Pump rebuild party
- Thread starter Last Mohecian
- Start date
blazeracer
New member
Sharkbit said:
Man. you NEED spray...
Last Mohecian
Administrator
Just talked to Tom at Jet Boat Performance. He is a board sponsor here. He said if you guys will get together and order your rebuild kits/parts at the same time he can save you on shipping and possibly make a group purchase deal on the kits. I'm sure he chas or can get what ever Impeller and wear ring you want.
http://www.performanceboats.com/html/forums/showthread.php?t=1562&highlight=impeller
A thread I was reading about impeller selection. So supposedly a larger imp will net a better holeshot yet lower top end rpm. I was looking at threads with larger boats since mine is 20 and while not the heaviest 20 footer out there, it's still a beast. Seems like they like A or AA.
I believe I have an A now, and with a mostly stock 454 it results in 4400 rpm and 56 mph. I currently have a reasonable enough cruise rpm to do laps around the lake if I want. I was thinking a B would give me a little higher top end.
I will replacing my impeller due to cracking throughout so if you guys would maybe give your thoughts about what you would do and why. Also I've read about Agressor impellers being slightly different, in that case which Agressor impeller would you run and why?
Thanks for reading the novel.
A thread I was reading about impeller selection. So supposedly a larger imp will net a better holeshot yet lower top end rpm. I was looking at threads with larger boats since mine is 20 and while not the heaviest 20 footer out there, it's still a beast. Seems like they like A or AA.
I believe I have an A now, and with a mostly stock 454 it results in 4400 rpm and 56 mph. I currently have a reasonable enough cruise rpm to do laps around the lake if I want. I was thinking a B would give me a little higher top end.
I will replacing my impeller due to cracking throughout so if you guys would maybe give your thoughts about what you would do and why. Also I've read about Agressor impellers being slightly different, in that case which Agressor impeller would you run and why?
Thanks for reading the novel.
blazeracer
New member
I've been going round and round with this for a while now. In the tread you linked the guy was trying to compare to a 4:11 rear end when impellers totally don't work that way. Comparing a C to an AA, the AA has a harder bite on the water and requires more power to turn a given RPM than a C, meaning at 5,000 RPM an AA will compress more water than a C, BUT the velocity will be close to the same on both which allows lower horsepower to turn that C impeller at the given 5,000 rpm. But without the volume of water the AA can push with more power, the holeshot suffers.
My opinion, calculate your horsepower as close as possible and use an impeller chart to keep your motor in the RPM you want it to operate in. Our cruiser boats could haul A$$ and turn the crap out of a B impeller, but I don't want to turn my motor that fast. I'm estimating 530-550 horsepower out of my aluminum head motor. Wanting to keep my RPM in the 5,000 area I should get an AA according to the charts. We'll see if that holds true, but my A impeller will be standing by..
Finally, word on the street is the Agressor impellers are worth one size bigger. An Agressor A compares to a Berkeley AA.
My opinion, calculate your horsepower as close as possible and use an impeller chart to keep your motor in the RPM you want it to operate in. Our cruiser boats could haul A$$ and turn the crap out of a B impeller, but I don't want to turn my motor that fast. I'm estimating 530-550 horsepower out of my aluminum head motor. Wanting to keep my RPM in the 5,000 area I should get an AA according to the charts. We'll see if that holds true, but my A impeller will be standing by..
Finally, word on the street is the Agressor impellers are worth one size bigger. An Agressor A compares to a Berkeley AA.
Gold Member
New member
I would try a B out if it was mine just because i like to go faster rather than take off quicker. Its all in what the person that owns the boat wants out of the boat1 think.gifSharkbit said:
blazeracer
New member
Motor Head said:
If you're only turning 4,400 RPM now you could go with a B and expect the RPM's to come 500 or so but gain 4-6 mph.
Last Mohecian
Administrator
No substitute for real world testing. You guys should get together and each buy a different impeller to test with. Swap them amongst each other and once you figure out what you each like in your boat sell the leftovers. think.gif
blazeracer
New member
Last Mohican said:
I'll be buying an AA and will still have a viable A, although it will most likely need a matched up wear ring. It would be cool to see what a B will do once springtime rolls around also.
Same boat, same weight, same day, different impelllers. Can test 0-50 times and GPS top speed.
Last Mohecian
Administrator
blazeracer said:
Maybe chad can use your A and send his cracked A out to be repaired and cut to a B
blazeracer
New member
Last Mohican said:
I'll bet my A has to be machined and a custom fit wear ring ordered with all the crap that's been sucked through that pump.
blazeracer
New member
Looking for info on the HTP top loader I came across this where a guy switched impellers from and AA to a B on a TX-19. I will quote what was written.
"The boat last year went 92.3 mph on gps with a 496ci chevy and a "AA" impellar 5200rpm no nitrous. Nitrous pass on 300 pills went 103.7 mph @ 5950 rpm. The new engine makes a little more hp but i put the "B" impellar in and its been so far 89.5 mph at 6100 rpm."
I still think an AA impeller turning at 4,800 RPM should be able to move my heavy hull at 70mph. With aluminum SCJ heads and a nice healthy cam 4,800 should be achievable. Along with forged piston, ARP bolts, and an array of other high quality parts.
Oh, he has the HTP top loader.
"The boat last year went 92.3 mph on gps with a 496ci chevy and a "AA" impellar 5200rpm no nitrous. Nitrous pass on 300 pills went 103.7 mph @ 5950 rpm. The new engine makes a little more hp but i put the "B" impellar in and its been so far 89.5 mph at 6100 rpm."
I still think an AA impeller turning at 4,800 RPM should be able to move my heavy hull at 70mph. With aluminum SCJ heads and a nice healthy cam 4,800 should be achievable. Along with forged piston, ARP bolts, and an array of other high quality parts.
Oh, he has the HTP top loader.
blazeracer
New member
Just read another thread where two different guys switched from A to AA impellers with no other mods. They both lost 500 to 800 RPM's but both went 3-4mph faster on the top end. One guy talks about incredible holeshot with the AA. Granted that both of these boats were probably overpowered for A impellers anyway.
http://www.riverracer.net/forums/showthread.php?76325-AA-vs.-A-Impeller-test-results
http://www.riverracer.net/forums/showthread.php?76325-AA-vs.-A-Impeller-test-results
blazeracer
New member
Sharkbit said:
A couple of winter Sundays watching ball games with that sewing machine chugging away and you'll have the cheddar covered.