525 SC upgrade
 

my friend has a 525 SC with the upgraded 8psi pulley and superchiller. what should be added next to get the most power for the money??? Ignition? Cam? ????

With the blower that is on the 525SC, I think that 8psi will be at the end of it's efficiency. He should see a very good increase of HP with those mods. If he wants more, he will have to step up to a bigger huffer. The motor already has good exhaust and breaths well.


Darrell

Been there done that. The next size pulley results in about 7.5 psi for me, and about 575hp. But it's REALLY spinning the supercharger fast.
If he's not fouling plugs, ignition wont provide any increase in hp for a given amount of advance.
A cam might give a few more hp, but I think the supercharger might be the limiting part of he engine.

we are trying to figure out how to get that next size prop.. it's currently running a 26 and works fine but when we go to a 27 we lose some speed. would a set of aluminum give us what we want?? if a bigger blower is needed what do you guys reccomend??

why dont you talk with a prop company.....im sure you will find some more mph there, if you havent already. Maybe shorty on the drive.

I upgraded to Crane 731 roller cam in my 525sc and picked up about 100rpms. I already had a 7.5# pulley on it without a chiller. The cam also had slightly better midrange acceleration.

I would have to agree that spinning it that fast was beyond it efficiency. The blower is spinning at or beyond its max recommended rpm. I think the max is 12500 or 13000rpms on the SC if I remember right.

I did all the typical mods to my 525sc and gained a few MPH. I think I am going to put in a roller cam and be done with it. I believe the 177 blower and bravo drive are close their limits now and hope the cam will not break things. I am building a spare drive:D

we are trying to get a true 75mph. the GPS is reading 69.8 on a 26ft baja. will the roller cam only give you more RPM's not more power??

A properly selected roller cam can only help. I am going to use RMBUILDER of marine kinetics (shameless plug). I have seen what he can do and it is impressive. He selected a custom grind for my friend who has a Baja 272 and it dynoed well over 1100 hp. Before it was around mid 900's for hp. The bad part is when he runs it NA it still whips my boat!!:angry-smiley-044:

You need about 100hp to get to a true 75mph from where you're at. A cam change will probably get you 25-30hp. More rpms with the same prop is more power.