4.5L Mercruiser mapping

[Tafflad]

The 4.5L v6 ... is physically the same in 200 and 250hp variants.
Therefore like motorbikes & cars the difference is the ECU mapping.

Does anyone know of a 'chip' or 'reprogrammed'. that will upgrade a 200.

I know of Magnum tuning .. but that does not provide a remap ... but fools the temp sensor ... but does liftvto 250hp.

Anybody know of remapping option.

 

[alldodge]

The 4.5L v6 ... is physically the same in 200 and 250hp variants.
Therefore like motorbikes & cars the difference is the ECU mapping.

Does anyone know of a 'chip' or 'reprogrammed'. that will upgrade a 200.

I know of Magnum tuning .. but that does not provide a remap ... but fools the temp sensor ... but does liftvto 250hp.

Anybody know of remapping option.

In diesels I would agree, but in gas motors no. Pulling an additional 50HP is not done by mapping alone. There would have to be cam change

 

[Scott Danforth]

Im going with injectors, maping, and cam

 

[Tafflad]

Interesting since posting ... googled and found a large thread on another forum ... they compared all key part numbers and they were identical.
Watched a TV program recently on tuning a fuel injected car .... they got a 49hp increase purely by remapping the ECU ...car was on a Dino at time so they adjust in real time.
So getting big gains by remapping does seem possible.
However if nobody sells such an upgrade - does not help.

 

[alldodge]

As seen on TV, You can do lots of things with smoke and mirrors.

First don't use what a car can be tuned to and compare it to a boat. A properly tuned motor runs within a Fuel to Air Ratio (AFR). A auto is set at 14.7 for best emissions. An auto can be run leaner up to 16 for fuel economy but don't even think about doing it with a boat. A boat is under a constant high load and for best power its set between 13.2 to 12.8, and any leaner and your going to melt a piston or warp a valve.

All that said it does appear your correct, the only thing that I can find "so far" that is different between the 200 and 250 motors is the PCM. The head, valves, crank, cam, injectors, fuel pump, regulator are all the same part numbers. The only thing that is different is the PCM. So Merc made a richer running 4.5 and a leaner running 4.5 as I can see.

Also looked at the 8.2 Base and HO, and it the PCM is the difference in it

Sure would like to know if anyone has compared the AFR differences between the motors?

Cost of 4.5 PCM is $1700 to $4000
Cost of 8.2 PCM is $1800 to $6300

It could be the highest cost one for each motor is the HO, but there are a few to choose from and would need to look into it further. Could be the high cost one also is setup for AXIS. If this is the case about $300 less for the 4.5 and $4000 less for the 8.2

 

[Tafflad]

Didn't mean to imply you could simply add car settings, just that you can 'up power' a fuel injected gasoline motor.

Glad you report same that my Googling around found - only the PCM is different
As you seem to know a lot more than me, would you be able to look any further into this.

I would have thought that now Mercruiser have adopted this approach - there would be after market 'remap' kits.
The Magnum tuning approach is only one I have found.
http://www.magnumtuning.com/en/detail/dyno-boost-boat-performance-chip/mercruiser/4-5l-200-hp

 

[alldodge]

Don't know of any marine apps as yet but I continue to look

 

[alldodge]

It looks like the differences in 8.2 Base and HO motor is a restrictor plate (flame arrestor adapter) and the PCM change. Have looked over the 4.5 and cannot find anything like the same kind of adapter. Both 4.5 motors use the same TB #8M0046460. It could be that the TB comes with an adapter already installed and gets removed if it is placed on a HO motor.

 

[Bt Doctur]

Delphi probable makes the ecm, ask them
http://softwaretopic.informer.com/ecm-programming/
http://mefiburn.com/

http://mefituning.com/contact

 

[DonziLover]

Interesting since posting ... googled and found a large thread on another forum ... they compared all key part numbers and they were identical.
Watched a TV program recently on tuning a fuel injected car .... they got a 49hp increase purely by remapping the ECU ...car was on a Dino at time so they adjust in real time.
So getting big gains by remapping does seem possible.
However if nobody sells such an upgrade - does not help.

Hi, I was doing a little research on ways to increase HP on my 200HP 4.5L and came upon this older blog. I own 2018 Donzi 18 Classic, my very first boat. I want more HP and was wondering if you could give me some advice. In reading the blog it seems it’s a PCM change. Could you give me some insight or anybody else who may read this?