I want to get a Magnaflow muffler which one would be best for more Torque? SI/SO, or SI/DO? 2002 F-150 4.6l w/ K&N FIPK. Thanks for the advice. JT

 

I have the mag si/so catback on mine. From what I have been told you get beter torque with the si/so setup. Thats what The people a Gibsons told me.

 

Go with the SISO cat back system. I have a SIDO shop special. Love the sound, look, and performance but I always know that to get the MOST performance I need to go with the SISO complete kit. You better believe that when I replace the current setup, it will be the Magnaflow SISO system from Troyer Performance.

 

Thanks for the advice, what is the cost on the si/so catback?

 

I got mine from HOTEXHAUST.COM and used the coupon code "fordtruck8" and it took almost $100 bucks off the price.

 

Thanks for the advice guys!!