Scion FR-S Boxer Engine

[L.Michael]

With this car operating a Subaru 2.0L engine, without Turbo, How is it pushing out 200HP?

[1996Battlewagon]

Direct injection.

[Dead91silvia]

I'm thinking it's called engineering... How is it that the first gen SR N/A motor's got about 160hp and the NEO SR's have 200 N/A? Time and tech... Also look at Honda and non-turbo Porsche motor's...

If your looking for a technical response, I cant give that to you.... haha

[phi11]

aliens

[L.Michael]

Then why are the 2.5's still only pushing out 173HP. Aren't the blocks built on the same mold, just internal/head components differ?

[1996Battlewagon]

No. The 2.0 is the new family of Boxers where as the 2.5 is still based on the old EJ. The 2.5 doesn't feature direct injection.

[L.Michael]

Ah yes, the FA engine. I'm just trapped in the EJ world of things I guess..

[1996Battlewagon]

I'm just trapped in the EJ world of things I guess..

It's a good world; a better world; a world of torque and simplicity.

[phi11]

BRZ engine code is FA20
new impreza engine code is FB20

[Wiscon_Mark]

Then why are the 2.5's still only pushing out 173HP. Aren't the blocks built on the same mold, just internal/head components differ?

Not only are they different engine series, but they're engineered differently. Subaru could easily get 200+HP out of a 2.5L engine but they may have to sacrifice certain characteristics about the engine, like enough torque for a heavier car like the Outback (The Outback is close to 500lbs heavier than the BRZ/FR-S) and there are also characteristics like having a higher redline to achieve more HP with the FA20. Honda achieved 240HP in a N/A 2.0L I-4 motor by giving it advanced timing and a 9,000 RPM redline. You really had to rev that car to make power.

Direct injection has also been mentioned. I'm sure they decreased the rotational mass of the drivetrain compared to a standard EJ series motor which would make the engine more zippy but also less smooth. You don't put a snappy, high-strung motor in a family car.

The EJ and now FB25 motors aren't built for a sports car, that's why they don't have the same numbers. They're built to be much more balanced than the FA motor is.

[1055]

The rotary is another prime example of advancements in technology...




...just kidding. Mazda really fucked that one up.

[Wiscon_Mark]

If the rotary had more R&D on it, I think it would have some interesting potential. The lack of additional moving parts could have major implications on efficiency and power (actually, it does on power, how else do you get 200+ HP out of a 1.3L engine?) but when you only put effort into and engine for one, low production model, it just won't get the kind of refinement it needs.

[1055]

There were so many ways they could have made it an awesome platform. The two rotor abomination in the rx8 is worthless. Not enough power and serious oiling issues.. emissions equipment is really what killed them. A turbo option would have been killer. Maybe even a direct injection three rotor.

[kimokalihi]

Mazda already has plans to bring the rotary back and they claim to have fixed the oil consumption and fuel economy. I read about it somewhere just forgot where.

Or how about this improvement on the rotary engine?

[1055]

If you posted something after that last sentence its not showing up.

I just want to stop doing motors in rx8's. Theyre not fun.

[kimokalihi]

http://www.howstuffworks.com/quasiturbine.htm

[L.Michael]

These graphs really give you an idea of what you're gonna feel when driving the BRZ/FR-S.
https://sl-i.net/FORUM/images/imported/2013/01/attachmentphpattachmentid4567d1328422528-1.jpg

https://sl-i.net/FORUM/images/imported/2013/01/attachmentphpattachmentid6204stc1d133424-1.jpg

Is there an upgrade to turbo option on these yet?

[Wiscon_Mark]

I believe there is a turbo kit (aftermarket).

It's only a rumor, but there is supposed to be an STi version coming out for the BRZ. No one has really nailed down whether it will be a turbo or not, but Subaru hinted 250HP.

[harrymaneuvers]

Not from the factory but there are aftermarket ones popping up.

[2000gtb]

Full-race is working on my FRS.. All I want is 400whp

[grayguy]

I just want them to sell enough BRZ's so in 10 years I can get a good deal on one haha

[ScaryFatKidGT]

Because its a performance engine and not a grocerie getter? Honda civic SI-197hp from 2.0, S2000-240hp from 2.2, Acura RSX-200hp from a 2.0. Nissan Sentra SE-R spec V made about that too.

[ouch1011]

How do you get 200hp from a 2L? Get it to breathe at high rpm. Lots of different things needed to achieve that, but that's the simple answer.

[1055]

Or high compression and direct injection.

[1996Battlewagon]

Or high compression and direct injection.

This. It really isn't that special. Honda has been making this kind of power from 2.0 liter and below naturally aspirated engines for years. And think about it: a stock USDM EJ25 with no direct injection, no variable valve timing and not-that-high compression made 165 horsepower - just 35 less than a FR-S engine. That was almost 20 years ago.

The FR-S engine really isn't that special.

[slaytalera]

Direct injection cools down the cylinder more then regular port injection, cooler temps means they can press for higher compression, higher compression makes a bigger boom, bigger boom makes more power

[L.Michael]

So with direct injection, is the fuel shot in right before ignition? or at the beginning of the intake stroke, just like indirect injection?

[1055]

It functions like a standard four cycle engine, the primary difference is the fuel is directly injected into the combustion chamber.. like a diesel.

Hence - direct injection. As to at which point in the process it is injected, that depends on the manufacturer and tuning points.

[r3v_v3ng3]

^yup. The injectors are not on the intake manifold, theyre somewhere in the head

[L.Michael]

Well lets say in this instance, subaru..

[1055]

Well, seeing as subaru got DI from toyota, I would imagine it is injected during the compression stroke. I dont see why subaru would have changed it. Also thinking about it logically, it would have to be injected during compression. HPLV injections with an open valve could lead to raw fuel escaping which would kind of defeat the purpose.

Infact I believe most manufacturers that use DI Inject during the compression stroke. I cant comment on multiport injection, but I would guess that there are multiple injections upon intake and compression strokes.

The real limit we've seen with the technology till late is that at higher rpms the injectors have less time to squirt. I'm sure someone some where has figured out how to cram the amount of fuel required to keep up with a large intake charge at higher rpms. Possibly just a bigger injector with higher pressures.

[Wiscon_Mark]

This. It really isn't that special. Honda has been making this kind of power from 2.0 liter and below naturally aspirated engines for years. And think about it: a stock USDM EJ25 with no direct injection, no variable valve timing and not-that-high compression made 165 horsepower - just 35 less than a FR-S engine. That was almost 20 years ago.

The FR-S engine really isn't that special.

In fairness, Honda changed to a 2.2L engine from the 2.0L for reliability reasons. That engine also had no torque. I think if you stayed below 4000 rpms, it was slower than a Toyota Paseo.

What makes the FA20 so special is that it has decent grunt at 2800 rpms while still having good high end power, not the 200HP peak figure by itself. It also achieves pretty good MPG for being tuned the way it is. Some of that has to do with the drivetrain and weight of the car, of course.

[1055]

Like a dead horse... look at the torque curve and numbers of a boxer motor compared to ANY other mass produced four banger.'

[1055]

The one exception to my previous post is the fiat multi air system. Mopar is about to corner the market with the multi air system and torque.

[hansvonaxion]

look at the torque curve

The one with the big hole in it?

They just can't help but include a VOD.

:lol:

[Wiscon_Mark]

No, you're right, but that design makes it driveable on normal roads with traffic, etc. A big fault of most "pure" sports cars is that they aren't very fun to drive everyday. It's a good compromise, IMO.

[bulmug]

another reason they can get that power is the compression ratio honda s2000 11:1 and the brz has a 12.5:1. but whats all this talk about honda's i thought this was a subaru fourm lol

[kimokalihi]

My friend is a honda guy and he was telling me about a video interview of the owner of spoon motorsports and how he was pointing out how the s2000 is better in every aspect than the brz and there's no point in buying one when honda made a better car years ago and its cheaper to buy an s2000 on top of the performance aspect. Ill see if I can find the video. I'd like to see it for myself. I do think its a bit overpriced for what you get but that's me. If they would have put the sti engine or at least the wrx engine then sure.

[1055]

another reason they can get that power is the compression ratio honda s2000 11:1 and the brz has a 12.5:1. but whats all this talk about honda's i thought this was a subaru fourm lol

Direct injection versus standard intake injection. Apples to oranges.

[Wiscon_Mark]

Except that the BRZ is a functional everyday car. The S2000 is not. They're not competitors. The RX-8 would be a better comparison.

[1055]

The rx8 is NOT a good daily usuable car. Its a total hunk of shit with the most detrimental emissions system of any vehicle ever produced ever.

[Wiscon_Mark]

The rx8 is NOT a good daily usuable car. Its a total hunk of shit with the most detrimental emissions system of any vehicle ever produced ever.

Yes, but I was talking about seating, trunk space, not a convertible, etc.

I didn't say the RX-8 was as good as the BRZ, just that it's more of the same cateogry as the BRZ than a 2 seat convertible with no trunk (well, not very much) and a 2,000 dollar add-on if you want a hardtop.