the initial #s are in
03-21-2007, 10:21 AM
#11
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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
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
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
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
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.
Last edited by Steve Zuckerman; 03-21-2007 at 10:23 AM.
03-21-2007, 10:36 AM
#12
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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.
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
Last edited by Steve Zuckerman; 03-21-2007 at 10:38 AM.
03-22-2007, 04:51 AM
#14
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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
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
03-22-2007, 09:08 AM
#15
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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
03-22-2007, 10:04 AM
#16
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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.
03-22-2007, 12:32 PM
#18
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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.
If you weren't so far away, you know
, 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
.........Best Regards,
Steve
Last edited by Steve Zuckerman; 03-22-2007 at 04:12 PM.
03-23-2007, 04:57 AM
#19
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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
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
