Turbo Exhaust Size

[Guest hgray14]

I keep seeing turbos (t3/t4) with 2 inch exhaust. When you guys are talking about better exhaust flow and modifying your exhaust to 3" are you talking about 1)adding a 3" exhaust to a turbo with a 2" exhaust outtake or 2) getting a turbo with a 3" exhaust outtake?

 

thanks

Houston

[Scottie-GNZ]

Houston,

 

not sure if this is going to answer your question but it sounds like there is a little confusion in the terminologies being used. A turbo has 2 outlets, one on the exhaust side (also refered to as the turbine side or the hot side). This outlet goes into a downppe which is then connected to the exhaust system. The other outlet is from the compressor and it goes to the engine and on a t3/t04 that outlet is usually 2" in diameter. In essence you could call that an exhaust but the word exhaust in the automotive world usually refers to the exhaust system. Typically, if you are running a t3/t04 turbo, anything 2" in size on the exhaust side will be a restriction when you start turning up the boost. Any compressor that has a 3" outlet is one big MUTHA!

 

HTH,

[zbuild]

If you are actually talking about the exhaust system as opposed to the inlet/outlets of the turbo, people usually go to 3"+ when they are upgrading an exhaust system. I run 3" ID from the dump pipe right to the back of the car. . .this includes thru the mufflers. The pipes that run through the mufflers are also 3" ID and have holes drilled in them rather than those pressed in perforations (which reduce exhaust flow). Mandrel bends are also highly recommended as they are formed on a machine (mandrel) that allows very smooth corners, no kinks or crushing, again, this keeps your gas flow up. Corky Bell's book "Maximum Boost" has a bit on exhausts that is quite interesting reading, another interesting read is "21st Century performance" by Julian Edgar.

Cheers