2015 Subaru WRX STI

[Whitigir]

Same old EJ25, but there are improvements...relocated intercooler, revised engine inlets....no words on any internal change yet.

The team reported this STI feels more confident, and is 1 second faster per lap than the last gen on the same track.

First time sequential manual trans is onto STI production, before they couldnt solidify the Reliability of it, now they do.

Though i am not sure of what they mean by the new Sequential Manual trans....just dont tell me that it only row up and down...lol

[Dave-ROR]

Eh. Literally zero interest in the car over here. Sigh. The BRZ may well end up being the only Subaru I've ever actually owned.

[Frost]

Doesn't do anything for me. It's amazing how the original North American STi had me drooling back in the day but now, the STi feels like an overpriced WRX.

The WRX has just risen so much in value over the years going from 215hp now pretty much a notch or two under the STi at 268hp.

[jflogerzi]

Originally Posted by wparsons

^^ IIRC the WRX is getting an FA20DIT and the STI is keeping the old EJ25.

Correct which I don't understand at all. The FA20 could clearly handle 300 WHP with a few minor internal improvements.

[serialk11r]

Originally Posted by jflogerzi

Correct which I don't understand at all. The FA20 could clearly handle 300 WHP with a few minor internal improvements.

You know that got me thinking. How often do car manufacturers actually ship engines with internal improvements? I always thought that was a cheap way to make a more powerful engine, but now that I try, I can't think of a single example where they actually try to do this seriously. Maybe the BMW S54 but that engine's horsepower bump had more to do with the fact that it was tuned to make power at a higher speed, and that engine had a whole different block.

For example my own MR2 and its Celica souped up 1ZZ...that makes 8 hp more. They put weaker rods and slightly bigger valves in it. Maybe the cost of making another engine variant is significant? But I don't really see how...maybe it's just penny pinching. Equities sure are going wild.

[Whitigir]

Originally Posted by serialk11r

You know that got me thinking. How often do car manufacturers actually ship engines with internal improvements? I always thought that was a cheap way to make a more powerful engine, but now that I try, I can't think of a single example where they actually try to do this seriously. Maybe the BMW S54 but that engine's horsepower bump had more to do with the fact that it was tuned to make power at a higher speed, and that engine had a whole different block.

For example my own MR2 and its Celica souped up 1ZZ...that makes 8 hp more. They put weaker rods and slightly bigger valves in it. Maybe the cost of making another engine variant is significant? But I don't really see how...maybe it's just penny pinching. Equities sure are going wild.

Seems that the STI in the Nurburing challenge has FA20 instead of EJ25. Because it is in SP3T class, which is for Turbo engine with 2 liters or less. Far as better built internal, 15 Mustang eco boost engine is that bullet proof built.

As for variant ? Every time manufacturer want to, they bump into problems of productions volume, sale number....etc. it only makes sense to put that variant into another different car than different trims..especially lower volumes.

Many people already saying that FA20 has Carbon problems, Subaru is not sure on it reliability status, so they stick with what works best....EJ25

[wparsons]

Originally Posted by Whitigir

Many people already saying that FA20 has Carbon problems, Subaru is not sure on it reliability status, so they stick with what works best....EJ25

Carbon problems? As in carbon build up on the intake valves? Are you talking about our FA20, or the FA20DIT?

As for what works best, if that were the case why would they put the FA20 in the WRX and the EJ25 in the STI?

[reni]

A turbo FA25 would be perfect for this car... although I wonder if they're not doing it because
1) The STi is too low production to justify the development costs
2) An FA25DIT is in the pipeline, just won't be ready for 2015

[Whitigir]

Originally Posted by wparsons

Carbon problems? As in carbon build up on the intake valves? Are you talking about our FA20, or the FA20DIT?

As for what works best, if that were the case why would they put the FA20 in the WRX and the EJ25 in the STI?

Their FA20 DIT. I have no idea why they put it in the WRX, but my guess would be that was the maximum what they felt reliable and safe to produce. In case of the STI, I guess they would have to bump it to 300+ hp, the number which they don't feel comfortable going, and using with.

My guess would be that they want people to try the FA20 first with Toyota DI (BRZ) Then taste it with Turbo but non Toyota DI (WRX) Then when they fully have the rights to Toyota DI, they will use FA20 Turbo Toyota DI all together. If I am right, then this will not happen until 2016 for BRZ STI, then 2017 for STI mid upgrades

[wparsons]

It's not surprising the pure DI version is having carbon issues, that's the only reason we have port injection at all on ours.

[STJ]

Originally Posted by Whitigir

Their FA20 DIT. I have no idea why they put it in the WRX, but my guess would be that was the maximum what they felt reliable and safe to produce. In case of the STI, I guess they would have to bump it to 300+ hp, the number which they don't feel comfortable going, and using with.

My guess would be that they want people to try the FA20 first with Toyota DI (BRZ) Then taste it with Turbo but non Toyota DI (WRX) Then when they fully have the rights to Toyota DI, they will use FA20 Turbo Toyota DI all together. If I am right, then this will not happen until 2016 for BRZ STI, then 2017 for STI mid upgrades

I think that the rest of the world will get a FA20
With around 330hp, i see no reason why not because the JDM Levorg and Legacy both have a FA20 that is making 300Hp while being eco tuned and only revving to 6000!

[serialk11r]

Originally Posted by wparsons

It's not surprising the pure DI version is having carbon issues, that's the only reason we have port injection at all on ours.

Port injection mixed with direct injection improves efficiency actually. Port injection produces a more homogeneous mix, direct injection is able to provide cooling and stratify the mix around the spark plug. Direct injection alone has problems at low speed for higher flow port designs.

[TIE Pilot]

Same 2.0 boxes engine + factory turbo
WRX: TURBOCHARGED
NEW 268-HORSEPOWER 2.0-LITER DIRECT-INJECTION
TURBOCHARGED SUBARU BOXER® ENGINE.
Gives the new chassis precisely the power it needs,
for the most balanced driving experience yet.
http://www.subaru.com/2015-wrx.html


2.5 Boxer
WRX STI: FULL-THROATED ROAR.
305-HP TURBOCHARGED SUBARU BOXER® ENGINE
Feel the tenacity of the high-performance SUBARU BOXER® engine
, designed for power and balance, delivering 290 lb-ft torque for strong acceleration across a wide power band.
http://www.subaru.com/2015-wrx-sti.html
[ame]http://youtu.be/dv2j5_zcnwA[/ame]



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[Porsche]

An FYI regarding the WRX video above:

For many prospective buyers the 0–60 mph acceleration times are important. This reviewer claims—repeatedly—that the 2015 WRX 6-speed manual transmission car turns in times of 5.5 seconds because it requires a shift to 3rd gear.

This car does NOT require a shift to 3rd gear to reach 60 mph. Fuel cutoff is at 6800 rpm = 61.87 mph in 2nd gear, while 6700 rpm redline = 60.96 mph in 2nd gear.

March 2014 Car & Driver WRX road test results show 0–60 = 4.8 seconds (in second gear). They elaborate by noting that it took them 14 tries. They achieved their best time when they dumped the clutch at redline (6700 rpm) and changed up into 2nd gear at 5300 rpm. Had this reviewer done the same, they'd probably have achieved similar figures, especially if shifting at a "mere" 5300 rpm, which keeps the engine near the torque peak, I would think. While it worked for them at Car & Driver, they suggest that the rest of us are more likely to turn 6+ second times in our driving. They also noted that the drivetrain did not utter a peep of protest under this brutal treatment; the clutch did not slip, the gearbox "responded exactly as it did when we started."

Car & Driver's refreshing candor about how they achieved this "remarkable" acceleration time highlights why we end users are unlikely to achieve similar results in "normal" driving, and why magazines that are more conservative (European?) turn notably slower times. I've noted over the decades that the American car magazines are competitive about their testing times, and so their numbers are not ones that I expect to achieve in my own car. It seems over the decades that there's a national competition amongst the American car mags to see who can turn the quickest times. I don't want to buy that used test vehicle when all of those guys are done with it.

While I find the appearance of this new WRX to be unremarkable (at best), the enthusiasm expressed by all of the reviewers so far about its handling dynamics reminds me of the initial reviews of our Twins. The WRX sounds like a great driver's car. It's unfortunate that Subaru won't be offering this in a hatchback version. Nevertheless, when we need to replace our Mazdaspeed3, I think we'll take a long look at this car.