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impeller questions

3K views 20 replies 9 participants last post by  Cruiser 509 
#1 ·
Ok, most know my set up, if not....

21' TPR deck. Very heavy boat. 736 hp. Running an alum "A" I spin the "A" to 6k. My peak hp is 6200. It dose not fall off much before 6k. Still in the 700hp range.

My boat dont have much of a hole shot at all. I can get my wife up on the wakeboard no problem when there are two people in the boat.

This weekend I had 5 people in the boat and still got my my wife up, but when a guy tried, the boats could not get him up. At about 4200 my pump unloads hard.

My shaft is cut for an inducer. I got one on order. How much is this gonna help?

Was also thinking aobut thowing a "AA" in there. What dose that do to top end speed and RPM? How bout bottom end? A "AA" will lower my cruising RPM, right?
 
#2 ·
AA will help the hole shot alot along with the inducer and will also lower your cruising RPM and it will affect the top MPH. Lets be honest here Dan your not racing the boat so why be concerned with a couple MPH and be alot happier with with the drivability of AA.
 
#3 ·
Your 100% right Joe, I have not even gotten an MPH on the top end yet. The reason I asked that part was more for education.

I know they will both help, but how much?
 
#5 · (Edited)
What kind of hardware is in the boat rideplate angle, shoe, and loader my dad has the same boat and been getting that thing to work has been a pain so far but its coming along we picked up 800 rpm and almost 10 mph on hardware and not even that close yet but getting better.The AA impeller is a must im pretty sure they have triple and quad A impellers also.
 
#7 ·
Dan,
I have a 21ft Carrera bow rider with a little over 500hp. I changed the "A" Dominator impeller to a "AA" Dominator. I can now put the boat on plane with very little bow rise. Mid range seems push you in the seat a little. The motor turned the "A" about 5200 and the "AA" 5050.
It appears to get a couple of more mph out of cruising rpm.

The boat ran on the speedo about 61-62 with the "A" and about the same with the "AA". I put a loader grate in it and gained a couple of mph.
In my heavy daycruiser I didn't lose any significant top end but gained a lot acceleration. For a heavier boat it appears to make sense.

I watched you launch out of Jack Smith around the end of the season last year. Your boat sounded great. The idle I remember was real high and had a lot of lope. If you do go to a "AA" you might want to try a little lower the idle as my boat picked up speed at idle and became a little more sensitive to put on the trailer. Talk to Tom at Jet boat performance he walked me thru the changing, and was extremely helpful.
 
#9 · (Edited)
Dan,
The motor turned the "A" about 5200 and the "AA" 5050..
So it looks like I will loose a 200 RPM. I gotta look at my dyno sheet again.

I watched you launch out of Jack Smith around the end of the season last year. Your boat sounded great. The idle I remember was real high and had a lot of lope.
So you saw me and never flagged me down to have a beer? HOW RUDE!! Next time flag me down, we need to have 2.:)hand

Thanks for the complements on how the boat sounds.
 
#8 ·
I have not looked at my hardware yet. I got the new moter in and enjoying it. Now I am gonna start playing with it. Bob Fry (the champ) took a quick look under the boat. I am not sure where any thing is set or what is in there. I dont know loaders or shoes.

I think I am gonna install the inducer at the river and take it up to Aha. I am hoping that Greg will take a look at the hardware and give me some tips.
 
#13 ·
I have not looked at my hardware yet. .
Start here for sure. It's alot cheaper than a AA impeller.

Dan in the CP an intake with an additional 1.5" blocker will make the pump cavitate pulling up a 160 lb. skier. Check your hardware first. Were you soft peddling it to get the skier up or mashing it ?

Sleeper CP :D
 
#12 ·
Dan, i saw you out in front of our sandbar on saturday or friday forget wich one it was,, but i was dealing with a kid and the fact i did not have a beer, so i left you alone, but i saw "Carrot top" out there wakeboarding, i did not know he was with you guys!:)devil
Nice addition with the flags!
Todd
 
#15 ·
I don't know who your talkin about. I was only pulling people on Sunday when no one was out.

Where is your place?

I have always had flags on my boats on the 4th. Never flown duels though. I am suprised they made it. They were showing signs of wear already.
 
#17 ·
run a 5 degree back cut shoe about 13 1/8 to 13 1/4 inch opening and cut the outside runners of the loadr way back maybe 5 inches bob fry will understand and when you make the shoe we did a .625 thick wish would of done a .750 and that will get you pointed in the right direction.those boats are horrible on the leave but just work at it and it comes aroun real quick.The boat is so heavy you can rn a big backcut opening up the outside strakes helps the leave of the boat a standard loader doesnt work so well in that hull.the inducer is a must.Tommy set the intake in the boat but everythig else is mpd stage 5 stuff not knowing what you have that info above has helped us a ton lke i said still woking at it so le me know if you try anything differently.
 
#19 ·
Dan Sorry about that but you looked like you were real anxious to get your boat in the water.

I will probably never ever "***" you down but will say hi next time I see you are around Needles.

I did see your boat at "TPR" a couple of times when I was buying parts. After seeing it I was contemplating a new boat and I really like the deck boat concept. Unfortunately reality set in and I decided I have to keep the cruiser.
 
#21 ·
Sleeper I have a dumb question for you. Since the cavitation is probably caused by not keeping the impeller loaded, could putting a bigger impeller requiring more water exagerate the problem.

Also if he played with the hardware and addressed the issue and then went to a "AA" would he have to dial it in again. Sorry just curious as my cruiser seems to work fine but probably could use some attention to detail some day.

Bob
 
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