You'll need a tune to run a straight pipe without a CEL; unless you mean behind the second cat, in which case go for it. It's not really loud either.
Have you any data? If the engine can breath more air by ways of freeing up the exhaust flow, the engine can make more power if tuned properly. The tiny turbo produces high egt's and if you remove flow restrictions post tubo, egt's would decrease thus making the turbo more efficient and thus make more power. I don't see why so many people on forums share bad information most likely because of some ridiculous agenda.Kind of hard to describe but I'll try.
The actual exaust outlet, post turbo, is about the diameter of a half dollar coin.
All exaust components are significantly larger than the outlet and the cats, by virtue of the internal volume, contribute nothing to back pressure.
So, if there is any source of back pressure it is the actual turbo outlet......nothing beyond that point contributes.......and that backpressure point is only at WOT near the engines redline.
Don't need data to see a small outlet leading to a large outlet.Have you any data? If the engine can breath more air by ways of freeing up the exhaust flow, the engine can make more power if tuned properly. The tiny turbo produces high egt's and if you remove flow restrictions post tubo, egt's would decrease thus making the turbo more efficient and thus make more power. I don't see why so many people on forums share bad information most likely because of some ridiculous agenda.
Robby is saying that removing a minor flow restriction downstream of a major flow restriction will not make a perceivable difference, which is entirely plausible.Have you any data? If the engine can breath more air by ways of freeing up the exhaust flow, the engine can make more power if tuned properly. The tiny turbo produces high egt's and if you remove flow restrictions post tubo, egt's would decrease thus making the turbo more efficient and thus make more power. I don't see why so many people on forums share bad information most likely because of some ridiculous agenda.
Flow is hurt when the tube I.D. increases, has a tight bend, goes into a catalytic converter, another tight bend, then abruptly necks down to 2". This is why bnr makes a catless downpipe from 2.5" mandrel bent tubing. The stock downpipe has terrible flow characteristics even with the cat gutted.