Cheap 496 mag upgrades (375hp)
03-01-2012, 12:09 PM
#151
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Well I don't know if you can gain performance from just a PCM reflash, but you can sure lose it. I have an early 2001 496 mag (#OMO61519) and I wanted to install a Mercmonitor on the boat. Mercury said that I had to have the PCM modified for this to work. I was skeptical of this since a scanner showed all the engine information was available, but Mercury built it and they should know. The reflash was free and part of a recall (Fix Campaign 2001-014).
Unfortunately I did not seem to get just a reflash, but a different PCM. Equally unfortunate is that I do not have the serial number from the original PCM as that may be of interest to this thread. In any event the different PCM no longer soots the transom up like my old one did, and it does provide a small improvement in fuel consumption, but I also lost 4 mph. No other running changes were made to the boat at this time.
Since the acknolowdged experts on the 496 seem to be following this thread, I thought I might fish for comments and satisfy my curiosity. Clearly if there are performance reductions in a "newer" programing spec, there might be performance enhancements available by reverting to an older specification.
Ray and others, does this make any sense to you and would you be willing to share your general knowledge of what programing changes Mercury may have made through the years?
Thanks,
Dan
Unfortunately I did not seem to get just a reflash, but a different PCM. Equally unfortunate is that I do not have the serial number from the original PCM as that may be of interest to this thread. In any event the different PCM no longer soots the transom up like my old one did, and it does provide a small improvement in fuel consumption, but I also lost 4 mph. No other running changes were made to the boat at this time.
Since the acknolowdged experts on the 496 seem to be following this thread, I thought I might fish for comments and satisfy my curiosity. Clearly if there are performance reductions in a "newer" programing spec, there might be performance enhancements available by reverting to an older specification.
Ray and others, does this make any sense to you and would you be willing to share your general knowledge of what programing changes Mercury may have made through the years?
Thanks,
Dan
03-01-2012, 01:40 PM
#152
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I've run them to higher rpm than stock, but the power drops rapidly past 5100 rpm so there really is no point in raising the rev limit. Peak HP with the stage 1 program was 5000 rpm. Even the Raylar 103 kits peak around 5200.
03-03-2012, 08:04 AM
#153
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The Raylar 103 pkg is designed to run at 5350 (Raylar's recommendation) and with the reprogram the limiter is set at 5450.
03-04-2012, 06:26 PM
#154
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My last statement got me to thinking, so I went back and pulled up some prop shaft dyno tests I've done. Interesting comparison. At 3000 RPM the 496 Mag made 445 Ft. Lbs of torque, the HO made 448 and the stage 1 HO made 479. That is a 30 ft. lb. increase over the stock HO program at the critical planing rpm and the gains carried all the way to 5100 RPM, where the stage 1 made 410 pshp and the stock HO made 395, the Mag made 351 hp @ 4700. Anyway, just more stuff to think about. Carry on...
Bob Lloyd
Full Throttle Marine
Bob Lloyd
Full Throttle Marine
08-11-2012, 04:32 PM
#156
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Awesome thread. This question was asked earlier but I didn't see a responce. For someone doing the mag to ho upgrade would it be better to run the stock ho cam or the 103 raylar cam? Not sure on the cost difference but wondering if it would be worth it.
08-12-2012, 10:55 AM
#157
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Ray has moved on this number a couple times possibly by pure accident; I don't know but I've noticed it.
In a constant rpm engine (marine) they should never be made to go any faster.
08-12-2012, 11:06 AM
#158
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Well I don't know if you can gain performance from just a PCM reflash, but you can sure lose it. I have an early 2001 496 mag (#OMO61519) and I wanted to install a Mercmonitor on the boat. Mercury said that I had to have the PCM modified for this to work. I was skeptical of this since a scanner showed all the engine information was available, but Mercury built it and they should know. The reflash was free and part of a recall (Fix Campaign 2001-014).
Unfortunately I did not seem to get just a reflash, but a different PCM. Equally unfortunate is that I do not have the serial number from the original PCM as that may be of interest to this thread. In any event the different PCM no longer soots the transom up like my old one did, and it does provide a small improvement in fuel consumption, but I also lost 4 mph. No other running changes were made to the boat at this time.
Since the acknolowdged experts on the 496 seem to be following this thread, I thought I might fish for comments and satisfy my curiosity. Clearly if there are performance reductions in a "newer" programing spec, there might be performance enhancements available by reverting to an older specification.
Ray and others, does this make any sense to you and would you be willing to share your general knowledge of what programing changes Mercury may have made through the years?
Thanks,
Dan
Unfortunately I did not seem to get just a reflash, but a different PCM. Equally unfortunate is that I do not have the serial number from the original PCM as that may be of interest to this thread. In any event the different PCM no longer soots the transom up like my old one did, and it does provide a small improvement in fuel consumption, but I also lost 4 mph. No other running changes were made to the boat at this time.
Since the acknolowdged experts on the 496 seem to be following this thread, I thought I might fish for comments and satisfy my curiosity. Clearly if there are performance reductions in a "newer" programing spec, there might be performance enhancements available by reverting to an older specification.
Ray and others, does this make any sense to you and would you be willing to share your general knowledge of what programing changes Mercury may have made through the years?
Thanks,
Dan
If you were to even bother with thinking about the time and labor to remove cam, you may as well buy the Raylar Cam if only because the stock ones are so bad it's not worth the time to reinstall. What's $400 these days in boat parts?
Just my opinion.
08-13-2012, 12:10 PM
#159
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Well, I've had the upgrade now for most of the summer and can happily report that it has been everything I expected and alot more! I can run a little over 5000rpms with the 28s and the low end torque is amazing! Picked up about 7mph to boot! They sound great and don't soot the transom anything like they did with the Mags. Perfect upgrade in my opinion!
08-13-2012, 08:20 PM
#160
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Well, I've had the upgrade now for most of the summer and can happily report that it has been everything I expected and alot more! I can run a little over 5000rpms with the 28s and the low end torque is amazing! Picked up about 7mph to boot! They sound great and don't soot the transom anything like they did with the Mags. Perfect upgrade in my opinion!
