Opinions Needed - Surface drive to outdrive re-rig

Frequency · 10-10-2007, 05:01 PM

Well, it's time to spend more money. I'm removing the surface drive from my Envision and replacing it with outdrives. Too much stern lift means I'm afraid to use the last 1100 rpm my engines have in them. I'd like some opinions on possible solutions.

Facts
The boat is 32' overall. Dry weight with motors and drives is 7200 lbs. Fuel capacity is 175 gal and the boat seats up to 8 in the cockpit, up to 6 in the bow. The hull deadrise is 24 degrees and has two sets of strakes. The inner strakes run all the way back to the transom. A 32' Envision powered by merc 525sc's runs mid 80's. Merc racing suggested they remove the inner strakes back to the CG in order to free up the bow and gain top end. My motors make 625 Hp at 5500 rpm and 630 ft-lbs at 4600 rpm.

Constraints
The motors are mounted low in the bilge to accomodate the rear couch. I'll need a shortie lower otherwise the drives will be buried way beneath the hull. Removing the strakes is not an option right now - uncharted territory. I've spent plenty already, so exotic ($$) solutions are out of the question. I don't want to give up easy planing and low speed driveability.

Thoughts
The straightforward approach would be to go with XR's and merc or imco shortie lowers. Even then the drives may be an inch deeper than factory but I'll give up a few mph and the boat will handle better.

I'll need steering rams at the transom as well - and here's where a question comes into play. If I can find an ITS setup somewhere I'll have the steering taken care of, but more importantly, the added setback may overcome the high stern lift and help leverage the bow.

So, based on keeping my current motors, what are your thoughts on what to hang off the transom?

Greg

f311fr1 · 10-10-2007, 09:03 PM

I think you are on the right track. ITS would be much better than a box and external steering rams. I might be intrested in your props. Eddie has my #. Joe Murray

Audiofn · 10-11-2007, 07:54 AM

I would go with boxes and bravos over ITS. I have yet to get together with anyone that has put the ITS's on their boats that like them better then the Brovo's on boxes. They are cleaner on the transom but I do not think the extra money is near worth it.

Jon

Audiofn · 10-11-2007, 07:55 AM

What about Konrads. They are on boxes, they have a shortie lower and will easily handle the power.

Knot 4 Me · 10-11-2007, 10:18 AM

You are borderline for XR's with those motors. At least the boat isn't too heavy. They should live you if are nice to them and are not flying the boat all the time. Mentalpause has 100 hours on his XR's/Short Sports/ITS running 600's in his 43' Sunsation F4 (@11,500 lbs) and no problems to date. I would definitely go with boxes to help with the X dimension. A Konrad Ace setup would be bulletproof and has the setback and steering built in. Would be pricey, though. Good luck and keep us posted with your progress. Pictures are always appreciated as well!!

Frequency · 10-11-2007, 01:13 PM

Quote:

Originally Posted by Audiofn

... I have yet to get together with anyone that has put the ITS's on their boats that like them better then the Brovo's on boxes.
Jon

Jon,

What were the problems? I would only do the ITS if I could find a deal. I'm not worried about my X getting to high, there's no way it can, so blowouts aren't going to be an issue. If the setback will improve the ride quality they would be worth it. The clean transom is just a bonus.

Elite Marine · 10-11-2007, 01:33 PM

For a bulletproof set up go with the Konrad. The box houses the trans and the steering is intergal to the box, not your transom.

If you need any info, pricing or assistance, please let me know. Starting from scratch, I think you'll find that the Konrads are very competitive with the Merc set up when you add up everything needed.

I have done this conversion and can provide much insight. I'm in IL also and am a dealer.

Kirk

Elitemarine@sbcglobal.net

Konrad Propulsion Systems, Custom Marine Exhaust and Gaffrig Gauges

Audiofn · 10-11-2007, 03:19 PM

The best comparison that I can give you is on a Formula 38 with boxes (Phantom Caos) and one with ITS drives. They were both set up the same but Norts boat drove MUCH better. It was faster and it also seemed to fly better.

excalibur32 · 10-11-2007, 04:03 PM

Rik Wimp should know how to fix it.

Frequency · 10-11-2007, 04:39 PM

Quote:

Originally Posted by excalibur32

Rik Wimp should know how to fix it.

Rik and I agree. Take off the inner strakes and add rocker and it may help. I won't know till I try it. If I rerig now I'll have a boat I can run and it will be marketable when I go to sell it.