Hi everyone,

I thought I would pose a question to all of you as to what size exhaust would work best with the 6.7 PSD? My buddy has an older F250 DRW and he has I believe 5" exhaust due to having an upgraded Banks turbo installed.

Would the new F350 benefit from such a big exhaust? How many of you have opted for bigger exhaust? It was my understanding that a bigger exhaust on a turbo engine would help it breathe better. Is this correct?

 

I went with all 4". With the stock turbo I am not sure you need to go to 5" but you can. Getting rid of the DPF helps it breathe WAY better.

Thanks

 

I'm not an engineer but I would think that if you are pushing the limits of air flow rate through a 4 inch pipe, a 5 inch pipe would help for sure. But the big question is, unless you are using a whole new fuel system, intake, and turbo, there is no way you would be pushing a 4 inch pipe to its limit.

Best I can tell, Darren is one of the experts in the area of tuning this motor so I would defer to his advice. He has a really nice set up.

 

Is there a high flow DPF available for the trucks?

 

No I am fairly certain there is not. IMHO, they have enough trouble keeping the stock one working properly.

Thanks ruschejj, first time I have ever been called an expert (at anything)!

 

I've always heard BIGGER is BETTER !!LOL

 

Bigger is not always better. Unless you can keep the exhaust temperature fairly high, there comes a point where a larger pipe will actually slow down and restrict the flow. Higher temperatures flow faster and a larger pipe promotes heat loss. There is no advantage to 5" or larger exhaust on an engine this size regardless of you fuel system or turbo.

Think about this. As much as I hate Gale Banks, he does actually research and engineer his products. His exhaust products are proven to provide some of the best gains on the market. If there was an scientific evidence that anything larger than 4" provided a gain, he would be offering it as an option.

 

I've read the same thing over at the GM forums. Nothing to be gained after 4". Now some guys have put on 5" tips just for the look.

 

720, Why do you hate Gale Banks? ( just curious)

 

X2 on this one?

 

I just went to the Banks site and saw this turbo upgrade kit...it sure seems expensive!

Industrial Injection 6.7L Compound Kit F67TT

and this is the exhaust kit

http://www.bankspower.com/products/show/366/91

 

This was interesting too!

 

Not sure this has much if anything to do with Banks, but this kit adds a second same as stock turbo.

 

Yeah not the turbo my mistake.

 

Sorry boss, I could not see the Bank link on my crapo phone for some reason!