I know a bigger blower would do the trick but I was thinking of starting small. Pulleys, carb, intake? Anyone have a 525sc and have any ideas? Also what is the max hp that a Brovo I can safely handle? I have a drive shower but not sure if any internal work has been done.
A bunch of years ago I was involved with intercoolers + larger pulley upgrade with a pair of 525SC's. I do not have the pulley parts #'s but remember we ran into an issue with style of pulley mounting. I believe there is a few different types over the years of the 525SC's.
Best place for 525SC performance upgrading info is at offshoreonly.com There are a ton of 525SC and 575Sci owners over there.
I did take notes when I tuned them.
Module's total advance finishes at 4200rpm, not 3000rpm as others suggested to me. With superchillers and 7lbs boost I ended up at 102 square for carb jetting.
Here's more info I gathered for the stock Merc configuration:
Holley Dominator 1050 carb (jetted 98 square + 6.5 high flow power valves front and rear )
177 supercharger w/Dominator carb flange
AC Delco MR41T spark plugs - gap .035"
35° Total timing
Premium fuel required. Merc suggests min 92 octane
And following hyd flat tappet cam:
Merc 400 / 420 / 425 / 525SC
We have done a fair amount of work and mods to those engines. The FIRST thing is to put a larger blower with two carbs. The little blower creates a ton of cylinder temp. and putting a smaller pulley to creat more boost only makdes this problem worse. They are border line with 91 as they are.
Great info. thanks for all the help. How much blower can that motor handle?
If it were here we would put a 6-71 with (2) 750 DP Holleys. 5 lbs boost with the stock bottom end. 7 lbs if you run an inner cooler.... but the rods may want to find a new home outside the block if you run it hard for long periods.