Ispeed

Get the Borla, you can mount it yourself and you won't be disappointed.

vanster

Cat question.
When I bought my '80 (California car) it did not have a cat but it does have after market headers that
went into a Y pipe then back thru the small muffler then into the stock real muffler (stock). It sounded great and ran strong. Of course to get past smog ( which it almost passed) I had to add a cat. It now feels like a potato was has been shoved up the exhaust and power is gone. I went back to the muffler shop in Berkeley and he told me I was nuts and first of all headers don't add anything and the cat does not reduce power. I asked him to take off the cat because I had passed smog ( before I found out that this was a felony offense...sorry about that. Now I am looking into finding an old cat and gutting it ( fake Y pipe) or even more drastic is to gut the new cat and deal with it in 2 years.
I have been told by others that headers add hp and the cat does take away power in early cars
Thoughts?
Van

Erik N

I have run the factory exhaust w/ stock cat, w/ gutted cat, and w/ modern high-flow cat.

The latter 2 both have a loud snarl. It is that old-school cat that quiets the thing down.

philesk

Most will agree that proper headers DO increase power, but only if other more restrictive elements are also improved and the car is retuned to take advantage of the higher flow rates.

I think many cats DO also reduce power. There are so-called 'high-flow' cats which may not reduce power. Since all new cats are expensive, I wouldn't recommend gutting a new cat. Better to find a junk cat and partially gut that one. You might be able to experiment with just how much cat 'material' you can remove and still pass smog.

concor

On the German ebay if you look for '928 Auspuff' you'll find several mufflers for around 300 euro: http://shop.ebay.de/i.html?_nkw=928+...aspufft&_rdc=1

google translate is your friend

Landseer

I've tried a number of setups and still prefer stock exhaust over everything else for street driving.
Second choice is use of newer generation high flow cats in lieu of stock.

Carving them up, going for noise and the last bit of power, that just seems a bit juvenile, especially on a 25 year old iconic classic GT car.
Might work on a Mustang or similar. Seems counter to the image on the 928.

vanster

Great points by all. I might go back to a Y pipe and save the cat till inspection time.
Thanks:
Onwards and sideways!

philesk

Well, it's done. The muffler fit fine. I did use a muffler shop to install. They bent a custom short "S" pipe to tie the new muffler into my mostly ANSA system. Came out great! Cost was $45 for muffler and $80 for install labor. Sound is mellow and slightly louder than OEM, but not as loud as my recollection of a Borla system I once heard. Just fine, if you are not after a hot-rod type racket.

Landseer

Nice solution.

concor

That muffler was only $45? What an awesome idea! Get a custom pipe that costs like nothing to avoid the 300 euro pricetag of the 928 muffler! I like it! Thanks for the great idea!

philesk

Yes, my all-in cost was only $125. The stainless steel muffler was actually only $24 on eBay (+ $17 S&H + $4 CA tax). We did have to trim a tiny bit of the plastic wheel well liner for clearance.

BTW, this muffler comes in all stainless, stainless fully ceramic coated black and ceramic coated but exposed tips (mine).


The all stainless version is only $18++ here:

http://cgi.ebay.com/ebaymotors/ws/eB...ht_6392wt_1083


And the all black version is here:

http://cgi.ebay.com/ebaymotors/ws/eB...ht_6448wt_1139

Fortunately, the remainder of the system was in good shape, so I didn't have to replace the whole cat-back.

911tracker85

I was about to get a magnaflow to replace my pumkin. this looks very nice and good price.

I had replaced the cat on my 84 with a Y pipe as it had an exhaust leak. otherwise the rest is stock.

I have come to the conclusion the baffles in my pumking have rusted out. w/out cat is too loud and when you back off the pop - burble sounds horrible. like coming from an empty garbage can.

thanks for the post.

philesk

On our early cars, the cat does most of the muffling. The muffler I used probably doesn't do much in the way of quieting. When I looked into the dual outlet tips of my new muffler, I could see straight through to the internal "Y" split and out the single inlet hole. I think there is little to no baffling in there.

Magnaflow products are very well regarded. Some independent testing has shown Magnaflow to have better flow rates than Flowmaster. That said, the Magnaflow may not quiet your beast much.

Therein lies the advantage of dealing with a good, professional muffler shop. Generally they will let you try out various combinations to get the sound you want. If you start out with the pumpkin just lopped off, you will then have a baseline sound check. Then you can maybe try out different mufflers to try to rid the pop-burbles. My guess is that you may have to also change the middle muffler to something with more baffling if a new rear muffler doesn't accomplish your goal.

For comparison, my other 928 (90GT) with stock exhaust system was slightly louder than my new 82 setup. With the RMB, the GT is really fairly raucous. Even though it still has the middle muffler, the GT has dual exhausts and high-flow cats standard (which in another post were deemed to add more noise).

philesk

Where did you go in Berkeley? I used Muffler Works in Albany. Mitch is a wizard. He does a LOT of custom work -- everything from Ferrari to hot rods. And, he has a wicked 914.

For a used cat, try EASY in Emeryville.

philesk

My new muffler weighed 9 lbs. as shipped. But shipping to the Netherlands?
And, you will need to find a muffler shop that has proper tools - tubing bender, flare maker etc. It took my muffler guy less than one hour to do everything,