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Discussion Starter #5
It would be nice to see a direct injected turbo engine with front mount intercooler on the new STI.

It has been awhile now since Subaru ditch their traditional hood scoop on pedestrian model but still retaining the TMIC. So, maybe that is some hint for what's to come.

Not to mention the S209 engineers admitted more power can be extracted if only a front mount intercooler is used.
 

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It would be nice to see a direct injected turbo engine with front mount intercooler on the new STI.

It has been awhile now since Subaru ditch their traditional hood scoop on pedestrian model but still retaining the TMIC. So, maybe that is some hint for what's to come.

Not to mention the S209 engineers admitted more power can be extracted if only a front mount intercooler is used.

Direct injection, twin scroll turbo, ELH, and FMIC would be great. I dont see why they cant give us a 350-400hp (crank power) sti out of the box. The technology is there and has been there. I mean if you look at an sti (ej257) with a stage 2/stage 3 package, its pretty much there.
 

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It would be nice to see a direct injected turbo engine with front mount intercooler on the new STI.

It has been awhile now since Subaru ditch their traditional hood scoop on pedestrian model but still retaining the TMIC. So, maybe that is some hint for what's to come.

Not to mention the S209 engineers admitted more power can be extracted if only a front mount intercooler is used.
but but... I like the skewp... how else am I supposed to know which Subaru to wave to?!:rolleyes:

The scoop is a nice reference point for driving, I've driven flat hood or can't see hood cars, and they're harder to drive. or at least make it like the BRZ with fender humps

I have a sore spot for direct injections, had to clean my sister's GTI intake because it was misfireing at 50k km (31k miles). All cars that my family buys from then on are dual injection only, cuz i'll be the one working on their cars :lol: unless Subaru come up with their own dual injection, or use Toyota's, the only Subaru I'll buy is the BRZ.
 

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Discussion Starter #8
Direct injection, twin scroll turbo, ELH, and FMIC would be great. I dont see why they cant give us a 350-400hp (crank power) sti out of the box. The technology is there and has been there. I mean if you look at an sti (ej257) with a stage 2/stage 3 package, its pretty much there.
That's true.

But as car manufacturer is better to trade power for longevity.

Having said that, 350hp sounds reasonable these days for flagship model.

Yet, I do think the next gen should be around 325hp.
 

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Discussion Starter #9
but but... I like the skewp... how else am I supposed to know which Subaru to wave to?!:rolleyes:

The scoop is a nice reference point for driving, I've driven flat hood or can't see hood cars, and they're harder to drive. or at least make it like the BRZ with fender humps

I have a sore spot for direct injections, had to clean my sister's GTI intake because it was misfireing at 50k km (31k miles). All cars that my family buys from then on are dual injection only, cuz i'll be the one working on their cars :lol: unless Subaru come up with their own dual injection, or use Toyota's, the only Subaru I'll buy is the BRZ.
Tell me about it, ahahha.

I do own a VW Golf TSI 160 twincharge model. Me old man owns CX-7. I quickly learned to add both water methanol injection and oil catch can on these cars. All of the modified VWs and Audis seemed to barf oil as oil would just pour out of their intercooler. Quite horrible.

But we are car enthusiasts and is not hard to even make your own oil catch can system once we figure out the PCV system.

Unless it is like a BMW...to be precise the N55 engine where the PCV during vacuum is straight into the cylinder head's intake port.
 

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bestcarweb.jp

The engines are all horizontally opposed 4-cylinder turbo, WRX STI is switched from traditional EJ20 turbo to direct injection FA20 turbo, and S4 and Levorg are newly developed 1.8L and 1.5L downsized direct injection turbo.

The 2L turbo is likely to have a specification of 320ps / 45.0kgm, the 1.8L turbo is 270ps / 35.0kgm, and the 1.5L turbo is 150ps / 25.0kgm.
These are still just rumors for the JDM models at this point. It's possible that the USDM WRX will keep the FA20 and the STI will get the FA24 since both engines are already certified in the US. It would be like Japan getting the EJ207 and the US getting the EJ257 since Americans love torque and "bigger is better".

Even then I would expect the next STI to be rated between 310-341 hp. I don't think Subaru will immediately outdo the S209's power figure.. they'll probably wait for a mid-cycle refresh.

The advantage to the FA engine is that it has a broader torque curve (thanks to the EL header, twin scroll turbo, higher compression, DI etc.) and responds better to bolt-ons & ethanol. The WRX's FA20 already makes 320+ whp with a "stage 1 flex fuel tune" with everything else being mechanically stock (just an AccessPort, flex fuel kit & tune). I'm guessing an STI version will be capable of at least 350 whp with a similar setup.

Not to mention the improved fuel economy as an added bonus. I got better fuel economy in my '16 WRX running E50 than I do in my stock '19 STI :)

Subaru has the potential to make a great car.. only time will tell if they actually do..

I wish the S209 would have received the EJ207. Instead we got the same EJ257 (without forged pistons), UEL header, and slightly larger HKS single scroll, journal bearing turbo.
 

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Discussion Starter #11
bestcarweb.jp



These are still just rumors for the JDM models at this point. It's possible that the USDM WRX will keep the FA20 and the STI will get the FA24 since both engines are already certified in the US. It would be like Japan getting the EJ207 and the US getting the EJ257 since Americans love torque and "bigger is better".

Even then I would expect the next STI to be rated between 310-341 hp. I don't think Subaru will immediately outdo the S209's power figure.. they'll probably wait for a mid-cycle refresh.

The advantage to the FA engine is that it has a broader torque curve (thanks to the EL header, twin scroll turbo, higher compression, DI etc.) and responds better to bolt-ons & ethanol. The WRX's FA20 already makes 320+ whp with a "stage 1 flex fuel tune" with everything else being mechanically stock (just an AccessPort, flex fuel kit & tune). I'm guessing an STI version will be capable of at least 350 whp with a similar setup.

Not to mention the improved fuel economy as an added bonus. I got better fuel economy in my '16 WRX running E50 than I do in my stock '19 STI :)

Subaru has the potential to make a great car.. only time will tell if they actually do..

I wish the S209 would have received the EJ207. Instead we got the same EJ257 (without forged pistons), UEL header, and slightly larger HKS single scroll, journal bearing turbo.
The one thing that I see EJ257 really lacks is actually the electronics:
1. no wideband reading 02 sensor
2. no post intercooler IAT (though this is std in JDM model).
3. I heard slow to respond ecu on GR model?

So to me the ECU is almost half blind as to what's really going on - should there be something that is outside the OEM tune/parameters.

Well I said that because looking at the Germans, for example my humble VW TSI 160:
1. It has 3 IAT sensors (intake side, intercooler outlet side and intake manifold side)
2. wideband reading 02 sensor
3. Fast learning ECU.
4. VW is famous of its CEL/EPC warning lights; but this is because it can detect just about any potential error way in advance before real damage is done.

I am no engineer, but common sense tells me if only the STI has such capable electronics then I am quite sure it can be tuned more aggressively and stay safe. The amount of mix and match parts / software VW crowds did to their cars are absolutely absurd - not that it actually works but it doesn't blew up their cars either.

And so I hope the next gen STI gets capable ECU along with critical sensors in place.
 

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Yes, electronics are definitely lacking and they've improved on the FA20.

The EJ257 is also lacking the obvious mechanical components compared to the EJ207 (EL header, twin scroll ball bearing turbo, better flowing heads, better cams, etc.).
 

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Discussion Starter #13
Yeah I read the FA20DIT has IAT sensor on its intake manifold and wideband reading 02 sensor.

The loveliest thing about my VW Golf and my old man's CX-7 is the fact that I can just slap on water methanol injection as a mean to protect the tune and it won't cost any hp. As a matter of fact, it recovers the otherwise lost hp due to heat. A friend's CX-7 was completely bone stock and we simply added Devils Own WMI and just use 1g/h jet (flows out 100cc/min in free air). The ECU likes it and it recovers all the lost hp and tq.

I am sure it is the same with any other modern turbo engine car, including the current WRX.
 

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In general subaru needs to step it up for the next gen sti. New modern engine with modern performance and engine management system. Having active or electronically adjustable suspension/driving style would be great to. BMW, VW, and other manufactures all do this for their "sports" cars. Like i said, the technology is there.
 

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In general subaru needs to step it up for the next gen sti. New modern engine with modern performance and engine management system. Having active or electronically adjustable suspension/driving style would be great to. BMW, VW, and other manufactures all do this for their "sports" cars. Like i said, the technology is there.
So, only because other do it Subaru should do the same...are you OK without a manual tranny
 

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A modern manual with rev match and launch control would be nice. But a PDK type would be heaven. Adding any weight to the STI is not ideal it's heavy enough. Depends on the performance gain really. ZL1 manual die hard were switching over for the newer 10speed auto purely because of the performance difference. If an auto would get us sub 4 second 0-60 I'd bite. Does subaru have access to any decent auto's? Toyota would have to step in? Do they even employ any or do they go through BMW?

For suspension a lot of manufacturers offer fixed as the better more expensive option, as Audi does with it's TTRS/RS3.

Knock sensor, wideband, HUD would be nice for little added factory cost too.

I do a ton of night/winter driving, I'd pay $2500 for night vision technology aswell similar to gm, audi, bmw.
 

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The FA20DIT already solves a lot of the monitoring "issues" of the EJ:
  • Wideband O2 sensor
  • Intake manifold temp sensor
  • Oil temp sensor
  • Fuel pressure sensor
  • 2 knock sensors placed for "better" detection along with an improved knock control strategy
 

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Oh maybe im miss naming it, or havent found it in the menu? Put on near 90,000km on the MY18 STI. The SSTC I could view live the degree of knock retard at any moment from the factory RPD. The STI has the same feature?
 
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