Exhaust and Down Pipe

[NFA Fun]

Can you tell me the pros and cons of going with a 4" down pipe? My old system was a 3.5" down pipe into a 4" at the transmission. Am currently looking at the Hog system with the high flow muffler. Anyone out there have this setup on a 6.0??

 

[Ford_Forgotton]

Less restriction, better heat evacuation, etc etc. No one has ever been able to prove to me that a 4" system has a "loss" of power/torque such as would happen on a gasser.

The turbo creates all the engine backpressure (equal to, or greater than your boost pressure) and the 6.0 has a variable vane turbo that can actually create more backpressure for use as an exhaust brake.

If your seeing high EGT's, then go for the 4". If your doing it just to say you did, well, I dont know if there is a major advantage then.

 

[bigdaddyTank]

I have read that putting a 4inch on the 6.0's is much harder than the 7.3's because the bigger pipe has problems clearing a pinch seam. Maybe someone who has done this could chime in if they did or didnt have problems with a 4inch down pipe on there 6.0. My dad has a 3.5 dp on his 6.0 now but we may go with a 4inch in the future.

 

[Car_nut57]

Ford Forgotten is correct. Our exhaust supplier has dyno runs showing small losses in power with the larger pipes. Also the 4" DP is pretty crowded in the 6.0L and may be difficult to install.

 

[Strictly Diesel]

Can you tell me the pros and cons of going with a 4" down pipe? My old system was a 3.5" down pipe into a 4" at the transmission. Am currently looking at the Hog system with the high flow muffler. Anyone out there have this setup on a 6.0??

4" Downpipe WILL require you to "massage" the firewall. With the VGT Turbo, I'm not convinced that there is any gains to be had going to a 4" downpipe over a 3.5" unit.

Dennis Schroeder
Owner - ITPDiesel
www.itpdiesel.com
[email protected]

 

[f100cleveland]

Can you tell me the pros and cons of going with a 4" down pipe? My old system was a 3.5" down pipe into a 4" at the transmission. Am currently looking at the Hog system with the high flow muffler. Anyone out there have this setup on a 6.0??

I'm not sure if the 6.0 reacts the same as a 7.3 but I G-teched mine before and after installing my 4" turbo back system. I lost a couple of tenths of a second 0-60 mph and gained a couple of mph 1/4 mile speed. The egts went down. This was with a 50hp tow chip and amsoil replacement air filter. I have thought about trying a 3.5 downpipe to restore bottom end torque but after putting in Jody's chip I really don't think I'll have to.

 

[BigRed CC dually]

I have read that putting a 4inch on the 6.0's is much harder than the 7.3's because the bigger pipe has problems clearing a pinch seam. Maybe someone who has done this could chime in if they did or didn't have problems with a 4inch down pipe on there 6.0. My dad has a 3.5 dp on his 6.0 now but we may go with a 4inch in the future.

You will get zero sympathy from the 94 - 97 guys You have not lived until installing a downpipe in an OBS truck and tried "clearing the pinch weld" it's a royal PITA with a 3" pipe and can be done with a 4" but requires major modifications to the pipe and the firewall unless you cheat and do a body lift, and even then it ain't easy.

 

[bigdaddyTank]

You will get zero sympathy from the 94 - 97 guys You have not lived until installing a downpipe in an OBS truck and tried "clearing the pinch weld" it's a royal PITA with a 3" pipe and can be done with a 4" but requires major modifications to the pipe and the firewall unless you cheat and do a body lift, and even then it ain't easy.

That sucks, that makes me even more glad he sold his 95 7.3 before we started doing anything to it, nothin personal but I like working on the new superduty more than on his OBS

 

[Mark Craig]

NFA Fun,

Save yourself a lot of headaches and stay away from 4 inch DP's on the 6.0. The turbo controls the need to go to 4.0 and the installation is a PITA for sure. Give us a call if you have any questions, we have all of the MBRP aluminized, 409 and 304 stainless systems available to select from.

Mark @ DPPI

 

[JohnBoyToo]

Agree - best of both worlds...
3.5" downpipe into a 4" exhaust the rest of the way....

and still not EASY to install... can't imagine the fight for a 4" DP !