Cheap 496 mag upgrades (375hp)
01-16-2011, 11:03 AM
#92
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OK, I put CMI Sportubes on an stock 496 HO, NO speed gain, NO rpm change. I dump the 496 and drop in a 525. Giving the benefit of the doubt let's rate the 525 at 540 hp. I added 115 hp. I picked up 9-10 mph. Let's call it 9 mph. That means that I picked up 1 mph per 12.77 hp. Of course I had to change props but I went from a labbed 26 or 28p Bravo 1 to a labbed 30p Bravo 1. So no change in prop; Only in pitch. I'm bumping the rev limiter at 5,400 rpm on a good day at 86 mph. Explain that please. (IMHO)
To clarify, I'm not familiar with the 22 Donzi as we don't see many of those out here on the west coast, so I can't comment on that boats specific handling characteristics.
2-6 mph on every install? Sorry but no. I already posted links to others who saw NO gain. One dual engine install gained 1 mph. That's almost 10 grand for ONE mph. Something is rotten in Denmark.....
Well, I don't see how you can possibly make a comment like that when you have very little knowledge of my product, my customers, or the amount of time we spend in boats testing this exhaust. One thing we don't do here is make BS claims. It wouldn't go very far in a small world industry. As far as the twin engine boat you're referring to, I don't know which exhaust was installed on that boat, but this is a classic example of the "power to weight issue" . An 8000 lb + twin engine boat is not going to see a big increase from 45 HP per engine. It's just not going to happen, the boat is too heavy. Not every aftermarket exhaust will yield the horsepower of Dana manifold system, so depending on which system was used, he may not have gained much HP.
Oh, and you can take "a pile of props" to test on any boat and pick up speed so I say the increases came from the prop dialing in and not the exhaust. Not all of us have access to piles of props.
In some cases you can add speed to a boat from prop work only. My interest for the conversation is the prop work after the extra power has been added. With added power, we can turn a bigger wheel. That bigger wheel turning the right RPM's will make more speed. I understand that many consumers don't have access to a selection of props, thus my reason for previously stating that most add-on's like exhaust are not capitalized to their full extent due to this very problem. That is where someone may want to consider having a professional shop do the work. Most of my install shops will run the boat before and after, scan tool on motor for accurate RPM's, GPS and/or Radar for speed and the good guys take portable O2 scanners with auxiliary bungs in the risers. With the right tools and the right products, you can dial in a specific boat/engine and make the most sense out of spending 2-3K on exhaust.
01-16-2011, 01:00 PM
#93
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It sounds like you're not exactly pleased with the results of adding CMI headers to your stock 496. I feel for you, that's alot of money for no results. Please keep in mind, my exhaust is much different compared to CMI and I publish our dyno results for the public to see. All of our dyno testing is on a SAE certified dyno, so there's no funny business or recalculations from a non-certified dyno. As far as explaining your speed increase with the 525 VS. the 496 with CMI exhaust, it's quite simple. In "most" cases you will find that a boat will have a significant speed increase with a 525 VS a 496 - reason - most boats, and I say "MOST", tend to have a significant difference in ride character when you add that kind of HP enabling a bigger blade to be spun. With added boat lift and enough power to carry the nose you will have less drag = more speed. You can't apply a basic mathematical formula to the situation, you crossed over a threshold with that extra 70 HP and it meant alot on your boat. Every boat reacts different to power increases, some boat bottoms simply work better than others - and some boats have different points in time where the boat itself begins working much better. A single engine 22 foot Daytona closed bow, did see an increase of 6 MPH, call Eliminator, it's been documented more than once. We've had customers insist that that our exhaust be installed on that very boat from the Factory after seeing Mitch Garlows new 22 Daytona pickup that kind of speed. Yes, the boat had a "pile" of props tried on it before and after, not just after.
To clarify, I'm not familiar with the 22 Donzi as we don't see many of those out here on the west coast, so I can't comment on that boats specific handling characteristics.
2-6 mph on every install? Sorry but no. I already posted links to others who saw NO gain. One dual engine install gained 1 mph. That's almost 10 grand for ONE mph. Something is rotten in Denmark.....
Well, I don't see how you can possibly make a comment like that when you have very little knowledge of my product, my customers, or the amount of time we spend in boats testing this exhaust. One thing we don't do here is make BS claims. It wouldn't go very far in a small world industry. As far as the twin engine boat you're referring to, I don't know which exhaust was installed on that boat, but this is a classic example of the "power to weight issue" . An 8000 lb + twin engine boat is not going to see a big increase from 45 HP per engine. It's just not going to happen, the boat is too heavy. Not every aftermarket exhaust will yield the horsepower of Dana manifold system, so depending on which system was used, he may not have gained much HP.
Oh, and you can take "a pile of props" to test on any boat and pick up speed so I say the increases came from the prop dialing in and not the exhaust. Not all of us have access to piles of props.
In some cases you can add speed to a boat from prop work only. My interest for the conversation is the prop work after the extra power has been added. With added power, we can turn a bigger wheel. That bigger wheel turning the right RPM's will make more speed. I understand that many consumers don't have access to a selection of props, thus my reason for previously stating that most add-on's like exhaust are not capitalized to their full extent due to this very problem. That is where someone may want to consider having a professional shop do the work. Most of my install shops will run the boat before and after, scan tool on motor for accurate RPM's, GPS and/or Radar for speed and the good guys take portable O2 scanners with auxiliary bungs in the risers. With the right tools and the right products, you can dial in a specific boat/engine and make the most sense out of spending 2-3K on exhaust.
To clarify, I'm not familiar with the 22 Donzi as we don't see many of those out here on the west coast, so I can't comment on that boats specific handling characteristics.
2-6 mph on every install? Sorry but no. I already posted links to others who saw NO gain. One dual engine install gained 1 mph. That's almost 10 grand for ONE mph. Something is rotten in Denmark.....
Well, I don't see how you can possibly make a comment like that when you have very little knowledge of my product, my customers, or the amount of time we spend in boats testing this exhaust. One thing we don't do here is make BS claims. It wouldn't go very far in a small world industry. As far as the twin engine boat you're referring to, I don't know which exhaust was installed on that boat, but this is a classic example of the "power to weight issue" . An 8000 lb + twin engine boat is not going to see a big increase from 45 HP per engine. It's just not going to happen, the boat is too heavy. Not every aftermarket exhaust will yield the horsepower of Dana manifold system, so depending on which system was used, he may not have gained much HP.
Oh, and you can take "a pile of props" to test on any boat and pick up speed so I say the increases came from the prop dialing in and not the exhaust. Not all of us have access to piles of props.
In some cases you can add speed to a boat from prop work only. My interest for the conversation is the prop work after the extra power has been added. With added power, we can turn a bigger wheel. That bigger wheel turning the right RPM's will make more speed. I understand that many consumers don't have access to a selection of props, thus my reason for previously stating that most add-on's like exhaust are not capitalized to their full extent due to this very problem. That is where someone may want to consider having a professional shop do the work. Most of my install shops will run the boat before and after, scan tool on motor for accurate RPM's, GPS and/or Radar for speed and the good guys take portable O2 scanners with auxiliary bungs in the risers. With the right tools and the right products, you can dial in a specific boat/engine and make the most sense out of spending 2-3K on exhaust.
01-16-2011, 03:12 PM
#94
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What's Real World?
Sometimes we all need to back up and take stock of what "real experts" we really are.
As a boat owner and specific application person and boat owner you tend to have a very narrow view of what works and what does not work. It's because you don't actually have any real experience most of the time with all things other than your own boat or a buddies boat, etc.
Sometimes your research and knowledge comes from what you read and share on forums like OSO and with a few other boaters. This type of knowledge is limited and not always a good measure of what the big picture really is. Lets all remember that all performance boats engine and drive packages, set-ups, boating water, conditions and air temperatures are all different and will almost always produce different results. It becomes easy sometimes to make broad judgments and statements that ultimately are almost misinformation for others to read and set their decisions from.
We should also realize that most all testing is not always very scientific in nature and as such results will vary greatly sometimes just based on conditions and test parameters.
Even as you should know dyno testing can be very distorted and inaccurate based on how and how often the dyno has been calibrated, whether correction factors were entered correctly and used and what state of equipment and accessories were installed and whether the dyno test was run using SAE standards.
Its sometimes easy and inaccurate to research an engine and possible upgrades and then remove that engine entirely and install a much higher rpm and HP engine and make statements that say the OEM engine was so inferior or not capable of equal performance with like increases in equipment and mods.
As an engine manufacturer and engine builder who by most accounts has more experience and knowledge of the 496-8.1L engine I will be the first to say that every engine type and model generally has its limits based on engine components and architecture, but I will also say every time we must compare "APPLES TO APPLES" in any judgment or determination as to what engine is worthy of upgrades or in measuring its performance and output. this also obviously applies to any engine components and systems such as headers and exhaust.
I have written numerous discussions and factoids here on OSO over the years about exhaust headers and manifolds and so have exhaust and engine experts such as Bob from Dana, Bob LLoyd from Full Throttle, Eddie Young, etc., etc.
To condense the comparisons, you must determine first, normally aspirated, or supercharged or Turbocharged, then you have to compare short runner manifolds and riser type exhausts like the stock Merc 496 units, Eddie Marine, Stainless Marine, etc. These should not be equally compared or likened to actual long tube tubular or manifold long tube headers like, Dana, Eikert, Imco Powerflow Plus, etc. It is also important to understand that exhaust headers or manifold headers that work well on normally aspirated engines do not always have any benefit on boosted engines, the two animals are different and they each will respond differently to tube length and tube size.
From all my testing it is very obvious that longer tube or passage header manifolds that have runner lengths in excess of 18" or so and have the 4 tubes merge into a collector make more power and torque on most naturally aspirated performance engines than the straight short runner-passage manifold exhaust systems that merge into a simple round riser. This has been confirmed time and time again by other valid testing in the industry by many independent users and engine builders who don't make and sometimes don't even sell exhaust upgrades.
On most naturally aspirated BBC engines of 450-502 cubic inches with 8to1 - 10to1 compression ratios with mild camshaft grinds, decent cylinder heads will gain 25-45HP changing from a straight short passage manifold and riser to a long tube merge collector type header or header manifold. Is it 60 plus horsepower, no not very often unless head, cam and other changes are made concurrently. Can the numbers be larger on boosted engines, You Bet! , they have to get rid of the extra exhaust volumes and pressures to make more power so the change from short -small runner manifolds and risers to larger tube or passage size headers or manifolds can show much bigger increases in power and torque and runner length is not as critical or necessary in these exhaust systems. Longer and equal length runner lengths for optimum performance from a normally aspirated BBC engine will up to a certain length and the rpm operating ranges, compression, cam size and head flow will determine the ultimate length. Are the header and exhaust systems for Bravo equipped BBC engines optimum, NO, the length and fit is restricted by available room and length to the transom and whether the exhaust is existing the header or manifold into a switchable exhaust, s-tubes, elbows and side hull exhaust detours and such.
Also when testing exhausts on dynos its important to test the header with similar size tips and exhaust length and with water entering the exhaust exactly as it does in the boat. water and water vapor alone in a marine header exhaust or even stock exhaust manifold will generally scrub out about 15-25 HP just for the water intrusion alone! So dry testing or exhaust into large exhaust tailpipes and mufflers totally distorts what will actually happen in the boat.
As for actual boat performance increase and bang for the buck every performance boater who wants to increase his boats speed, acceleration and performance must be prepared to look at other items on the boat such as prop rework and proper prop tuning to the power changes. boat bottom configurations, designs and finish and the old drive height and drive length issues which can play such huge influences on ultimate boat speed and boat performance at all speeds and trims.
And lastly I think its important to always keep in mind and remember that all hulls and boat types are different and will respond differently to added power, torque, rpms and speeds in almost every case!
Its so easy to over simplify performance engine upgrades, exhaust upgrades, drive and prop changes that it really tends to further confuse and frustrate performance boaters that they sometimes probably think, hell why try any, most of these changes tend to be so good or so mediocre or bad that why should I spend my hard earned money with an experiment in performance.
The real answer is try and deal with people who are real experts and make a living producing real results and stay in this game year after year making far more boaters happy than they piss off or abuse!
I am not trying to bash or discount the comments and findings that a lot of performance boaters make here on OSO, I am just trying to get us all thinking and realizing that each individual situation can be vastly different based on a lot of variables and some of the comments and input come from boaters who do not do this work day in and day out for a living or have much real engine expenience, exhaust building experience or boat setup and rigging experience.
If you where about to be opened up on the operating table for brain surgery, would you be discussing the methods and impressing your ideas on the brain surgeon whose trying to save your life! Think About It!
Best Regards,
Ray @ Raylar
As a boat owner and specific application person and boat owner you tend to have a very narrow view of what works and what does not work. It's because you don't actually have any real experience most of the time with all things other than your own boat or a buddies boat, etc.
Sometimes your research and knowledge comes from what you read and share on forums like OSO and with a few other boaters. This type of knowledge is limited and not always a good measure of what the big picture really is. Lets all remember that all performance boats engine and drive packages, set-ups, boating water, conditions and air temperatures are all different and will almost always produce different results. It becomes easy sometimes to make broad judgments and statements that ultimately are almost misinformation for others to read and set their decisions from.
We should also realize that most all testing is not always very scientific in nature and as such results will vary greatly sometimes just based on conditions and test parameters.
Even as you should know dyno testing can be very distorted and inaccurate based on how and how often the dyno has been calibrated, whether correction factors were entered correctly and used and what state of equipment and accessories were installed and whether the dyno test was run using SAE standards.
Its sometimes easy and inaccurate to research an engine and possible upgrades and then remove that engine entirely and install a much higher rpm and HP engine and make statements that say the OEM engine was so inferior or not capable of equal performance with like increases in equipment and mods.
As an engine manufacturer and engine builder who by most accounts has more experience and knowledge of the 496-8.1L engine I will be the first to say that every engine type and model generally has its limits based on engine components and architecture, but I will also say every time we must compare "APPLES TO APPLES" in any judgment or determination as to what engine is worthy of upgrades or in measuring its performance and output. this also obviously applies to any engine components and systems such as headers and exhaust.
I have written numerous discussions and factoids here on OSO over the years about exhaust headers and manifolds and so have exhaust and engine experts such as Bob from Dana, Bob LLoyd from Full Throttle, Eddie Young, etc., etc.
To condense the comparisons, you must determine first, normally aspirated, or supercharged or Turbocharged, then you have to compare short runner manifolds and riser type exhausts like the stock Merc 496 units, Eddie Marine, Stainless Marine, etc. These should not be equally compared or likened to actual long tube tubular or manifold long tube headers like, Dana, Eikert, Imco Powerflow Plus, etc. It is also important to understand that exhaust headers or manifold headers that work well on normally aspirated engines do not always have any benefit on boosted engines, the two animals are different and they each will respond differently to tube length and tube size.
From all my testing it is very obvious that longer tube or passage header manifolds that have runner lengths in excess of 18" or so and have the 4 tubes merge into a collector make more power and torque on most naturally aspirated performance engines than the straight short runner-passage manifold exhaust systems that merge into a simple round riser. This has been confirmed time and time again by other valid testing in the industry by many independent users and engine builders who don't make and sometimes don't even sell exhaust upgrades.
On most naturally aspirated BBC engines of 450-502 cubic inches with 8to1 - 10to1 compression ratios with mild camshaft grinds, decent cylinder heads will gain 25-45HP changing from a straight short passage manifold and riser to a long tube merge collector type header or header manifold. Is it 60 plus horsepower, no not very often unless head, cam and other changes are made concurrently. Can the numbers be larger on boosted engines, You Bet! , they have to get rid of the extra exhaust volumes and pressures to make more power so the change from short -small runner manifolds and risers to larger tube or passage size headers or manifolds can show much bigger increases in power and torque and runner length is not as critical or necessary in these exhaust systems. Longer and equal length runner lengths for optimum performance from a normally aspirated BBC engine will up to a certain length and the rpm operating ranges, compression, cam size and head flow will determine the ultimate length. Are the header and exhaust systems for Bravo equipped BBC engines optimum, NO, the length and fit is restricted by available room and length to the transom and whether the exhaust is existing the header or manifold into a switchable exhaust, s-tubes, elbows and side hull exhaust detours and such.
Also when testing exhausts on dynos its important to test the header with similar size tips and exhaust length and with water entering the exhaust exactly as it does in the boat. water and water vapor alone in a marine header exhaust or even stock exhaust manifold will generally scrub out about 15-25 HP just for the water intrusion alone! So dry testing or exhaust into large exhaust tailpipes and mufflers totally distorts what will actually happen in the boat.
As for actual boat performance increase and bang for the buck every performance boater who wants to increase his boats speed, acceleration and performance must be prepared to look at other items on the boat such as prop rework and proper prop tuning to the power changes. boat bottom configurations, designs and finish and the old drive height and drive length issues which can play such huge influences on ultimate boat speed and boat performance at all speeds and trims.
And lastly I think its important to always keep in mind and remember that all hulls and boat types are different and will respond differently to added power, torque, rpms and speeds in almost every case!
Its so easy to over simplify performance engine upgrades, exhaust upgrades, drive and prop changes that it really tends to further confuse and frustrate performance boaters that they sometimes probably think, hell why try any, most of these changes tend to be so good or so mediocre or bad that why should I spend my hard earned money with an experiment in performance.
The real answer is try and deal with people who are real experts and make a living producing real results and stay in this game year after year making far more boaters happy than they piss off or abuse!
I am not trying to bash or discount the comments and findings that a lot of performance boaters make here on OSO, I am just trying to get us all thinking and realizing that each individual situation can be vastly different based on a lot of variables and some of the comments and input come from boaters who do not do this work day in and day out for a living or have much real engine expenience, exhaust building experience or boat setup and rigging experience.
If you where about to be opened up on the operating table for brain surgery, would you be discussing the methods and impressing your ideas on the brain surgeon whose trying to save your life! Think About It!
Best Regards,
Ray @ Raylar
Last edited by Raylar; 01-16-2011 at 11:58 PM.
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01-17-2011, 10:52 AM
#96
Thanks, Ray and Dana marine, for your in depth explanations.
I have spoke to ray several times and has always been very knowledgeable and helpful in these matters.
I will more than likely be trying the camshaft and reflash come spring. So will keep everyone posted...
Thanks again for all the info!
01-21-2011, 01:16 PM
#98
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Yes, I do. As far as I am aware Whipple is the only one liscenced by Merc to reflash the PCM555 ECU that comes with the Merc 496HO & Mag engine. Lots of people can do the various MEFI computers but buyer beware. Software is available to purchase where you could do the MEFI recals as well.
Last edited by Rage; 01-21-2011 at 01:18 PM.
01-21-2011, 10:07 PM
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It was $800 back in 2006 for my first custom recal. Half of that went to Mercury for the ECU unlock code. After that ~$150 - $200 each time depending what you needed to be done. But for custom recals you have to supply the AFR and MAP vs rpm data from idle to WOT to Dustin so he knows what needs adjustment. These must be accurate or wrong adjustments may be made. The AFR vs rpm would come from instrument like Innovate LM-1 with an rpm converter. The MAP vs rpm would come from a Diacom recording. These two data streams would need to be combined and normalized to the same rpm. Then there is the issue as to if the AFR you are supplying is of a single cylinder of the eight available, one manifold collector combining all four cylinders from that bank or both banks or all eight individual cylinders. You would need to discuss this with Dustin Whipple. Optimum (and quickest) would be to provide the engine to Dustin to calibrate on the dyno.
Last edited by Rage; 01-21-2011 at 10:11 PM.
