Reflash ECM for more power?

[brody66]

I was at a Centurian dealeship and he was telling me about how they just reflash the ECMs and that ups the horsepower to the next level, he said that is much better than spending the extra money on the upgraded engine, anyone ever done this or is it true?

[da.bell]

Not sure if flashing would do that alone. Reprogramming the ECM could possibly do that.

[chpthril]

You can, on most engines, increase the performance by changing the fuel map and spark curve. Problem is, someone has to write it for the engine manufactures eng/ecm package.

[chpthril]

Not sure if flashing would do that alone. Reprogramming the ECM could possibly do that.

With the EEPROM ecm's in use these days, a re-flash and reprogram is the same thing.

[ragboy]

With the EEPROM ecm's in use these days, a re-flash and reprogram is the same thing.

Well, reflash would normally mean, reflash the same data as before, to verify there is no corruption or something of that nature. Reprogram means to update the chip with updated firmware or program.

[da.bell]

Well, reflash would normally mean, reflash the same data as before, to verify there is no corruption or something of that nature. Reprogram means to update the chip with updated firmware or program.

That is exactly what I thought also.

[chpthril]

Well, reflash would normally mean, reflash the same data as before, to verify there is no corruption or something of that nature. Reprogram means to update the chip with updated firmware or program.

That is exactly what I thought also.

In the automotive/marine repair biz, a re-flash is to erase the current program and replace it with the new program containing all the corrected/changed lines of code (or what ever you geeks call it) instead of reprogramming the ecm by scanning through all the lines of code and changing/replacing the necessary ones.

A re-flash takes minutes, where a reprogram may take an hour(s). In the PC world, you guys are correct, in the land of wrench heads, a re-flash is the usual terminology.

[KonaKing]

In the automotive/marine repair biz, a re-flash is to erase the current program and replace it with the new program containing all the corrected/changed lines of code (or what ever you geeks call it) instead of reprogramming the ecm by scanning through all the lines of code and changing/replacing the necessary ones.

A re-flash takes minutes, where a reprogram may take an hour(s). In the PC world, you guys are correct, in the land of wrench heads, a re-flash is the usual terminology.

What he said

[Waterski-Rebel]

So, I have the 335 HP motor. Is the only difference between it, and the 340 in the software? If so, any idea of what it would cost to get those extra 5 ponies?

[brody66]

Thats what im asking

[zad0030]

Im pretty sure it can make is more fuel efficient but im not sure about more power....I dont see why not

[R&T Babich]

In the automotive/marine repair biz, a re-flash is to erase the current program and replace it with the new program containing all the corrected/changed lines of code (or what ever you geeks call it) instead of reprogramming the ecm by scanning through all the lines of code and changing/replacing the necessary ones.

A re-flash takes minutes, where a reprogram may take an hour(s). In the PC world, you guys are correct, in the land of wrench heads, a re-flash is the usual terminology.

Erasing a program and replacing it with a new program is "reprogramming". Scanning thru a program and changing lines of code is not really how it's done these days. A line of code may need to be replaced with 2 or many more lines creating "patches" which are messy. I had done both for many years working on the F-14. To me a re-flash is an erase/reload with the same program. An erase/reload with a new program is a reprogram.

If you have a 350 MAG MPI with the MEFI 3 (1999) or the MEFI 4 (2000+) it's neither. According to the guys at OBD Diagnostics the programming is generally the same in all the ECM modules, it's the data files that are changed to "reprogram". The MEFI 3 is an open-loop system and the MEFI 4 system is closed-loop with improved idle. The MEFI 3 is ECM 16236999 and on the charts is marked with an * Used by Mercruiser. What this really means is it's "locked" with a password by Mercruiser. The guys at OBD can't reload the data files without the password. I have another MEFI 3 module that was for the 350 Ramjet engines and is not locked. The guys at OBD say this module will probably work quite well as is, because they've seen the data files for the Merc version which are strange and tend to run rich.

http://www.obd2allinone.com/sc/toplevel.asp?cat=32

[formandfunction]

If you have a 350 MAG MPI with the MEFI 3 (1999) or the MEFI 4 (2000+) it's neither. According to the guys at OBD Diagnostics the programming is generally the same in all the ECM modules, it's the data files that are changed to "reprogram". The MEFI 3 is an open-loop system and the MEFI 4 system is closed-loop with improved idle. The MEFI 3 is ECM 16236999 and on the charts is marked with an * Used by Mercruiser. What this really means is it's "locked" with a password by Mercruiser. The guys at OBD can't reload the data files without the password. I have another MEFI 3 module that was for the 350 Ramjet engines and is not locked. The guys at OBD say this module will probably work quite well as is, because they've seen the data files for the Merc version which are strange and tend to run rich.

http://www.obd2allinone.com/sc/toplevel.asp?cat=32

But how much good could it really do?Make your mileage worse I assume.

[FacePlant]

All they would do to improve power is to increase timing (spark advance) and maybe lean out the air/fuel mixture a tad. Might pick up 10-20hp, which really won't be very noticeable at all. Not really worth it if you ask me. If you want more power, spend the $ for a Whipple charger and go crazy. Just be prepared to replace the shortblock when it grenades........

But how much good could it really do?Make your mileage worse I assume.

If they lean the tune slightly, you will actually see better fuel economy. They make the stock tunes pig rich strictly for engine safety. Rich = SAFE!!

[CP3]

I seriously doubt you are going to get more than 15 to 20 hp by reflashing the ECM. you might could get 30 if you totally reprogramed the spark curves for 91 octane but who wants to do that with gas prices???

*EDIT
and the other thing is I doubt you will even notice the hp increase. its not like a car where you can feel it..... again