New FR-S BRZ Technology Info! Engine specs, CoG, Drag Coefficient, Dimensions, etc.

[serialk11r]

Maybe the CoG claim was relative to the chassis, not the ground lol. Although I guess the Miata has a pretty high looking stock ride height too.

[Slide]

Originally Posted by Dave-ROR

Doesn't that make it even more sad that even with today's technology and engineering they couldn't best that though? My primary point though was that I bet there's a fair number of cars that will beat the frs in terms of cog but we'd have to find a list, the examples I gave were just ones that I knew about and I only brought up an out of production car because the NA Miata was mentioned (I specifically didn't mention in my first post on the topic). Also the frs has no sunroof so comparing it to cars that came with them by default like the rsx-s or gsr make less sense no sunroof is great IMO though

I'm also bitter that Toyota lied about the cog.

Subaru has also lied about this.

[Aki]

Originally Posted by Deslock

That is exactly what it means.

But it's OK... with this engine/layout, we knew all along it would have struts in the front. It's not a deal breaker.

It's far too simplistic to say whether a car's supension geometry is superior just based on whether it has struts or not. Wheel rate/motion ratio, chassis rigidity, rebound/compression tuning all make an impact. In short, we can't draw any conclusions of how this car compares to a Miata or an ITR.

Dial in enough camber up front and the downside of Mac struts are compensated for, it's not that big of a deal.

[Dimman]

What if they're messing with us with these 'leaks'? The 210 hp/170 lb-ft number has also been floating around. And this 151 lb-ft with all the fancy tech and high compression is not making me super happy.

BMEP at hp peak is 185.7 psi
BMEP at torque peak is 186.6 psi

Again something is fishy. Those are very close numbers, over only 400 rpm. Weird.

Compare with the IS350's motor.

BMEP @ hp peak: 177.6 psi
BMEP @ torque peak: 196.4 psi

What if they 'mixed up' the numbers?

Say the car will actually make 210 bhp (maybe PS) @ 7000 rpm and 170 lb-ft @ 6600 rpm?

This would give us ~195 psi BMEP @ HP peak and ~210 psi BMEP at torque peak. As I've mentioned elsewhere the max BMEP is a bit less than a new Porsche 911 motor, so not super ridiculous.

Basically I think this 200/151 number is as bogus at the one that gave the 210/170 (@6500/4000).

So what do people think of this?

210 @ 7000 rpm (~195 psi BMEP)
170 lb-ft @6600 rpm (~210 psi BMEP)

Even though the BMEP drop over 400 rpm seems pretty high compared to other high-hp motors, but I still think it is more accurate than both the other figures that have nearly identical BMEP numbers for their torque and HP peaks (this DOESN'T HAPPEN).

[suprachica79]

Originally Posted by Dimman

What if they're messing with us with these 'leaks'? The 210 hp/170 lb-ft number has also been floating around. And this 151 lb-ft with all the fancy tech and high compression is not making me super happy.

BMEP at hp peak is 185.7 psi
BMEP at torque peak is 186.6 psi

Again something is fishy. Those are very close numbers, over only 400 rpm. Weird.

Compare with the IS350's motor.

BMEP @ hp peak: 177.6 psi
BMEP @ torque peak: 196.4 psi

What if they 'mixed up' the numbers?

Say the car will actually make 210 bhp (maybe PS) @ 7000 rpm and 170 lb-ft @ 6600 rpm?

This would give us ~195 psi BMEP @ HP peak and ~210 psi BMEP at torque peak. As I've mentioned elsewhere the max BMEP is a bit less than a new Porsche 911 motor, so not super ridiculous.

Basically I think this 200/151 number is as bogus at the one that gave the 210/170 (@6500/4000).

So what do people think of this?

210 @ 7000 rpm (~195 psi BMEP)
170 lb-ft @6600 rpm (~210 psi BMEP)

Even though the BMEP drop over 400 rpm seems pretty high compared to other high-hp motors, but I still think it is more accurate than both the other figures that have nearly identical BMEP numbers for their torque and HP peaks (this DOESN'T HAPPEN).

I don't have a clue what BMEP is or what you just explained, but I like 210/170 a whole lot more than 200/151

[WingsofWar]

Originally Posted by Dimman

210 @ 7000 rpm (~195 psi BMEP)
170 lb-ft @6600 rpm (~210 psi BMEP)

Even though the BMEP drop over 400 rpm seems pretty high compared to other high-hp motors, but I still think it is more accurate than both the other figures that have nearly identical BMEP numbers for their torque and HP peaks (this DOESN'T HAPPEN).

I find myself believing that number than any of the other figures floating about. Even if some of those numbers came from a brochure.

What would be trollin if Subaru and Toyota downplayed the power figures to attract a certain crowed or cheated some law or government restriction. But put it on the dyno and its shows that the engine plays a different tune than on paper.

I remember when the Nissan GTR was released and weeks later shops that had it on the dyno said that Nissan downplayed the figures upwards of 15%. It was making more power at different RPMs than said on paper. Then months later several shops with different dynos confirmed this.

[Dimman]

Originally Posted by suprachica79

I don't have a clue what BMEP is or what you just explained, but I like 210/170 a whole lot more than 200/151

BMEP is an average of all cylinder pressure (how much the pistons are getting pushed down). They are pushed down hardest at torque peak. At max power peak, they are being pushed down less hard, but more often. So it is always highest at torque peak and decreases to power peak. ALWAYS.

Both the figures that have leaked have had pretty much identical (maybe there was some math rounding errors on my part, but super damn close) BMEP numbers at the power peak and torque peak. Which doesn't happen.

So I'm calling BS on these 200/151 'leaked' numbers. The 210/170 (at the 200/151 rpm figures) are closer to a 'real' motor's BMEP output.

Not saying I'm right, just that the other ones seem wrong.

[Kostamojen]

Originally Posted by Dimman

Basically I think this 200/151 number is as bogus at the one that gave the 210/170 (@6500/4000).

Considering the FB20 is 148hp@6000rpms and 145ftlbs@4200rpms, I'd think 170ftlbs is a bit on the high side. Its rare to see a 2-liter motor to make that much torque even with 200hp.

I really hope its 210/170, but I just don't think thats going to happen. If it were a 2.2-2.5, I'd think it would be closer to those numbers.

[KaliKev]

Originally Posted by suprachica79

I don't have a clue what BMEP is or what you just explained, but I like 210/170 a whole lot more than 200/151

lol Agreed!

[Dimman]

Here are some expanded thoughts.

(And as for the torque peak of a 2.0L motor, keep in mind that Yamaha squeezed 159 lb-ft from the 3SGE BEAMS motor at 11.5:1 CR without direct injection. Also 86mm X 86mm by the way...)

Here's where my brain is at right now.

We have been given a couple of weird output figures. They are either completely off the mark (bogus) or we are being played with (reminded of Google bidding in factors of pi for some patents).

Assuming we're being played with by TMC/FHI We've basically been given two BMEP figures. ~186 psi and ~210 psi.

These would equate to the BMEP of the power peak (186 psi) and the BMEP of the torque peak (210 psi). Now working back to power and torque numbers is interesting. (and speculative, but bear with me...)

We can go back from the 210 psi to 170 lb-ft of peak torque, but we don't know where it peaks in the rev range.

As for horsepower we've been given a figure of 200 hp @ 7000 rpm ~186 psi BMEP from) and one of 210 hp @ 6500 rpm. Now if they have 'split' the BMEP leaks, this would mean that the 200 hp @ 7000 rpm is an accurate figure. It's realistic, unlike the 210 @ 6500, so I'm going to use it. Now we have an rpm figure to work with.

Going back to the 2GRFSE, it drops to 90.4% of its max BMEP at 133.33% of the rpm. Put another way its torque peak is at 75% of its power peak. And there are 1600 rpm separating the two.

With the assumptions on the FA20's BMEP figures, it drops to 88.6% of max. But over what rpm range? If we use the 75% of peak power rpm for the torque peak we get 5250 rpm, (a 1750 rpm drop), and interestingly
enough, very close to the 5252 rpm where torque and hp are identical. It is also very close to the average of the two claimed torque peaks (4000+6600)/2= 5300 rpm. Also interesting that Toyota has thrown out minimum torque output *ranges*like 90% of max from 3000-6000 rpm (or whatever the LFA-s range was).


So here is my final prediction:

Peak power of 200 hp @ 7000 rpm (from the brochure and is reasonable)

Peak torque of 170 lb-ft @ 5300 rpm (from the reviews throwing the 170 lb-ft number around plus an improvement over Yamaha's previous best, the BEAMS)

Minimum of 151 lb-ft from 4000-6600 rpm (from the high and low torque predictions, and the brochure)


Redline 7400 rpm (brochure and tacho seen in the race version)

Do I win a prize if I'm right?

[Dave-ROR]

BMEP difference at peak torque and HP will always be close if the peaks happen close to each other right? Unless torque falls off heavily which won't happen if peak HP follows peak torque within a few hundred RPM. The BMEP for the two peaks being close to each other doesn't sound off to me if the peak RPMs are correct. The ITR is about 2PSI different two with 500RPM seperating the peaks.

[Dimman]

Originally Posted by Dave-ROR

BMEP difference at peak torque and HP will always be close if the peaks happen close to each other right? Unless torque falls off heavily which won't happen if peak HP follows peak torque within a few hundred RPM. The BMEP for the two peaks being close to each other doesn't sound off to me if the peak RPMs are correct. The ITR is about 2PSI different two with 500RPM seperating the peaks.

It's not consistent with current engine designs. They are trying to separate the torque from power peak, which improves driveability. Look at more modern engines like the M3's V8, the new Porsche 3.8L, etc... and you don't see the tight rpm range between torque and power like the ITR (which was had no continuous cam phasing ability, just profiles 1 and 2). So that trend, plus the calculated BMEP peak being LESS than it was on the decade+ old BEAMS motor is what I'm basing my assumptions on. (LFA has about 1900 rpm of separation).

[tripjammer]

I predit it's going to dyno at 200 hp to the wheels!

[serialk11r]

Dimman, I think there's a problem. BMW has variable lift, Porsche has variable lift, THIS DOESN'T. The pictures show just a cam, follower/actuator, and valve. Meanwhile, D4-S is supposed to improve fuel mixing at all speeds. I think what is going on is that this engine is it is rev limited because of insufficient rod length (I calculated 1.55 rod/stroke ratio, considering that the dimensions seem similar to FB20) or something like that, and that power doesn't actually drop off that much. 170ft-lb would be 85ft-lb/L, and the 2GR is 79.4 ft-lb/L. With the same valve setup, I don't see this engine beating the 2GR out in specific torque.

Best case scenario would be this engine is underrated. 197hp is definitely very fishy, hopefully they didn't put a retarded exhaust that chokes the motor like crazy so you can opt to buy their expensive optional exhaust

And I still say they are going to add major revisions to this in a few years, unless there really is nothing that can be done about the motor being too wide to fit more stuff into the heads. I just looked at Valvematic again and I noticed that the cam sits to the side of the adjustable follower, so it actually doesn't take up too much space...if they could make the connecting rods a tiny bit longer, throw in Valvematic, this could easily make close to F20C power with 8000rpms to play with.