Dyno results
 

I just finished dynoing my engine. So now we have some more very good data to play with. First remember my 28 Heat Mid cabin runs a consistent 86 with a best of 89, running in 95+ degree weather at around 800 ft. elevation. I've never made a pass in it with the temp below 90 degrees. With that said, I pulled the engine out of the boat and put it straight on the dyno, changing nothing. The dyno sheet is attached. What I find interesting is that peak HP occurred at 6100 RPM. I never turned it past 5600, so I was leaving a couple of MPH on the table. I'm rebuilding it this winter and doing some improvements. The second dyno pull is with 2 more pounds of boost. It likes boost!

Re: Dyno results
 

Bob,
Aren't dynos the ****! The second chart is sweet. Just prop for 5800 and set the limiter at 6000 and let her eat :D ............
What are you planning for the winter?
Looks like all you needed was the dyno sheet and the smaller pulley :cool: !
Regards,
Steve

Re: Dyno results
 

I really thought it would peak around 5800 with that cam and heads. I'm sending the heads to Jim V for a serious massage. I want to lower the compression a little and run more boost. I'll install a cam more suited to a supercharged engine. Mainly I have to freshen it up because one cylinder was having a lot of blowby, so it was time. It has over 300 hours on it. Looking at the second dyno run it looks like I am running into a flow restriction somewhere because the boost shot up and power fell past 5600 RPM. I think the heads are too small. They were configured for it being naturally aspirated.

Re: Dyno results
 

Bob,
Looks like a 900HP summer 07 for you :D ...............
I am proceeding with modifying my 575 this winter with Dart/marine aluminum heads, roller cam (suggestions welcome, am getting recommendations from KE and RM Builder), and raising compression to 8.5 from 7.5 static.
Boost should be 7 PSI intercooled (which it is now).
I don't know how my drive is going to like this, but I think I will like it a lot :rolleyes: :cool: :D ..................
Regards,
Steve

Re: Dyno results
 

Wow. And that's before freshening it up!!!! Can't wait until next summer. :D

It'll be really interesting to see "another" dyno to compare! :D

When we looked, I had room didn't I? :evilb:

Re: Dyno results
 

Room?? for a supercharger???? Yeh, you've got plenty of room. Especially in your house after Mary leaves....LOL

Re: Dyno results
 

LOL, so when can you start? :evilb:

Re: Dyno results
 

LMAO.......

So you think if we pull my engine out again this winter Brenda might leave me???????????????????????????????????????????????? ?????????????? NOT!!!!!!!!!!!!!!!!

Re: Dyno results
 

Here's a link to the video of this dyno run if anyone is interested.

http://media.putfile.com/FTM-800-EFI-dyno-test

Re: Dyno results
 

Bobl,

Look at the fuel column on your dyno sheet.
Fuel goes way up, your power does not, yet your AFR is good.
The fuel is going somewhere.

I think your cam overlap/center/duration is pumping the fuel into you exhaust.

I also noticed that you are burning a bunch of fuel to make 820Hp..Again I point the finger at your cam.

I have been down this road before and had the same thing happen....Then again, my wife says I am a moron!:rolleyes: :D

Re: Dyno results
 

The second pull with more boost is starting to detonate over 7 pounds of boost. Thats why the power rolls off so quick. At 6100RPM and 9 pounds of boost, its a blow up motor for sure on pump gas.

Re: Dyno results
 

Question is, why is boost coming up at that point? I don't believe detonation will cause the boost to rise. This is a Whipple supercharger, so boost should stay pretty constant unless something happens to increase restriction. Notice the 5.5 psi pull it stayed pretty even all the way. That's what it should be doing.

Re: Dyno results
 

Bobl

Think you are right at 6100...Could be a bit of restriction there.

Don't know about detonating the motor. You would have to check the egt's on another dyno pull. Linster could be right, but I think it is a fairly standard Whipple dyno curve.

Try to compare your dyno sheet to others. Look carefully at the Lb/Hr to horse power relationships.
It takes a certain amount of fuel to make 800Hp. No more or no less.....Should be around 70 Gal per hour.

Burning more means that your tuneup is wrong.

Looks like you are well on your way though...Big power and big torque=Fun Ride:D

Re: Dyno results
 

Uh oh, does this mean when the goggles come out it's going to get even more serious? :D

You may need to install a few more OSH's? (Oh Sh|t Handles) LOL :evilb:

Re: Dyno results
 

I would think that the reason the boost goes up so fast at that point is the blower has saturated the engine intake ability. It jumps 1 lb from 6000 to 6100. Keep in mind, detonation is firing before the spark plug ignites and the valve is closed, which would cause clyinder pressure(Intake Pressure) to rise. That may answer why the pressure jumps so fast at the end. Just a thought, dont know for sure but sounds like the problem to me.