I have a ISB 300 in my 03 Coachmen 38 class A. I'm not impressed with the stock 3.5" pretzel exhaust and air intake. As an old time trucker who owned a 03 Dodge with a hot 5.9 cummins I appreciate the benefits of big exhaust and lots of fresh air on the intake side.
Has anyone here tweaked their ISB 300 cummins with larger exhaust, air intake modifications and maybe CPU tweaks? I'm looking for a little more power and fuel mileage without breaking the bank. Love to get some feedback on this.