We have one Heat that did not like the spacer however two that loved it.
The one that did not like it was the fastest of the three if that matters. Tended to walk a bit with the spacer and Bravo.
A 30 P5-X tuned by TU ran 94.3 GPS at Lake Powell (3600 feet elevation) last year in 105* degrees, 5 people and over half tanks.
This year with a stock 32 Bravo it banged the rev limiter at 5950 and ran 98 and some change in Havasu in 90* temps. It was not done pulling but a gear change here would be the only reasonable switch but then he would lose his high altitude benefits which is where it spent most of it's time.

So the P5-X can be worked to run very well. He actually used it most for long cruising at Powell because of the overall better efficiency, handling through the canyons, etc... but it is no slouch by any means.

Hope that helps some,
Dave

What kind of power and gear ratrios are these boats running?

It's actually one boat running those speeds and it has a 548ci R-Tech Supercooled M3 Procharged EFI setup running 1.5:1 Max Machine Worx drive.

The two that liked the spacer were an HP500EFI and a Whippled 496HO set up (full build) with ~700hp. These both benefitted very well from the spacer. Much better cruise and a 1-3 mph gain on top.

Dave

X-dimension update: 09 Heat

The distance between the notch and the bottom of my transom assembly is set at 6 3/4 inches. This gives a propshaft depth 0f 3.5 inches below the keel when the outdrive is set parralel to the keel angle. I could not get the boat to hook up very well in this configuration, and it shot a rooster tail that looked like a jet boat. I installed a one inch spacer (which brought the propshaft depth to 4.5 inches) and the boat feels much better. I am continuing testing,

Chris

Chris,
Interesting. That's exactly the same XD as mine. It looks like the factory sets the XD according to moon phase :rolleyes:.
I thought they got the memo from us, if not the dealers, that 19.25"s was too high. I guess they didn't..............
You're on the right track.
Keep us posted with your progress.
Steve

That's right where I'm at, but I think I'm a 1/2" too low.

What kind of numbers are you running now compared to before?

Southocg,

I agree that because of your extremely low slip numbers, your prop is probably 1/2 inch too low for optimum speed on your boat. I think that each boat probably needs a little different x-dimension based on weight, horsepower, balance, open-bow vs closed bow etc. I don't understand why Nordic is continuing to put the x-dimension so high. I am even considering going 1/2 inch lower to see what it does with my boat.

I was having problems with the Smart-Craft shutting down the motor when the trim was anything above neutral trim. The trim sensor was incorectly adjusted from the factory, and the Smart-Craft throttles down the motor when it thinks the boat is over trimmed. Tim from OCM finally figured this out, and he and I fixed the problem on Saturday. We have not had a chance to truely test the boat since then, but I will be out on the lake on Thursday doing testing.

Best speed to date is 80.1 mph spinning a stock 30 Bravo at 5100 rpm. This is with the nose of the boat burried because we could not trim it up without the motor shutting down. We thought it was hitting the rev limiter, and could not figure it out at the time. I took the boat out on Sunday with my family, and was able to trim it out, but was not going to open it up with 4 kids on board.

I will let you know how things go on Thursday.

Chris

P.S. Even though we have been running negative trim with our testing, the spacer was worth 2 mph

Chris,

Keep me posted with your numbers.... I'm curious to see what changes.

I more then likely will be swapping to a 1" shorty and then space from there. Like I said, I think I'm about a 1/2" too low.

If I picked up a couple MPH, I would run a legit 90+ at sea level maybe a hair over, 91 or 92, which would be pretty respectable for that boat with that power.

thanx,

Jim