So I've just recently replaced my cat with a 3" test pipe. (Totally feels faster, stronger, and harder) I've run a straight downpipe before, I posted a few pics and vids in a thread. I wasn't worried about backfiring or backpressure before because of the cat, but now I wonder if it is safe to attempt this for a day. I want to know what it would sound like with a straight exhaust dumping under the car. Am I in danger of backfires toasting/igniting my undercoating? Will the lack of backpressure do anything besides reduce my turbo's power? I dont want to spend money on a downturn peice for this little gag thing.

So I open up my thread to you haha.

 

I went around the block like that, sounded like ****. smelt up the cabin, and was hot under neath when i went to put the rest of the exhaust back together

 

haha, so you would recommend no? I'll be driving no more than 10 miles, just want to get some noise for awhile.

 

Nah, why bother risking it? Just to annoy the neighbors? You have a little 1.8T, not some monster V8. So, be sneaky, be stealthy, put the exhaust back together, and surprise the **** outta the the guys with the big loud V8s (who make it loud just to sound loud).

 

Test pipes are good if you want to build more power because cats restrict flow.

Will the lack of backpressure do anything besides reduce my turbo's power?

No. You want just enough back pressure to make all your emissions **** run. This is why all hi-power diesels are running 4" exhausts at the minimum. If you have a high or stock pressure exhaust system then the turbo and engine have to work harder to push the exhaust out and now you're loosing power.

Am I in danger of backfires toasting/igniting my undercoating?

No. Test pipes are one of the oldest tricks in the book to pass visual emissions while running a straight exhaust.

As for the sound factor; run it for a day or so and see how you like it. Everyone is different and you may like the sound and smells.

 

if you were in my neighborhood you would have bullet holes in the side of your car.

the only backpressure you need is produced by the turbo. you need it so that the valves operate correctly. on a N/A car, exhaust size matters. it doesnt really on our cars.


he said he wants to run without the exhaust, from the test pipe directly to atmosphere. which is a terrible idea.

 

I can think of a million better things to do. Dont waste the time, or **** of your neighbors for no reason.

 

O. My bad. I left my reading glasses at home.

 

i wouldnt think a 4 cy would sound good w.o a pipe if you want louder get the cats hollowed out

 

Wha...?