 or 3.5 inch piping and having it fabricated at an exhaust shop. I've done that on other cars and it is pretty inexpensive. You just have to do all the leg work to decide what you want to do. I've also ordered aluminized steel madrel bends from JC Whitney of all places believe it of not, that did a great job of
being able to piece together a mandrel bent system on other cars.

Another useful threads
https://rennlist.com/forums/928-foru...dded-pics.html

karl ruiter

Somehow I have a Y on my '79. I think it happened when I had the car in LA and we cut out the cat and welded in a Y and put and aftermarket cat down stream. In any case my current configuration is a Y in the front , with a glass pack in the middle, and the tail end of a Borla cat back in the rear. Seemed like a good idea at the time but it sounds like crap. Also, on a CIS car without any cat in there, you get that unburnt fuel smell at times that you don't normally associate with a 928. So it sounds and smells like an old Camero. Not quite what I was after.

LT Texan

When catalytic converters came out, we all thought they smelled funny.

Petza914

I have the stainless 928MS Y-pipe on my '79 with Borla cat-back setup. Sounds pretty good and seems to work well with the SC setup as I'm getting about 300 HP & 300 lb.ft. (292 & 308 to be exact).

AirtekHVAC

Here is my Y pipe, made by my friend. Cat was cut out, and y was welded on.

Ad0911

How realistic is it to fit cats on a non cat 1978 car with CIS? It may be the only way the government will allow me to drive my car from 2016

karl ruiter

Fitting a cat on a non cat car is not a problem directly. You remove the front muffler/Y and bolt in a cat/Y. The question is how well will it hold up/ work with no O2, and no EGR. I assume your car has an air pump. The US CIS cars had no O2 sensor, so you should be ok there. I had Euro S heads on my '79 when I was in L.A. so no EGR. It actually passed California smog that way. One set of numbers was near the high limit and the smog test tech told me I might need to replace my EGR! So, basically, I think you should be fine.

ROG100

Stainless Steel Y pipe - About $600 with fitting kit and the Borla cat back.
We supply the Y pipe but search for the Borla and you should be able to get one for circa $600