Proof of larger DP/ Fluid Dynamics

[niterydr]

Originally Posted by S2kracka

By "16G crowd" I don't think Steve was referring to the turbos people are running. Maybe I'm the only one who laughed after reading that

No, I chuckled as well.

[TalonFiero]

Originally Posted by niterydr

No, I chuckled as well.

I cried.

[CVD]

Think velocity. For one thing you would need a smooth transition to maximize gains. For another, you are allowing the gases to expand to fill a 4" diameter pipe and then "compressing" them back down into a 3" pipe. Regardless of how you look at it that will take energy, and I think you would agree that it would be a waste of energy. So, you MAY see gains from an ass-backwards setup like that, but they will be very inefficient gains.

I actually had a 2.5" downpipe on the stock catback. This setup was basically to keep the car quiet on the street. The catback was to be removed at the track. Did I see gains over running the stock DP? Well, yes. Not significant gains though, where I would say "this is a decent upgrade for poor kids like me" and probably due in part to the amount of exhaust leaking where they met. If you think you need that size piping, then run it all the way back.

So from my theory based perspective and my real world experience, I think you should just get a whistle tip. They go woo woo.