Engine technology thread.

[Dimman]

Originally Posted by Kostamojen

No TGV's on this motor. The new DI turbo motor next to it is however, which is rather interesting.

Hmmm, intake runners look enormous compared to the exhaust primaries. Any idea how thick the plastic is on the manifolds?

[old greg]

Originally Posted by Dimman

In the side view, when they come off the plenum they look narrow, but they flare out to quite wide towards the head where the port injectors are.

The runners are fairly tall/narrow up near the plenum, but Subaru heads typically have short/wide intake ports. My guess is that the cross-sectional area is constant, it's just that the geometry is changing to match up with the shape of the intake ports.

[Marrk]

Don't know if this is of interest to anyone:

Honda Previews New Engine Lineup: Direct Injection and CVTs Coming

http://www.autoguide.com/auto-news/2...ts-coming.html

[Ryephile]

Well Dimman, now that all three cars have been revealed, and 197 HP @ 7k RPM and 151 LbFt @ 6600 RPM are the numbers consistent across all three [ok, Scion is saying 200 HP @ 7K RPM], it looks less likely that your hidden torque theory will pan out.

Of course, the real story will come when people start putting the cars on known-quantity dynos. The OEM trend lately is to markedly underrate the engine, that way even the worst and most ignorant break-in regiment [i.e. following BMW's guidelines] will result in advertised power & torque.

[Dimman]

Originally Posted by Ryephile

Well Dimman, now that all three cars have been revealed, and 197 HP @ 7k RPM and 151 LbFt @ 6600 RPM are the numbers consistent across all three [ok, Scion is saying 200 HP @ 7K RPM], it looks less likely that your hidden torque theory will pan out.

Of course, the real story will come when people start putting the cars on known-quantity dynos. The OEM trend lately is to markedly underrate the engine, that way even the worst and most ignorant break-in regiment [i.e. following BMW's guidelines] will result in advertised power & torque.

I have been noticing that my missing torque seems nowhere to be found in the official documentation. But I am still looking for it! Just more quietly and humble-like maybe...

The key for me is that every single document about power production seems to indicate that there is a distinctive and fairly consistent intake airflow-speed difference between torque peak and power. It has to do with turbulence within the combustion chamber. It is backed up by looking at other production motors. This is where the TINY rpm difference confounds me. This is anomalous.

A possible explanation would be where the intake/exhaust reversion would be causing flat spots in the mid-range which is often one of the trade-offs for chasing high-rpm power/torque. But this leads to the problem of the lowish-peak. And the fact that 7400 rpm redline is hardly astronomical.

With the combustion benefits of the D4-S, and the huge (more than a 2000 Ferrari F1 engine) compression ratio, 151-lb-ft seems terrible. Especially in comparison to previous and current Toyota engines (3SGE BEAMS and 2GRFSE).

I didn't just arbitrarily decide that 151 at 6600 sucks...

[serialk11r]

I think no one disagrees that the output figures suck, but I don't think your theory explains it.

@ Marrk hmmm so no word of AVTEC whatsoever. I guess they ditched it? Good to see Honda attempting a comeback but I guess we'll need to wait and see how this turns out.

[Syldrin]

does anyone know if the unlocked ecu made it in to the production car or not?

[Ryephile]

Originally Posted by Dimman

I didn't just arbitrarily decide that 151 at 6600 sucks...

I know you didn't, but without knowing the rest of the torque curve, it's all speculation. If the torque curve ends up being a shelf of 150.4 LbFt from 3500 to 6500, will that seem rational to you?


Separately:
I just wanted to put this attachment somewhere, I was playing with Chrome's Awesome Screenshot plug-in. The photo is from the Scion FR-S press release from yesterday. This is the best chance we've had to date in seeing a production North American engine bay. Note they photoshopped the red body color in, the silver paint is missing on the letters on the intake manifold cover, and the wiring and brake lines are much cleaner with a left-hand drive car.

[Syldrin]

are those the fender liners? by the strut housing?

[old greg]

Originally Posted by syldrin

are those the fender liners? by the strut housing?

The black plastic things? Yes.

[Syldrin]

wtf...... why leave it open? seems..... flimsy

[serialk11r]

Hmmm reading cyde01's comment in another thread about how the D-4S system is the next gen system and how they were apprehensive about sharing it with Subaru...I take back what I said about this engine being disappointing because they didn't have time to make it as good as possible. New theory: the engine sucks because Toyota didn't want to share all of their tech with Subaru, and it is not very likely a revised engine will come out. Well this seems disappointing.

[Snaps]

wtf...... why leave it open? seems..... flimsy

Save weight? Maybe with a modern chassis it doesn't add much strength having it covered.

Most of the reviews have been raving about the chassis...

[mines13]

Originally Posted by Snaps

Save weight? Maybe with a modern chassis it doesn't add much strength having it covered.

Most of the reviews have been raving about the chassis...

this.