Impeller Comparison

[HotDogz]

I have been getting conflicting opinions on impeller size vs. manufacturer.
I want to know if an Aggressor AA impeller is the same size and output of a Berk AA impeller, requiring same HP and producing same revs.
Been told an Aggressor A is the same as Berk AA or something like that. Need some experienced info here.

[Taylorman]

Been told an Aggressor A is the same as Berk AA or something like that. Need some experienced info here.
This is correct.

[HotDogz]

Then on a Berk chart, is the Aggressor AA compared to a Berk A-3? :confused:
Just stuffed an Aggressor tenzalloy AA in my pump. Wondering if I made a mistake. Replacing a Legend B so I dont have a direct comparison to work with.

[HBjet]

Just stuffed an Aggressor tenzalloy AA in my pump. Wondering if I made a mistake. Replacing a Legend B so I dont have a direct comparison to work with.
Yes, Mistake!
Really, what RPM were you turning the Legend B at?
HBjet

[SmokinLowriderSS]

It is my understanding that an agressor impeller pushes as much water as a full cut size LARGER berkeley.
Just to throw some stuff at JPCalc, a Legend B takes 330 HP to spin 4800 RPM. That comes pretty close to a shaves Berk A (not quite an "AB" half-cut)
A berk AA spins 4500 RPM on the same 330 HP. I can't put a Berk AAA or an agressor AA in it.
According to comon occurence (if I get this right), another 300 RPM is lost on that cut larger, so 330 HP spins that Berk AAA or Agressor AA to 4200RPM.
Since you are now farther away from your HP peak, you no longer can assume to have that HP, and RPM falls further.
Without knowing your previous RPM, or your engine HP, this is all an exercise, but, yes, you put too big an impeller in it. Take it out and have it cut to something suitable.

[Riverjet502]

If you were running a Legend "B" then you should run a "C" cut with your Aggressor to run the same RPM as before with the Legend impeller.

[HotDogz]

Doh!! Another setback...:cry:
Was spinning my Legend B to 5200-5300 rpms, just wanted to lose about 500r's or so. Hoping to change to aluminum heads next spring and figure they would make up for the difference when installed on my .060 over, restricted Olds455. In the mean time, my greenhorn calculations figured I was going to be at about 47-4800 rpms with an AA (Berk) until then. I have alot of low end torque, figured that would be ok.
I appreciate the feedback, going to send impeller back to shop to be cut down.
Ha.. live and learn. I think thats why experience is so valuable, these lifes little lessons are just priceless. :p