SoCal Jet Boats
Tech Talk => Jet Pumps => Topic started by: bahner80 on September 23, 2017, 03:34:14 PM
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Changed everything over the winter and thought the change was for the better, but........ now she's riding really wet.
-Dominator 12s suction housing
-Berkeley split bowl
-full droop snoot
-place diverter (manual)
-inducer
-detailed A impeller
-no loader
- no ride plate -(removing intake wasn't in the budget)
-461 bbc approximately 550-575 hp
Only got about 8 hrs on pump and motor.
She's only seen 5k rpm no wot just yet.
I know a ride plate is a necessity and that will come when uncle Sam gives me some coin but it's bugging the shit outta me she rides wet with all the upgrades and seem to be outta the water a bunch more with the stock berk 12jc.
-1980 bahner sprint
-delta pad bottom
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Pic
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Here's something to look at. Since you don't have a ride plate yet use a straight edge off of the bottom of the boat. I use a 4ft steel ruler.
I have a ride plate. The rule is the bottom pin of the droop should be about 3/4" above the bottom of the plate.
I would put the straight edge right against one of the intake fins a couple feet in. Measure the distance from the pin to the edge of the ruler. I would use a right angle slide ruler off the straight edge to the pin.
If you can get help snap a pic from the side. Your description sounds like the thrust height needs to be tweaked a bit with wedges. Down or up doesn't matter, you can adjust trim with place diverter.
Hope this makes sense, it's been a while since I worked on mine to achieve the proper thrust height.
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Didn't have an extra set of hands so here's where I'm @ seems way off from the "rule of thumb"
About 1 34" difference. Can wedges make that up?
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Didn't have an extra set of hands so here's where I'm @ seems way off from the "rule of thumb"
About 1 34" difference. Can wedges make that up?
You mean 2 1/2"? I would like to see the pic that would show the straight edge at the pump. Yea you'll need 4 hands for that one.
I wedge mine down 6 degrees on my Daytona to get it to the right height so yes in my opinion you should wedge this down to try and find the sweet spot for what you have.
I would wedge it down to about 1" and run it. See what 4 degree's does to the height.
If Flusher see's this he'll give us some insight on where you should be with this hull.
It would be a good idea to bring some wedges to the lake so you can run it, make a change and see how it reacts. I find it amazing how 1 degree can make a significant difference when you get close to where it should be.
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1 3/4" to get to the 34 rule of thumb.
2 1/2" total rite now.
Wedges it is! I'll have to hunt some down this week hopefully do some testing on the weekend.
But going outta town for work this week puts a wrench in my plans.
Thanx for the insight and replying just wanna make her work well with what I got for now until I reset.the intake,ride plate,shoe etc.......
Again thank you
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1 3/4" to get to the 34 rule of thumb.
2 1/2" total rite now.
Wedges it is! I'll have to hunt some down this week hopefully do some testing on the weekend.
But going outta town for work this week puts a wrench in my plans.
Thanx for the insight and replying just wanna make her work well with what I got for now until I reset.the intake,ride plate,shoe etc.......
Again thank you

I wouldn't suggest going a full 1 1/2" down with the thrust height. Go half way and see how it reacts. I went past the sweet spot in both directions when trying to find it. For me to low caused a porpoise condition then to high I couldn't get the hull to ride high enough.
This is the thread that I used. You have a different hull & no ride plate so I'm not positive on where you'll end up, but going lower will definitely help.
http://www.performanceboats.com/jet-boats/50706-pump-setup-daytona.html (http://www.performanceboats.com/jet-boats/50706-pump-setup-daytona.html)
I also consulted with Chris & Joe at B1 Racing, good advice and quality workmanship on the parts I picked up from them.
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Sounds good hopefully work doesn't get in too much of the way I'll post up my findings try and get a fore and aft video of how she rides if I can figure it out!