Im building 4 inches titanium exhaust and I don't find a 4 inches titanium muffler and v bandband help please

 

is there a reason you are building a 4" exhaust? 3" should suffice for most.

 

Yes my friend put one on his car but aluminum and pick hp
I have 3 inche know

 

You won't pick up HP going from 3" to 4" unless the 3" is restricting flow. Unless you're making 600-700+ whp, it's not

 

a different tune could easily bump you up in power.

 

Bump help

 

We did help. We told you to build a 3" exhaust because 4" is useless for 98% of evos

 

I have a friend who builds Ti exhausts...you're probably going to have to make your own muffler with that diameter

 

If you insist on going bigger in diameter just order the ETS 3.5" Titanium Exhaust and never worry about it again.

 

There is always this exhaust

 

ETS offers a 4" Ti exhaust for the supra. Maybe they will sell you the "pieces" you need separately.
http://www.extremeturbosystems.com/E...st-System.html

 

I'm no expert on this but isn't maintaining gas velocity important as well, especially on a turbo charged engine?? In a perfect world you'd want an exhaust that creates minimum back pressure so it doesn't restrict the engine but keeps the gasses flowing as fast as possible. Having a huge exhaust would lower the gasses speed making you lose power generated by the turbine I believe

 

I am no engineer, but I have always heard back pressure = bad.

I am sure the math is all very complex and all, but the Bill Nye example would be put a banana in your tail pipe to increase back pressure and watch the power drop.

Remove the exhaust and add a dump tube and watch the power go up.

 

I agree back pressure is bad but high gas velocity is good, and to keep the velocity high there needs to be a certain amount of restriction in the exhaust. Like I said, I'm no expert but I think it's all about finding the right balance between keeping the backpressure as low as possible while keeping the gas velocity high. Keep in mind it's the exhaust gasses that spin up the turbo and it's not going to spin very fast if the gasses are barely moving.....

 

The exhaust gasses play virtually no part in turbo spool after they've been exited from the turbo