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Unread 25th June 2016, 12:03 AM
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pezimm pezimm is offline
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It's obvious that the tune these engines come out from factory are subject to a few things:
- an average setting that will - huh, on average - suit most roles played by the vehicle
- tight emissions controls, so when you tune in complete liberty, you may putting the environment at risk (I know, I know... But this should matter to us all)
- normal process variations, as in the claimed kW and Nm figures will have different curves and values for every car produced because they are all made by different bits of steel and plastic.

Having said all that, Subaru engineers design the thing! Spend their entire careers to get a competitive edge and make their cars better than the other ones. So logic would say there aren't a lot of low-hanging fruit without an effect in another area - like fuel economy, wear and tear of parts, the environment, etc... Sure you can carve a massive amount of extra torque and kW out of these engines, but as others have said before: you play, you pay.
Lifted Forester XT Auto - MY07
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Unread 25th June 2016, 12:35 AM
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I agree with you - to an extent.

The variation in parts etc means the default tune is 'safe' for extremes of part tolerances.

The 'fuel economy' part of the tune will be biased towards whatever the official city & highway economy test regimes are, and that's within whatever environmental regulations an in effect (especially hard to meet stuff like cold start emissions). They do not reflect real life.

That - plus all the other constraints, like cabin noise, etc mean the tune isn't optimised for your car, or your driving style.

Everything is a comprimise -- better to have that compromise skewed towards what you like, rather than what the average punter or new car buyer wants.
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Unread 25th June 2016, 04:33 AM
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Ratbag Ratbag is offline
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Gidday Pedro & Duncan

I agree with all the points you both raise, to a degree .

However, I also believe that one should buy cars that are already fit for the intended purpose, making modification relatively minor without compromising the longevity or legality of the vehicle.

IOW, if you want an XT or STI, for goodness sake buy one! Don't buy something like our N/A Foresters, then try to make it perform like one of those ... .
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Unread 25th June 2016, 05:29 PM
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Sorry but in the case of the XV NOTHING and NOWHERE does the car run properly. I have been working with road and race engines for a very long time and this motor's tune is crap.
If the car is designed as well as you indicate why does it have a auto stop start system that causes immense wear on the starting hardware ( I have replaced a lot of ring gears in my time).
There in NO average setting at which it runs right. It pings even on 95. There is no excuse for that in a modern car with modern head design. It the clkutch appeared to shudder every time it was used ( now gone I thought it was a dud clutch but the fuel stutoff at closed throttle was entirely to blame).
My partners 1800cc Corolla would pull our very light trailer up hills at highway speed without changing gear or slowing down on the cruise control. The 2 litre Subie would slowdown until the Cruise control shut off then I would have to go down to 4th to get it up the hill at constant speed. If you think that is the holy subaru engineers doing it right , you unquestionably live in another reality to mine.
The car now feels like a car to drive, not a pedal car. It is smooth, accellerates properly, gets better fuel economy ( now confirmed unloaded), doesn't shudder on takeoff and is way more controlable in the dirt.
Subaru did NOT do it right for average use. It did it wrong.
There should be LESS wear in a properly running motor not more.
It gets better fuel economy.
I don't have semis bearing down on me at highway speeds because my car won't maintain speed up hills.
It is less tiring to drive on long journeys as I can use the cruise control without it switching off all the time. And I do a lot of long journeys.
And lastly 70Kw as opposed to 110Kw is NOT normal variation. It is a complete lie. Not even claiming that it is rear wheel HP as opposed to crankshaft HP is a remotely valid arguement. If you manufacture a car with nearly 40% power loss between the crankshaft and the wheels you need to manufacture something else other than cars
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Unread 29th June 2016, 03:48 AM
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All good and valid points above.

A few points from being knee deep in this stuff since ECU flashing was becoming common

-"Tuned" (ECU) Subaru's have been proven to still pass emissions regulations in Australia. with the added power and economy gains.

-Tuned Subaru's have proven to reduce engine failures caused by the tune.
Big end nearing failure, ring-land failure and "some" Head-Gasket failures are caused by the immense spikes of in-cylinder pressure, attributed to two things.
#1, the "oversquare" design of some engines (2.5 and 3.6) which makes precise ignition timing crucial to reduce pinging
and #2, poor Ignition timing values from factory tunes.

-Suabru's will generally lose approximately 30% of flywheel power when measured on a rolling-road dyno, they do hit a wall of about 50kw of loss, once you get a lot of power out of them. Simple example, a stock as a rock GT Forester (130KW) will measure 90-95KW ATW.

-Most Factory Subaru ECU Tunes are derived from the Japanese variant,
the mapping is computer simulated and modified to remove fuel to pass emissions regulations in the relevant country.
Japanese fuel generally is higher in octane that most fuels we see here (although they do use a different rating system too) but the timing maps are not adequately compensated for a leaner, and lower octane fuel mix.

So the main tings to come out of this by tuning your ECU
-Fuel Economy and Engine Efficiency is increased.
-Power and Torque and Increased
-Engine Longevity is Increased
-Driveability is Increased
-Emissions are not adversely affected
-Engine Failure Rate is Decreased

-Chance of getting a speeding fine is increased due to increase in engine smoothness, power and torque..
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Unread 29th June 2016, 06:24 PM
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You forgot for the pros: car is more fun to drive : car can be driven in the sand and mud MUCH easier as the throttle/engine connection is easier to control. ie less likely to get bogged/lose control.
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Unread 5th November 2017, 07:01 AM
weaponofchoice weaponofchoice is offline
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I see this is a bit of an old post now...however reading the above I'll certainly vouch for Matt (Throttlehappy).

My XT was tuned by him at 190k, and he has tuned it a number of times due to me modding then de-modding however it continues to run beautifully even now at 244k.

Fuel consumption is still at about 9-10 l/100, turbo spool is much earlier than stock and general drivability is fantastic. No oil usage or any dramas at this many k's.

For all of 2016 I was running a "safe" tune and was dyno'd at 200kw atw (obviously with supporting mods) and the car was reliable and fun.

Long story short, I'm happy with it, his tunes are great (most negative reviews are people trying to get massive amounts out of the engine), and I agree with the pro's by Robbks, I expect the engine to go well over 300k.
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