Raylar

Were getting 556 HP with a stock block 496HO with new aluminum heads and manifold and cam change. This is with the Merc stock ECM programming. This just about says what the future of the HP525efi will be. More horsepower, more torque and a helluva lot less money! I am Sure Mercury racing will come up with something like a 540 cu.inch motor with more compression and hump out about 600 to 625 reliable horsepower. The real question is when is someone going to build a 600ft/lb torque capable outdrive that does not require a second mortgage to purchase???

Hydrocruiser

Well Mercury offered a choice of the XR or #6 on the HP 575 SCI 550 HP motor. The good news about the dry sump in the #6 obviously is that it requires less oil in the sump reduces friction, adding 50 to 80 prop-shaft horsepower for improved overall boat performance. You can use an XR but you will loose around 100-160 HP on a twin application. That is a HUGE loss. The # 6's swept-back Dry-Sump Six drive improves handling and overall boat performance at higher speeds. The innovative "dry-sump" lubrication system features a precision-oiling pump that sprays a metered portion of oil to lubricate vital internal components. I think personally that anything over 500 HP needs the #6's. I wouldn't buy a boat without them if you plan on going to 550 HP and up.

525 EFI are fine with XR's. #6's for everything above. Plus the 6's look so cool and are so very efficient. Why loose 10% per engine at the prop with XR's if you have the $$ for a 550+ HP engine??

cigarette1

Big big big difference between an XR and a #6 setup
$$$

RHC

Drives::: This months Powerboat Mag has a blurb about Mercs new Bravo for 2005,,,, has a reinforced upper and some inuendos about other upgrades ,,, One should not lump all Bravos in the same conversation::: The XRs are very good and now with the upgraded case structure it will be even better,,,, some of the aftermarkets IE::: Max Machine and Imco have good products also,,,,, Too many Guys just try to add horsepower and not upgrade the drives ,,,, then they put the big power in heavy boats and the problems start!! Thats in my opinon of course!! We have over 200 hrs on upgraded XRs and plan on going thru them after this season,,,, easy up, easy down,, Run as hard as u want after that !!!!
RHC

WickedWon

Uh.. Hydrocruiser, you're confused #6's and tranny's INHALE HP ! The parasitic drag and weight of the #6 package will cost the typical rig 5 mph at a minimum ! Thats why THE DAMN BRAVO BOATS ARE SO FREAK'N FAST ON SO LITTLE HORSE POWER!!!....... till they break.

Falcon

WickedWon,
You are right about the tranny (at least the hydraulic shift ones), but the MC6 actually uses less hp than a Bravo, and the difference increases with rpm. The problem with the MC6 is mainly drag, it's got an awfully big skeg. Look at how some notice the difference between the Sportmaster Bravo and the IMCO, mainly because of the slightly larger skeg on the Sporty. Also the MC6 is turning some very heavy props designed for much more hp and of course the package weight, especially with the cast iron cased tranny. Some of the teams in SC Light that have switched to the MC6 have suddenly noticed more parity by running a crash box and having less weight penalty. Another issue is that many boats are really designed around Bravos and weight placement and step location for the MC6 packages isn't really optimized.
I just wanted to point out that it isn't really hp to the water that is the difference.

testdrv321

I'm not sure about the Bravo not being up to 600hp. I have 600 hours on my Bravo I with the last 1/3 bolted to a 625hp 540ci. The XR should be up for the challenge. Mercs abuse tests for drives are obscene! I spoke to Cummins about a possible TD setup for a performance 36-40' and the big problem was the drives. Merc did not want to mate the drive to 700lb ft of torque. The cummins guy said the drive was tested and failed. The test was full power cycling in and out of the water to simulate full load / zero load conditions for offshore. The drive failed at something like 800 hours instead of the 1000 required. I understand that Merc is conservative and wants to deliver an indestructable product, but man, this is rediculous.