Mercury 500 EFI
01-29-2008, 09:36 PM
#21
Organized Chaos
Platinum MemberThread Starter
Join Date: Jan 2008
Location: Montgomery
Posts: 30
Likes: 0
Received 0 Likes
on
0 Posts
This boat runs approximately 75 mph! I would like to do at least 80 MPH! I know,I know the Baja's are so heavy and they have no steps. I think HP is my only option!
01-29-2008, 09:40 PM
#23
Racer
I did the same thing I used the 741 but put a pair of Dart 310 heads out of the box No cnc porting and made 587 HP with the bigger throttlebody. Then I put a set of fully cnc ported 315 AFR heads on and only gained 15 HP. Then I thought the intake and throttle body was holding me back so I put a Holley Intake on and a 2000 cfm throttlebody on and gained almost 40 HP but lost a lot of torque. Then I put the 500 efi manifold back on and cut a 4" by 4" hole in the top of the stock plenum and mounted the 2000 cfm throttlebody on and gained the same 40 HP and gained all the torque back plus some. That's why I made the new tops to go on the 500 and 525 engines when camshafts and head work are done on these engines.
01-29-2008, 09:42 PM
#24
VIP Member
VIP Member
I have had the cam, switched to alum heads this year, and computer work. I went from 72 mph to 77 mph and with the head and mor comp work I am hoping to be at 80. I have a straight hull 2000 Cig Tiger with pumped up twin 500 efi's and bravo xr's. i have a 9800 lb pig and it moves great for 42 ft long.
01-29-2008, 09:44 PM
#25
VIP Member
VIP Member
I did the same thing I used the 741 but put a pair of Dart 310 heads out of the box No cnc porting and made 587 HP with the bigger throttlebody. Then I put a set of fully cnc ported 315 AFR heads on and only gained 15 HP. Then I thought the intake and throttle body was holding me back so I put a Holley Intake on and a 2000 cfm throttlebody on and gained almost 40 HP but lost a lot of torque. Then I put the 500 efi manifold back on and cut a 4" by 4" hole in the top of the stock plenum and mounted the 2000 cfm throttlebody on and gained the same 40 HP and gained all the torque back plus some. That's why I made the new tops to go on the 500 and 525 engines when camshafts and head work are done on these engines.
01-29-2008, 09:54 PM
#26
Organized Chaos
Platinum MemberThread Starter
Join Date: Jan 2008
Location: Montgomery
Posts: 30
Likes: 0
Received 0 Likes
on
0 Posts
I have had the cam, switched to alum heads this year, and computer work. I went from 72 mph to 77 mph and with the head and mor comp work I am hoping to be at 80. I have a straight hull 2000 Cig Tiger with pumped up twin 500 efi's and bravo xr's. i have a 9800 lb pig and it moves great for 42 ft long.
01-29-2008, 09:59 PM
#27
VIP Member
VIP Member
01-29-2008, 10:01 PM
#28
Organized Chaos
Platinum MemberThread Starter
Join Date: Jan 2008
Location: Montgomery
Posts: 30
Likes: 0
Received 0 Likes
on
0 Posts
Guys you have been a big help. Thanks again. Tyler if you dont mind Ill be in touch. Im interested in the reflash and the throttlebodies. Im signing off. Hope to see you guys at the Emerald Coast Run
01-29-2008, 10:14 PM
#29
21 and 42 footers
Platinum Member
be fair though Russ you made 540's out of yours and went through everything, he is asking about smaller things that can be done and they are plenty. comp changes, throttle bodys are the main, you can change cam and mill the heads for more. mine were 575 hp and not that expensive to do.
I know, I was coming back to post the 540 info....but I still say run the hell out of stock 500's and re-build more often as necessary.
01-29-2008, 10:15 PM
#30
VIP Member
VIP Member
if you are in Al, go see mark at precision marine in Kenner LA, he did my comp and they rock..if not him tyler will hook ya up...
