Exhaust Modification Questions

[davzog]

My 07 Classic HD2500 with a 6.0L gas engine has a 50 series Big Block Flowmaster muffler on it...I like the sound...not too loud, but I am thinking about twin tailpipes.

 

A local muffler guy can build a "Y" pipe to go behind the muffler and make two tail pipes...

 

He recommends going to 2 1/4" pipes (the exhaust is 3.5") rather than 2 1/2" tailpipes. He says that Chevys particularly are prone to loss of low end torque and mpg if the loss in back pressure is too great, and the 2 1/4" tailpipes would help keep things in line....

 

Any ideas???

 

Thanks in advance...Dave

[davzog]

bump

[certifiedcustom]

We always used 2.5". The 6.0L is a fairly stout motor. We picked up 8-10hp at the tire over stock due to reduction in backpressure. Did not notice low end torque loss.

[onac255]

Well I don't have a 6.0 but I lost a bunch f Low end grunt when I opened up my exhaust with two separate 2.5 inch Flowmaster 40s.

 

Had to fix it with a programmer. After the programmer the low end grunt was back and better than before.

[certifiedcustom]

Well I don't have a 6.0 but I lost a bunch f Low end grunt when I opened up my exhaust with two separate 2.5 inch Flowmaster 40s.

 

Had to fix it with a programmer. After the programmer the low end grunt was back and better than before.

Yes, I do recall losing low end torque with the 5.3L, just not the 6.0L. My old age sucks...

[davzog]

YEp, towing a 5th wheel is why I am concerned about losing low end torgue....less back pressure tends to move the torque up the rpm range, and I don't want to tow at 5000 rpms....thanks