500 efi ATECO head kit
 

Anyone done this or know of anyone with this set up? Thanks

http://www.offshoreonly.com/classifi...o52850-en.html

Yes, Joe at Anchor Marine has had the kit on his 382 Formula and loves it. I think he's got over 100 hours on it now.

Im a fan of kits like this. I hate engine component speculation, so I'd buy this because it is a proven combination that they have tested.

Your restriction is going to be in the intake as it will only flow about 750 cfm. This kit is not going to get you past 605-610 HP without some others changes. I have been working on a combination with Bob Madara that we dynoed for the first time yesterday and made 608 HP and 618 TQ on the first pull. As you can see on the dyno sheet we are running lean and have some fuel re-maping to do on Monday. Our goal is a 630-640 real #'s HP package.

Brian41: Will it be available as a kit? Will you address fuel pump/injectors with the kit?

Yes we are addressing the fuel system, custom work to both upper/lower intakes and throttle body. This package will be available through Bob once we get everybody happy......maybe today.

Hey Brian, I am not looking for a big gain. I was just thinking about a top end refresh and this
looked interesting. I have about 412hrs on mine and they are still original even the springs. Might just have you or Reno do the springs.

I agree with what brian has said. Im at 645hp and 670 tq with mine. By just bolting all this on and not changing away from the merc cool fuel, its a time bomb. I have afr 335 heads and bigger injectors, the merc cool fule goes down to an ID of 1/4 inch. Also by using either a 525 thtottle body or a mono blade you can get the right numbers mine have been great. Mine were done by dave at MDG and a program from mark at precision marine.

Anyone else have any first hand knowledge of these? Not looking for 700hp just info on these or something similiar.

I would also like to see more information on the numbers made with these kits. I will start a new thread about our project this evening. We hit our goal and will be water testing Thursday.

Brian, is that a 500EFI intake or 525EFI intake?

I need more power from my 500 EFI
 

:cartman:I have a 2001 35 motion xp with a pair of 500 efi motors on boxes running bravo xz drives with b-blades bravo props. Boat runs 105-107. Looking for an upgrade that will give me a little more!!!!! How much are these kits and what do I have to do to the motors once I have these in hand? thanks!!

Hey guys, We have a 2001 35' motion xp with stock 500efi's on stellings standoff boxes running bravo xz drives. 34'' bravo one props by B-blades. Boat runs really well as is but we are looking for a little more. Toying with Whipple or Procharger but we are trying to keep the outdrives alive. Wanting to know more about these kits because it seems to make the power we are looking for. Would like to know the exact dollar amount these are going for. What comes in the kit and what do we need to do with the ECU's or other components before these will work. Thanks so much. Shaun.

5250rpm @107 mph with stock 500EFI

At least change the springs asap !!!