I'm sliding down the slippery slope big time. Now that I have the Stage 4 on there with the piston pump I noticed at high RPM I get a rasp in the exhaust which is a telltale sign that I need a bigger pipe. My 3" ain't cutting it any more . I have two really nice very short radius mandrel 90's, just need the adapter from the turbo flange to the 4" and some 4" pipe stock.

I need therapy, I can't stop....

 

Well your in luck, Dr. Loch is in the house. Now listen carefully and i will help you. First take a deep breath and balance your check book, then go get your parts. Its the only treatment avalible (besides buying a ford). I am sorry this bombing bug has proven in all testing that there is no cure.

 

I get rasp out of my 3" too. I'll soon be getting the shopdiesel 4" system (minus downpipe), then bright headlights, then a piston pump, then... I know how it feels

 

I thing that HTT sells the flang, by it self and then all you would need to do is weld the 4" to it!

 

I built my own. I bought a 10 foot piece of 4" from the local Internation harvester dealer. It was only $40 at the time. I had 4 mandrel bent 90 degree elbows laying around. I built my own system in a 2WD truck from turbo to behind drive axle.
My reducer off the turbo is not pretty but gets the job done.
with a little math we know that to remove 1" of diameter than we must remove aprox. 3" of the circumfrance. my spelling sucks.
So I marked the end of a 4" elbow in thirds and cut a 1" pie shape out in 3 places and tapped it back together and welded it back together, in a since making a taper from 4" down to 3" on the end of an elbow.
a picture would be great but It would take me a month to get a photo and figure out how to post it here
You need to get creative or shell out the cash.
Good luck and dont give up

 

Mark, you'll like the 4 inch downpipe and exhaust. Are you going to do straightpipe?

I have Rip's downpipe and 4 inch straightpipe with a Diesel Dynamics Jammer turbo, and it sounds sweet.

 

Yes, I'm going to stick with the straight pipe. I'm addicted to the sound, and don't feel too badly about the noise pollution because of the wide open spaces we have here