That engine though. Where will it sit among the great 4cyl NA's?

[TylerLieberman]

Originally Posted by NoHaveMSG

We do know that it makes peak torque at 3700rpm and which could be good or bad. For street driving that would be nice.


Sent from my iPhone using Tapatalk

The additional mid range torque is promising, as is the fact that peak power is still made at like 7k, so it shouldn't fall on its face at the higher end of the revs.

But there's literally zero real world info on this engine yet. For all we know, it could be a dud when pushed, or susceptible to a bunch of reliability issues relatively early on.

I'm optimistic about it being a nice step in the right direction compared to the current unit, but I'll hold my applause and celebration until I see how this engine actually handles real world and more extreme conditions while racking up miles.

[NoHaveMSG]

Originally Posted by TylerLieberman

The additional mid range torque is promising, as is the fact that peak power is still made at like 7k, so it shouldn't fall on its face at the higher end of the revs.

But there's literally zero real world info on this engine yet. For all we know, it could be a dud when pushed, or susceptible to a bunch of reliability issues relatively early on.

I'm optimistic about it being a nice step in the right direction compared to the current unit, but I'll hold my applause and celebration until I see how this engine actually handles real world and more extreme conditions while racking up miles.

Yeah I agree. The specs look promising be the reality is we do t know anything but paper specs. I got a good laugh in the other thread where people are debating FD ratios already.


Sent from my iPhone using Tapatalk

[sato]

Originally Posted by Tcoat

It will probably be a nice engine that will probably be able to put close to 200HP to the ground on pump gas but I highly doubt a one off bastard child of a Toyota fuel system and Subaru internals and block is ever going to hit the engine museum of honour.

If only they'd talk with Yamaha...

[Baldeagle]

Originally Posted by TylerLieberman

The additional mid range torque is promising, as is the fact that peak power is still made at like 7k, so it shouldn't fall on its face at the higher end of the revs.

But there's literally zero real world info on this engine yet. For all we know, it could be a dud when pushed, or susceptible to a bunch of reliability issues relatively early on.

I'm optimistic about it being a nice step in the right direction compared to the current unit, but I'll hold my applause and celebration until I see how this engine actually handles real world and more extreme conditions while racking up miles.

I agree. Cautiously optimistic. Here is what I believe is a dyno of a stock 2.0 (units are PS and Nm). Oddly, I could not find a dyno in HP and lbs-ft. that confirmed peak torque at 6,400 rpm. Moving on, while this chart shows peak torque at 6,400 rpm, it also shows nearly that same level around 3,200 rpm.

My point for discussion is if this engine had just a few more lbs-ft (PS) of torque at 3,200 rpm, it would have achieved peak torque at 3,200 rpm. While one might initially conclude this engine has a fat mid-rpm torque curve based on peak torque occurring at 3,200 rpm, it would still possess essentially the same torque dip just a 1,000 rpm higher. With regard to the 2.4, all the feedback I’ve read or viewed on youtube videos states the 2.4 has more mid-rpm torque (3,700 rpm), which is nice, but we still do not know the shape of the curve. It might have the exact same personality, just more of it.

[Dave-ROR]

Originally Posted by Tcoat

Head units change from region to region and even model to model. There is no single head unit common to every body. Makes it confusing as hell!

And I'm not sure a good Subaru or Toyota HU even exists. Every Toyota and Subaru HU I've ever touched has been absolute rubbish.

[Dave-ROR]

Either way, once I buy a wrecked one (I'd prefer whichever of you wreck yours first, please rear end someone, front end hits are easier to fix) I'll just LS swap it and throw the FA24 in the trash.

[Tcoat]

Originally Posted by Dave-ROR

And I'm not sure a good Subaru or Toyota HU even exists. Every Toyota and Subaru HU I've ever touched has been absolute rubbish.

I could tolerate the one in the FRS. This however pure garbage.
The specs look great on paper though!

[Blighty]

Originally Posted by Tcoat

Which, not coincidently, is exactly what it was originally designed to be in the F configuration!



You really love your paper racing don't you?
By your standards of determining how effective an engine is you should be looking at diesels! Gobs and gobs of torque. More than you could ever want. Won't work worth shit in a sportscar but in the parking lots you will be the torque bragging champ!

Dude. What is your problem?

[Blighty]

Originally Posted by Baldeagle

I agree. Cautiously optimistic. Here is what I believe is a dyno of a stock 2.0 (units are PS and Nm). Oddly, I could not find a dyno in HP and lbs-ft. that confirmed peak torque at 6,400 rpm. Moving on, while this chart shows peak torque at 6,400 rpm, it also shows nearly that same level around 3,200 rpm.

My point for discussion is if this engine had just a few more lbs-ft (PS) of torque at 3,200 rpm, it would have achieved peak torque at 3,200 rpm. While one might initially conclude this engine has a fat mid-rpm torque curve based on peak torque occurring at 3,200 rpm, it would still possess essentially the same torque dip just a 1,000 rpm higher. With regard to the 2.4, all the feedback I’ve read or viewed on youtube videos states the 2.4 has more mid-rpm torque (3,700 rpm), which is nice, but we still do not know the shape of the curve. It might have the exact same personality, just more of it.

According to the actual description of that graph, its not based on final engine data.

Which you would imagine why it covers far less data points than a real dynograph.

[Blighty]

I did some quick imagine analysis on the built in graph show on the BRZ 2022.

I found that at least 95% of torque (so ~175 lbf⋅ft) begins from ~2800rpm and is available through until ~6750rpm

This is dependant on all the factory details, so without drivetrain loss - which given the tranny and diff, should be a similar amount to what we have.

Its not perfectly precise because the image quality (from the video) isn't the best and the amount of aliasing on the lines makes it a little difficult to find the center.

The method I used was simply to count the pixels between the 3 and 4k revs (using the center of the the number as the marker), using that you can work our where 3700rpm is, then counting the pixels from the bottom line to where the torque line intersects.

From there it was just a matter of drawing lines at 95% of the that length across to see what was covered. The good news is while it does waver a little, it remains above that line until the engine starts to get out of breath, basically 4k of joy right there.

[ZDan]

FWIW here's my effort at plotting my '17's dyno results (178rwhp on Dynojet) vs. the dyno plot shown on the '22 BRZ dash scaled by the same rwhp/hp factor of 178/205 = 0.87:

[Ohio Enthusiast]

Originally Posted by ZDan

Dyno chart

The part that worries me is between 6000 and 7000 RPM. The FA20 gets a bump of torque at around 6400 and barely drops at 7000. The FA24 is a down-trend torque with the big drop starting at 6800. I really like how the FA20 pulls from 5000 on and I don't think the FA24 will be as good at the top end (other than the obvious increase in peak HP, I'm referring more to the power delivery).
Still, the FA20->FA24 transition does look better than K20->K24 or FC20->FC22 (for comparable NA engines that got more displacement). Honda maintained HP, lowered peak RPM/redline and increased torque. Subaru increased HP, kept peak RPM/redline and increased torque.

[NoHaveMSG]

Originally Posted by Ohio Enthusiast

Still, the FA20->FA24 transition does look better than K20->K24 or FC20->FC22 (for comparable NA engines that got more displacement). Honda maintained HP, lowered peak RPM/redline and increased torque. Subaru increased HP, kept peak RPM/redline and increased torque.

Stock for stock yes. You put springs and retainers and a type S oil pump in a K24. Hello 8200 RPM and it can be done engine in the car in half a day.

[ZDan]

Originally Posted by Ohio Enthusiast

The part that worries me is between 6000 and 7000 RPM. The FA20 gets a bump of torque at around 6400 and barely drops at 7000. The FA24 is a down-trend torque with the big drop starting at 6800. I really like how the FA20 pulls from 5000 on and I don't think the FA24 will be as good at the top end (other than the obvious increase in peak HP, I'm referring more to the power delivery).

Don't worry... Peak power still at 7000rpm, it's not like it's falling on its face above 6800.
FWIW my friend and competitor dynoed his car at the same time I did mine, his '13 did 164rwhp, my '17 did 178rwhp. The difference was pretty much my torque increased from 5000 up, his decreased, looking a lot like the FA24 curve. Both had hp peaks at 7000. At the track I didn't really notice the difference. And neither did speed traces from data! He had a slight weight advantage, our accelerations down the big straights pretty much fell right on top of each other.

Anyway I'd way way WAY rather have FA24 torque that goes 155-154-149 rw-lb-ft from 6000-6500-7000rpm, vs. FA20's 132-137-134!

Still, the FA20->FA24 transition does look better than K20->K24 or FC20->FC22 (for comparable NA engines that got more displacement). Honda maintained HP, lowered peak RPM/redline and increased torque. Subaru increased HP, kept peak RPM/redline and increased torque.

I'm psyched that peak-power rpm is the same at 7000, and redline rpm is UP to 7500. Slightly less hp/liter at peak is a small sacrifice for a filled-in torque curve, which many will appreciate. But this will still be an engine that wants and needs to be revved to redline to extract max performance.