adding the new cmi exhaust on a pair of 496ho's running already 75mph gps . what should I expect top speed would be if each engine would gain the reported 50-60 hp ?
This add should put you at 485 horsepower a side (assuming 60 PSHP), so speeds should be that of 500EFI's or a touch faster, not considering torque, which I have no idea how they compare.
Post your boat length, your prop type and pitch,weight including gear and fuel, your final drive ratio, water you run in ,salt or fresh, your altitude where you boat mostly and I can use our calculator to refigure your boat speed. My guess would be about 4-5 mph but I am still a little suspect on these headers adding a real 60HP on a stock 496HO and ECM. Time will tell hope you get even better results!
I'm with Ray on this one myself.... I just can't see that 60hp claim as being realistic, no matter how good the battery's are in the calculator. That's a BIG claim to make.
Platinum Member
Commercial Member
Re: cmi on 496's twin application ?
