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21 Daytona
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Discussion Starter #1
this thread is for Tips and Tricks for the 21 Daytona or splash Supersoaker this means you also.
I thought it would be interesting and infomative to share and discuss setups and tricks
in one thread.
 

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21 Daytona
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5,291 Posts
Discussion Starter #2
Originally Posted by Phat Bastard

I have a 1998 21 Daytona with a Dominator pump attacked to a Mersch intake. The engine is a 10.2:1 496 ,pump gas, solid roller ,single 1150, lightning headers, Top proline 320 cc heads Dominator. I turn a GS prepped stainless "b" to 6200-6300 rpm with 35psi on the suction side of the intake. I ran the boat all last season with a base line set from GS marine to get the feel of the boat. I feel this engine makes in the 650-680 hp range .

I picked it up as an empty hull with the pump installed and built the rest from there at home. It had a 13.5" opening with a 2 degree tapered shoe, even with the keel as a baseline. Open loader grate with the ride plate at 3 degrees up, 3 degree wedge and a droop. This ran ok but had a mild top end porpouse and a top speed of around 82at 6100-6150 rpm.

With help from a member of the 509 boat crew I have been playing with a 2.5 degree back cut shoe about .200" up in the hole, same opening and a 1 degree wedge for a new base line. With that I hit 85.9 last wekend at the lake into the wind ( El Cap-700' elivation roughly)

My buddy took pictures of the run and the boat looks pretty flat with the water breaking about 3 feet from the rear of the hull. This has been my issue for ever, how to sail 21', 2000lb boat at my low speeds(compared to fast 19' Daytonas.

This sunday, I removed the inducer and made no other harware changes to see what it would do a single change at a time. The boat ran a best of 88.3 into the wind, same lake still riding pretty flat and wet. This was with a steady pump load and unload ,basically was on and off hooking up for the last run. It seemed to hit 6350-6400 rpm without the inducer on this run.

I honestly feel I will hit 91-92 with just a fully loaded pump. The 88 a constant surge, on and off and still ran a decent # for my engine hull package.

I also feel I to get the boats tail up alot more some how. First I plan to return to the shoe at even keel and see if I can get rid of the massive unloadign I'm currently seeing.

Maybe a 4 degree back cut and maybe a 2 or 3 degree wedge on the droop and maybe 4 on the ride plate to sail the boat a little more once I'm seeign a consistant pressure at top speed.

A friend mentioned to try a loader with a blocked center to help lift the tail.

All of this is the direction I headed before Memorial weekend and my first river trip. Need to get low 90's to run down a few friends, maybe hit 95 down river with the current.
 

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by lowering the shoe depth with a backcut, it will add lift. it sounds if it is surging that it is running out of water, keep shimming that shoe down until you start seeing negative results.
 

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Hit it where you fit it
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Advice from a HB member last year for a base line 21 set up.

You should be running a back cut shoe.
Make your opening no more than 12.5 inches from the front mount of the loader to the center of the bitting edge of the shoe. You may need a bigger shoe.
The back cut should be around 2.5 to 3 degrees to the keel of the boat.
Once you have this done set the bitting edge of the shoe flush with the keel for a starting point.
Then drop it down a little bit at time & see if this helps pick the ass of the boat up?
Also your ride plate should be in the neighborhood of 2.5 degrees up & this is a starting point as well.
Check the depth on your loader. I have experimented with mine & ended up dropping it down along with my shoe.
At the current I am running somewhere around 5/8 down below the keel on my shoe & close to the same on my loader.
With the bigger boats if you can get an extension built for your droop this will help big time.
This gives you more leverage to pick the bow up after you start lifting the ass more. Sort of a teeter toter effect.
When you extend the nozzel back it takes less angle to carry the bow & focuses the thrust in a forward direction.
 

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Hit it where you fit it
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Talked with Greg this morning and found out a few new details, like I thought I had a "B" and I actually have a "BC" cut impellor.

Took it out this afternoon and with the addition of an .085" shim to the shoe and a 3 degree wedge

I hit a new high speed of 90.8 mph at about 6350 rpm. This puts my 2 degree back cut shoe at about .125" above the keel.

There are no real signs of ill handling with the adition of the shim so I will add another and will be very close to "even" with the keel with the back cut shoes' biting edge. This and work on the loader will be my next few steps.

Is a loaders height measured from the keel ( bubble) or the flat portion of the hull on either sides of the bubble?

My loaders stingers are basically even with the keel line when measured on the bubble. If measured off to the sides ( where hull is flat) it is about 3/8" lower.
 

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this thread is for Tips and Tricks for the 21 Daytona or splash Supersoaker this means you also.
I thought it would be interesting and infomative to share and discuss setups and tricks
in one thread.
Hey outlaw, my Daytona performed absolutely great! No leaks, cam is now broke in timing was perfect, cruised at 55 in white caps. 45 mph at 3500rpm. Pump set up from hi-tech with agressor intake, berkley suction housing agressor bowl, flowed bronze B, inducer, loader, shoe, ride plate, straight HTP snoot with I think six degrees up on wedges. Water regulator works perfect. Header water seems right on also. Jet Away is kinda wierd at 1000 rpm idle, oh ya didn't tighten baffle bolts, now looking for baffles.
 

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21 Daytona
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Discussion Starter #7
Hey outlaw, my Daytona performed absolutely great! No leaks, cam is now broke in timing was perfect, cruised at 55 in white caps. 45 mph at 3500rpm. Pump set up from hi-tech with agressor intake, berkley suction housing agressor bowl, flowed bronze B, inducer, loader, shoe, ride plate, straight HTP snoot with I think six degrees up on wedges. Water regulator works perfect. Header water seems right on also. Jet Away is kinda wierd at 1000 rpm idle, oh ya didn't tighten baffle bolts, now looking for baffles.
great sounds like it got a little windy up there.

OOps... there is a thread here somewhere about some cheap baffles.
was it too load for you?
 

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21 Daytona
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Discussion Starter #8
.

Is a loaders height measured from the keel ( bubble) or the flat portion of the hull on either sides of the bubble?

My loaders stingers are basically even with the keel line when measured on the bubble. If measured off to the sides ( where hull is flat) it is about 3/8" lower.
I was told to measure everything from the actual keel?
maybe someone will chime in here and set us straight.
 

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great sounds like it got a little windy up there.

OOps... there is a thread here somewhere about some cheap baffles.
was it too load for you?
It was OK, but but still too loud for the wife. I couldn't figure out why it sounded like it was missing on one bank. Had the ear plugs in so didn't notice the other till too late. I was glad it was windy since this was my first time in a tunnel. I was impressed. I will miss being able to cut it on a dime but the ride and lack of "ouch" on my back makes up for it. I may have found a couple of buyers for my other two Sleekcraft Kauais I have for sale.
 

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...
Is a loaders height measured from the keel ( bubble) or the flat portion of the hull on either sides of the bubble?...
It was suggested to me years ago my stingers be no more than 1/4' below keel (center hump) for the water I usually run (chop). This helps keep the pump loaded and prevents the pump from skipping.
I have mine about 1/8'th below center hump and my stingers are cut back on not quite a 45% angle like an arrow head. It still stays loaded good in the heaver chop and in the smoother water when I let off the throttle it doesn't feel like it's dragging.
 

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this thread is for Tips and Tricks for the 21 Daytona or splash Supersoaker this means you also.
I thought it would be interesting and infomative to share and discuss setups and tricks
in one thread.
OK Outlaw :)hand

Still need to test one more time, but I have/had?? the same porpusing as PB has and been trying for two seasons to fix. This year I did take a small hook out the bottom (transom drop). It did help some but still porpoise from 82mph on, the faster I went the more it porpoised:mad:. Then I tryed this set up and it made a totally different boat. Old set up ran 85mph.

Tryed a 3deg backcut shoe .175 above center of keel..... (old was flat .300 above)
loader was .200 above keel...... (old .400 above)
mouth opening 13in .... (old Was 13 3/4)
rideplate 2.5 deg up ... Same
droop w/6deg pins.... Same
wedge 6deg up ... Same

Boat ran 90mph gps with NO porpoise :D:D For two runs then my diverter cable broke:mad:

Will try to test tomorrow and then up date.:)devil
Turning an A imp. 5500rpm
 

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Hit it where you fit it
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I just went and had my boat and trailer weighed together and seperate.

empty hull with steering rack and cable 900lbs
trailer 1120lbs
I was always curious what the hulls weighted. Prior to this boat I had a 19 Daytona splash with a 2.5 Merc. I remember towing the hull and trailer around and it felt a little heavier that the 19 w/motor.

I pulled my loader today to check it out and saw it was cracked at the rear in the center support area. I put it in mid season last year and in about 15-20 trips it has cracked, I will check it more frequently from here on out.
 

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Hit it where you fit it
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136 Posts
OK Outlaw :)hand

Still need to test one more time, but I have/had?? the same porpusing as PB has and been trying for two seasons to fix. This year I did take a small hook out the bottom (transom drop). It did help some but still porpoise from 82mph on, the faster I went the more it porpoised:mad:. Then I tryed this set up and it made a totally different boat. Old set up ran 85mph.

Tryed a 3deg backcut shoe .175 above center of keel..... (old was flat .300 above)
loader was .200 above keel...... (old .400 above)
mouth opening 13in .... (old Was 13 3/4)
rideplate 2.5 deg up ... Same
droop w/6deg pins.... Same
wedge 6deg up ... Same

Boat ran 90mph gps with NO porpoise :D:D For two runs then my diverter cable broke:mad:

Will try to test tomorrow and then up date.:)devil
Turning an A imp. 5500rpm

I have a 3 degree wedge and 3 on the plate . Adding the droop and intake I have a total of 6 degrees up. This was nice when making passes by myself but when my 170lb passenger hopped in to leave the lake I developed a mean porpoise at about 75 and up.

I need a diverter to get the best of both worlds. I felt riding solo I could have used another degree or two "up" and it would have really sailed the nose, but when passenger weight was added, it was fighting to carry the nose and rocking on the ride plate. It is much more sensitive now with weight the more I get the boat out of the water in the rear.

F - hitting 90 , thats old news :D, the new goal is 95mph on the motor.

The boat has a whole new feel from last season, it has a much harder mid range hit by not plowing through the water as much as before.
 

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F - hitting 90 , thats old news :D, the new goal is 95mph on the motor.

The boat has a whole new feel from last season, it has a much harder mid range hit by not plowing through the water as much as before.
same here looking for 95 :D
And the mid range hit is harder
 
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