So, I did a little math on Subaru's new 2.0...

[Dimman]

I'm with Snaps and NESW20 on this one. It's not a power or torque curve. Using the extremes of the graph it is showing that a motor that produces 210 lb-ft will roughly need 5000 rpm to create the target 200 hp. On the other end if it produces only 115 lb-ft it will need about 9000 rpm for 200 hp.

Edit: Some more number rambling...


Now what is a good starting point for more detail? Let's look at some of the airflow to torque and power numbers produced by some relevant engines: the IS350's V6 (for Toyota's direct/port combination injection) and Subaru's 3.0L H6 (newer FHI design, and chop off two cylinders and we get a 2.0L H4).

At its torque peak the 3.5L V6 is consuming 297.6 cfm to produce 277 lb-ft (3.5L @ 4800 rpm). This gives us 1.07 cfm/lb-ft.
At its power peak the 3.5L V6 is consuming 395.4 cfm to produce 306 hp (3.5L @ 6400 rpm). This gives us 1.292 cfh/hp.

At its torque peak the 3.0L H6 is consuming 222.6 cfm to produce 215 lb-ft (3.0L @ 4200 rpm). This gives us 1.04 cfm/lb-ft.
At its power peak the 3.0L H6 is consuming 349.5 cfm to produce 245 hp (3.0L @ 6600 rpm). This gives us 1.427 cfm/hp.

Now a hypothetical 2.0L hybrid of the 3.5L V6 and the 3.0L H6 cut down. We'll spin the motor to 6600 rpm and use the 1.292 cfm/hp figure for 233 cfm (2.0L @ 6600 rpm) and 180 hp.
Now 2.0L @ 4200 rpm and 1.07 cfm/lb-ft gives 148.3 cfm and approximately 140 lb-ft.

So based on a non-Yamaha head were looking at:
2.0L with (existing tech) direct/port injection, dual VVT-i, DOHC 16V H4:
180 hp @ 6600 rpm
140 lb-ft @ 4200 rpm

This is a reasonable output to reliability number, if not quite the magic 200 hp number that we're all looking for.

What the Yamaha head would most likely do is move the efficient range of the motor up the rev range. Say its efficiency allows it to maintain the 1.292 cfm/hp up until 7200 rpm. This gives an output of about 197 hp. And hopefully keep the low rpm air velocity (and therefore torque) up.

[Matador]

^ Got the cfm figures on the 4th gen 3SGSE Beams engine?

[Dimman]

Originally Posted by MatadorRacing_F1

^ Got the cfm figures on the 4th gen 3SGSE Beams engine?

Black-Top Dual VVT-i, 11.5:1 CR version, 2.0L
207 hp @ 7600 rpm
216 Nm @ 6400 rpm (too lazy to look up how to convert to lb-ft...)

Edit for imperial: 164 lb-ft @ 6400 rpm.

207 hp @ 268.3 cfm = 1.296 cfm per hp. Teensy bit worse than the V6, but for our purposes, equal. However it is at a much higher rpm than the 3.5L V6 which is why it makes more hp to displacement.

216 Nm @ 227.2 cfm = 1.052 cfm per Nm (in imperial, somebody?)

Edit for imperial: 1.385 cfm per lb-ft This isn't great compared to the previous numbers of 1.07 or 1.04.

I'll edit this to lb-ft at a later time to better compare the torque outputs, but I'm betting the V6, thanks to the direct/port injection, is better.

Edit for imperial: So the speculation was pretty bang on. The BEAMS doesn't do too well in the torque department. The reasons for this are likely due to its lack of lift control. So at lower rpm with big lift, air intake velocity is low and combustion is impaired and it needs the higher air velocity produced from higher rpm to get good cylinder filling and combustion. Something that Valvematic could fix...

What we're looking for out of Toyota, Yamaha and new tech like Valvematic, is to allow us the high rpm efficiency such as from the BEAMS and keep the lower-rpm driveability of the 2GR-FSE or EZ30.

[Snaps]

Originally Posted by Dimman

What we're looking for out of Toyota, Yamaha and new tech like Valvematic, is to allow us the high rpm efficiency such as from the BEAMS and keep the lower-rpm driveability of the 2GR-FSE or EZ30.

Bingo, this is exactly what we need in the FT engine.... D4-S, Valvematic, Dual-VVT-I (As Valvematic can't adjust timing)!

[Matador]

Originally Posted by Snaps

Bingo, this is exactly what we need in the FT engine.... D4-S, Valvematic, Dual-VVT-I (As Valvematic can't adjust timing)!

VVT-I is an integral part of the valvematic technology package.

p.s. @ dimman, don't remember the conversion, but the beams puts out 164ft/lbs tq.

[Dimman]

An exciting thing about Valvematic is that if they decided to go with dual intake and exhaust runners per cylinder they could smoothly turn it from a 2 valve to a 4 valve as needed. This can create incredible cylinder filling potential and really throw out a lot more down-low torque.

Edited the BEAMS post (in blue) above.