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The "Tuning MS V8 for Economy" Thread


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Yeah I mean I could buy a transfer case and worst case make a good one out of mine with different gear set, but I assume most will be alright.

Ideally buy one from trusted source of course!!

Had considered 4.75 CWP while back!

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Please see this post as an anecdote and not advice.

I run as high at 18:1 and advance as much as 44 degrees.

At normal cruise it's about 16.2:1 and about 37 degrees. I could go leaner as I'm not getting any surging but I'm too scared. I honestly can't notice any loss of power as compared to 14.7:1

Temps are hotter here and our distances greater and haven't blown up anything yet. But take that with a LOT of salt and my normal disclaimer about global nuclear war applies.

At WOT I run 12.5 and somewhat less advance than you guys run as our fuel is not great.

Other things to look out for:

WB voltage: check MS is actually reading the correct value. I see many saying it does not read the same as real volts. My MS underreads a constant 0.6 volts on battery voltage, for example, but my lambda is fine. If it is out then to are not getting the A/F you think you are getting.

If your WB has a gauge then this is easy to check

The way I tested this was to hook up a 1.5v battery to the blue wire from the (disconnected) controller and check the voltage with megatune. I then repeated with 2 batteries in series and checked for 3 volts. It read the same as read with an accurate mutimeter. Did not even have to start the motor.

I found econ improved when I set a severe limit on lambda correction as I think the MS1 correction algorithm is a bit wild. Mine is at 3% at cruise. I allow more correction closer to WOT because of the altitude and air temp changes. This is opposite from what the designers intended.

Fuel cut on overrun: set this to cut the fuel when map is several Kpa below your idle, rpm > x and throttle is closed.

decel enrichment: Little bit of a misnomer but mine is set to 75% enrichment (ie leaner) when I lift the pedal. Anything less and the truck bucks, anything more is wasted.

Injector dead time: Mine is set to about 0.8. I find with a correct dead time you can go a bit leaner at idle and still keep a good tickover. I still haven't quite solved the altitude and air temp problems though.

None of these things will make a huge difference but every little bit helps.

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Hi Nige! :

Fitted today and by Jove even just moving out of the workshop, noticeable difference!

Yes the plan hopefully is to head out tomorrow for a tuning run!

Should I retune on easy or hard do you think?

Cheers, Sam :)

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Well

It drives a LOT better! :D

Not had chance for any motorway time yet but a short stretch at 70 odd saw me in the 14.somethings on my retuned power map, at 3k rpm

Will spend some more time on it soon!

Bloody transfer case has an oil leak :o

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oh hardy har har :blush:

the intermediate shaft hole was just fine, nice and round, its actually leaking (at first inspection) straight out the bottom of the front housing where it meets the main casing.

admittedly the gaskets were not that thick and there might be a slight imperfection in the casting.

anyway, i'll clean it up and source the leak and make a plan.

not what i needed as i particularly wanted the job boxed off last week! :blink:

cheers :)

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  • 3 weeks later...

Well

Here's an update.

I haven't bothered to fix the oil leak, seems to be fixing itself slowly :D (yes it still has oil in!)

So fitted the case and retuned for an hour or so.

Jumped on the motorway on Saturday fully loaded with gear and fuel to go off roading in Wales. This resulted in a dead injector but that's another story.

Anyway on the drive there I took it fairly steady so cruised at 75mph approx

This now gives me rpms around 3000

My MAP was around 65kpa :D

My AFR was around 14.7-15.5 :D

This is without an Eco tune!

Result! :D

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  • 2 months later...

So

Here an update:

After a run out yesterday up the M62 and back, I was yet again astounded at how well the old girl is running after the transfer box change.

Performance wise, it's delightful to drive, cruises at 65/70 in near silence, is very happy at 75ish but just cracks 3000rpm so makes a lovely PARRRRRRRRRM sound as you cruise past lesser vehicles, and will do 100mph if you have enough road! :D

All these things are previously unknown quantities to me!

Regards mpg, it's hard to say for sure as I haven't done an accurate test but accurate guesswork puts motorway driving in the region of 18-20mpg, likely more if kept under 3000rpm, that's not easy though :D

She now cruises at 70 in the early 15:1 AFRs and late 14s above 3000rpm ish.

This is an excellent result for me, a simple transfer change and quick retune and I can cruise on the motorway at above 15:1 on my regular map.

I have 35psi in the tyres which helps and they are not too knobbly/noisy.

All in all, excellent so far!

Thank you gents!! :)

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So

Here an update:

After a run out yesterday up the M62 and back, I was yet again astounded at how well the old girl is running after the transfer box change.

Performance wise, it's delightful to drive, cruises at 65/70 in near silence, is very happy at 75ish but just cracks 3000rpm so makes a lovely PARRRRRRRRRM sound as you cruise past lesser vehicles, and will do 100mph if you have enough road! :D

All these things are previously unknown quantities to me!

Regards mpg, it's hard to say for sure as I haven't done an accurate test but accurate guesswork puts motorway driving in the region of 18-20mpg, likely more if kept under 3000rpm, that's not easy though :D

She now cruises at 70 in the early 15:1 AFRs and late 14s above 3000rpm ish.

This is an excellent result for me, a simple transfer change and quick retune and I can cruise on the motorway at above 15:1 on my regular map.

I have 35psi in the tyres which helps and they are not too knobbly/noisy.

All in all, excellent so far!

Thank you gents!! :)

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