Hello,
any suggestions regarding upgrading performance on my stock 6.5 Turbo ? (1999 Suburban, 265,000 miles). Looking at replacing stock air filter unit. Which brand/model works best ? Then looking at going 4" with the exhaust pipe after cat. converter: Is it true that cat. is useless and removing won't increase noise ? Any other ideas ?
Thanks

 

Diesels have what is called a 'scrubber.' Looks like a cat, in the place of the cat, but it is not a cat. It just 'scrubs' the black crap out of the exhaust gases, and can get clogged over time and increase backpressure.

I would do the 4" kit (no muffler) and 2.5" crossover. ONLY use the stock GM air filter, the K&N gets the oil sucked out by the turbo and is a waste of money.

Diesels ain't loud like gas engines. You can straight pipe it and it is still mellow and unobnoxious.

The turbomaster and new tuned PCM combo will get you some horses too. Also installing an F intake will gain power.

Past that you will have to spend a bunch of money to make more power.

 

Thanks InheritedDiesel !!!
Much appreciated !!!