Your fountain performance report will have X dimension on it. I should add that I think raising your drive will increase prop slip... possibly losing more speed? Interested to hear what others think.

Sounds like your so high in terms of slip that a 5 blade is the way to go. Testing is the only way when dialing in. You can ask a million questions, but untill you bolt the prop on, you are not going to know. Also keep in mind, that you went with a 250lbs lighter motor, so sternlift is most likely not the way to got. Dp you know how much your B1 is pitched up. Personally I'd run a stock 28 B1(27"-27.3") and a 15 5/8 X 26" Maxie. The 90$ that's going to cost are money very well spent to get some accurate numbers.

Give me a call we can help you out.

Just curious if you called Reggie or Wyatt Fountain to get dialed in correctly.

I talk to Reggie shortly after he posted that reply and I thought I should maybe try a 5 bladed prop. He said it would definitely get rid of the slip. He also thought if I go with a 5 bladed prop I might want to try a shorter outdrive at the same time. He told me that I’m just going to have to play around with it and see.
At the beginning of June I’m planning on trying a IMCO -2 lower and a Herring 5 bladed 25p and I’ll go from there.

That makes sense, let me know how that works out, my friend with the same boat as yours is having the same problem.,w/ a 525 EFI single, Bravo1 prop, has tried both 26 & 28 pitch props

You got it!

I know it's been a little while since I've posted something on this subject but I've been out of commission do to a back injury. Anyway I decided to take Reggie's advice and try a 5 bladed prop with a shorter outdrive. It turns out that I've been running a 1.34 gear ratio and not a 1.50 so Troy setup the new lower with the same gear ratio. So our first run was with a -2 lower and a 5 bladed Herring 25p. Slow to plan and top speed of 73mph with an RPM of 5000. The WOT range on the Ilmor 625 is between 5800 and 6000 so we're way off. On a positive note the slip has come down quite a bit from my previous run at 27% (26p 1.34gr and 81mph) but unfortunately it's still a little high at 17%. I'm having Troy change the gear ratio to 1.50 and we'll try again next week.

Send us some pictures. Im interested in seeing how it urns out as well.

:food-smiley-007: Great thread to read, awesome project, keep us posted.

+1!! :nicethread: Love the Ilmore v10 in the 29' Fever! Very interested to see what prop/gearing/x-dimension ends up yielding the best performance for you with this package.

Thanks and definitely will keep you up to date. I'm still out of commission but Troy's got my boat down Supreme Marine and he's going to test it for me. I've still got another month or so until I can finally use it again so while he's got it I'm having him shorten my windshield and I'm also having him fix a couple of minor marks in the paint and I'm having him clear coat it as well. I've seen some boats that they cleared and it's a night and day difference. They do a 5 layer clear coat that's a smooth mirror finish.
Besides that he's already changed the gear ratio to a 1.50 from a 1.34 so now I'm just waiting for him to test it. He's been a little busy down there but I'm sure he'll have it done by the time I'm ready to use it........... I hope anyway.

Keep us updated. It sounds like a very fun combo!!

29 fever
 

I have put v-10's in 5 different boats. Donzi's, Fountains and Eliminators. The weight is the biggest difference! When you remove that much weight from the rear of the boat it changes the whole center of gravity. It puts the front of the boat deeper and makes it bow steer. In the 42 we took out the hardware in the cabin and it changed everything. On a Donzi shelby 22 we needed a shorter drive and a setback box with large 380 tabs. The boat was built at Fountain and they are the experts. They should be the ones with the most knowledge to help. Put 400 lbs of sand in the rear and measure the water lines front and rear. When you take it out measure it again and mark it. This will give you an idea on how much different the boat rides with the motor swap. Remove everything from the cabin and run it (even the Ice chest and all the wood around it) It will ride different. I hope this helps. joe

Finally got it back on the water!!
 

I finally got a chance to get the boat back on the water to prop test it again. Since I was going to be out for several months after my back surgery I had Troy at Supreme Marine do a little custom work for me and which turned out great. I had him cut down the windshield and clear coat the boat.

Windshield Before:

http://i1215.photobucket.com/albums/...t/3ED9440A.jpg

http://i1215.photobucket.com/albums/...t/2DFC9C82.jpg

Windshield After:

http://i1215.photobucket.com/albums/...t/DDA84018.jpg

http://i1215.photobucket.com/albums/...t/4D62A266.jpg

http://i1215.photobucket.com/albums/...t/E79BEB69.jpg

I know you can’t tell from the pictures but the clear coat really makes a difference, it looks like a brand new boat.

Besides the cosmetic stuff I also had him change to gears in the lower from 1.34 to 1.50 so for the prop test we’ve got a -2 lower, 1.50 gear ratio, and a 25p Herring 5 blade. Acceleration was a little slow to plane but not terrible. Top speed was 77mph, RPM was 5600 or 5700 (hard to tell) which is giving me a slip of 13 to 14% but we’re short about 300 RPM. I talked to Herring and they seem to think they can get it dialed in a little better for me to get the RPM I need and make it plane a little faster. I’m going to send it back to them to have them rework it for me and this weekend I’m going to try and Hydromotive 25p P5X.

http://i1215.photobucket.com/albums/...t/CAC89A89.jpg

http://i1215.photobucket.com/albums/...t/1D8E9BF4.jpg

windshield looks great... I think it makes the boat!!!

That's one of the best looking 29's I've seen, awesome work!

Well I ran the Hydromotive 25p P5X and the reworked Herring and I’m still off. The Hydromotive 25p P5X gave me good acceleration and a top speed of 77 @ 6100rpm (almost rev limit). The Herring was a little better to plane (but not as good as the Hydromotive) but only gave me 74 at 6100rpm. When I sent the Herring back they said they were going to take a ¼ in off the diameter which would make it 15 1/4in. They thought this would help with the hole shot. They also said they would release a little cup to help out with the rpm. As I mentioned the hole shot was better but not as good as the Hydromotive but now the slip is too high at 23%. It seems like the 15in diameter is giving me a best hole shot so one would think cut the diameter down on the Herring and add cup to both to fix the slip and bring down the rpm's right? Herring isn’t 100% sure that would work, but of course if I want to send it back they’ll be more than happy to rework it for me. This is very frustrating! My best so far is 81 so I’m obviously going the wrong way here.
After my last run I’ve decided I’ve had enough trying to figure this out myself. I’ve been talking to Mark Wilson over at Wilson Custom Marine over here near me in Stuart, FL about this project and he seems to think he can help. I know WCM are experts with the Ilmor’s as well as Fountain’s so I told him to work his magic and get this thing dialed in for me. Let’s see what he comes up with.

I think the maximus props would be an all around better prop , you could get ahold of bblades and rent a set or any other props .

Where's the prop shaft in relation to the hull with that -2?

I'm looking at my performance report from Fountain, stock with a XR there is a "19" in the blank after X-demention. I'm assuming that's 19 centimeters if that isn't a typo. That would mean about 7 1/2 inches stock minus 2 inches for my current setup. Does that sound right?

19" should be the distance from the bottom of the hull to the crank centerline i.e your X dimension. With the stock bravo lower your propshaft should be around 3" below the bottom of the hull.
With the -2 you must be around 1" below. Try to space down 1".

Gotcha, I guess I was under the wrong impression of what the x dimension was.