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

[Matador]

Valvamatic D4-S FA20.... mmmmmmm #drools

[Ryephile]

Originally Posted by Dimman

It's not consistent with current engine designs. They are trying to separate the torque from power peak, which improves driveability.

So what's the beef? Are you concerned with the torque curve being mountainous, or dissatisfied with the rather good BMEP?

[Dimman]

Originally Posted by Ryephile

So what's the beef? Are you concerned with the torque curve being mountainous, or dissatisfied with the rather good BMEP?

Just that both figures given to us are odd, and either impossible (first one with 210 psi BMEP at both torque and power peaks) or inconsistent with current design issues (1 psi drop over 400 rpm, but only a 186is psi peak).

Compare with:

the 2GRFSE 177 psi @ power peak 6400 rpm and 196 psi @ torque peak 4800 rpm, drops over 1600 rpm.

The automatic-tuned BEAMS 3S 183 psi at power peak 7000 rpm and 197 psi at torque peak 4800 rpm, drops over 2200 rpm.

[Ryephile]

Having a tight torque and power peak isn't typical for production engines, but seems more common for Japanese designs, where high-revving is typical.

Ok, stepping into the current benchmark for n/a high-revving; the Ferrari 458 Italia. The BMEP numbers are 178 PSI @ 3250 RPM, 222 PSI @ 6000 RPM, and 183 PSI @ 9000 RPM. Those are some fantastic and even numbers given the almost 6k RPM range.

Another benchmark, the M-B SLS-AMG, has peak torque BMEP of 191 PSI @ 4750 RPM and a peak power BMEP of 173 PSI @ 6800 RPM.

For the FA20 to have a 187 PSI @ 6600 RPM and 183 PSI @ 7000 RPM is only giving a short window of its torque curve. Those BMEP figures are respectable for a modest-cost engine; they're competitive with both the Honda S2000 engines. The AP1 S2000 had a torque to power peak window of only 800 RPM, with only a 3 LbFt drop in that window. That's not too far off the 3 LbFt drop in 400 RPM the FR-S specsheet is claiming. If that torque drop is even, that would put the BMEP around 179 PSI at the 7400 RPM redline. Seems OK to me.

I'm sure we'd both like to see the full torque curve, but at this time, the two data points we have point to a respectable engine, especially considering its alleged price point.

[Dimman]

Originally Posted by Ryephile

Having a tight torque and power peak isn't typical for production engines, but seems more common for Japanese designs, where high-revving is typical.

Ok, stepping into the current benchmark for n/a high-revving; the Ferrari 458 Italia. The BMEP numbers are 178 PSI @ 3250 RPM, 222 PSI @ 6000 RPM, and 183 PSI @ 9000 RPM. Those are some fantastic and even numbers given the almost 6k RPM range.

Another benchmark, the M-B SLS-AMG, has peak torque BMEP of 191 PSI @ 4750 RPM and a peak power BMEP of 173 PSI @ 6800 RPM.

For the FA20 to have a 187 PSI @ 6600 RPM and 183 PSI @ 7000 RPM is only giving a short window of its torque curve. Those BMEP figures are respectable for a modest-cost engine; they're competitive with both the Honda S2000 engines. The AP1 S2000 had a torque to power peak window of only 800 RPM, with only a 3 LbFt drop in that window. That's not too far off the 3 LbFt drop in 400 RPM the FR-S specsheet is claiming. If that torque drop is even, that would put the BMEP around 179 PSI at the 7400 RPM redline. Seems OK to me.

I'm sure we'd both like to see the full torque curve, but at this time, the two data points we have point to a respectable engine, especially considering its alleged price point.

To me the 400 rpm range says that they threw a lot of effort at a narrow operating range window, to achieve a meh BMEP number. Look at the other Toyota numbers I put up.

Consider that the BEAMS motor is port injected, has 11.1:1 CR and kicks the ass of these hypothetical FA20 brochure motor's output. 197 bhp @ 7000 (same 200 PS) but 159 lb-ft @ 4800

Now consider that the D4-S injected 2GRFSE gains 7.5% BMEP with 3.2% more rpm at power peak and 8.2% increase in BMEP with 2.1% more rpm at torque peak, over the conventional 2GRFE.

For the BEAMS motor to hit the 210/170 number thrown around it would only need a 6.6% gain at power peak with no rpm increase (less frictional losses) and a 6.9% gain at its torque peak.

Now if Yamaha could pursue the FA20 as an extension of its 3S development, it could be entirely plausible that this thing makes 210 bhp @ 7000 rpm and 170 lb-ft @ 4800 rpm. Or they could spread it around and give us 200 bhp @ 7000 rpm and 170 lb-ft @ 4000 or something...

What basically started this thinking is that I'm suspecting that these press releases, leaks and such are deliberate mis-information.

Another thing is the 53/47 split, yet aluminum H4, firewall mounted battery and aluminum hood? Compare with a Supra's 53/47, long steel hood, long iron L6. WTF?

[Matador]

Originally Posted by Dimman

Another thing is the 53/47 split, yet aluminum H4, firewall mounted battery and aluminum hood? Compare with a Supra's 53/47, long steel hood, long iron L6. WTF?

Maybe that maybe intentional? Conventionally, I know that anywhere between 45:55 and 52:48 is "best" but... Maybe they have come up with something and intentionally done it this way? They seemed to have toyed with a distribution quite a bit, and that's what they decided on.. I guess we will eventually figure out why.

That being said, static distribution of "50:50" is often thrown around, but it really means jack shit when the car is being driven.

[Syldrin]

just curious but with this vehicle being a direct injected car does that mean lowering the comp ratio will ruin the combustion cycle? i've just heard that direct injection are difficult to change compression ratios on. please clarify. i really want this car but i don't know if i want if i am limited to my power options.

[Dimman]

Originally Posted by MatadorRacing_F1

Maybe that maybe intentional? Conventionally, I know that anywhere between 45:55 and 52:48 is "best" but... Maybe they have come up with something and intentionally done it this way? They seemed to have toyed with a distribution quite a bit, and that's what they decided on.. I guess we will eventually figure out why.

That being said, static distribution of "50:50" is often thrown around, but it really means jack shit when the car is being driven.

It's not so much the number, but the situation around the number.

With the short, rear-mounted H4 instead of the long iron L6, they needed to fight to get the distribution to 53/47 with a light hood and rearward battery?

Something isn't adding up...

[Ryephile]

Originally Posted by Dimman

To me the 400 rpm range says that they threw a lot of effort at a narrow operating range window, to achieve a meh BMEP number. Look at the other Toyota numbers I put up.

Consider that the BEAMS motor is port injected, has 11.1:1 CR and kicks the ass of these hypothetical FA20 brochure motor's output. 197 bhp @ 7000 (same 200 PS) but 159 lb-ft @ 4800

Now consider that the D4-S injected 2GRFSE gains 7.5% BMEP with 3.2% more rpm at power peak and 8.2% increase in BMEP with 2.1% more rpm at torque peak, over the conventional 2GRFE.


...............

Another thing is the 53/47 split, yet aluminum H4, firewall mounted battery and aluminum hood? Compare with a Supra's 53/47, long steel hood, long iron L6. WTF?

That's where you're making an assumption; you don't know the torque curve beyond the specified 400 RPM. For all we know, it could drop only 1 LbFt all the way down to 3k RPM. We just don't know.

Comparing engines that are in a much higher price bracket and/or never met USA emissions regulations is not playing fair. Ok, so it's a couple percent behind the 2GR-FSE in peak BMEP, IMO it's not worth getting in a tissy about.

Let's wait until the official SAE verified specs come out and then we can make rational comparisons.


Re: Weight distribution: As I'm sure Dragonitti can agree with me here; the popularly marketed "50/50" weight distribution isn't the be-all end-all to good handling. Fantastic-handling examples of heavily biased distributions include my Lotus Exige S, Porsche 911's, even MINI's and ITR's. Everyone comes up with a different answer. Formula 1 is mandated to have an approximate 46f/54r distribution. Nissan did a study for their Z back in the day [IIRC] and came up with 52f/48r being the "ideal" distribution for an FR chassis. BMW is famous for touting/bragging 50/50, yet none of their current models have very good chassis feel, though admittedly it's not the fault of the distribution. 53f/47r is totally fine. The fact they got the rear end as light as they did with an all-aluminum engine & hood means they didn't add weight to the rear-end just to go down the BMW path of false-positive advertising.

[Dimman]

Originally Posted by Ryephile

That's where you're making an assumption; you don't know the torque curve beyond the specified 400 RPM. For all we know, it could drop only 1 LbFt all the way down to 3k RPM. We just don't know.

Comparing engines that are in a much higher price bracket and/or never met USA emissions regulations is not playing fair. Ok, so it's a couple percent behind the 2GR-FSE in peak BMEP, IMO it's not worth getting in a tissy about.

Let's wait until the official SAE verified specs come out and then we can make rational comparisons.


Re: Weight distribution: As I'm sure Dragonitti can agree with me here; the popularly marketed "50/50" weight distribution isn't the be-all end-all to good handling. Fantastic-handling examples of heavily biased distributions include my Lotus Exige S, Porsche 911's, even MINI's and ITR's. Everyone comes up with a different answer. Formula 1 is mandated to have an approximate 46f/54r distribution. Nissan did a study for their Z back in the day [IIRC] and came up with 52f/48r being the "ideal" distribution for an FR chassis. BMW is famous for touting/bragging 50/50, yet none of their current models have very good chassis feel, though admittedly it's not the fault of the distribution. 53f/47r is totally fine. The fact they got the rear end as light as they did with an all-aluminum engine & hood means they didn't add weight to the rear-end just to go down the BMW path of false-positive advertising.

I disagree. The Yamaha BEAMS motor is probably the closest relevant example. Whether or not it met emissions 13 years ago hardly matters (if that, and not the Lexus/3-series fighter marketing, is in fact the reason it didn't reach NA). First, that Altezza was heralded as a spiritual successor to the AE86 as well, and second it is an 86mm X 86mm Yamaha re-work of an economy engine. Third I used the lower rated motor designed for the automatic in my example which omitted the titanium valves, and other expensive bits. Yamaha had been working on that motor since I think 1986. They've kaizen-ed the hell out of it.

From an airflow/combustion/acoustics point of view, the 86mm bore/stroke is probably more important to all of their accumulated R&D than whether it is an H4 or L4.

In the 13 years since the BEAMS was introduced, there is the chance to apply new knowledge to what has already accumulated with the 3S valve events, port and chamber design. Plus they get to work with stuff like lighter, less friction, finger followers now, that they've had on bike motors, and a more balanced layout.

What I'm getting at, is I'm calling BS that the motor's torque peak is 151 lb-ft @ 6600 rpm. But that doesn't mean it doesn't make 151 lb-ft @ 6600 rpm. Get what I'm saying?

[rmagic]

ideal weight distribution is "50/50" the center of mass is mid-way between the front and rear axles
when you building the high performance car it may not be as importuned but when you trying to build the true sport car weight distribution is one of the most important part of DNA of that car, you can see it in RX8 , S2000, Miata. when some one saying natural handling it comes mostly from the wight distribution , but it doesn't mean FRS will have a bad handling because of it , you can always trick the suspension to get the car the way you wish.

[SUB-FT86]

I have a hard time believing this engine is around 170 lb ft. I believe the guys who drove it was so excited that they forced themselves to believe it. They thought the DI would add that much more torque I bet.

[tripjammer]

Originally Posted by Ryephile

That's where you're making an assumption; you don't know the torque curve beyond the specified 400 RPM. For all we know, it could drop only 1 LbFt all the way down to 3k RPM. We just don't know.

Comparing engines that are in a much higher price bracket and/or never met USA emissions regulations is not playing fair. Ok, so it's a couple percent behind the 2GR-FSE in peak BMEP, IMO it's not worth getting in a tissy about.

Let's wait until the official SAE verified specs come out and then we can make rational comparisons.


Re: Weight distribution: As I'm sure Dragonitti can agree with me here; the popularly marketed "50/50" weight distribution isn't the be-all end-all to good handling. Fantastic-handling examples of heavily biased distributions include my Lotus Exige S, Porsche 911's, even MINI's and ITR's. Everyone comes up with a different answer. Formula 1 is mandated to have an approximate 46f/54r distribution. Nissan did a study for their Z back in the day [IIRC] and came up with 52f/48r being the "ideal" distribution for an FR chassis. BMW is famous for touting/bragging 50/50, yet none of their current models have very good chassis feel, though admittedly it's not the fault of the distribution. 53f/47r is totally fine. The fact they got the rear end as light as they did with an all-aluminum engine & hood means they didn't add weight to the rear-end just to go down the BMW path of false-positive advertising.

You da man...I like your explanations....I am learning.

[Ryephile]

Originally Posted by Dimman

I disagree.
What I'm getting at, is I'm calling BS that the motor's torque peak is 151 lb-ft @ 6600 rpm. But that doesn't mean it doesn't make 151 lb-ft @ 6600 rpm. Get what I'm saying?

Ok, so you think the spec sheet is erroneous? What grounds do you have that the torque peak is more or less than that? Are you just going off a hunch, or hope, that the peak BMEP is in the 190's "just cuz", or some assumption that there simply "must" be a noticeable delta between peak torque and peak power BMEP? I'm willing to believe you, but you're going to have to lay down something more concrete than "they did it back then with something else".

New engines are released all the time with lackluster specs despite new technology...just look at basically anything Honda has done lately. Also, discounting the ever-changing emissions regulations is at your peril, as it does make an impact to performance.

Originally Posted by rmagic

but when you trying to build the true sport car weight distribution is one of the most important part of DNA of that car

Seriously? Stop repeating what some advertisement told you. Are you saying that Ferrari, Lotus, and Porsche aren't "true sports cars"? They all have noticeably rear-biased weight distributions. That doesn't mean their polar moments aren't better [or worse] than a bloated new BMW that has a "magical" 50/50 distribution. Blurting out one spec isn't anywhere near the whole picture; go back and combine polar moments along with corner weights, CoG, fuel tank distribution, driver location, instant centers, and suspension geometries [i.e. camber curves, bump-steer, and anti-dive] to start to get a competent picture of how each car behaves. Any half-wit can get a car to balance out 50/50 static, it takes skill to make it actually handle and be communicative to the driver.