HP500EFI and AS&M Monoblade throttle valve?
 

Looking for some one who has instaled this set up from Arizona Speed and Marine.

They claim 25 hp with this monoblade throddle body and a computer recal. And a little opening of the maniforld to match the new valve.

I run a 288 Sunsation and I'm looking for 2 or even 1 mph.

AS&M cliam I will see an increase, but I thought before I spend, I'd ask for first hand thoughts, or experiences!

Here is the Monoblade valve. Thoughts?

Re: HP500EFI and AS&M Monoblade throttle valve?
 

Oh, they also recal the computer diferently than regular with this thorttle body!

Re: HP500EFI and AS&M Monoblade throttle valve?
 

Jeff:
Our expierence has shown that the MEFI computer recalibration is responsible for the added power if anything. Your engine in stock form won't need more cfm at full throttle than the throttle body you have now. The bigger throttle body is really for bigger cube engines and big cams etc.
Hope this helps,
Raylar

Re: HP500EFI and AS&M Monoblade throttle valve?
 

I talked to a guy who did this to his Fountain 35 with twin HP500 EFI and he said his mid range was stronger, but did not pick up anymore top end.

Re: HP500EFI and AS&M Monoblade throttle valve?
 

Baja Bailey, thats what I am afraid of!

Raylar, This makes sence, I kinda have the same thought, just hoped for better feed back. I guess this engine can't suck any more air than the way Merc has set it up. With out changing manifolds and air path.

Any advice? I only need 1 or 2 mph. Very important! I already run a lab.

Re: HP500EFI and AS&M Monoblade throttle valve?
 

Easiest and cheapest is to take weight out of the boat, remove the windshield if you have one.
The only thing on the engine I can think of without changing heads intake...is to maybe have the intake extrude honed. But that will require removing the intake and I have no known knowledge this will get you your increase....but it does help in auto's to the tune of around 20hp.

Re: HP500EFI and AS&M Monoblade throttle valve?
 

Jeff, I just installed 1.8 to 1 crane golds instead of new stock 1.7 to 1's on my 500efi. It is definately stronger than previous. I am at the rev limiter so I will have to change gears before I can tell if I got any mph but it gets there quicker.

Re: HP500EFI and AS&M Monoblade throttle valve?
 

Airpacker, 1.8 to 1 what?? Springs? You've lost me?

Re: HP500EFI and AS&M Monoblade throttle valve?
 

Rocker arm ratio,makes the cam a little bigger

Re: HP500EFI and AS&M Monoblade throttle valve?
 

What he said :)