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Discussion Starter #1
So I put a closed center loader with longer ramps into my boat to see if it would be better than the open center loader that was in it. I really like how the boat handles, with the diverter all the way down, feels real loose and does not porpous at all. The front could be a little higher, as it is riding a little wetter than I would like. If I put the diverter up one click, it porpouses very bad. I have never really gotten this boat to take a nice set.....Yet.

The boat is a 18 foot mako, delta bottom, dominator pump, 1/4 inch shoe, pump is set way back, handhole cover is outside the boat. It has a droop, diverter and one small wedge and a ride plate that is pretty much set all the way up. It also has a nozzle insert in it, I believe it is the blue one.

With my old loader, we were having problems getting pump inlet pressures above 20 psi, just couldnt do it, not even with a 5/8 shoe. With the new loader, our pump inlet pressures were around 35-38 psi with the 1/4 shoe. I think this is a good thing? The engine is a sbc 388 with an intercooled blower on it, spinning a b impeller 6000-6100 rpms at 84-85 miles per hour. I know it will run better if I can just get it to take a set already.:|err With the diverter down, where it does not porpous, there is zero roost.

Where would be a good place to start, should I try the larger shoe? Last time I had it on, the boat road really really wet. Or should I mess with the ride plate for starters?

I am still learning with this but do seem to be making some progress, and I think my hull really likes this loader.

Thanks, Ryan
 

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So I put a closed center loader with longer ramps into my boat to see if it would be better than the open center loader that was in it. I really like how the boat handles, with the diverter all the way down, feels real loose and does not porpous at all. The front could be a little higher, as it is riding a little wetter than I would like. If I put the diverter up one click, it porpouses very bad. I have never really gotten this boat to take a nice set.....Yet.

The boat is a 18 foot mako, delta bottom, dominator pump, 1/4 inch shoe, pump is set way back, handhole cover is outside the boat. It has a droop, diverter and one small wedge and a ride plate that is pretty much set all the way up. It also has a nozzle insert in it, I believe it is the blue one.

With my old loader, we were having problems getting pump inlet pressures above 20 psi, just couldnt do it, not even with a 5/8 shoe. With the new loader, our pump inlet pressures were around 35-38 psi with the 1/4 shoe. I think this is a good thing? The engine is a sbc 388 with an intercooled blower on it, spinning a b impeller 6000-6100 rpms at 84-85 miles per hour. I know it will run better if I can just get it to take a set already.:|err With the diverter down, where it does not porpous, there is zero roost.

Where would be a good place to start, should I try the larger shoe? Last time I had it on, the boat road really really wet. Or should I mess with the ride plate for starters?

I am still learning with this but do seem to be making some progress, and I think my hull really likes this loader.

Thanks, Ryan
You may want to look at the bottom before making any more r/p and shoe changes! If you have a large hook in the bottom trying to drive the bow down you could have a ride by hull and ride by intake fight and it will be a fight that you will never win!!!! Straight edge the bottom and that will tell the story. Manufactures build boats for a good ride and if you try to free the boat up with out working the last 4-5 feet it is a costly and never ending battle. M
 

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Discussion Starter #4
The bottom of the boat is flat, I had the boat upside down after I put new stringers in it, and spent some time on it.

I have not tried taking off the droop, but have thought about it.
 

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Some boats like them some boats don't, have heard of them causing probs before. Of course who knows if a short droop will work better or a straight snoot might work its all trial and error. I would start by just removing it and see if it helps at least it won't cost anything but time.
 

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What the Hell is That?
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Ask Shoemaker. I think he is the setup guru
 

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B1 Racing
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35 psi is good compared to your old numbers. Having to lay the boat over with your diverter to avoid the porpoise is killing you. You should have a 4-5 ft. roost.

I would try and eliminate the porpoise with the droop,etc. on the boat, in the long run its probably something you will want on the boat. Moving weight around in the boat would be a fix for the porpoise but its always hard to move things around, try less rideplate angle, that still probably wont fix it, Id be looking into a small set of trim tabs if you cant get rid of it by working on the setup.
 

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Discussion Starter #9
I do have some weight in the boat, there are a pair of 12 inch subs under the front, as well as a couple of amps. This is lake boat and tunes are needed for the sandbar.


I am going to try a drastic change on the ride plate today, just to see if the boat handles different, I know in the past, it has not, but maybe with this new loader things will be different.

I will say though, with the diverter down, this boat has never rode so nice:)devil, but you can definatley feel the boat loosen up and pick up speed when you raise the diverter up a notch or two. The boat has always run the fastest with the roost about 4-5 feet high. You can feel it slow down when it comes down on the porpous, killing speed. Thanks for the input, I really appreciate it.

Ryan
 

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Discussion Starter #10
What degree is youe ride plate set to? Blockers are used to give lift and make the boat think it's got more ponies (more RPM's)

I cant remember the exact degree it is set to, and would have to check it with my angle finder, but I do know that it is all the way up right now. If I was to guess I would say 8-10 degrees up. This was where it rode the best last year.
 

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The bottom of the boat is flat, I had the boat upside down after I put new stringers in it, and spent some time on it.
do you have any pictures of the bottom on the boat? You state the bottom of boat is flat but how about the next set of outside strakes?
ted
 

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Discussion Starter #13 (Edited)


I wet sanded the bottom from the area where I started in this picture, down to the first ridge, and all the way to the back of the boat. Then speedcoated that area.


This is when it was in primer, I blocked it out from the center skag, (should have removed it) all the way back, it is completly flat with no hook or rocker.


 

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I may be talking out of place here but I feel that your bottom desing is not going to give good results with a lot of bow lift. I feel that without the spoon the loaders with too deep of lift ramp will only block the shoe.
 

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loose the droop snoot!!!!! best thing youll ever do. call duane a htp and get his straight snoot and try 6 degrees of wedge. you have way to much wedge in there already. it porpuises because you dont have enough power to run the boat that far out of the water. my boat is a delta pad and does not like to ride high like these v's and tunnels. call duane, a droop is like treating a symptom, instead of an illness
 

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sleekcrafter said:
Blockers are used to give lift and make the boat think it's got more ponies (more RPM's)
not hardly. where did you come up with that theory? somebody's old wife???


if you place a straight edge along the keel centerline, what is the depth of the shoe biting edge (1/4 or 5/8), and what is the depth of the loader ramp leading edge?
when you know the depth of the ramp leading edge(s) compared to keel centerline, measure your loader as described at the bottom of this page:
http://home.pacbell.net/jmcclure/Loaders.html then you'll know exactly what you are changing with respect to ramp location with any other loader...

going from a 5/8" thick shoe to a 1/4" thick shoe is a massive change. the biting edge of the shoe and the ramp leading edges should both be very close to keel centerline, with both functioning to load the pump as equally as possible.
short story... several years ago, there was a guy that would routinely run 120s and would win his class, but his boat always had a porpoise to it. he sold it minus engine, and the next owner brought it out. at 105-110, it was porpoising even worse. looking under it, the loader ramps were almost an inch above keel centerline. i asked the previous owner about it - it was the same loader he had always run. since our boats were similar, i loaned him my mpd loader that placed the leading edges -slightly- below keel centerline, and prestochango, with no other changes there was no more porpoise... after several offers to buy it (no way), i got it back at the end of the day and he ordered his own... still no porpoise several years later.

getting pump loading squared away may not affect your porpoise, but you should look at it anyway. beyond that, i agree with cs - work with your plate, and if it's still there, consider installing small tabs... there is a track record of tabs resolving this issue when all else fails.
 

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Discussion Starter #17
The shoe that is on it right now is 1/4 below the keel, the loader that was on it was about 1/8 above the keel. When I ran the 5/8 shoe with the original loader, the boat ran smooth, but also ran very, very wet.

This new loader is about 3/8 below keel. The ramps on it also seem to go much higher than my other loader, towards the top of the impeller.

I am certain that the loader is blocking most of the shoe at this time.

I tried turning down the ride plate a bunch to see if there was a massive change in how the boat handled, and there was not much change. The ride plate is set right now around -5 degrees off the bottom of the boat. I am going to change it back to +5 degrees, and install the thicker shoe I have. The shoe should stick about 1/4 below the loader. Easy change to try. If that does not help, I am going to try removing the droop.

The wedge has nothing to do with this porpous, because I can change my diverter angle.

As far as not having enough horsepower, I dont think that is the problem either, small block powered boat running mid 80's, with full gear, and stereo? I just want it to run a little smoother, and faster:p. 200 pounds of stereo equipment in the bow does not help, plus the engine should probably me moved forward a little bit as well, just dont want to give up seat room.

I have talked with Duane a bunch last year, I just dont like bothering him with every question that I have.

I will tell you one thing though, this is the best intake pressure I have ever seen with this set up, and I think we are headed in the right direction.
 

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The shoe that is on it right now is 1/4 below the keel, the loader that was on it was about 1/8 above the keel. When I ran the 5/8 shoe with the original loader, the boat ran smooth, but also ran very, very wet.

This new loader is about 3/8 below keel. The ramps on it also seem to go much higher than my other loader, towards the top of the impeller.

I am certain that the loader is blocking most of the shoe at this time.
slowboy, are you saying that with shoe "a", the biting edge is 1/4" below keel centerline, and with shoe "b", the biting edge is 5/8" below keel centerline???

if your new loader ramp leading edges are 3/8" below keel, that's a bit deep, but if it's working stick with it.

why would you be certain the loader is blocking the shoe??? do you have empirical evidence to support that, or is this another story from an old wife???

if you take a close look at the loader, the ramps should gradually curve upward into the intake. they should NOT be "straight", like a piece of straight stock. the reason they're curved is the same reason people add spoons, or add material to the front of the intake to "curve" upward into the suction piece - that curve creates a low pressure on the backside of the ramp, causing water to flow up behind it. consequently, if the loader is designed and constructed correctly, the biting edge of the shoe will always be in the water.

I tried turning down the ride plate a bunch to see if there was a massive change in how the boat handled, and there was not much change. The ride plate is set right now around -5 degrees off the bottom of the boat. I am going to change it back to +5 degrees, and install the thicker shoe I have. The shoe should stick about 1/4 below the loader. Easy change to try. If that does not help, I am going to try removing the droop.

The wedge has nothing to do with this porpous, because I can change my diverter angle.

As far as not having enough horsepower, I dont think that is the problem either, small block powered boat running mid 80's, with full gear, and stereo? I just want it to run a little smoother, and faster:p. 200 pounds of stereo equipment in the bow does not help, plus the engine should probably me moved forward a little bit as well, just dont want to give up seat room.

I have talked with Duane a bunch last year, I just dont like bothering him with every question that I have.

I will tell you one thing though, this is the best intake pressure I have ever seen with this set up, and I think we are headed in the right direction.
you are making some really huge changes with your shoes and ride plate, that may be taking you from one extreme to the other. it's very difficult to evaluate your shoes without seeing them. it's not difficult at all to make shims for the 1/4 shoe, and drop it down in smaller increments. i can make an 0.030 change in shoe depth, and see a definate change in suction pressure. if i dropped half an inch, handling would be ridiculous and downtrack it would blow the tail... a 10 degree plate angle change is also huge...
another approach would be to make a small change, make a pass and write down what it did (if it porpoised, at what speed? with what setup?), then do it again with the next change. it's nice-to-have someone watch it that knows what they're looking at, and can write that down too, but that's not always an option...
 

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Discussion Starter #19
slowboy, are you saying that with shoe "a", the biting edge is 1/4" below keel centerline, and with shoe "b", the biting edge is 5/8" below keel centerline???

if your new loader ramp leading edges are 3/8" below keel, that's a bit deep, but if it's working stick with it.

why would you be certain the loader is blocking the shoe??? do you have empirical evidence to support that, or is this another story from an old wife???

if you take a close look at the loader, the ramps should gradually curve upward into the intake. they should NOT be "straight", like a piece of straight stock. the reason they're curved is the same reason people add spoons, or add material to the front of the intake to "curve" upward into the suction piece - that curve creates a low pressure on the backside of the ramp, causing water to flow up behind it. consequently, if the loader is designed and constructed correctly, the biting edge of the shoe will always be in the water.



you are making some really huge changes with your shoes and ride plate, that may be taking you from one extreme to the other. it's very difficult to evaluate your shoes without seeing them. it's not difficult at all to make shims for the 1/4 shoe, and drop it down in smaller increments. i can make an 0.030 change in shoe depth, and see a definate change in suction pressure. if i dropped half an inch, handling would be ridiculous and downtrack it would blow the tail... a 10 degree plate angle change is also huge...
another approach would be to make a small change, make a pass and write down what it did (if it porpoised, at what speed? with what setup?), then do it again with the next change. it's nice-to-have someone watch it that knows what they're looking at, and can write that down too, but that's not always an option...

The loader ramps are curved like you mentioned, but do stick down below the keel about 3/8 of an inch. The shoe that is currently on the boat is 1/4 below the keel, which means the loader ramps are blocking the shoe at speed by 1/8 of an inch.

I was trying drastic changes because I messed with small changes all last summer and really did not get anywhere. I was willing to try anything to see an improvement. I wish there was somebody around here that knows more about the setups than me, but am afraid there is not.


I adjusted the ride plate up today so that it is dead level with the bottom of the boat. We ran the boat, and it has never ran better, hardly any porpous, smooth. The boat could be running a little more out of the water, but it really is not all that bad. Finally got most of the porpous out of this thing, now I can fine tune the ride plate. I think the loader sticking down in the water is working good for this hull. I know this hull really does not have the best bottom design, certanially not designed for the speeds I am running it at. I plan to paint the boat this next winter, and was planning on doing some major bottom work. Thanks for all the help, :)devil Ryan
 

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Not sure if we missed it in all this text but what intake and what degree is it at versus true keel ?? kind of looks like the "Alpha" that I have in my Mach 1 and Josh is using in his Beezer ? any pics of the top of it ? I may have some Ideas if it is Tom
 
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