the initial #s are in
 

Many thanks to Eric Betty and Troy Lannom at EB Marine for all their hard work on my behalf this winter.
Same goes to my good friend RB Hixson who worked with us like it was his own motor.
All along I was hoping to get 90 MPH, and figured anything over that was a bonus. To say the least I am very pleased with 2 quick passes (91 @ 5900 and 93 @ 6000) with my old prop (28" P5-X). I thought it would be good to establish an apples to apples baseline with my best prop. 72os, 1/2 tanks, 1 person.
I think there may 2 or 3 MPH left with some tuning and prop testing.
What a great way to start the season:D :drink: !
Regards,
Steve

That is awesome...way to go Steve! What did you do with the drive?

Gary,
Thanks. Could be a few MPH left. You know, if you haven't been in the saddle for months, 93 seems pretty fast:rolleyes: ......so I didn't milk it, and I'm probably under propped. I'll try a 32" Merc lab B1 and and a 30" P5-X soon.
Re the drive (I'm still using a standard length Imco with a 1" spacer), haven't done anything yet, but plan to do some cryo treating of the gears. I think they're in for a hard time this year:D ..........
Regards,
Steve

Awsome speed Steve....So, what were the dyno numbers???

Bob,
Weeeellll, tha's a whole 'nother story as we says down South:rolleyes: ..........
I'll show the pull as soon as I get the dyno sheets. They are at Eric's shop. I hope you're sitting down, it made around 650HP @ 6000, and 718 @ 6500. Not our dyno. Not a typo. Bad correction factor? Bad calibration? Bad moon phase?
If I ran 93 with 650HP, I must have the best rigged, lightest Heat in the world (helium in the gas tanks maybe:rolleyes: ), which of course I doubt.
Go figure......What do you think it's making :confused: ?
Regards,
Steve

Bob,
I just ran the #s through go fast's boat speed calculator, and it says 816HP, which sounds more realistic to me.......
Regards,
Steve
www.go-fast.com

:evilb: :evilb: :evilb:
Very nice!!

Nice dyno...You were making substantially more than that when you started :D
Do you have fuel #/hr and A/F numbers?
What kind of conditions were you running in?

Nice work...

Thanks Dave,
I'll try to post the pull today. Please feel free (everyone) to analyze them. I am scratching my nuts over the way the boat is running, but I'm sure as hell scratching my head over the dyno #s:confused: .................
The weather was pretty good for here this time of year.
We had a cold front blow through, so it was around 50os with low (I think like 35%) humidity.
I asked the guy who owns the machine shop (does great machine work BTW, mostly race cars) what he was using for a correction factor. He says he plugs in temp/barometric pressure/humidity into the computer and the software calculates the correction factor. We did find some more HP while we were there by redegreeing the cam, so it wasn't a totally wasted effort or $.
What's the old saying, "there are lies, damn lies, and statistics"?
Regards,
Steve

What are the cam and head specs? Interesting that it gained 60+ HP from 6000 to 6500 RPM. It surely is making more power than 650. Get the data posted and let's see what it looks like. What was the boost? It's gotta be over 800 to run that fast. Get the raw dyno numbers from him too.

Steve,
Just a thought and refresh me if I'm wrong but...
The stock 575SCi (~620cshp dyno from Merc) ran pretty consistently 74-77 when you first bought the boat from Toby.
You added the Superchiller kit and bumped the boost up substantially to get it to ~770+cshp and ran ~84 all the time (BTW, same as BobL and his 770 dyno hp)
You then rebuild very nicely and now it dynos at 650-700 and you picked up 7-9 mph...WTF :o

Your numbers are in line with 850hp. That is in fact what we calculate the Supercooled/ProCharger boat is at when running at 5000 feet elevation (which BTW it runs 93+ with a P5X 30 at 5800 rpm, near 100 at Havasu at just over 1000hp)

I have to believe the error is in the dyno run...

Bottom line is, contrary to the dyno sheet, your making some killer power!
Great job :evilb:

Dave,
Yes to everything you say (except the intercooler is a Whipple).......if you had been in the dyno room with us, you would have seen 3 or 4 guys with the WTF? look on their faces. Whenever I questioned the #s (correction factor/etc), the owner said that's the way he always does it.
But as we always say, the water is the best dynamometer, and I totally agree with your analysis.
Best Regards,
Steve
PS, I am picking up the dyno sheets tonight, and will post them ASAP.

Bob,
Agree on all. If the go fast.com HP calculator says 816 (pshp?), then that works out to about 850cshp, which seems more likely to me.
Another interesting thing you'll see when we post the dyno sheet, is that the power never falls off. I guess if we had turned it up to 7000 (we stopped @ 6500) it would have made even more? Really didn't want to because I have no plans to run it that way on the water, nor did we want to blow it up on the dyno.
Oh yeah, boost was actually the same as it was with the former setup @ same RPMs (6 @ 5500). It did climb to 8 @ 6000, and 10 @ 6500.
Regards,
Steve

Ok Guys,
Here's the best "corrected" :rolleyes: #s.
Fire away.
Regards,
Steve

Steve

That dyno has to be way off, you are making more power than that to get that speed increase. Dont get to wrapped up in the numbers. Just keep passing people. Great job.

LH

Linster,
Thanks. That's my perspective on the whole thing too. See you at the Nordic Regatta. Obviously you are a Corvette aficianado........have you ever been to the Corvette factory and museum in Bowling Green? If not, I would cruise over there and check it out. It's about an hour west of Jamestown.
It's way cool!
Regards,
Steve

Yep, those dyno numbers are crap. The first red flag is the torque reading. It stays constant in the 560-570 range the whole pull. No way! It looks like something was going on with the dyno that it could only read up to that amount of torque. The fuel flow number don't even look correct unless it's boost referenced and increasing fuel pressure with boost. You didn't even get A/F numbers or exhaust temps. I also don't believe the peak HP at 6500. Since it wasn't reading the torque correctly, the HP is just a mathematical function of RPM. That's really too bad. A total waste of time and money.

:(

Looks like trip to FTM is in order :D

Well Bob,
If you weren't so far away, you know:rolleyes: :D , we would have come to you. Would you consider relocating to Nashvegas (2 lakes, 1 river, good economy)? Looks like we need an accurate marine dyno here. Glad to hear you think the #s are BS too.
I guess the good thing that came out of it was we were dissapointed in what we all now agree are bogus #s, and scrambled to find a few extra HP, and did by redegreeing the cam. I don't think we would have had we tried to just tune it on the water.
What do you think the problem is......bad software, bad calibration, bad correction factor, operator error, all the above???
BTW, we did have Eric's A/F meter, and those #s are good. Maybe some final tweaking on the water with my wet exhaust. Are you bringing your prop shaft dyno to the regatta??
Many thanks again to Eric and Troy at EB Marine for building me one hell of a motor, whatever it's putting out:D .........
Best Regards,
Steve

Great numbers, Steve. Congrats.
I've been considering a motor rebuild at some point.
Actually got to the point I talked to Larry Peto last fall.
What's 93 feel like in the Heat?

Dave

Steve,
Look at the postive in this, you can show the insurance company the dyno sheet and get a good rate.

In2Deep..........fast:D. rv, I have a stock Merc 575/550pshp!
Thanks,
Steve

Hey Dave,
I have a guys 496HO from a Heat down at Larry's now. It experienced an overheat condition that caused some damage.
However before that it was a pretty good runner. I don't like to touch what I don't have experience or time with so we sent it to Larry for the full monty. 3.3 Whipple, forged crank, rods and pistons, cam, ports heads and it made 750hp on Larry's dyno with 7 lbs of boost. It ran consistent 78 mph on the GPS speedo at Powell and hit 80 once. I think it would run a consistent 82-83 at Havasu with the 750hp. Boat idles very well and starts up just like a stock HP500EFI.

From my experience the Heat runs rock solid up to 100 mph in good water conditions . That being said, with any boat you must respect everything at that speed no matter what hull :eek:
My ass still eats the back of the bolster :eek:

Figure full hydraulic steering and a drive upgrade into the equation as well.

Hope that helps...
Dave

One other thing that I forgot to mention in my earlier post(s) about how the boat is running..... Handling can obviously become an issue in a vee hull boat at these speeds. Even though I haven't been in the boat (ie, no seat time) in months, it ran like it was on rails. It always has, but you never know what another 7-9mph can bring. I think all the earlier mods we've done (new tabs/Imco drive with spacer/P5-X/etc) are really paying off now.
I could have literally taken my hands off the wheel @ 90. The extra horsepower has allowed me to use less trim, keeping the propshaft angle almost parallel to the hull (2.5 on the Livorsi guage, 0-10 range), which usually results in efficient slip #s and good handling. Tabs retracted all the way.
I'll be testing some props over the weekend and I'll let you guys know how it goes.
Regards,
Steve

Steve, you bring up a good point on the props...
Although under propped, the 27 P5X with added cup was very squirlly at best. The tuned 30 P5X is rock solid.
That being said, setup is key.
Another note...The spacer did not work out on this particular setup at all

Thats the ticket!:evilb: :drink:

BTW, nice numbers!

I guess the numbers that count are on your speedo and not the dyno. I tried to dyno mine down here but the guys equipment was just not cooperating. At least running it on the stand gives you a chance to check for leaks and makes adjustments easier.

I would love to see a flyby vid of your heat in action. (I may not make it to the regatta)

Great job on a killer heat!

Dave,
That's interesting. When I was racing outboards, I always used higher transom heights (x dimensions in this world) when the boats I was setting up had a higher HP to weight ratio. I actually set a few of my boats up with the propshaft above the bottom of the hull. I've seen a few high X dimension offshore race tunnels with similar propshaft heights.
I think when you have the HP that the 97MPH boat has, it just has the power to carry the bow, even @ 19 1/4"s. And if you can get away with it, you'll have a very efficient setup because you're not dragging the gearcase as deeply.
I've wondering if I could ditch my spacer with the extra HP I have now. Maybe with a 5 blade.
I did run the Merc lab 32" B1 today. It ran 90MPH @ 5600. OK, but not earth shattering. It would be better with a little more cup to lock it up and carry the bow a little better. The boat didn't like the 30" stock P5-X at all. Handling was off a little, and it only ran 87MPH @ 5700.
Looks like my old faithful 28" P5-X may the ticket. This motor really likes to rev. I will also try my old 30" B1, and would really like to try a 29" P5-X blueprinted. Hey Bob:D !
Regards,
Steve

Thanks Casey. We're getting there:D ........
Regards,
Steve

I'd be happy to send it to you. It's still boxed up from when Dave's friend tried it. I'll be happy to ship it to you to try, but I need it back within a couple of weeks, since I hope to have my boat finished.

Bob

That does. I'm not sure whether I'm going to have time to accomplish this year. I'm hunting down a house at LOTO.
Or, perhaps, a bigger craft? 28' at LOTO is entry. 35 is more the ticket.

Zuckerman, you've been through all what I'm just starting so I will ask the pro. Took the new boat out yesterday...42 sonic w/ 575's. With the stock 4" pulley's it was pulling 7 lbs at 5100! I thought stock was 4 lbs? I was going to remap and go with a smaller pulley but I can't if it is already there. Does cool air make that much difference? Thanks for the help.

Bob,
We are going to cryo treat my gears. So I may be down for a little while (a week or so). Thank you for the kind offer.
I will give you a shout when I'm back together. I still have your # on my cell. How is your motor coming? Sounds like you're getting close!
Regards,
Steve

Forester,
Cool air does help the boost level on the 575, but not 3 PSI, in my experience. Maybe 1 PSI.
Were both engines reading the same boost level? You can cross reference that way.
Here's my experience with the Weiand/Merc 256 on this motor.
stock 4" pulley at stock rev levels (5100/5200) = 4 PSI
3.5" pulley with revised ECU (5600 limited) = 6 PSI
3.5" pulley with Whipple intercooler = 4.5 PSI
3.25" pulley with " " = 5.5 PSI
3.0" pulley " " " = 6 PSI
3.0" pulley " " " @ 6000 RPM = 8PSI
Reprogramming the ECU to 5600 limit and an intercooler really helps these motors out. The low compression ratio (7.5 to 1) responds well to increased boost levels. Spinning the W256 to these boost levels unfortunately generates more boost heat, which makes the intercooler a nice addition. You should be able to pull a very reliable 700+HP out of your motors with these "bolt ons". Beyond that, gotta go to internal surgery:rolleyes: :D !
Good luck. Keep us posted.
Regards,
Steve

I just haven't had time to work on it. I've got a couple of builds in front of it that I've got to finish first. The long block is assembled. Just need to bolt everything on and get it on the dyno.

Steve, forgot to ask...Buddy has a new heat closed bow, went in the mold Thursday, with 525efi. We are @ 1300 ft with 80* air temps. What I'm I gonna be up against? And yes, both gauges were reading the same boost on the sonic. Thanks.

forester,
#1, I would advise your friend to have Nordic install his drive @ 18 1/4"s X-dimension. For some reason, they seem married to a generally too high 19 1/4"s. That's why so many of us have to use 1" spacers on our drives.
I'm not familiar with your altitude and the issues it causes. These boats run almost 80 at sea level and good conditions, to 75ish with 525s under hot humid summer conditions and lower altitudes. I don't think they've made any bottom changes with the new boats.
Regards,
Steve

Steve,
Do you have a Diacom?
I'd be interested in your intake air temps with that blower at 6000 rpm.
Thanks,
Dave

Hi Dave,
Unfortunately not, but I think I know where you are going with this train of thought. No doubt, I was spinning the hell out of it before @ 5500 with a 3" pulley. @ 6000 it's crazy fast, like 57% OD.
We are going to test a 3.5" pulley as soon as the drive is back together. I think the slower rotor speed will reduce my boost, but also reduce intake temps, hopefully offsetting each other.
Eric thinks I may lose some acelleration, but the top end #s will be similar, if not the same. And that hard working W256 may live longer too:rolleyes: .........
What do you think?
I have a friend here who's putting Blower Shop 871s on his 575s/42' Fountain. We have before #s. Should be an interesting comparison vs the W256s. Wish I had the vertical room to do the same. I have another friend with the same space issue (29' Fountain/575) as I do who's replacing his W256 with a BS 250 low profile billet blower. Should also be an interesting comparison.
Regards,
Steve

Steve, just some food for thought. You really have no idea where your peak HP occurs(from dyno run). Something kept the dyno from reading torque above 570. My guess is something mechanical, like the torque arm hitting something that limited it's movement. So, all we know is the torque stayed above 570 up to 6500 RPM. The boost should stay fairly constant with a roots type SC. The fact that it started climbing at the upper RPM may be an indication something is not quite right. Your power may have started falling off as the boost was climbing.

Bob,
Thanks for your analysis. Something was definitely amiss with our dyno tests. All we can do at this point is test pulleys/boost, and A/F ratios/timing/etc and props. I think we're pretty close based on the way the boat is running. I figured boost normally climbed with RPM?
Hopefully we'll arrive at the right combination. How much horsepower can your propshaft dyno safely test?
Regards,
Steve