Hey guys, I have a 2000 F250 PSD and I will be putting a 4" exhaust on it. I need to know what size downpipe to run. I keep hearing that if I go with a 4" downpipe turbo won't spool up till much higher RPM and that using a smaller downpipe creates more exhaust velocity and spins the turbo fast/sooner. If that is the case, is the stock 3" OK or should I jump up to a 3.5"? There will be no muffler on the exhaust and I am currently running an 80hp SuperChip, K&N filter and Wicked Wheel. What are you running and what would you recommend?

Thanks in advance,
Cory

 

Wierd, lots of downpipe questions tonight. I'll offer you the same advice I just posted in this thread

 

4" downpipe is the only way to go

GENE

 

thanks for the info guys

 

Look into the Magnaflow exhaust system. The reccomended downpipe size is 3.5" with the balance of the system being 4". The 3.5" downpipe allows for the proper backpressure for the turbo. I have also heard of sealing/connection issues when going from the stock 3" to the 4". Going with the 3.5" allows for a better connection fit.