If I were to put a 3" piping from the cat back with the stock turbo would I experience boost creep or get any CEL's because there would be not enough backpressure?

 

Any input would be great. Thanks

 

you shouldnt have any problem doing that in regards to your CEL. In regards to turbo creep, not sure - but you dont need back pressure on this motor - the cat and 2.5" factory downpipe is suffiecient backpressure......why 3"? your downpipe is 2.5", do 2.5 and save some ground clearance.

 

Why not spend the money on a 3" cat and 3" downpipe and a smaller/normal exhaust for back pressure instead? I don't see what you're gaining with a 3" exhaust from a 2.5" cat/downpipe. From what I understand, a 3" cat and 3" downpipe going into a 2.5" or 2.75" exhaust should provide sufficient back pressure. Correct me if I'm wrong please.

 

Well, with 3" piping I know that the turbo will not get as hot(not by much but a little temp difference) and you are supposed to get less turbo lag because the turbo can spin more freely. I was just wondering about the boost creep because all the info I have is with turbo setups on japanese imports and I am fairly new to the tuning of Audi's. I realize that jap imports and Audi's are two totally different types of tuning and that is why I got out of the jap tuning world, and also why I am these types of questions so any feedback is helpful. So thank you, and keep the advice coming.

P.S. Lovin the forum. Lots of good knowledge.

 

i hade some boost creep with my turbo and it stoped when i installed a MBC. i have herd that 3" is a little over kill on a k03 but if a BT is in the works later then deff do 3" so you dont have to redo it

 

If your staying stock turbo use 2.5

 

u only need 3 inch when makin over 400 hp

 

Why? Tons of people are using a custom 3" or on the b6 and are nowhere near 400 with some of the BT setups. Like said if you are going BT gt28rs and bigger then a 3" will be fine, a little overkill, but most places dont carry 2.75" tubing which would be the ideal piping size. Milltek is 2.75" for the quattro but is pricey.

 

haha glad this was posted cause i was wondering myself about what size pipe to redo my system with.

i got the 2.8 v6 and was thinking of running 3" from the y pipe (where the dual joins to single) into a 3" Borla.

hummm to little backpressure for the v6??? might sounds nice......