///M5

What sort of power gain do you think 6-10psi of boost will give? *I know I cheated and used a flat power gain (in %), but I couldn't find a comparable engine on the dyno pre and post boost. **Looked in the engine bay this afternoon, won't be trivial to get it in.

No because I know how hungry boosted vehicles are. Granted it may be different on water. That's a whole different animal, tune, and drag, so I may be wrong, but with a vehicle, if you are into the boost, you are using up a lot of fuel. Keep in mind you are forcing air in and compressing it where as the NA can only suck air in. The more air you have, the more fuel you need, so the blower is always going to need more fuel and a lot more. I was summoned to bed about the time I read this, so you know what I thought about all night (well not the first 15 minutes). Went through a huge calculation to "verify" things this morning, but am missing some information to really prove anything out. I have some conclusions however. Currently my boat pulls: 5200rpm at 38mph using 32 gallons/hr 3420rpm at 25mph using 4 gallons/hr Conveniently it is easy to calculate the different fuel used as the ideal gas law is linear. PV=nRT so if we increase the pressure x% we increase our oxygen intake the same and therefore assuming we keep the same fuel to 02 ratio we are golden. That being said going all the way up to 10psi of boost yields 1.68x the gas at the same RPM. (24.696/14.696). Then the question becomes propulsion and can you pick a prop with the right pitch & diameter such that the rpm of the motor will change, but keep the boat speed the same. I am not a prop guy so I'll make the assumption that this is possible. I do know there are a crap ton of props and that mine has an extremely aggressive prop (14.25 pitch which means one revolution with no slip moves the boat forward 14.25inches - as a reference my bass boat has a 27p prop and tops out near 80 at nearly the same RPM's as the Malibu doing just under 40mph and has nearly double the pitch). The only other question is do you have the power to turn it? In order to get there, the boost comes into play. Here I eyeballed: http://www.powerbloc...bang4buck/0703/ and came up with a power table. From my table you can see that in current stock form my boat makes around 220hp at 3450rpm where I cruise at 25mph. Even if I only gain 30% from 10psi I would only need to be spinning 2950rpm with the right prop to maintain that speed. 25mph is where my hull is the most efficient. The spot that makes this near impossible to determine is knowing my current fuel consumption curve. I only have two points. 25mph at 4.5gal/hr and 38mph at 32gal/hr. Since that curve looks far from linear it is hard to tell what drives it. One thing is for sure though, with a 40% gain in power I should be making around 340hp at 3700rpm instead of 5200rpm. This should mean that I'd be an awful lot closer to the 4gph than the 32gph (and then of course we adjust by 1.68x) which seems to me that it'd be more efficient where I am using it. So that being said I do think I will see both a top end improvement and efficiency improvement through lowering the rpms while running at a real cruising speed. If I had more points on the actual consumption of my boat so I could determine a curve I could really dial this in including exactly how much boost to use for what prop and such...or so I think anyways. Don't forget increased frictional losses! . j/k It's ridiculous that I took an IC engines class last semester and I've already forgot a good sum of it. I will consult my book soon just to double check Frictional loss goes out the window when I am optimizing efficiency for one speed on the hull.

You're funny. You know damn well there is no "normal driving" when you have more fun under your foot. In a boat there is. Most of my driving is at one rpm

No because I know how hungry boosted vehicles are. Granted it may be different on water. That's a whole different animal, tune, and drag, so I may be wrong, but with a vehicle, if you are into the boost, you are using up a lot of fuel. Keep in mind you are forcing air in and compressing it where as the NA can only suck air in. The more air you have, the more fuel you need, so the blower is always going to need more fuel and a lot more. I was summoned to bed about the time I read this, so you know what I thought about all night (well not the first 15 minutes). Went through a huge calculation to "verify" things this morning, but am missing some information to really prove anything out. I have some conclusions however. Currently my boat pulls: 5200rpm at 38mph using 32 gallons/hr 3420rpm at 25mph using 4 gallons/hr Conveniently it is easy to calculate the different fuel used as the ideal gas law is linear. PV=nRT so if we increase the pressure x% we increase our oxygen intake the same and therefore assuming we keep the same fuel to 02 ratio we are golden. That being said going all the way up to 10psi of boost yields 1.68x the gas at the same RPM. (24.696/14.696). Then the question becomes propulsion and can you pick a prop with the right pitch & diameter such that the rpm of the motor will change, but keep the boat speed the same. I am not a prop guy so I'll make the assumption that this is possible. I do know there are a crap ton of props and that mine has an extremely aggressive prop (14.25 pitch which means one revolution with no slip moves the boat forward 14.25inches - as a reference my bass boat has a 27p prop and tops out near 80 at nearly the same RPM's as the Malibu doing just under 40mph and has nearly double the pitch). The only other question is do you have the power to turn it? In order to get there, the boost comes into play. Here I eyeballed: http://www.powerblocktv.com/sites/bang4buck/0703/ and came up with a power table. From my table you can see that in current stock form my boat makes around 220hp at 3450rpm where I cruise at 25mph. Even if I only gain 30% from 10psi I would only need to be spinning 2950rpm with the right prop to maintain that speed. 25mph is where my hull is the most efficient. The spot that makes this near impossible to determine is knowing my current fuel consumption curve. I only have two points. 25mph at 4.5gal/hr and 38mph at 32gal/hr. Since that curve looks far from linear it is hard to tell what drives it. One thing is for sure though, with a 40% gain in power I should be making around 340hp at 3700rpm instead of 5200rpm. This should mean that I'd be an awful lot closer to the 4gph than the 32gph (and then of course we adjust by 1.68x) which seems to me that it'd be more efficient where I am using it. So that being said I do think I will see both a top end improvement and efficiency improvement through lowering the rpms while running at a real cruising speed. If I had more points on the actual consumption of my boat so I could determine a curve I could really dial this in including exactly how much boost to use for what prop and such...or so I think anyways. Holy Shit Sean! Your statement had me dream all night. Almost to the point where I was going to look to see where I could get a flowmeter for "demo" purposes to run on my gas line to really map out my usage. Obviously not worth that effort. Should just baseline and go from there.

And egads I may end up doing nothing, but I'd love a project to put this powerdyne to use!

Of course, I'd rather put a 351w in her.

Consider my ramblings thinking outloud. Part of me wants to do it, just to do it saying fuck fuel economy and what not, but the other see's potentially an advantage. Just upping the HP by 40 with the stroker motor allows running significantly more pitch and because of that and the ridiculous pitch my prop has my opinion is that my boat is underpowered. As for the a/f ratio, I may be stuck there. Not sure who around here could do tuning on the boat/water anyways so I may be stuck making my own map for which I know nothing about. Obviously erring on the side of a little rich is what I'll do so not sure that my ratio would be progressive or change. Of course if I do some more reading and get directed differently I am wide open. If my stupidity with playing with it really screws it up, there are LS motor mounts available for my boat so an LQ9 could easily be dropped in.

Probably the same test Don did with his CLD tiles. Lol, nice response. Don didn't test damping and that was exactly my point. You can't put a piece of material on two different parts and test it which is exactly why measurements weren't made. The OP just feels that it works better but has absolutely nothing other than his subjective opinion to go on based on a very flawed test.

Crap M2

LOL. Specs are crap. No way, no how do those specs portray reality.

Feeling like you should be a part of the ballast? yes What's your standard work week like? (hours/days) Probably pulling it out tomorrow to put MN registration, wax, and add the 1100lb fat sac to it. Friday I am up to Fargo, but may be able to squeak out during the week. If not this one, then I'm off to CA and back the following weekend but its a bumblefuck on Labor weekend and I'll have the kids. After that back and completely read for a day nearly anytime. Perhaps I can even get "sick" I work 8:30-5:00p, however I can always ask for a day off. I'm unfortunately more available than I expected...... No fall semester for this guy. :( Need to confirm what plans my boss has for me this week and the weather... Sorry on the lack of fall semester

No because I know how hungry boosted vehicles are. Granted it may be different on water. That's a whole different animal, tune, and drag, so I may be wrong, but with a vehicle, if you are into the boost, you are using up a lot of fuel. Keep in mind you are forcing air in and compressing it where as the NA can only suck air in. The more air you have, the more fuel you need, so the blower is always going to need more fuel and a lot more. You have to also take into account that, like Ryan said before, the boosted engine has more fuel. So more RPMs don't necessarily mean more fuel. Not saying that it does or doesn't but it's something to consider. I meant air on my last post. A boosted engine with have more molecules of air in it because it is compressed which means you will need more fuel to make a complete combustion. Again that doens't mean that happens at the parameters you mentioned, but it could. If it already has a s/c I would run with it It doesn't have one, I do

No because I know how hungry boosted vehicles are. Granted it may be different on water. That's a whole different animal, tune, and drag, so I may be wrong, but with a vehicle, if you are into the boost, you are using up a lot of fuel. Keep in mind you are forcing air in and compressing it where as the NA can only suck air in. The more air you have, the more fuel you need, so the blower is always going to need more fuel and a lot more. You have to also take into account that, like Ryan said before, the boosted engine has more fuel. So more RPMs don't necessarily mean more fuel. Not saying that it does or doesn't but it's something to consider. I had, goal though in a boat is to have enough power to turn a prop at a logical rpm based on the hull efficiency. The rest is definitely going to chow fuel, but I should be able to plan a major gain on cruise speed.

And that Yamaha was VERY efficient and was running wide open all the the time. What is it BTW? A Powerdyne? Powerdyne indeed

No because I know how hungry boosted vehicles are. Granted it may be different on water. That's a whole different animal, tune, and drag, so I may be wrong, but with a vehicle, if you are into the boost, you are using up a lot of fuel. Keep in mind you are forcing air in and compressing it where as the NA can only suck air in. The more air you have, the more fuel you need, so the blower is always going to need more fuel and a lot more. I was summoned to bed about the time I read this, so you know what I thought about all night (well not the first 15 minutes). Went through a huge calculation to "verify" things this morning, but am missing some information to really prove anything out. I have some conclusions however. Currently my boat pulls: 5200rpm at 38mph using 32 gallons/hr 3420rpm at 25mph using 4 gallons/hr Conveniently it is easy to calculate the different fuel used as the ideal gas law is linear. PV=nRT so if we increase the pressure x% we increase our oxygen intake the same and therefore assuming we keep the same fuel to 02 ratio we are golden. That being said going all the way up to 10psi of boost yields 1.68x the gas at the same RPM. (24.696/14.696). Then the question becomes propulsion and can you pick a prop with the right pitch & diameter such that the rpm of the motor will change, but keep the boat speed the same. I am not a prop guy so I'll make the assumption that this is possible. I do know there are a crap ton of props and that mine has an extremely aggressive prop (14.25 pitch which means one revolution with no slip moves the boat forward 14.25inches - as a reference my bass boat has a 27p prop and tops out near 80 at nearly the same RPM's as the Malibu doing just under 40mph and has nearly double the pitch). The only other question is do you have the power to turn it? In order to get there, the boost comes into play. Here I eyeballed: http://www.powerblocktv.com/sites/bang4buck/0703/ and came up with a power table. From my table you can see that in current stock form my boat makes around 220hp at 3450rpm where I cruise at 25mph. Even if I only gain 30% from 10psi I would only need to be spinning 2950rpm with the right prop to maintain that speed. 25mph is where my hull is the most efficient. The spot that makes this near impossible to determine is knowing my current fuel consumption curve. I only have two points. 25mph at 4.5gal/hr and 38mph at 32gal/hr. Since that curve looks far from linear it is hard to tell what drives it. One thing is for sure though, with a 40% gain in power I should be making around 340hp at 3700rpm instead of 5200rpm. This should mean that I'd be an awful lot closer to the 4gph than the 32gph (and then of course we adjust by 1.68x) which seems to me that it'd be more efficient where I am using it. So that being said I do think I will see both a top end improvement and efficiency improvement through lowering the rpms while running at a real cruising speed. If I had more points on the actual consumption of my boat so I could determine a curve I could really dial this in including exactly how much boost to use for what prop and such...or so I think anyways.

I had a tree felled last October and still haven't rented a splitter...but I know where I can.

I don't need bribes, just a time that works.

Feeling like you should be a part of the ballast? yes What's your standard work week like? (hours/days) Probably pulling it out tomorrow to put MN registration, wax, and add the 1100lb fat sac to it. Friday I am up to Fargo, but may be able to squeak out during the week. If not this one, then I'm off to CA and back the following weekend but its a bumblefuck on Labor weekend and I'll have the kids. After that back and completely read for a day nearly anytime. Perhaps I can even get "sick"

See you guys next week.

Doesn't that company make shoes?

Not worth going too nuts, the hull on the boat is designed to do the opposite of most. Meaning it has a rather terminal velocity. Instead of raising the bow the faster you go it is designed to raise the stern to minimize the wake. Obviously sucks balls for gas mileage, lol. Also makes 800hp absurd. 340 isn't enough though

I have lots of free intercooler water, lol.

Since we are leaving in 10 minutes I should probably pack, lol. I did pack the food, but the rest isn't so important.

Next Friday I drive to Fargo for my Fantasy Football free agent auction. Two Friday SHOT

Feeling like you should be a part of the ballast?