Subaru Boxer and Toyota D-4S Engines - FT-86 and 086a Engine

[West]

I wanted to start a thread to throw around what we know and speculate about the new Toyota FT-86 and Subaru 086a engines.

What we know:
1. Both will be based on Subaru Boxer engines
2. D-4S is a toyota technology created in 2003, and used in a few cars built by Toyota/Lexus.
3. D-4S = fuel injection system, which combines in-cylinder direct injection and intake port injection.

Not True:
1. Its not a C-45 engine as previously reported.

Toyota's current D-4S offerings:
V6, 3.5-liter, direct injection gasoline engine (2GR-FSE)
V8, 4.6-liter, gasoline engine (1UR-FSE)

So I guess Subaru's EJ could be a possibility at this point...

Please add what you know, and speculate!

[soulska]

Ej Ftw!!!!!

[Cal]

I am curious about the Turbo/NA aspect of it. To me given the WRX and STI it makes sense for the Suby version to be boosted and the Toyo to be NA. But I have been seeing the opposite speculated in the news.

[RJF]

So, has anyone seen a picture of the engine bay at the Tokyo Motor Show, or was that engine bay filled with fluffy bunnies?

I'd like to see a Turbo.

[Cal]

I would believe fluffy bunnies before turbo.

[West]

So how I understand it, it will be a Subaru engine with a Toyota head, at least in yoda flavor.

We at least saw it "drive" at the tokyo motor show, was quite possibly by fluffy bunnies. I have been harping at everyone at the Tokyo motor show to get a picture of the motor and undercarriage and run for the hills!

[dflwrx]

I'm also pretty interested to see some details as far as engine specs. Direct injection holds a tremendous amount of promise for boosted applications due to the fact that it can partially "compensate" for the tendency toward knock on pump fuel at higher boost levels.

Personally, I'd either like to see a boosted engine, or a performance minded mid displacement engine. If driveline durability is in question, we might be more likely to see a high revving NA engine than a boosted engine in order to keep torque in a more manageable range without providing too much disappointment in the power department... That's my hope at least.

As long as the power output ends up in the department of 10lb/hp or better for at least one factory model I'll be pretty pleased.

[West]

To make the car hit the mark it needs to have enough power to make it toss-able, with the suspension, small size , motor, and good distribution it sounds to be a winner even with the 200HP rumored. I just don't want to see the old AE86 that was kind of sloppy in stock form. Considering the 350Z is very drift friendly in stock form at its 3500lbs, the FT-86 should be just as good with 200HP and 2500-3000lbs.

[dflwrx]

I can definitely agree with that. I certainly don't think 10lb/hp is essential to make this a fun car. Although I have to say I'd like to see 250hp+ as a factory option for at least one model. I think it'd be nice to see enough topend power to compensate for what will likely be lackluster low end torque if it's a smaller displacement engine.

Afterall, I can't risk my wife passing me in her WRX :-P

[TheRealWRX]

turbo ej25 needs to happen.

[Artie]

Being in aftermarket business, I would like to see high rev(8500rpm) 2.0 close deck or at least semi-closed with direct injection, shimless buckets and better flowing heads. I do not like "dog leg" on subaru heads. I think headers could be better as well. If it's a turbo version I'd like to see turbo under the engine just like new Legacy. This will result in less turbo lag.

[dflwrx]

The closed deck shortblock configuration isn't much of a benefit until you hit seriously high power levels. Even the open deck subaru blocks will support 500+whp before they run into problems with cylinder wall deformation/deflection. If it's an NA motor I'd definitely want open deck or semi-closed deck for weight reduction. An NA 2.0 will have a hard time generating enough cylinder pressure to deflect the cylinder wall enough to matter.

The engine you're describing above sounds like a pretty good description of an EJ207 with direct injection, instead of a turbo

Equal length headers really would be a good improvement, so I definitely agree with that.

[Artie]

Good point dflwrx, I just know myself I would not go stock for long. With direct injection and NA version I would expect 11:1 compression, so it's little bit different then EJ20. You have a 2.0WRX, did you replaced your short block with semiclosed?

[Exitspeed]

I'd be keeping the engine stock for the most part. At least for a while so I can enjoy the car in stock form. Becuase you can never quit get that feeling back again.

[Cal]

I'd be keeping the engine stock for the most part. At least for a while so I can enjoy the car in stock form. Becuase you can never quit get that feeling back again.

So would I, well except a FMIC. I would be thinking along the lines of I don't want to mod my DD so soon. Modding is fun, reliability is king.

[dflwrx]

Good point dflwrx, I just know myself I would not go stock for long. With direct injection and NA version I would expect 11:1 compression, so it's little bit different then EJ20. You have a 2.0WRX, did you replaced your short block with semiclosed?

My car has a build Ver.8 EJ207 shortblock and Ver.5 EJ207 heads and cams


So yeah, it's semiclosed deck. I would have built an ej205, but I wanted the Ver. 8 crank since it's balanced to 10k+ rpms from the factory and is also nitrided and has additional cross drilling for improved oiling and weight reduction. That's the main reason I built the EJ207 shortblock instead of the ej205. On top of that, my car's setup to push 500whp on the road course so the semiclosed deck block is nice to have in that context. In my opinion it's the best combination of light weight, reduced cylinder wall deformation during prolonged high load use, while still maintaining the improved cooling of the open/semi-closed platform when compared to the closed deck platform.

So in short, my reason for going with the Ver. 8 EJ207 over the EJ205 was to get the crank. The block casing wasn't a big concern for me, although the semi-closed layout is obviously better at higher cylinder pressures


11:1 definitely doesn't sound like an EJ207 :-P Other cars running Direct injection in boosted applications are running Compression ratios beyond 10:1. I think it'd be pretty exciting to get something NA with 11:1 or even 12 or 13:1 compression. Both of which are realistic possibilities with DI. Exciting stuff... As I've already said, I can't wait

Imagine how clean a direct injected engine bay would look with ITB's

[freshADR]

Yeah, I would love seeing a high revving NA EJ. As much as I love boost I do miss NA.

[Artie]

NA is very good for the road racing. This is helps with smoother and faster acceleration out of corner.

[I was Imprezed]

NA is very good for the road racing. This is helps with smoother and faster acceleration out of corner.

very true... Theres other reasons Road racers perfer Natural aspiration to forced induction. N/A cars tend to be more reliable, and are cheaper to buy and maintain. With that said i think Subaru should offer both. A high revving N/A high compression motor, and for the higher classes create a twin turbo bored out ej257 or perhaps even a flat 6 twin turbo..similar to 997 turbo motor!?

[DownhillMR2]

That, sir, sounds like wishful thinking. But it does make me wonder what Subaru will do in North America. Will they produce it as an AWD Turbo, and we just won't see a RWD version at all? Or will they make both, a RWD base-trim, and an AWD "STi" style version that's a bit pricier? I just hope the Australian Subaru attitude doesn't cross borders, with it's silly "Subaru doesn't need a RWD car! We've based everything on AWD and always will!" etc.

[Artie]

^+1 With growing popularity of Subaru in road racing community it's only make sense to offer rear wheel drive car. This will help to broaden the clientele and make Subaru very competitive choice in professional motor-sport(Koni Challenge, etc).
There is also new trend growing with Gymkhana and Drifting.

[dflwrx]

I think the generalization that "NA is more popular for road racing" may be a bit misleading.

If this is being discussed for sanctioned racing series I think it's important to consider whether or not FI is actually legal and whether or not the cars using FI are forced to run restrictors. There are a lot of solutions out there to improve throttle response on FI cars, antilag and flat foot shifting are just a couple examples. Although, as mentioned previously, some series may not allow antilag... making FI relatively less attractive than NA.

I think it's important to consider the context of discussion... I think in any situation where there are not regulations limiting power output, or handicapping the FI cars to allow NA cars to compete with them, Forced induction would be almost universally preferred.

That is, in series where maximum power to weight ratio is not mandated, restrictors aren't required for forced induction vehicles, or displacement limits aren't lower for Forced Induction vehicles most teams/drivers would select to run a boosted vehicle.

That's my .02, on the other hand, as mentioned before NA is MUCH cheaper to race on average. So that's likely an important consideration for most people.

[I was Imprezed]

I think for a really talented driver boost may be better in road racing but not necissarily. I think the average driver n/a is plenty of power...remember road racing is not about hp but suspension,brakes,chasis, and last power. Keep this in mind i raced a 160hp n/a 944 spec car and posted quicker lap times than my stage 2 (220whp) WRX at Limerock. Granted that was on Potenza RE-01's and the 944 had Toyo RA-1's but the point is i had almost half the hp but more grip, better balance, better brakes, and less weight. Thats what the Toyobaru needs to be.

[dflwrx]

I think for a really talented driver boost may be better in road racing but not necissarily. I think the average driver n/a is plenty of power...remember road racing is not about hp but suspension,brakes,chasis, and last power. Keep this in mind i raced a 160hp n/a 944 spec car and posted quicker lap times than my stage 2 (220whp) WRX at Limerock. Granted that was on Potenza RE-01's and the 944 had Toyo RA-1's but the point is i had almost half the hp but more grip, better balance, better brakes, and less weight. Thats what the Toyobaru needs to be.

Well the NA vs. FI debate really has to be predicated upon the idea that other factors, mainly chassis/suspension/tires have to be held equal. A more appropriate comparison would be a similarily prepared 944 turbo vs the 944 spec car.

You definitely don't need FI to have a fun well balanced car. However, unless you're talking about NA engines making truly ludicrous amounts of power it's hard to argue that adding FI will not improve lap times with an experienced driver.

[Artie]

It's interesting how this thread turned into a discussion about what is better.

I remember when Subie Sport Magazine had a 2.5RS and built a NA engine to compete with a turbo engine, well they failed. Does it mean that NA is bad? Maybe, at least I think so.

However, looking at this past year of professional racing, NA FWD Honda Civics outperformed more powerful AWD Subarus. Subaru lap times were better, but the Civic did not have to stop for 2nd or 3rd pit stops to refuel.

In time attack or club racing it's a totally different story. You only need to be competitive for 20 minutes or less. Overheating rarely becomes a problem and tire wear is not as major of a concern. Unless of course your pushing serious power or really do not know how to drive.

Getting back to the discussion, what is most likely going to happen, I would like to post this link TOYOTA: Company > Technology > Improving the Environmental Performance of Internal Combustion Engines �\ Engine . At the bottom of the page you will find that the OEM Toyota engine has close to a 12:1 compression ratio.

[dflwrx]

At the bottom of the page you will find that the OEM Toyota engine has close to a 12:1 compression ratio.

That's my kind of production NA engine


Sorry for getting the thread off topic, I think that was mostly my doing... Thanks for getting it back on track

[West]

No new news on the FT-86 engine, so it can get off topic

[dflwrx]

Off topic post of the day: If the FT-86 engine lends itself well to high-RPM NA use, mine may need an ITB transplant

[mRodiek]

ITB sounds good to me!
Even if they offer a turbo version I think Id rather have the NA one to save money and I want the stripped down car anyway.

[Darkman]

The STi variant HAS to have the EJ257 or im not buying the car.