Thread:

Suction housing pres. tap location

Hi Greg... a while back, you posted up in jets(if I remember right) to put the tap location either at 10:00 or 2:00. That either of those would show a good mix(for lack of a better word) of the loader and the shoe. Before reading that I had tapped mine at about 2:00 and about 4-4:30 ish. In your opinion is the lower tap pretty much worthless. Just curious on you thoughts. I know the(my) bottom tap always reads lower than the top. I've dropped my shoe down level with the keel to try to raise the bottom #.....it didn't seem to make much difference...

Originally Posted by greg shoemaker

No pressure sensor is useless in the suction housing the problem is that most of or data has been taken from those spot on the suction housing so if your were to tell me pressure reading I would not have any data to refer to. On the new boat we have installed a Race Pack system so we have as many as 72 sensors so we will be able to able to receive more data than we will know what to do with.

Greg, Got any pictures of this thing? More than a little curious..What kind of transducers are being used?

Thanks in advanced...

GT

Originally Posted by GT Jets

Greg, Got any pictures of this thing? More than a little curious..What kind of transducers are being used?

Thanks in advanced...

GT

I'd like to see a set up like that also. Out of curiosity, what kind of suction housing pressure #'s would be good to shoot for on a 21 daytona(either top or bottom tap). I have my shoe pretty much level with the keel(maybe a hair up) and the loader is is a hair below the keel. I'll try to stick up a vid of the gauges on a wot run. At wot(70ish) I'm 20-25ish on the top and about 12 ish on the lower. Is that too low?????? After watching Kjell's thread on his 21 in it made me want to throw rocks at my boat.lol
I had second thoughts about putting up this vid because it's so shaky,it was a lil ruff that day. If you freeze frame it(hit stop) you can see the gauge on the far right never really gets over about 10(until I let off)...that's my bottom tap. Anyone care to comment on these pres. #'s???

Originally Posted by greg shoemaker

Ran Kjell's boat over the holidays. Made numerous changes and finally made some difference on bowl pressurs but still have a handling issue on the top end. kjell and I got under the boat and discovered a number of problems. Hook, keel size and shape and just how the intake had been set originally. We were seeing pump pressures in the 50 to 60 lb range which we felt was to high. We finally got it down but in the 40 to 50 range but decided that the keel had been done wrong so no matter what we did the results were pretty much the same.I was impressed that 97 to 98 mph on 700 hp was very impressive in that size of boat. Once we get the bottom sorted out I think we will see 100mph or better out of this package.

10 is a wee bit low for the bottom tap, isn't it?? I truly don't know. Someone suggested the the loader may be blinding the shoe. I'm a little reluctant to cut the loader back much more because I don't think my top # 's are high enough either.
I'm going to try a back cut shoe this spring, do they typically load a pump harder than a tapered shoe, or the other way around? Thanks for the help BTW.

Originally Posted by greg shoemaker

Ran Kjell's boat over the holidays. Made numerous changes and finally made some difference on bowl pressurs but still have a handling issue on the top end. kjell and I got under the boat and discovered a number of problems. Hook, keel size and shape and just how the intake had been set originally. We were seeing pump pressures in the 50 to 60 lb range which we felt was to high. We finally got it down but in the 40 to 50 range but decided that the keel had been done wrong so no matter what we did the results were pretty much the same.I was impressed that 97 to 98 mph on 700 hp was very impressive in that size of boat. Once we get the bottom sorted out I think we will see 100mph or better out of this package.

What kind of handling problems? Had the keel be modified from the original?

Originally Posted by greg shoemaker

Yes the keel had been modfied and we run into this problem all of the time.The stock bottom on the 21 is just fine you can run well into the 20's without any mods to the bottom.This kell had been modified where the ride pad had the wrong angle in relation to the outside sponsons so no matter what you did to the hardware the center keel was in a big fight with the outside sponsons. I've always tried to hardware with the least amount of keel yet maintaining a good solid load to the pump.

What does " you can run well into the 20's without any mods to the bottom" mean?

Originally Posted by greg shoemaker

You should be able with good hardware and the stock bottom and of course good power to get a 21 to run over a 100mph with 800hp quite easily. Kjell came very close with 700hp

So, that means my stock '04 21 with around 750 hp, does not yet have the correct hardware setup. Cool, I have something to do now....

Originally Posted by greg shoemaker

You should be able with good hardware and the stock bottom and of course good power to get a 21 to run over a 100mph with 800hp quite easily. Kjell came very close with 700hp

Can this be done with a stock Dominator intake?? or do you need a low pro intake

A stock intake should have no problem