Just searched 40 pgs of thru hull and didn't see my answer. I need to clear something up with some friends. Talking about stock exhaust and engines. Is there any HP increase when going from the Y pipe to thru hull exhaust? If so what HP engine will it make a difference on? I'm not talking about huge power, just arguing that I believe there is some measurable difference when you go from Y pipe to a thru hull configuration. Please straighten me out if i'm smoking something or confirm what I believe. Thanks

You will pick up some because of back pressure, It's kind of like dualing out a car.

Stock motor....more sound than speed increase.

I've switched my 502's back and forth when running and noticed nothing measureable

i have a 502 in a 25 outlaw when i go thru the hull i pick up about 100-200 rpm ,i would say 10-20 hp this is at wot