5EK Cat

The one a had was made like Pitts power but a few inchs longer and alot cheaper but would have to move an air tank. boost was down about 4lb on hills above 1600. You may be right about the noise, could have been afraid to push on it

 

A turbocharged engine of any kind will run better with the least amount of back pressure possible but the gain you see may be almost impossible to notice if backpressure was already low. The power that drives a turbo is the pressure inside the manifold pushing out to the lower pressure inside the exhaust pipe. Example...if you have 50psi inside the exhaust manifold and no backpressure in the exhaust system then you have 50psi driving the turbo however if you have 50psi inside the mainfold but have 10 psi backpressure in the exhaust system the in reality you only have 40psi driving the turbo.
In my experiance the gain from free flowing mufflers with a cat is ususally a drop in exhaust temp and an improvement in fuel economy rather than a noticable increase in power but it depends what back pressure you have to start with.

Its possible the reason you saw a drop in boost a high rpm was because without the muffler the turbo was spinning faster and drawing more air through the engine which exagerates the inlet restriction your truck has (ie. air filters and intake piping) causing boost to be lower when the engine is drawing maximum air through.

 

I hear these 550 CATs dont hold a candle to the N14

 

your funny .post the specs on the real truck.. the Volvo must be your girlfriends .

 

Hahahaha......... Yes

 

umcha umcha yaaa

Is that your signature under your user name? LOL

Another classic case of my hoof in mouth disease

 

What happened to your LARGE CAR KILLER in your sig ? girlfriend find out you were braggiing about her truck and made you remove it ?

 

Haha that was 550 talking crap.

 

question, can the 525 red top out do a 550cat? i have battled wit once and he was cross i had 2tons more load and he almost wanted me off his bumper, [i was behind him]