ATP cat delete racing downpipe

**kyran A4** · 07-09-2008 01:44 AM

I heard some negative things from my mechanic today about this. He said it causes the car to lose low end torque which is already really bad in the 1.8T. Is this true or was he pulling my leg? He told me that straight pipe high flow cats were the way to go because it doesnt lose the low end torque... ?

**kyran A4** · 07-09-2008 10:23 AM

bump

**RED1.8T** · 07-09-2008 12:28 PM

Not 100% sure but I would call bullshit

**Groove1797** · 07-09-2008 12:50 PM

Originally Posted by kyran A4

I heard some negative things from my mechanic today about this. He said it causes the car to lose low end torque which is already really bad in the 1.8T. Is this true or was he pulling my leg? He told me that straight pipe high flow cats were the way to go because it doesnt lose the low end torque... ?

Your mechanic is wrong. Back pressure is necessary for N/A cars but not turbo charged cars. The 1.8t (especially with a ko4) shit loads of low end torque and with a test pipe the power will come on faster and harder

**mike-2ptzero** · 07-09-2008 01:15 PM

Actually it is some what true, because it is a internal wg turbo not external. The exhaust will always take the path with the least resistance and by decreasing the back pressure just behind the turbo means the resistance at the wg opening will lower more then the resistance thru the exhaust wheel. This will cause the turbo to take a little longer to spool up and reduces low end power.

**SlappyB6** · 07-09-2008 01:19 PM

I put a test pipe on my car only because the cat was going and I didn't want to spend $1100 to replace it. My car is out of the federal emissions warranty, too. The turbo spools much sooner and pulls harder, but I think I lost a little up top.

**Killerteve** · 07-09-2008 01:38 PM

Originally Posted by SlappyB6

I think I lost a little up top.

That's where the butt dyno lies. One of the main reason to go with a free-er flowing exhaust is to have more volume for the air to flow out at all rpm's, especially top-end.

**ComfortRacing** · 07-09-2008 01:38 PM

i have a ATP test pipe on my 1.8t and have noticed no such thing but increased spooling and sound. i would thank him for his opinion and ask him kindly to install it.

**audikid66** · 07-09-2008 02:56 PM

yea with out a doubt i think he is wrong.. wen i installed mine all i felt was wayyyy better throttle response..meaner exhuast tone, and pulled harder and at lower rpms..

**SlappyB6** · 07-09-2008 03:35 PM

Originally Posted by Killerteve

That's where the butt dyno lies. One of the main reason to go with a free-er flowing exhaust is to have more volume for the air to flow out at all rpm's, especially top-end.

Quite possible. I did beat a late model Grand Prix GT just the other night to 80. Pulled him by about 1 car length to 80, and I revved it to at least 6K or 6.5K.