Indmar 350 performance mod's - Anybody?

[Warren]

I'm looking for any info on performance mod's on a 1994 MC Maristar w/Iindmar 350 tbi. Heads, cam, intake?
Exhaust mod's?
Great boat, great condition, need more H.P.!

[SmokinLowriderSS]

Need more HP, take 350, remove and put in a car (or sell), buy 454 with heads, choose an apropriately beefy cam, new intake & exhaust, and install. Happiness Guaranteed. EVERYBODY needs a big block. ;) :D

[Warren]

That's one way of doing it! I'm thinking more along the lines of doing something to this motor. Any self-respecting 350 oughta be putting out at least 350 h.p. these days - (And I know that's not hard to do). Just wondering if there are any specific concerns with marine parts, and if the tbi fuel injection can accomodate the H.P. increase? Or will I have to change that out - (or go carb)? Also, any concern with the Tranny holding up???

[Flyinbowtie]

Warren;
I have the 350 Mag MPI engine in my 98 Sanger DLX. It is rated at 315 HP. It has the dry 2 bbl throttle body injection, with the injectors in the manifold runners.
I would like more HP myself, but the boat will run about 50 at 5000 RPM pulling a 3 blade 13x13 OJ prop, thru the trans, which is 1 to 1.
I can pull up two skiers with 6 people in the boat. Launching a 200 lb. wakeboarder requires about 30% throttle. I don't really know what I would do with more HP. I have been told by Sanger that I can see a major improvement by going to an ACME 13x12 prop. Sanger is now delivering their boats with ACME's, and I was told by a Sanger Exec. that the ACME will add both top and bottom end due to it's superior design. I have a buddy that went to ther ACME and his boat feels like it gained about 75 HP..
I am told the Velvet Drive will "take" around 400 ponies, and Sanger will on a special order build some of their boats with the 496, which clearly is going to deliver more torque to the trans than most mild or stock small blocks..

[Warren]

Alright! I've posted this thread on several message boards with no luck! I appreciate the information!!! I'm confident I can get 300 + H.P. and increased torque, with a little valve work, a cam, and an intake. I will take a good look at my TBI system, yours sounds like a similar set up. I already plan to go to the Acme prop. Sounds like the Tranny is no problem. I know these boats are primarily tow boats, but I do like a little top end. 50 mph would be nice, 55 - 60 mph would be even better. (Nothing crazy for sure).

[bigd1]

Your hull is working against you for speed. Don't hope for more than 50 MPH. Too much wet.

[Warren]

True, these boats are definately designed to stay "in the water".