Do extension boxes pickup speed on Fountains?
 

I am always looking to increase the speed in the boats I own. (That's why I own Fountain) I am considering adding Imco boxes to my 06 38' Lighting w/staggered 525's and xr's with sportmaster lowers. A friend of mine told me that Fountians do not like extension boxes however he does not have any first have experience. So I pose the question to you. Have you added boxes and if so what was the results.:cool-smiley-011: :cool-smiley-011:

There's ALOT of "variables" that come into play when you're adding boxes, especially if the boat was'nt origionally setup for them. What you will probably have to do, is raise the X dimension to get the drives, or should I say the props higher in the water.

If I were you, I'd call someone with hands on knowledge of what you're trying to achieve here. Your best bet would be to call Scott Shogren at Shogren Performance Marine in Waukeegan Ill, and I personally know that he's got plenty of experience with trying all the possible combinations that there are to gain speed. He'll steer you in the right direction, otherwise you'll be throwing out good money after bad, chasing problems that arise from buying the wrong components, only to find out that you did'nt gain the speeds that everybody told you you'd see. Everything that Scott touches, seems to run fast and effiecient.
Everyone has their opinion, but you know what they say about opinions. Scott's opinion is one that you can count on.

Frank

Thanks Frank! I will definatly call him on Monday. I watched a buddy put Whipples on his 525's and after spending another 20k to fix the problems that developed, he still is disappointed in the results. :D

this is what I was told By the Reggie Man when I asked the same Question .." If my boats ran faster with them I would have installed them" .. my reply (Thanks)

no first hand experience but the 42 I have now had boxes and they were taken off as the boat loast apprently 6mph or something.........it did however work very well in rough water though.

good luck........Jay

Good points, thanks

Maybe I will go with Vortech blowers?

This is very interesting! I have tried to find out if it helps, but no one can answer me.

I have a 29 Fever with twin Merc 377 Scorpions. this boat flies when I trim it out to 5,5 on the indicators. I guess adding a real set-back extention box would increase the bow lift dramatically, and then be able to get the sme angle of attack with less positive trim...? It is DANGEROUS to pass wakes with that trim. Was almost thrown out of the boat one time, I did not see the wakes....

29 is not a "full stepped" boat. Runs much like an old ordinary Vee.

All inputs apprechiated VERY much!!!!!!

I have spoken with a couple of the people at Fountain when I was looking at adding boxes. They told me the same thing that others have said - Fountains normally don't like the boxes unless the boat was specifically set up to run with them. Shorties are a different thing depending on the x-dim.

I hate to say that boxes don't work, but when setup properly, they work great.
My boat was setup from the factory with Gentry twin turbo'd 527 cu. in. engines that made around 950 hp, boxes and SSM IV's. If you look closely, you'll see how high the boxes had to be installed. They had to cut the rub rail to raise the boxes to get the x dimension high enough. With the boxes on, my prop shafts are an inch below the bottom of the boat, if you were to run a straight edge along the bottom back to the nose cone of the drive.
When I run in normal water, I keep the drives about dead even with the bottom of the boat, which is about 2.5 on the indicators. Tabs evenly straight with the bottom also. I never trim the drives out more than 3, or it will lift the nose ridiculously high and really take off when you hit those unexpected "bigger" rollers that seem to come up out of nowhere when you running in the triple digets.
Before you spend all the money to convert to boxes, try some different props like some 5 blades. The boxes are the cheapest part of the conversion. Then all your steering brackets will need to be changed, some shortie drives will be on order, and the props that you are using now, will more than likely be of no use anymore. I'm not saying it won't work, but I'm saying that you're in for a major expense. Be prepared.

Frank

Every boat that I have been on that had boxes put on, ran slower but handled a ton better.

Alot of the time folks end up over analyzing things. If you sit down and think, common sense can answer alot.

When I think of boxes I think slower because the prop is not up under the ass anymore, and more leverage for the same reason - the prop is further back. Could be totally wrong but that is what I think of.

Nice rig Frank!!

boxes do work.

so do blade , diameter, pitch, and ring changes.

the biggest improvement will come from a good c.g .

boxes fail due mostly in part of the c.g .
you cant change prop pitch upwards without adding more power, thus you cant move the point of leverage without effecting the c.g . too many people spend bucks on big ticket items with poor results as said above simply because of info.

as for the whipples, and i am assuming the new 5 litres. they work fantastic on the 525's depending on configuration they will make over 1000 h.p . my friend mr. sgro has em on a set of engines, boat went from 107 or so to almost 140. huge difference. engines now have 60 hrs i believe with no failures and run like kittens at idle.

I have boxes behind 525sc and they did nothing but helped handeling. the boxes are mounted as high as they can , and with this and the swim platform when the drives are tilted out they hit the swim platform. not good. I think with the boxes mounted as high as thy can and -2 shorties I would pick up as much as 5mph. But a new boat looks more impressive than spending money on a used one.

How do I get in contact with mr. sgro? I would like to talk to him before I install blowers.

Alson what is c.g. ?

Center of gravity.

When you push the props farther back, they're grabbing "cleaner" water, and they need to be raised, otherwise you'll be "dragging" them in the water cause they're way too deep. That's why most of the time when boxes are added, the props are not high enough, and you will see a loss in speed. But like mentioned previously, they do work when installed correctly.

CENTER OF GRAVITY. as stated.

a good analogy to boxes and leverage effecting c.g and running attitude would be to try and pull a nail from a 2 x4 using a claw hammer but holding the handle at different distances from the head of the hammer effects how easy you can pull said nail.
same relation to the drive pulling the bow up.

as for sgro send me a p.m with your number.

i.t.s is almost as long asa standoof box and does in fact increase speed, which is why the factory uses i.t.s as standard now.

is this center of gravity? :sport009:

NO,,,,,,,,,,,,, THAT would be NO gravity over a center. of a wave that is

THIS would be the result of a good c.g

Which Sportmaster's are on there now, standard length or the -2's?

Monstaaa: Do you have more pics of that 42 Poker Runner??? I have seen it once, and that boat looks UNIQUE!!!! Any info about engines and speeds?

Boat is listed on OSO.

OK, I see on another post you have the standard lowers.
I think having Whipple re-cal your computers for the 35HP upgrade and also using a custom prop shop to dial in your props to your boat for top end will get you the biggest bang for the buck.
Going the with the boxes you would lose speed with the standard lower...going to the -2 lowers, then your talking 5-6 blade props and steering modifications... Way to much F'in around for what you would get out of it over the other route.

monstaaa can u explain to me the diff. between I.T.S. and extension boxes? and has anyone ever messed with ext. boxes, or I.T.S. on a 32 fever? sorry, new to the education on drive placement and pricipals.

i.t.s is merc's intergrated transom sterring. its a set back with steering built in to it. there is no need to mount external rams.

exstension or standoff boxes are after market boxes made of aluminium that space the gimbal/ transom assembly off the transom usually around 11".

in either case the result is putting the prop into cleaner undisturbed water for better handling and less prop slip amongst other things.

as for the 32 , i personally have not tried them on one.

No that is poor fuel economy, but one good time.

Well said!!

Moms new car??? haha

Well spoken -Well Said

Let's set up a race 38!

Hell yeah, i seen some 1000+ steerling engines in the classified section... ONLY 85000!

http://www.offshoreonlyclassifieds.c...o22218-en.html