tblrklakemo

What about the intake side of the motor? Any replacement parts or mods that arent real expensive and are direct bolt ons? Of course paired with the exhaust.

suntimes

Great testing and control of the variables. Would be nice to see the dyno difference between stock and Dana exhaust after the Rayler upgrade is performed

bobl

I'll be testing it.

bobl

Kirk, I'll be retesting after the Raylar kit next week. If you have a set that I could test with I'd be happy to do so. I could run stock, Dana, Lightning and CMI back to back. I'd certainly be willing to do it.

cobra marty

Great job. Finally doing what Powerboat and HotBoat rags should have been doing all these years. Oh yeah can't piss off the advertisments with truth about their product. I'll just subscribe to your thread.

bobl

Just as an FYI, so we're comparing apples to apples. I just spoke to Tyler Crockett. The CMI test that he conducted was run with no water mixing with the exhaust just as Dana tested theirs. There is no doubt in my mind that when you mix water in with the exhaust that it changes the performance of the exhaust system significantly.

Escape Velocity

Fantastic research project! If the opportunity ever presents itself, I'd like to know what the torque curve looks like with the K&N filter you show in the picture vs. the stock flame arrestor. Also, I switched from a Bravo X to a Bravo XR drive and would love to know how much more horsepower, as a percentage, it is absorbing.

Quent

It is a shame that GM is moving away from the 496. I suppose that there are more reasons than meet the eye for the decision but profitability at GM drives decisions and, unfortunately, marine considerations are probably not in the equation when fighting Toyota.

I been told by a boat manufacturer that Mercury has been pleasantly surprised by the success of the 496 and just when the folks who know how to make them run get fine tuning locked in it looks like the motor is going away eventually, probably sooner rather than later.

My feeling is that "bobl", Raylar and others will always find a means to get the appropriate HP and torque from what ever is out there to help satisfy our need to tear up drives. Thanks guys. Quent

pol98xc6

What are they going to replace it with?

Vinny P

Bob,

Great information with interesting results. I am a bit confused at one thing. You said..

"One last Myth to bust. How much horsepower does a Bravo drive absorb? For those of you that are observant, you’re probably ahead of me. It’s certainly not 25 or 30 HP like many have come to believe. It is a percentage. In this case with a Bravo X drive, right at 10%. I’ve done testing on 600 HP engines and lost 60+ HP to the drive."

I am certainly not doubting your claim to this, but how can a drive absorb more hp at a given rpm, with the only variable being a more powerful engine? Wouldnt a drive require the same hp at 5000 rpm regardless of what is turning it? I can see the additional horsepower turning the drive to a higher rpm, thus requiring more horsepower to turn it. I dont understand that a drive absorbs power on a percentage scale.

Vinny