Is going from a muffler with 25.5 mbar of pressure to one with 20 mbar a big improvement or not?

 

You want a strait through and no backpressure post turbo

 

Straight thru, as in, not a baffled design, and if you use something louvered, there's potential for a little better flow if you run it backwards, so the louvers don't scoop into the exhaust flow.

Any improvement is an improvement. Where did you find flow specs for a muffler?

 

They say its a straight thru that drops the pressure by 5 mbar, good?

 

That's 1/5th of total back pressure. I'm no exhaust engineer, but I'd say thats decent, if that claim is legit. What exhaust is this?

 

Its a Remus axel back for the new TT and they claim about 10 moreHP and TQ. Got them to give me 20% off and free shipping for a review to put on the thier site. I guess I will be one of the first to try it so they gave some. Still kinda expensive but the cheapest thing out their right now for our car.

 

what size is it? The MKI catbacks are the same diam as stock, totally not worth the money.

 

You don't necessarily need a bigger pipe, we've gone thru this before. Big pipe, slow exhaust cools. Cool exhaust is dense exhaust. Smaller pipe, exhaust moves quick, exits before it cools.


The gains would be in the muffler, depending on the flow characteristics, and its gotta be better than the chambered stock muffler.

 

more air into the engine = more exhaust volume

The stock diam is fine for stock hp, but you will see more gains with a larger exhaust, more so with more psi.

 

Well I think the stock pipe is already 2.5 and from what I hear that is what GIAC considers when they do their files so for the axel back Im pretty sure 2.5 is good. Now I would love to have a 2.75 or 3 in DP to my stock piping.

Plus Im still stock intake with a K&N filter.