brian41

iTrader: (1)

Rich,
Yes its helpful in getting you closer to a prop to start testing with but every hull/set-up reacts differently.... to many variables.

Are you splashing this year?

Me.... maybe.

Spring run theme is " If is not a cat...it must be a dog"

the deep

iTrader: (8)

Brian , If you have t-shirts made with that saying on them I've just got to have one . Let me know where to send the $$ . Cat killerz my azz .

michigan troll

Crocket dynoed ours and it was an all day affair. We ran it on the same fuel from a gas station as you run every day. Broke it in on the dyno. Tuned it on the dyno with all my pumps regulators pulleys belts and CMI exhaust.
After it was in the boat we took it to him and with me driving he retunned in the water to a full boat with 3 people on board and 3/4 tank of fuel.

ICDEDPPL

iTrader: (1)

Some tool bag

I couldn`t post the vid from my tablet for some reason, here it is:

http://33outlaw.zenfolio.com/img/s2/...972750-210.mp4

ROTAX454

What I was referring to is the precise Torque and HP peaks. Say for example that a given motor has a peak HP of 550 at 5400rpm. Starting a 5500 and beyond, that HP curve starts dropping like a fat girl off her bar stool.

Yes given the fact as you stated reference hull/set-ups react differently, but you now know NOT to exceed 5400 (better put kept it precisely at 5400) rpms when under WOT.

Same with the torque peak. If the boat falls flat on it's back (reference made to the fat girl-------difference is she bounces a few times while the boat just stays flat) and has a very hard time gathering forward motion (speed) at the torque peak, then further prop tweaks are necessary.

In conclusion, put her on a diet. No, not the girl-----the boat.
Ok, both.

ROTAX454

That was the plan. Wrote a large contract that starts up in mid-May. Hey, gotta follow the money. Will get to the boat build after the contract is finished (mid-July). Hopefully get some late summer boating and the fall run.

You going to have the cat in the water? Several more cats in Leopa. Should be interesting. Do like the saying.

To stay on the Thread Content folks. Brian does know what he is talking about. He owns/operates a prestine high end dyno cell at his shop.

brian41

iTrader: (1)

Rich,
What we use when selecting props is 1000 RPM's past max TQ to unload the drives. For the most part the aspirated engines we build Max TQ in between 4700-4900 RPM's and HP starts falling off at 5700-5900 RPM's. So yes we set our props up at the point HP falls off on these engines.

Chasing cash has been the hold on getting the OE done for the last 2 years but enough is enough this old man needs to have some fun.

As far as the theme for the spring run goes, I was kidding about that but it is the new shop saying.

Budman II

iTrader: (1)

Well, as luck would have it, I'm not having much luck finding anyone in my area who can dyno this thing at all, much less with pump gas. You would think a city the size of Louisville would have more shops with a dyno. If anyone knows of one within an hour or so, let me know. I might have to talk to Eddie to see how much he gets for a dyno session, but that will probably have to wait until after the summer with the way everyone is booked up right now.

It's real tempting to just wing it and drop the thing in the boat with a conservative tune on it and ease it through the summer, then pull it out in the fall and dyno / tune it. Either that or go the O2 wideband route. In the mean time, I might even just find another engine to drop in it for the rest of the summer. I could keep that engine to drop back in it if I ever sell the boat.