no muffler no cats if u want to sound like a jet hehe

 

A more restrictive exhaust will help not hurt your boost creep problems. I had a STI and stock exhaust were ok , but Big aftermarket units without enough backpressure allow the boost to creep up due to the lack of B/P. If you research this and find me to be wrong, call me on it. No one person knows it all. This is the way I understand it.

Ogkevin, Hows that hideaway intercooler workin out?

 

I'll admit I'm not sure how it works. What I do know is that I had the about 10-12 inches of straight pipe after the turbo and was at 8 psi. I put on 21 inches of 3.5in. muffler and a turndown and it went to 10 psi. Nothing was else changed. I can't imagine that being less restrictive. But this truck is so weird it doesn't surprise me.

 

Slowec....I'd say go a single 3.5" all the way out....3" would almost be too small for a turbo. The D-max uses 3.5". Its not about power necessarily but the EGTs.

 

As I said above, I used a dynomax camaro muffler.

Haven't been able to log in in daaays!! Damn internet pipes must be filled up with gambling chips.

 

I had a 3" in/outlet dynomax rv bullet muffler on the sy. It was quiet at part throttle and roared at WOT. Lack of b/p causes boost spike/creep and excessive b/p can also cause it too. (had a magnacharger with a 8psi pulley see 12psi with a 2 into 1 muffler.)

 

Lowering backpressure downstream of the turbocharger increases the effective expansion ratio across the turbine, resulting in higher turbine efficiency / more turbine output power for the same massflow and temperature.

This will generate more boost if your wastegate / boost controller is not functioning properly, as the turbine can drive the compressor harder.

First post on here - work with this stuff for a living, thought I'd chime in.

- Matt

 

Dynomax ultraflo bullet from summit (3"), $hitty bend for a turndown . Just welded this up a minute ago. I'll post how it works out.

 

http://youtube.com/watch?v=N0IztgcOi24...

check out this link... this is my cady.. I run 3 inch exhaust straight thru... 3 inch after into a 5 inch diesel tip... it makes it echo.. sounds absolutely amazing.. no muffler, still have the cats

 

Thanks for the replies. I welded the setup on tonight. I am gonna remove the cats later, but now it is so quiet. i don't know how the boost was affected . Just drove it home.