Kelly O

Best to use the additional torque of Stage 4 to prop up and keep rpms below 6k

ImLate

did you re prop when you upgraded to the stage 3?

Madman7

My boat was already tuned before I bought it, but I think I should go up 1 pitch.

Stage 4 has a ton of cooling and fuel issues. Takes a lot of time and money to get them to run right. From what was told to me, if you aren't happy with your current performance at Stage 2 or 3, buy a different boat.

Marginmn

iTrader: (1)

What are the HP and torque numbers for stage 2 and 3?

HPHQ

We"ve actually done several stage 3 and stage 4 kits without any issues. The stage four is just a 525 cam so it's not anything crazy radical. The tunes are really nice and clean. Valvetrain is key, ya gotta use good quality components, and might i throw out that we have T&D shaft rockers systems for the Merc head!!

Coolerman

If the big difference on the stage IV is just a higher rpm limit, I would see no problem as long as the valvetrain is upgraded with a shaft rocker system and although this is highly debatable, I would go with a solid cam over a hydraulic if doing stage IV (I'm sure many will argue this).

On any of the stages, make sure a water system is up to snuff, I'm sure Boos or Teague could make sure you are setup on that side of things.

ImLate

i talked to boos and he said the stage 4 can have some cooling issues from time to time... seems like stage 3 is the way to go

HPHQ

The heat exchanger on the 525-700 start to become inadequate at around 800 horsepower. You have to really hang it out for awhile to see the issue though!

BUP

iTrader: (9)

We have a stage 3.5 for the 700 sci. All done in house. we have done 6 engines so far with very good results.
And we have upgraded about a handful of stage 3 to the stage 3.5 for 700 sci s.

three point five the only one doing this

flat rate

iTrader: (3)

please tell us more ! we are currently looking at a 42 700 boat