Question Stock 7.3 turbo down pipe replacement

[Racinghcr]

Has anyone replaced their stock 7.3 (3.5 inch) turbo down pipe with w MBRP 4 inch pipe? I have a stock straight exhaust(no muffler) 3.5 inch pipe on my 2001 F-350 S-Duty that works really well,but heard the stock 3.5 inch down pipe was too restrictive. I can order one for less than $100,but can the average guy get the old one off and install the new 4 incher. How could I hook this 4 inch pipe to my 3.5 stock straight exhaust system? Is this worth the trouble ,and how much HP and Mileage Difference can I expect? thanks

 

[bretthousewright]

I bought a complete mbrp 4" system for $270 on ebay. The worst part of the install was removing old exhaust. Downpipe was not too bad, hard to hold in place to clamp by myself but I found a way. I would suggest someone to hold it. As far as mating 4" to 3.5" I would say you could clamp or weld a reducer to make the connection.

 

[BJS]

yes 4" is better but unless you are heavily modified then you are wasting your time and money. Oh and going from a 4" downpipe to a 3.5" exhaust will gain you absolutely nothing. Keep in mind that for the OBS trucks a 3" downpipe is an upgrade from stock and you are already doing better than I am currently with my aftermarket stuff.

If you upgrade to a 4" downpipe you are simply creating space for the exhaust to expand then you will have to compress it for it to flow back into the exhaust on the rest of the truck, you should never step down in exhaust once it leaves the turbo it should only increase in size.

 

[Racinghcr]

I bought a complete mbrp 4" system for $270 on ebay. The worst part of the install was removing old exhaust. Downpipe was not too bad, hard to hold in place to clamp by myself but I found a way. I would suggest someone to hold it. As far as mating 4" to 3.5" I would say you could clamp or weld a reducer to make the connection.

Bretthousewright--thanks for the help on my exhaust ! can you fill me in on some of the Lingo on our site? Hope these Questions are not too silly!What is door seal mods and the intake wrap mods? I have drilled out the panel (zodad?) beside the radiator to let more air into the intake box and installed an AFE (oval & oil treated filter) in the stock air box. this seems to help with mileage and performance. We will be pulling our Designer 36 ft Fifthwheel near you this week on our way to Pine Island for the Winter--what's diesel going for in the Sushine State? it's about $2.69 here ! Thanks again ! any other mods ? Harry

 

[BJS]

door seal mod is placing tubing inside the door seals to help them seal better as the foam looses the original shape over time and conforms to the door and there is little to no pressure on there to keep the wind noise out.