Welcome to the IHoP

[dem beats 1,223]

Due date?

I'm laying down praying I don't get more anxiety attacks. I can't do another all nighter.

[Tmax98 3]

where is picture of sean's new boat?

Haven't been around for awhile.

[sefugi 166]

where is picture of sean's new boat?

Haven't been around for awhile.

[Penguin4x4 1,761]

[dem beats 1,223]

The suspension in my expy is shot. I heard one of the shocks make a hissing noise this morning.

Damn speed bumps in the parking lot at work have demolished her old creeky hips.

[dem beats 1,223]

In light of that I think I'm going to get a new suspension system. I've been looking at Race Car Dynamics the most but if anyone has any suggestions.

I'm just going for a beefy set up that will allow more articulation and confidence on crappy roads. I don't want 11" of lift though. even with 5" it will make me unable to get into most parkign garages.

[///M5 2,833]

If running at 24mph you use the supercharger and the prop to make it so that you turn 3500rpm with the s/c and 4500rpm with the n/a with the only changes being the tune and the boost wouldn't you expect the s/c application to use less gas?

24 isn't super arbitrary as it is the sweet spot for fuel economy on my hull

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.

[///M5 2,833]

I only took a minor bump in mileage on the SHO with this s/c. Definitely was worse, just not that much but it was fun!

Oh, Ford ftw!

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

Powerdyne indeed

[///M5 2,833]

If running at 24mph you use the supercharger and the prop to make it so that you turn 3500rpm with the s/c and 4500rpm with the n/a with the only changes being the tune and the boost wouldn't you expect the s/c application to use less gas?

24 isn't super arbitrary as it is the sweet spot for fuel economy on my hull

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.

[///M5 2,833]

If running at 24mph you use the supercharger and the prop to make it so that you turn 3500rpm with the s/c and 4500rpm with the n/a with the only changes being the tune and the boost wouldn't you expect the s/c application to use less gas?

24 isn't super arbitrary as it is the sweet spot for fuel economy on my hull

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

[dem beats 1,223]

Math for the win!

[///M5 2,833]

You know what I think you should do for your boat Sean.

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

[dem beats 1,223]

I'm actually crushed by what happened at the school. It was pure nonsense. I'm actually so mad about the situation I can't talk about it right now as I have to do presentations today and need to keep my happy face on. And to top it off I have 10 hours of work to do, in 45 min today.

I will NOT be getting it done, and thus have to come in at 4:30am tomorrow just to catch up to the curve.

[Tmax98 3]

boat looks very good Sean!

[///M5 2,833]

Crap M2

[vladd 26]

sorry to hear it Matt

[vladd 26]

I am follwing this supercharged boat thing like crazy. I know on road vehicles you're way better off with forced induction because normal driving doesn't use the boost and therefore you aren't losing your efficiency. Under boost you'll friggin drink fuel but who cares when your asshole is chewing a hole in your seat. With a boat I assume you'd be under load way more often than in a car and therefore using the boost way more frequently.

as far as fuel consumption being linear all I know is tuning the a/f ratio on turbo cars, you really start to lean out near full throttle and that's where you really have to worry about becoming too lean. So I would assume you have the most efficient burn at or near full throttle/boost. When driving along you rarely have a constant a/f ratio and when you do it's well away from lean.

another question would be does your a/f ratio need to change with RPM, I would assume it doesn't but assumptions are the mother of all fuckups. It is possible that a lower RPM would allow you to run a more lean mixture.

I say find an intercooler and find a way to pipe in fresh water from the lake too!

[///M5 2,833]

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.

[///M5 2,833]

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

[///M5 2,833]

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

[topgun 262]

Drop an LQ9 with a turbo in there. Time to really suck down the fuel.

[The enD 467]

Poor Second Skin trying to get their sales up by any means.

[Tirefryr 1,742]

If running at 24mph you use the supercharger and the prop to make it so that you turn 3500rpm with the s/c and 4500rpm with the n/a with the only changes being the tune and the boost wouldn't you expect the s/c application to use less gas?

24 isn't super arbitrary as it is the sweet spot for fuel economy on my hull

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!

[Tirefryr 1,742]

I am follwing this supercharged boat thing like crazy. I know on road vehicles you're way better off with forced induction because normal driving doesn't use the boost and therefore you aren't losing your efficiency. Under boost you'll friggin drink fuel but who cares when your asshole is chewing a hole in your seat. With a boat I assume you'd be under load way more often than in a car and therefore using the boost way more frequently.

as far as fuel consumption being linear all I know is tuning the a/f ratio on turbo cars, you really start to lean out near full throttle and that's where you really have to worry about becoming too lean. So I would assume you have the most efficient burn at or near full throttle/boost. When driving along you rarely have a constant a/f ratio and when you do it's well away from lean.

another question would be does your a/f ratio need to change with RPM, I would assume it doesn't but assumptions are the mother of all fuckups. It is possible that a lower RPM would allow you to run a more lean mixture.

I say find an intercooler and find a way to pipe in fresh water from the lake too!

You're funny. You know damn well there is no "normal driving" when you have more fun under your foot.

[Adrian_D 520]

Busy day today...

Me and dad started moving one of the garages. It's made out of concrete and only has walls + roof, 22000 lbs total. The plan is to lift it enough to get some pipe under it and roll it to the new position.

Ended up doing leg press exercises on the crowbar, with my head against the ceiling since I wasn't heavy enough to lift the garage. It worked perfectly. Time for pipe tomorrow.