I'm a believer!
 

OK...just walked in the door from testing my 28 Heat after adding a 1" drive spacer. Why in h$ll don't they set the "X" dimension like this from the factory! It now holds a solid plane at 30 MPH @ 2200 RPM. Before it was at least 35 to hold a good plane. I lowered my cruise RPM by 200+ RPM at 40, 50 and 60 MPH. And best of all, top end increased over 3 MPH at the same WOT RPM! Unbelievable. I ran the boat last weekend right here at my house. The inlet air temp was 115 degrees(on the computer) and about a 6 inch chop on the lake. It ran 83.6 GPS with the bow cover installed. Today it was 4 degrees cooler and the lake was glass...not one ripple. It ran 86.8 and that was without the bow cover installed(which is usually worth 1-2 MPH). The boat gets noticably higher out of the water with trim. FYI..I'm running a 555 CID engine with EFI & a Whipple at 5 PSI boost(Approximately 750 HP). It has an ITS drive package and Hydromotive 29" P5X. Now I will send the prop to Julie and see what she can do with it. Then we'll bump up the timing and boost! I'm thinking 90 won't be too difficult with cooler weather, even without raising the boost.

Re: I'm a believer!
 

I believe it. My heat threw out a small rooster, I think there was a very slight surface piercing effect. :mad:

Re: I'm a believer!
 

Glad to hear it! Bye the way. I am going to be down your way next month. My sister lives is spicewood. and I am going to visit. I would love to stop bye the shop and B.S. in you don't mind
Marc

Re: I'm a believer!
 

Bent told me you had a sister here. Small world! I'd love to get together while you're here. I'll be out of town the first week of November(at the SEMA show), but other than that I'm here. Give me a call some time. 830 6935591
Bob

Re: I'm a believer!
 

So Bob lets install a 2 inch spacer on mine and just forget the Raylar ...LMAO..........

Lets see 1inch spacer gets you 3 MPH

2 Inch spacer =6MPH

3 Inch Spacer = 9MPH

4 Inch = 12MPH

I am thinking a 4 inch spacer for mine LMAO

Re: I'm a believer!
 

Is just for the stepped hull boats or is this for all Nordics. Just curious my is a 99 pre step hull.

Re: I'm a believer!
 

I don't know about the pre stepped version. You just have to experiment and see if it does any good. Calculate your prop slip. If it's 17% or more then it's a good bet the spacer will help. My slip was running 17-18% with a 5 blade P5X(21% with a Bravo 1). The spacer brought it down to 15%.

Re: I'm a believer!
 

Bob how much was the one inch spacer? What need to to be changed to add one?

Re: I'm a believer!
 

Nitro:
Check with Trick Marine. He's got great pricing.
Bob:
Very interesting test and results. Glad it worked. Have you ever asked Lonnie how they came up with their X dimension for the step hull Heat? It's such a radical departure from 1999 and older set up, you have to wonder what they were thinking.
Surely they did some testing that led them to believe that the high XD on the step hulls was working (even though it doesn't)?
Regards,
Steve

Re: I'm a believer!
 

EXACTLY........We request it lower for all our 28 builds ... it works.....glad you saw positive results :drink:

Re: I'm a believer!
 

Hey Boatingbent:

You might be on to something here, if one were to install those new tricyclical exhaust bearings they might even see plus 20mph. They would have to wear those new aerodynamic x-ray vision goggles though to see where they were going!

Ray @ Raylar

Re: I'm a believer!
 

LOL@Ray

Re: I'm a believer!
 

Magic:
There are three other Heats here in Nashville, all pre-step, pad vees like yours. They all have a much deeper X dimension. You probably don't have this issue with your's either. By the way, all three of these boats run very well for their respective horsepowers. One has a custom 496 (454) stroker/blower motor, one has a 525SC with intercooler, and one has a stock 502Mag. All three of them have plenty of bow lift. I think it's due more to the deeper XD than the different hull.
Regards,
Steve

Re: I'm a believer!
 

Steve,

Thanks for the info.

Re: I'm a believer!
 

Got the drive back together yesterday (thanks Eric), and added a 1" drive spacer, hoping to repeat your #s BobL. Unfortunately, on my boat the #s were exactly the same on top end 85MPH GPS @ 5600RPM with a 28" P5-X. I did have more usable trim range, and it did lower my cruise RPMs by 100 (3600 RPM @ 50MPH). Holeshot was good, but was good anyway before the spacer.
Weather was 80o, 1' chop, light load in the boat.
My conclusions are:
My boat must be pretty close to being dialed in if there wasn't any difference in a 1" lower (18" now) XD.
It still may carry a heavy load a little better.
It may work with 4 blades now, with the prop shaft deeper. 4 blades should be easier to turn, and I have several 30/32 B1s that I will try before I winterize. I'll let you know how it goes.
Regards,
Steve

Re: I'm a believer!
 

YUP.....go 4 blade I bet you will see a difference

Re: I'm a believer!
 

Steve,
If you get a chance, measure the distance from the bottom of the transom notch to the bottom of the transom housing.
I have an old list in Excel that myself, Steve (Indy), RV, Toby , Rick Young etc…all took this measurement.
The interesting thing with this old data log (yes, we do keep data logs ;o) is this; all of the measurements (11) came in at 6-7/8” except RV’s 1997, which was an older non stepped hull, and Toby’s (yours) 2001. I have those two listed at 4-7/8” meaning the X dimension on RVs and yours was 2” lower. Could you verify your measurement when you get time? It is an old spreadsheet :(
If this “is” the case, you may looking at a 1” shorty to get to what we are considering 1” lower :eureka:
Note: The ITS has no relation to these measurements.
Toby tried the 1” spacer on your set up with only a 4 blade to test and it showed zero improvement anywhere.

Let me know,
Dave

Re: I'm a believer!
 

Dave:
Interesting. If I measured my X dimesion correctly, it was IMHO high @ 19"s. The way I do this is driveshaft to pad bottom vertically (not along the transom angle). I haven't taken this measurement, but I suspect it's closer to 6 7/8"s. I'll let you know.
BTW, look at my tabs. I would have mounted them closer to the chines, had I rigged the boat. They can't retract very far because of the hydraulic steering mounts, and mounted in this close to the drive may be dragging somewhat. What do you think? I always understood that the further out they are mounted, the more leverage and less drag they have when deployed.
Were your tabs mounted likt this?
Regards,
Steve

Re: I'm a believer!
 

Steve,
Not sure about the tabs??? Never had or felt the need on the Heat. I have K planes on the Flame now and am still learning how to use them :cool:
I do agree with your logic though.
Dave

Re: I'm a believer!
 

My boat does not have tabs either. I don't think they are necessary on the heat, but while running on Lake Michigan they would definately be a plus. I am really impressed how this boats rides in 2-4 ft without tabs, it really carries the bow nicely and does not want to go airborne straight up. I think tabs would be nice to keep the boat level in cross winds etc.

Re: I'm a believer!
 

Dave and MM:
The other three Heats here do not have tabs, and they all seem to handle pretty well without them. But rough water here is a 3'er. After boating in what I call rough water at he LC Poker Run, inconsistent 3/4'ers with some nice 5/8'ers thrown in just for sh-ts and giggles, I can tell you that the tabs do help. They also allow for a low bow rise planing with heavy loads. In heavy traffic areas I hate losing sight of what's in front of me for several seconds. I've seen jet skis appear out of nowhere when the bow falls, and I'm sure if I ever hit one of these bastards, it would be "my fault".
They also work pretty well to even out lateral imbalances. One other thing that I've noticed versus the other Heats is that mine seems to bridge rollers better at speed, even when they aren't deployed. I think they hold the transom up, after launching off a wave, and keep the bow from kiting as much.
Regards,
Steve

Re: I'm a believer!
 

I feel it is absolutely necessary to have tabs on the mid cabin boats to be able to level the boat. People are constantly moving around, fore to aft and side to side while underway, so I end up constantly working the tabs to keep the boat level. It's not uncommon to end up with 6 people all sitting on one side of the boat. Instead of yelling at eveyone to move all the time you can just adjust the tabs. You don't have that issue with the closed bow boats.

Re: I'm a believer!
 

As for prop testing yesterday............
the boat seems to work fine now with 4 blade B-1s. If for no other reason than they're less expensive than 5 blades, I guess that's progress.
The best running one ran just about the same as my lab 28" P5-X. This is a weird prop. It came on my buddy's 29' Fountain. It's a 30" B-1 that the factory apparently ground ALL the cup out of. Very weird looking, but on his boat with the stock 575, it worked pretty well (83/84ish). After adding the boost kit, it would break loose with any throttle. He had our local prop guy add cup back to prop. This was in the reduced blade area left behind from the factory grinding. With only this mod, it was 400 RPMs faster than my factory 30" B-1. I think there is plenty left, as this prop has never been balanced, thinned, or sharpened. It ran 84.5 at 5600 on my boat. I think his best was 87 or 88 at similar RPMs. By the way, the X dimension his 29' Fountain is................19 1/4s".
I'm sending this prop along with my stock 30 to Matt. Matt has probably seen this Fountain factory "blueprint/mod" since he's worked on everything fast, but in case he hasn't, they do seem to be on to something here. We'll have him work his stuff from there, and then copy the results over to mine. I think there is another 2/3 MPH left in this prop, but we're getting close to the old limiter (5800 on our modified ECUs).
I also tested a 32" Merc lab B-1. I can't pull it, 5300 @ 84 MPH, and it took a country mile to get there. In the summer, it would be even worse.
So, is it the 1" spacer, taking my X dimension to 18 1/4"s, or the Imco gearcase loading the props better? I think it's some of both. The P5-X seems happier to me @ 19 1/4"s. The Bravos seem OK where they are. We'll get Matt to work the 30s over the winter, and test again next spring, with and without the spacer.
Dave, the dimension to the bottom of my transom bracket is 6 7/8"s. It would be less if Toby measured from the bottom of the trim line " junction box" that extends below the bottom of the bracket.
Regards and Happy Thanksgiving to Everyone! Anybody going to Key West?
Regards,
Steve

Re: I'm a believer!
 

BobL:
I have similar issues when my "social friends" ie wife's girlfriends, are on board. They don't understand, and you don't want to come off like Captain Blye with the bikini crew :D . Rather just hit the tabs and try to blow their tops off. I only got one this summer :mad: ............I'm sure it's worse with even more seating area.
Are your tabs mounted like mine?
Regards,
Steve

Re: I'm a believer!
 

Nope, mine are on the outside. My exhaust is close in, but I don't have the steering arms to deal with since I have the ITS.

Re: I'm a believer!
 

Bobl,
Thanks.
I wish mine either retracted more, or were closer to the chines so they just caught the spray coming off the corners of the transom at speed.
I guess I'll have to remove the tabs, and tie up the rams next spring, to see if they are slowing me down.
Regards,
Steve

Re: I'm a believer!
 

Steve,

By looking at your pic the tabs look like they are parallel to the hull. Are they all the way up?? The transom confirguration of the heat makes any upgrades very interesting.

Re: I'm a believer!
 

Magic,
They are actually about 2o + at full retraction, like the picture. However, when a boat rocks back on it's tail at high speed, tabs mounted close to the keel can drag on the surface, holding the nose down.
The transom on my boat is full and tight, and that is probably why the factory mounted the tabs where they did. I wouldn't have done it that way. It would have been better had the tabs been mounted closer to the chines. I may have to move them.
Steve