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2017 Forester XT, 2015 3.6R Ltd (sold)
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What are you gonna believe ...reading or physics?

100 hp per liter would require nearly 88 lb-ft per liter at 6000 rpm,
(that would correspond to peak torque well over 95 lb-ft per liter).

Mazda's 2.0 DI engine generates peak torque of only 75 lb-ft/liter,
and less than 68 lb-ft per liter @ 6000 rpm (peak hp). Their 2.5L
direct injection engine has nearly identical figures.

Please identify JUST ONE naturally aspirated production automotive
engine that generates 100 hp/liter @ sane rpm -- on 87 octane fuel!

Looby
I have to agree. The highest specific output DI engine that runs regular gas is probably the GM 3.6 with DI. In a performance tune, only available in certain models, it produces as much as 89 HP per liter. Even if a direct injected 3.0L flat six from Subaru could match that output, which isn't likely, we'd still only be looking at maybe 270 from a 3.0L displacement.
 

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2006 Outback XT
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228 Posts
Even if a direct injected 3.0L flat six from Subaru could match that output, which isn't likely, we'd still only be looking at maybe 270 from a 3.0L displacement.
...which is exactly why I think we are most likely to see the current 3.6 shortblock with fancy new heads. They can do that for a few years, and by then the buying public will be at least somewhat more attuned to the idea of 4-bangers with snails, batteries or both to do the big-car job.

Regarding the DI-specific issue of fouled intake valves-

I've thought about that one for a while, but I haven't put much research into figuring out how various automakers are coping with this. An obvious, low-tech solution would be to add a throttle-body injector for part-time usage to wash the residue off the valves. It seems to be easy to skirt many rules if the solution involves a mechanism that is only used for a fraction of the total run-time.

I imagine that would be a lot cheaper than creating a direct crankcase vapor injector and associated plumbing- to introduce vapors directly into the chambers without passing them across the valves. I just don't see that as workable.

I've also wondered about somehow condensing it into a fuel wash, thereby diluting the contamination and then supplying that mix to the fuel injectors. Again, sounds kind of iffy and expensive.

Another thought would be to dynamically pressurize the crankcase itself in phase with the crank, to prevent blow-by in the first place. But this would require much stronger seals and I imagine would incur significant pumping loss.
 

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2013 OB 3.6R (former)
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2,778 Posts
Discussion Starter #43
Ok, let's put it otherwise: how much power will the new 7 pax need?

The 3.6R has plenty enough for the OB. Today I went down a wash and then out the same way. As usual, a pair of nice guys who were leaving did not fail to express skepticism about the car's ability to get out claiming they have seen 4wd not make it (are all ATV owners obliged by contract to scare others off? :) ). The slope was not long but it was steep and extremely loose, with a couple of sizable rocks mixed in for more fun (cherry-picked my line and did not touch, but was glad to have triple armor). Though the OB had to earn its way through the first rock, I accelerated for fun after the second and the car just blasted out of the wash in an exhilarating fashion--"impressive" is the only word to describe it. Needless to say, by the very end of the trail, which involved two other nice down and ups, I had caught up with the ATV.

Once out of the wash I immediately began to wonder if my 2008 Tribeca could do it. I think it can (though probably not with the YK 520 tires it now wears). But how about the B9?

That would lead us off topic but the point is simple. The 3.6R is more than enough for the OB. It allows the 2008- Tribeca to climb steep interstate grades at speed perfectly fine--where the B9 used to work too hard.

Of course, I think that the new 7 pax needs to be larger than the Beca. But not too much so. I think that if it maintains the current weight-to-power ratio, power won't hurt its sales. Failure to be noticeably more economical than the current one will. The Beca mpg numbers are now pickup territory. For the model to succeed, its engine will probably need a little more power, but a lot better mpg--and definitely regular gas.

EDIT: throw in a 3.0 with strong mpg numbers and a battery? I think it would make a lot more sense in a 4,300-4,500 pound vehicle than having batteries in the Crosstrek.
 

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2010 OB 3.6R limited
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Ok, let's put it otherwise: how much power will the new 7 pax need?

EDIT: throw in a 3.0 with strong mpg numbers and a battery? I think it would make a lot more sense in a 4,300-4,500 pound vehicle than having batteries in the Crosstrek.
The 7 passenger Toyota sienna weight abt 1000 lbs heavier than the outback. And it put out 265 hp . So, a 256 HP 3.6R engine should have no issues powering something like Honda pilot size 3 row suv.
 

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The 7 pax is mostly a family hauler so adequate power is all most buyers will want, and the 3.6R fits that bill. If you want to take 6 of your friends up the mountain really quick with 4 bikes on top and 3 more on the back you'll can always custom fit a supercharger :D
 
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