Best Subie Engine?

^ I should have been more explicit.

IMO, the best 4 cylinder donk Subaru have ever made ... :cool:.
 
Gidday CW

I hope so too ... :iconwink:.

As I mentioned above about my Impreza's EJ-18, and keep on mentioning about the EJ-20 Forester donks, these were seriously underpowered from day one. They have the headline figures, but with a torque curve like an inverted ski jump ...

Much better economy under shopping conditions, but not really much better on the open road. Very compromised if towing anything.

Under ideal cruising conditions on real world roads with hills and such like, Roo2 will return about 7.3-7.5L/100 kms. That's with two adults, aero roof bars and a modest amount of gear. That's far better than I ever got from my Impreza (~ 1.5 better than the Impreza under similar conditions). The Impreza was much more economical around town (~ 1.5 less than the Forester under similar conditions). Using freeways/tollways and 80 kmh roads around town dramatically improves the economy of my Forester.

Modern superchargers offer most of the benefits of a turbocharger, without the drawbacks IMO. They both stress the engine much more than having a N/A engine of the same capacity ... 7 psi boost equates to a doubling of the stress on an engine.
 
Maybe you should have been more explicit,
Best SOHC EJ engine.

IMHO, you can't go past the Quad-cam EJ20 variants from across the years
Especially the 204's with AVCS, they were just hampered by the heavy cars they have been put in really.
a 140KW 204 stuffed into a GC8 hatch would be a good ride.

Any EJ25 has poor bore/stroke ratio and they just don;t make the power or torque that a better designed 2.5 NA engine can
hence the use of offset conrods in the EZ30 and the FA/FB engines to get some stroke length back

But really, boost negates all the issues,
Modern high capacity turbo's, run on sensible boost into relatively high compression engines give exceptional performance, and great off-boost dirvability and economy
 
clearwater99 said:
sooner or later they will make one for my outback I recon

https://www.raptorsc.com.au/subaru8.html
Click to expand...

Are you sure they don't? They have MY04 - MY09 kits for 2.5 liberties.

Would be easy to adapt to < MY04 EJ25. Probably just bolts up.

The 'kit' is really just brackets and pipes that fit your engine/bay.

The tricky bit will be engine management depending on your year.

EDIT: They've got pictures of impreza and Foz installations on their website - so I'm more that certain they could bolt one up for you.
 
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Robbks said:
Maybe you should have been more explicit,
Best SOHC EJ engine.
Click to expand...

Disagree. The FB engine has been plagued with problems, notably and not least the oil burning issues.

IMHO, you can't go past the Quad-cam EJ20 variants from across the years
Especially the 204's with AVCS, they were just hampered by the heavy cars they have been put in really.
a 140KW 204 stuffed into a GC8 hatch would be a good ride.
Click to expand...

DOHC engines are a good idea when the rocker arms from a SOHC become too long with ideal valve placement and angles, thereby increasing the inertia of the valve system rather than helping performance. e.g. The DOHC engines in Astons and Jags were good because the heads were very broad.

It is my understanding that the quad cam (DOHC) variants of the EJ engines weren't very successful because of more peaky torque curves than the SOHC variants and because the power loss through driving the second pair of camshafts could never be made up for with better efficiency.

Any EJ25 has poor bore/stroke ratio and they just don;t make the power or torque that a better designed 2.5 NA engine can
hence the use of offset conrods in the EZ30 and the FA/FB engines to get some stroke length back
Click to expand...

Then how is it that the EJ-253 has the flattest torque curve of any of the EJ or prior engines?

There is certainly no evidence that the FB engines are better than this, and introduced several major problems that did not exist in the EJ-253 ...

Comparing any 4 cylinder engine with a higher capacity six cylinder engine is not sensible, IMNSHO.

But really, boost negates all the issues,
Modern high capacity turbo's, run on sensible boost into relatively high compression engines give exceptional performance, and great off-boost dirvability and economy
Click to expand...

The turbo EJ-25 actually produces less torque at low revs than the EJ-253. It's not until the engine gets up to around 2500 rpm that the boost makes up for the losses of the DOHC design and other engine differences. The EJ-253 is getting around 80% of its maximum torque by a mere 1200 rpm. This is very evident when driving the car in real road and off road situations.

If one is after sheer performance, then the turbo route makes sense. If one is after other attributes (as I am ... ), then the N/A route makes more sense.

Horses for courses ... :poke: :biggrin:.
 
The problem with most of what we're talking about here is Factory tuned engines that are required to meet emissions standards and the everyday driver with less than stellar throttle and clutch control.

the EZ30 in my Gen4 Liberty as an example.
From simply allowing the car to consume the required amount of fuel at 2000rpm gave the car a 100% increase in available torque at 2000rpm
Not the engine's fault it's doughy from the factory.

big issue with most turbo engines, take your EJ255 fitted to the SG XT.
it can make much more torque at lower rpm, but to pass emissions standards the turbo is not allowed to spool as fast as it can, the engine load is limited and the engine is starved of fuel
Secondary to that it's fitted with a much too small turbo for it's capacity, which chokes the exhaust side of the engine, causing heat build up and as such has to run on reduced timing (reduces torque output) to compensate.

But then Subaru came up with a great idea... :D
Turbo Diesel

pity that it's hamstrung by the DPF and EGR hung off the front of it,
again, Emissions regs.
 
^ Actually, Rob, Roo2 gets around the same mileage as my Morris Mini 850 did on the open road at the speed limit (more or less ... :lildevil: ), nearly 40 mpg (UK).

This is an absolutely fantastic achievement, showing the incredible improvement/s in engine technology and engineering over the last 5 decades.

Around town, there is no getting past the laws of physics - it takes far more fuel to move 1.5 tonnes off the mark than it takes to move 0.5 tonnes! Regardless of engine efficiencies.

TBH, I am more than happy with the fuel economy and performance of Roo2, for my purposes. It goes much faster than my licence will permit, and gets to that speed all too quickly :lol: :biggrin:, with or without my camper trailer behind it.

I gave up making serious modifications to my vehicles after my last Morris 1100, Kimberley and Landcruiser (about 25 years ago ... ). Since then, I have purchased vehicles that suit my purposes, and have made whatever (very) minor modifications they might have required to suit my purposes better.

e.g. Roo2 came with a mighty tow bar.

At the right price, I have added:

SubaXtreme front bar;

UHF radio and aerial;

Light bar;

SubaXtreme sump guard.

I further propose to lift it marginally (25 mm), which will still be only a couple of mms over the OEM spec maximum suspension height.

Note that all of these things relate directly to my safety, and the car's, for my uses.

In every other respect, it suits my needs perfectly, out of the box ...
 
IMO The JDM EJ207 is the best 4 Cyl engine Subaru ever made. Overall it is without a doubt the EZ30.

My opinion for 4 Cylinders:

JDM EJ207 for best overall
EJ257 my actual favorite for drivability
EA81 for most legendary/ character and pure awesomeness for its time



I wish Subaru made a factory EZ30 Turbo, or a H8 :lildevil:
 
Davidov said:
IMO The JDM EJ207 is the best 4 Cyl engine Subaru ever made. Overall it is without a doubt the EZ30.

My opinion for 4 Cylinders:

JDM EJ207 for best overall
EJ257 my actual favorite for drivability
EA81 for most legendary/ character and pure awesomeness for its time



I wish Subaru made a factory EZ30 Turbo, or a H8 :lildevil:
Click to expand...

well, there's always the 600hp 1235
 
A little off topic but worth mentioning for fun....
Unsure if you gents follow 'Mighty Car Mods' but those guys built a Turbo'ed EZ36 in a Gen 2 Liberty Wagon. Google 'MCM Super Gramps' for an 11 part build series on youtube, it's fascinating viewing.
 
Ratbag said:
Modern superchargers offer most of the benefits of a turbocharger, without the drawbacks IMO. They both stress the engine much more than having a N/A engine of the same capacity ... 7 psi boost equates to a doubling of the stress on an engine.
Click to expand...
The future in car engines is turbocharged petrol because they are now so reliable, economical (much better than an equivalent non turbo with the same performance) and have incredible drivability. BMW haven't replaced their world best 6 cylinder engines with turbo fours and Mercedes their supercharged 4's with turbo fours because they don't know what they're doing. And progressive European manufacturers like VW, Peugeot, Renault, Volvo & Ford are now all into turbo fours that are providing the desired characteristics I have mentioned. I even own one that recently won the COTY and after 2 years and 80,000km I'm still gob-smacked by its superb character. And that comes from a fan & owner of a Subaru turbo.
 
^ Throw away society syndrome?

Our Camry was like that. When it needed some simple repairs, the cost of removing and refitting the engine made those repairs totally unviable. The car was designed in such a way that the engine was all but (economically) impossible to remove.
 
Best engine has got to be the EJ25 turbo in my Forester XT... Don't take my word for it, it was named 'International Engine of the Year' on the 2.0-2.5L category twice: 2006 (EJ255) and 2008 (EJ257)

More here
 
My comment was specifically directed at the N/A engines.

I personally do not like 'domestic' diesels or turbocharged engines. That's from the perspective of a retired cost accountant, and car user ... :poke: :iconwink:.
 
guzzla said:
The future in car engines is turbocharged petrol because they are now so reliable, economical (much better than an equivalent non turbo with the same performance) and have incredible drivability. BMW haven't replaced their world best 6 cylinder engines with turbo fours and Mercedes their supercharged 4's with turbo fours because they don't know what they're doing. And progressive European manufacturers like VW, Peugeot, Renault, Volvo & Ford are now all into turbo fours that are providing the desired characteristics I have mentioned. I even own one that recently won the COTY and after 2 years and 80,000km I'm still gob-smacked by its superb character. And that comes from a fan & owner of a Subaru turbo.
Click to expand...

we are drifting off track here... but the future (present really..) will include hybrid electric/exhaust turbos which can also act as generators when there's excess exhaust energy.

Think of a turbo that can reach max boost (supercharger style spin-up with the electric motor drive), then rather than vent excess exhaust through a wastegate when at max boost, start loading the turbine with the generator for electrical power (for hybrid drive or storage).
 
^ I tend to agree, Duncan.

As a species, we simply must become far, far more in tune with our environment - and more importantly, share it far more sympathetically with all our companion species on the planet. If we don't, can't or won't, we are dead meat.

Around 1900, there were about a billion humans on this planet. Now there are around 7.3 Bn. We simply cannot keep doing this!
 
Don't get me started on Hybrids....
The huge cost both economically and ecologically to mine, build and replace batteries...

I agree with the semi-CD EJ207 with AVCS being extremely good.
This is where variable vane turbos like that fitted to the EE20 and AVCS come into their own.
You never waste exhaust, intake or scavenging energy, you control it precisely at all times for the required power.
 
Don`t get me started on population!!!!!!!!!!!!!!!!!!!!!!
I am just glad I won`t be about for when the brown stuff really hits the fan in another 30 or 40 years if indeed it takes that long.
Don`t forget that we can add a couple of flexible solar panels to the horizontal car panels as well for their small contribution.
 
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