I will be needing a new downpipe for my T2 project, and am thinking about the one that corksport makes, that flares from a 3", down to 2.5" to bolt to the main cat (Which is a high-flow Bonez unit I have..) Anyway, just wanted to get everyones opinion on this. I know it wont be as good as a full 3" system, but Im thinking that it may help the turbo spool a bit quicker, as there is more volume to fill in the 3" section of the downpipe, than their would be in just a straight 2.5" Is my thinking correct on this?

 

Well, it should help since your creating less of a restriction.

I am thinking of getting this too since I already have the CS 2.5 to 3inch on my GTU and I'm about to do a Jspec swap to it.

 

From personally experience going from a 2.5-3 inch (dont remember) straight pipe set up to a 3 inch corksport downpipe and high flow cat there was not much loss of power. It seemed to spool a little slower but what do you expect. I say its a good investment for the price.

 

You mean it spooled slower with the 2.5 over the 3", right?

 

When I bought the car it came with straight pipes, not sure if it was 2.5 or 3 inch. With my current setup in my sig, the loss in power wasnt as bad as I expected. Turbo spools a little slower than before.