Optimax V6 ECU

[mikesyam]

Hi
I do car electronics including remapping for a living and im looking for a scrap Optimax V6 ECU to have a look inside to see what processor is used and to see if its possible to play a bit, will pay for it and the postage by paypal.

Thanks Mike

[Bigmuz7]

Why did you pick this engine ? IMHO Mercury make several brands of their engines including semi-race brands available to the general public, but they have mechanical mods to cope with extra power. Do you think the V6's are underpowered, but have strong gearboxes ?

[Dirk Diggler]

Originally Posted by Bigmuz7

Why did you pick this engine ? IMHO Mercury make several brands of their engines including semi-race brands available to the general public, but they have mechanical mods to cope with extra power.

Why not, most people would be happy with a few extra cheap horses. As for mech mods, not necessarily. For instance, the crank in both the 150 Opti and the XS200 race motor is the same item!!!

[Bigmuz7]

Originally Posted by Dirk Diggler

Why not, most people would be happy with a few extra cheap horses. As for mech mods, not necessarily. For instance, the crank in both the 150 Opti and the XS200 race motor is the same item!!!

Kinda what I was getting at .. its the kind of tech we dont get to see.. but for somone taking an interest like this, so I was interested as to why the OP was looking at this motor, as I totally agree with you Dirk .. take the Verados for example.. all four/three (cant remember now ) of the original line up used the same 2.5 block, but the power outputs varied immensely and must only be down to mapping etc or supercharger size .. but I wonder if they did swap some lower leg components to accomdate the extra power

[mikesyam]

Hi
Wanted a V6 Optimax one as I run a 150 myself and I could use mine to play on but most likely the ECU will be sealed in resin or similar and I want to open a spare one up to see whats inside before I touch mine, still have not got one so any ideas where I might source one would be great.
Thanks Mike

[Searider]

I seem to remember that there's a company in Sweden who will remap Mercury ECUs - so it can be done.

Looking at the 135/150/175 Optimax I believe that the 135 has a different gear ratio but that the 150 and 175 are physically the same engine.

When i've looked at the throttle butterfly on my 150 it doesn't open fully at WOT - despite adjustments being as per Mariner spec and all throttle linkages being locked of with a resin type locking compound. I suspect that this restricts the power down from 175 to 150 - but it can't simply be opened up without remapping the ECU otherwise you run the risk of running lean at the top end?

[Dirk Diggler]

Originally Posted by Searider

Looking at the 135/150/175 Optimax I believe that the 135 has a different gear ratio

Nope, all 3 available as 1.87:1 and 2:1

[Dirk Diggler]

Originally Posted by Searider

When i've looked at the throttle butterfly on my 150 it doesn't open fully at WOT - despite adjustments being as per Mariner spec and all throttle linkages being locked of with a resin type locking compound. I suspect that this restricts the power down from 175 to 150 - but it can't simply be opened up without remapping the ECU otherwise you run the risk of running lean at the top end?

If only it was that simple. The throttle body is the same part no for the 115 opti through to the 200XS, so all the 2.5 litre motors share it.

[Rogue Wave]

I like standasrdisation

[9D280]

Originally Posted by Searider

but it can't simply be opened up without remapping the ECU otherwise you run the risk of running lean at the top end?

Well, unless of course the ECU thinks it's a 175 and as far as it's concerned has a driver at the wheel who is too scared to open the throttle fully? Suz DT25 / 30 had a similer setup 20 odd years ago.

Remember - the more you can standardise & up the volumes, the cheaper they get to make, but Joe punter (i.e. us lot out here) will happily pay lots more for that extra 25 horses.......

[HUMBER P4VWL]

we bought a 175 opti in the end. However we nearly bought a similar rib with a 150 where the "nameless" dealer said he could just source a 175 ecu to up the power. Only problem was that the warranty would be invalid. Wouldnt be a problem if you had a 150 outside of the warranty already. He had quoted £1200 i think for the new fitted ecu.

Whether or not the 150 ecu can be toyed with to produce the 175 power will no doubt be found out. All the car boys do it, however when you chip a 150bhp 1.8 golf gti turbo for example, you get about 197bhp max (as i have) but when you chip the 180bhp same model engine you can get about 210. Same engine and ancilliaries but ecu itself must be different. Probably like the 150 and 175 opti (i know the TT and other VAGs used the same engine, but they had different ancilliaries to produce 225 which can be chipped to 245 plus.)

Point it, it must be possible to do something. Good luck to the thread starter i say, though i doubt massive gains can be made due to there being no turbo?!!!

[Searider]

Originally Posted by Dirk Diggler

Nope, all 3 available as 1.87:1 and 2:1

But does the 135 not have a different ratio as standard offering?

[Searider]

Originally Posted by Dirk Diggler

If only it was that simple. The throttle body is the same part no for the 115 opti through to the 200XS, so all the 2.5 litre motors share it.

That's what we're getting at - similarities. The important thing to know / find out are what are the differences between the engines?

I have been told that the ECU is different. But at over £1200 to change it it's not good value.

I can see that my throttle butterfly doesn't open fully - does it on the 175?

What's the difference between a 150 and a 175?

An extra 25hp would be handy if it's simple, cheap and reliable to achieve.