I decided to flush out my exhaust with some high pressure water. All that came out was carbon-lots of it! So the exhaust is O.K.? Mike

 

Mike, did you ever watch that movie "Mouse Hunt"? Maybe you should...

 

Mach 1 Boom- Right over my head. NOT a sniff what your saying? Mike-Just thinking- does this have to do with gerbils too? Mike

 

In that movie these guys go to extreme lengths trying to get a mouse out of their house. It's actually a very clever movie. Anyway, near the end, one guy stuffs a hose in the mousehole and cranks it on. A short time later, the house is so full of water it collapses under its own weight.

Anyway... I'm pretty sure sticking a hose up your exhaust pipe and cranking up the water pressure is a BAD thing. That goes for your car too.

 

If I tried to flush my cat (or my cat's exhaust) I'd come away with some nasty scratch and bite wounds...

 

Technically speaking, the procedure is called an enema - wear rubber gloves and stand back!

 

just cut the cats off i did.

 

 

I did it on my 79 and they rusted out, watch for the water to settle, make sure it is dry on the inside.

Richard

 

Perhaps hook up two pressure guages and check for restrictions first.

 

Hi Jack 84- If I cut the cats off and go for straight pipes will it be any louder with the stock exhaust. And THE MAIN QUESTION any more H.P or any quicker throttle response. I'm not doing any mods for NADA. Thanks fellas'-Enema-sheesh!

 

Well straight pipes will be loud. People say not to cut the cats off, but my cat didnt want to last 20 years lol. You will be able to tell a diffrence. I would suggest removing the cats, the porsche mufflers resonaters if you have those on it and running a free flowing muffler such as a borla or flowmaster. My flowmaster is loud if you floor it. But just driving around it isnt loud. I had better throttle response but my cat was clogged.

 

Jessa: That was funny!

Mike: You can remove your cats and gain about a whooping 3% of horsepower while producing about 20-30 times as much toxic fumes. It's a really sophisticated way of improving your 928, following the hightest and latest American engineering standards. More than the HP it will increase your coolness factor by about 10, and your pride of having defeated both common sense and government pollution regulations will be immeasurable. Go for it - if you don't, you are by default a tree hugger and will be required to wear plaid shirts for the rest of your life.

Of course, there is an alternative: leave the cats as long as they work and then replace them with high flow metal cats that offer some neat "side effects", like similar power increases as removing cats AND lowering the 928s emissions below what even new factory cats could do. But that would be a really dumb thing to do, wouldn't it?

 

New cats cost money. Removing old ones costs me like 20$ at the local muffler shop. See where i live we dont have any silly regulations. Like california has.. I think it was a little more than 3% power anyway. Because before when i hit 2nd at wide open throttle it would just chirp the tire. Now it lays down some rubber so my butt dyno said it was goood.

So 3% of hp rated from porsche would be around 6-7hp roughly?
I dont think i would tell a diff of 7hp. It felt like it gave me 20hp. This could be due to it being clogged but there is no way im paying 150$+ for a new cat. Unless the government comes down here and tells me i have to.

 

Sad that sometimes it takes a government to make people do the right thing...