I recently picked up a 2003 Cobalt 226 runabout for cruising around my lake. Obviously, not the typical boat for this site, but fiigured this place would be the best spot to get some questions answered.

The boat is equipped with a Mercruiser 6.2 BIII motor & drive; that's totally stock, with the through-prop exhaust. I was looking for a boat with the 496, but ended up settling on the 6.2.

Ideally, I'd like to get a little bit more power and sound out of the boat; so was wondering what the logical steps would be to achieve that. Would headers / aftermarket manifolds do much if I retain the stock exhaust exit? (I'm a bit apprehensive about cutting holes in the transom). Would doing a captain's call setup add much if I retain the stock manifolds? Are there any other basic performance upgrades that people tend to do to this engine?

A lot of Cobalts will have silent choice out the side exhaust but really not much gain there - basically just the noise level. No offense as Cobalt makes a really nice boat but they are not fast nor have a fast bottom plus weigh a lot. You have a Bravo III on top of in which is not the fastest outdrive either but works very well on heavy pleasure boats especially if they have lower power levels. Also the work well on Cobalts.

IMO silent choice and your best bet would be to make things lighter in your boat plus maybe reposition things for better balance. I would enjoy your boat and leave it mostly stock plus in most cases stock will give you the best longevity if properly maintained. Cobalt makes a really nice pleasure boat and that's what it is intended for.

http://www.youtube.com/watch?v=M1xCNjj8z_s

You can make them loud, strait through with no baffles, but you have to make sure your exhaust is high enough. Won't go any faster, and with the 6.2 other than a whipple or a pro charger you are better off building a new engine and selling the 6.2. Plus you will make the boat worth less if you modify it.

We have a 2000 Cobalt 226 with a stock 7.4mpi Bravo III and Captains Call exhaust. With a 1/2 tank of fuel we hit 63 mph-- which isn't too shabby. From my experience the Captains Call exhaust adds about 3 mph to the overall speed. I agree that this boat will never be a speed demon when compared to some of the big guns on this site- but I will say that the quality of workmanship and smoothness of the ride is exceptional.

Regarding Captains Call on our boat - we have both the molded and extended swim platforms. At idle there is a lot of resonance with the extra swim platform - but once on plane - oh does it sound nice.

Safe boating

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Is that GPS speed? So far mine's topped out at 52.6GPS, with a fairly light load.

Obviously, I'm not really looking to go 70mph, moreso just gain a little bit of power without sacrificing reliability. The boat is a pleasure craft that I also ski behind (so captain's call is a definite requirement if I do cut into the transom).

Would doing headers / manifolds, while maintaining the stock exit location give me much (or anything) in the way of power? or just lighten the load in the transom?

Every runabout I've owned with Captains Call (both big block boats) there was no noticeable difference in speed with the exhaust opened or closed. Only add CC if you want the noise. Contact Bob Lloyd at Full Throttle Marine if you want options/pricing on mods to the 6.2 MPI that net real world speed gains. Be prepared to open your wallet.

I will only echo what most others have said. You have a great boat in it current form. Adding Captains Call or an equivalent system will gain you absolutely zero performance increase. It will add noise and cost money. I had a small block with cut outs and it performed the same open or closed other than the sound difference.

For any measurable performance increase you would need to open up the motor or bolt on a power adder (supercharger). You can make a potent 6.2, but it will take a fist full of cash. I'd run the boat until the motor dies then modify it.

Best of luck.

Yup all good advice here. I have potent 6.2s but it took a fist full of cash as mentioned.

I do have my silent choice for sale if you want it though. PM me.

Will add your usual Cobalt buyer for resale is a stock boat buyer so hot rodding a Cobalt will devalue it and possible a very very hard sell down the road if you ever wanted to get rid of it. Also 70 % of Cobalt owners when looking to upgrade for a boat will buy another Cobalt. Just throwing that out there. At one time I had a 1998 Cobalt 220 BR that went 64 -65 mph. It had a 300 hp HO MAG 350 MPI.. I put silent choice in it, played with the Bravo III props along with taking some weight out of the boat.

do you remember what props you put on? Currently I have a set of 28P and we have been getting 63mph 1/2 tank of fuel and not much else in the boat. Ours is a 7.4 mpi


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