Jump to content
Sign in to follow this  
boardrider

Corsa exhaust on a 265ssi

Recommended Posts

Now I’m thinking of fitting a Corsa side dumping exhaust system to my 2004 265ssi (at the same time as I fit my new engine) now the question is not love them or hate them. It’s has anybody had problems with them leaking? And /or is there anyone that makes a better system?

Share this post


Link to post
Share on other sites

Inless you are pushing 500 cubic inches or more beyond 5,000 RPM, don't expect any performance gains. Your midrange will be a bit softer, and with the extra weight, your WOT MPH will be about the same. Captian's Call if you must.

W

Share this post


Link to post
Share on other sites

Inless you are pushing 500 cubic inches or more beyond 5,000 RPM, don't expect any performance gains. Your midrange will be a bit softer, and with the extra weight, your WOT MPH will be about the same. Captian's Call if you must.

W

+1 waste of money.

Share this post


Link to post
Share on other sites

Not a waste of money (IMO). I love the sound of mine (glad it's switchable though). It significantly adds to the experience for me and I'm glad every trip out that I spent the money on it.

Underwater lights seem expensive to me, don't add performance gains, but lots of people are spending money for lighting. Not for me.

Just depends on your priorities.

All that said, for all the enquiries this board gets regarding adding it aftermarket, I don't recall anyone actually doing it. Doing it when replacing an engine would seem like an ideal time, however.

boardrider, I've not heard anything bad about Corsa (since you specifically mentioned not to judge). That didn't work, did it?

Share this post


Link to post
Share on other sites

That's the beauty of being able to switch off and on . . .

But the OP is interested in reliability and quality, not the pros and cons of having it . . .

Share this post


Link to post
Share on other sites

An additional negative that never seems to be comprehended are the thousands of water front and water oriented property owners who have to endure the poker runs and the idle in and idle outs at this cove or that. How many times have the go fast minority shut off their rides to a round of applause from the reasonable majority. Most states have laws on the books that state it is illegal for any engine sounds to be audible beyond 400’ onshore. Here we have supercharged triple engine big blocks pushing 1,800 HP each pushing down the bay at speeds approaching 100 mph. You can hear them approaching from over 2 miles away, and the owners know that the existing laws are virtually unenforceable. The laws however still represent the will of the majority. It’s a free country and you have the right to burn up $3,500 a day in gasoline but it remains a free country because most of us obey the law. It’s like the guy that turns 50, buys his Harley, and immediately figures that everyone else needs to hear it.

I’m a true motor head and built race engines for years, and if your engine is exhaust restricted, then so be it but if you are riding around with a stock engine and just want to annoy your neighbors, and usually your wife and family, then I can’t think of a better way to do it. I also believe that most owners forget that at speed, the majority of the objectionable noise is behind the boat, and not audible to the driver. I say record a real go fast exhaust note, and buy a pair of head phones and an MP3 player.

OK, I’m done. Worked 60 hours this week and I’m crabby.

W

Share this post


Link to post
Share on other sites

The reliability and quality really boils down to who installed it and parts used. Use stainless t-bolt clamps not worm gear type and always double them up. Make sure the sealing surfaces are perfectly flat. Use Trident Marine Silicone exhaust hose instead of rubber.

You get the idea. If it can wear, leak, or break use the best parts possible not what came in the box. The exhaust itself is just metal pipe it will last the life of the boat.

Share this post


Link to post
Share on other sites

It's has anybody had problems with them leaking?

Not a first hand experience, just an observation ...

Thru hull exhaust adds two more thru hull holes to a set of 6-9 you already have. That is 20-30% increase in a chance of a leak somewhere near/below water line. These two additional holes are large in diameter and the apparatus is exposed to vibration and change in temperatures more than any other thru hull except for transom shield. For me, it would be too much risk for something that is functionally negligible.

Share this post


Link to post
Share on other sites

If your thru-hull exhaust is below the water line you have some serious issues.

Please note, side exit is the only way to go on I/O. Rear exit exhaust in addition to wave action if you're slipped can result in water entering the engine and you buying a new engine when you try to start it. Side exit you'd have to get hit by a hurricane.

Share this post


Link to post
Share on other sites

have them on mine no maint. problems...yet, would not spend the $$$ to order on new boat, do like the sound when i do use them, and they seemed to help when at higher alt. 6500ft and 3500 at powell.......but smaller props would have helped too.... good luck.....alot of areas around here are adding noise rules every day.......

Share this post


Link to post
Share on other sites

The reason that I was thinking of fitting them was that it was just one of the things I had always fancied on my 265. Like many other owners that have them fitted I will more than likely have them turned off alot of the time so as not to be antisocial. The other things I would like to add are an extended swim platform and Bennet trim tabs and a new engine. I'm in a very lucky situation where the cost is not so important. The main reason that I bought a 265 was because of it's looks. The boats of today over here in the uk all look like floating caravans, and come #$^% or high water I'm not going around in an ugly boat. Now you might well ask why am I only fitting a 6.2 and not a 496 big block. Simple... over here gas cost over $8 a gallon and although I could afford it I would rather spend the extra fuel money on something else.

Share this post


Link to post
Share on other sites

Now you might well ask why am I only fitting a 6.2 and not a 496 big block. Simple... over here gas cost over $8 a gallon and although I could afford it I would rather spend the extra fuel money on something else.

I am not sure about it ... as was discussed elsewhere on this forum, you can search and find out more. The conclusion I came up with is:

Smaller engine is more fuel efficient … really?

Let's take (RPMs) x (displacement cc) x (throttle opening %) at a given RPM and you get a fuel consumption number. So, of course, a 6.2L will consume less at 3000 RPM than a 8.1L at 3000 RPM, or at any other given RPMs with all else being equal.

Now let's consider the performance of a boat equipped with either engine …

The consensus as expressed on the Chaparral Boats forum and in BoatTest tests is that the pre-2010 Chap 270 Signature and similar boats with 8.1L engine cruises at around 30-32 MPH turning at 3100 RPMs burning 12-13 GPH.

Trailer Boats magazine article tested a 2009 SeaRay Sundancer 270 with a Merc 6.2 Bravo III setup. The SeaRay 270 is very close in size and weight to a 2008 Sig 270. Cruising at speed of 31 MPH, the SeaRay 270 with 6.2L needed to spin at 4000 RPM and burned 14.8 GPH. The similar test results can be found on BoatTest site.

So, the small block (6.2L) ran 29.0% faster while its displacement is 76.5% of the big block (23.5% cc less than 8.1L). Therefore the 6.2L burns more fuel than the big block (8.1L) at the same speed over water under these particular conditions.

This is not a comprehensive, empirical calculation, just an indicative factor that the 8.1L engine can be as fuel efficient, or more efficient than 6.2L engine under comparable conditions.

In conclusion

It all depends on how you use your boat and engine, and you have to find your boat's sweet spot. Let's look at the real world results based on BoatTest.com test done on 2010 Doral Venezia boat.

vp-_test_560.jpg

Worth noting is the hallmark of this Volvo Penta 8.1L engine ... it is equally very efficient in two ranges, in 1000-1100 RPM and in 3000-3100 RPM. In both ranges the engine achieves 2.5 MPG or better mileage.

I do 80% of my boating in these two ranges. With the F4 props my VP 8.1L engine tends to be most efficient when operated in the upper limit of these two ranges.

If one has to drop from 3000 RPM to 2500 RPM or 2000 RPM, one will be getting only half or less of that mileage. If one needs to go the distance, it's more efficient to go at 3500 RPM than 2500 RPM since one will get twice as many MPG at 3500 RPM than at 2500 RPM.

Note: the MPG is a better indicator of fuel efficiency for a particular boat and engine than the GPH which is fuel usage indicator under particular conditions or an averaged fuel usage over time.

Share this post


Link to post
Share on other sites

I have the Corsa's form the factory, no leaks or problems with mine. I have read articles where the actuator will fail over time and the default position when the actuator fails is "closed". Good luck with your project(s).

Share this post


Link to post
Share on other sites

There is also another reason for getting the 6.2 merc, that was weight. It may only be about 85 kg lighter than the 496, but that small differece is the difference between being legal to tow and not being legal. That is also the reason that I was thinking about the 383 Stroker, a little more power and a little less weight (7kg) but that was another posting.

Share this post


Link to post
Share on other sites

My boat is 8 years old and has 300 hours. I haven't had any problems with the Corsa exhaust, and I love the sound. The only thing that would sound better is TWO big blocks with big cams and open exhaust.

If you like the way the boat performs, you will really like it with the big block. It's a heavy boat, and even heavier with fuel, water, gear, and passengers. The 496 puts the boat on plane fully loaded with only 3/4 of the throttle applied. Where as my last boat, a 23 footer with a 5.7L v8 had to be floored to get on plane when fully loaded. The big block burns more gas if you want to cruise over 3300 rpm, but keep it around 3000 to 3200 and it gets pretty good fuel economy. Keep in mind that the small block (even a stroker) will need to work harder at 3000 RPM than the big block would. The big block's torque curve is similar to that of a diesel. it has loads of torque at low RPM, (1000 rpm to 3500 rpm) where as the small block makes most of its torque at the mid to high range of the engines speed (3500 rpm to 5200 rpm). This is why a big block gets similar fuel economy to a small block at cruising speeds. (Again, i emphasize "cruising speeds". ) If you want to save fuel, spring for a diesel. Can you tow it with an empty tank of gas to save weight? What if you also drain the fresh water and waste tanks? I don't think there is a huge difference in weight between the 8.1 and 6.2. And the difference in performance would be worth it.

Share this post


Link to post
Share on other sites

If you want noise go for it! My boat has it. Use some time sounds cool. New chaps. have hole in sides with or without exhaust.

Share this post


Link to post
Share on other sites

Hey keep in mind if it has the big block it will sit lower in the water, look at anyones 256 or 265 with a big block and side exhaust you will see the corsa 1/2 below the water line not like the photo above. If this is the case make sure you have the taller manifold risers on your boat. If not you might not have enough air gap between water line and riser and water could come back up. I just switched out my risers to avoid this.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

×
×
  • Create New...