Bolt-on HP estimates?
 

What are some good estimates the 2nd gen hp will be with all the 1st gen bolt on mods? Tune, header etc?

Do you think the 2.4 will respond better to mods?


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In all seriousness I wouldn't be surprised if the new ecu has a few tricks in it to make tuning more difficult but I'm guessing 225 whp to be possible with e85 once the bugs are worked out.

My 17' hit 186/148 wheel on 91 with catless header and tune.

Baseline was 170/133 with header on.

Thats an improvement of 9% whp and 10% wtq

170 / 205 = 0.829 so about 17% HP drivetrain loss from stock
133 / 155 = 0.858 so about 14% TQ drivetrain loss from stock

Assuming next gen has close to if not the same drivetrain loss, 228/184 equals to about 189/158. Which is pretty close to my car.

Assuming we get the same gains from NA bolt ons as last gen and add 9%whp and 10%wtq we end up with 206/180 wheel.

Its been stated that the 2nd Gen does ~195whp+ on a SAE Dynojet which is similar to a E85 on an otherwise stock Gen1. It should scoot pretty good. JDM tuners already have their hands on them and it appears the ECU is just as flexible as before.

Better? No. Just has more displacement.

The only way it would respond better is if it was more conservatively tuned, leaving room for tuning. The redline is already the same with bigger pistons. Unless they fixed springs and oiling, there probably isn’t anything left rpm wise with just bolt ons and a tune.

Did they keep the same sized throttle body? That could use a bump maybe. I wouldn’t expect much of a difference overall besides displacement. It already is a high strung motor.

They use a larger TB. I forget the size but it was over 68mm I believe.

Thanks and Grams is 72mm.

I think Irace86's point is reasonable, but at the same time even if we get similar gains out of the 2.4L it will still be a good improvement over what the 2.0L cars get with bolt-ons. I think this will be very competitive in NASA and other racing classes (which the pessimistic-side of my brain tells me that will lead to NASA furthering the handicap on the 86 platform).

Link on 195 claim?

https://www.everydaydriver.com/singl...ew-86-is-close

I am interested to see what the FI possibilities are on the new engine with more displacement but a higher compression rate.

Back when I modded my FRS in 2013 the Edelbrock kit wasn't out, that piece looks the business. I was just looking at some dyno charts for it. If I do decide to go with forced induction again, at first I was thinking about going the turbo route this time since I have more experience with turbo cars now than I did back then. But now....I would want to see what Edelbrock does with their kit first because that is a very nice, clean part that IMHO looks good in the engine bay.

It will probably be a good long wait before the tuners get really comfortable with the new engine though. I'm just speculating/rambling. :thumbsup:

Compression rate is the same as last gen. Please read the latest official press releases.

My mistake :bonk:

Still, that is even more interesting then. The 2.0 liter responded well to mods and forced induction. With more displacement + stronger rods I can't wait to see what the tuning shops can do with the 2.4.

Yeah, the Edelbrock kit almost looks stock, such a clean kit. I also like the idea of supercharger over a turbo because it retains the spirit of the car, essentially having the same power and torque feel as an NA car, just larger displacement.

Keep its NA. e85 +tune and header is all this car needs. Really gonna put the old car to shame.... hum 2 years till my next smog and it might be time for an upgrade if some of the mods carry over like brakes, suspension and wheels and tires

I think it will be a lot faster to get to reliable tunes and hardware this time around.

Another question is "why?".
The reason everyone wanted bolt on power upgrades for the first gen is that it needed more power. FA24 from the factory has more power than most NA FA20s ever made. Is it just modding for the sake of modding?

It's quite possible that a lot more people will keep the engine stock this time.

Because modding. Remember, too much power is almost enough.

Every single car lacks 50hp, even the modified one.

Figure 210-215 whp with whatever bolt ons and gas tune and maybe 225 or so on corn. That's provided that it shows around 200 whp stock.

One thing we all should know by now is to keep our money in our pockets initially and let the cream rise to the top in terms of aftermarket parts. Lots of money wasted on the first gen by owners being overzealous and purchasing absolute garbage.

Why not? It's not the chassis couldn't handle another 25-30 whp from corn/header/tune.

Just because something can be done, doesn't mean it
should be, or that most people will do it.

Sure, more power is always nice, but if there's less power deficit,
there will be fewer who invest thousands of dollars into adding power.

I'm not saying nobody is going to mod the powertrain :)

It is simply a disease. I have and will modify every car I own, cannot be helped. Rather have the power and not use it then to not have it. But my limit is reasonable reliability. For example, my 04 WRX is stage 2 etune, stock turbo, still fast but reliable. I could go big turbo, but that would lead to a blown EJ for sure. My BRZ is header and stage 2 tune, likely very reliable, would love a SC but worried about reliability. Need this BRZ for my 119 mile round trip commute 3 days a week.

Sure, maybe someone who modded their 1st gen, might think the 2nd gen is enough and either doesn't care to, or may be busy with other parts of life now to do it.
But I think the larger engine will also attract (or retain) buyers that thought the last platform was too slow to get into, and thus lure them into modding. Basically, I don't think the number of power-modded owners goes down, just shifted slightly.

It's still going to be slower than a lot of other cars and a header/tune wouldn't hurt a soul would it? :D

Yep, no cure for this one! :burnrubber:

Looks like HKS already has a supercharger ready to go
https://www.youtube.com/watch?v=uYlTbGNxktU

FWIW Monster Sport got 240hp(@6800rpms)/189tq(@5800rpms) out of their fully turned 2.4l build. That was with a catless header and a full head job (port/polish, valve job with stock cams.) Adding more aggressive cams (which weren't available at the time of the build such as the HKS or Piper ones should push the power band a bit more to the top end. Keep in mind that Japan also runs a higher octane fuel (98-100) for their premium unleaded gas than most of the west readily offers.


I wouldn't be surprised if a little tweak to the headers, and front cover's mounting bracked was the only change they had to make for their existing products to work.

Did they say the rods where stronger? I mean they could have added just enough material to compensate for the heavier pistons..


I'd be more interested in if they improved the oiling system.

Go read my post about the in depth changes to the FA24.

Just a note, Japan uses the RON method of measuring octane. The US uses AKI ((RON+MON)/2).

93 AKI = 98 RON
91 AKI = 96 RON
E85 is 94-96 AKI = 102-105 RON

So if you live in a place that has 93 octane gas, the difference between what you have at the pumps and the best pump gas in Japan is minimal. And if you have access to E85, you have even higher octane available at the pumps.

All it would take would be rod bearings similar to King's with oil slots rather than holes

So why is this engine less efficient than the FA20 anyway? Any thoughts? Less aggressive cams emphasizing more low-end?

I mean, with the same redline and a similar torque curve I’d expect a horsepower increase to be roughly equivalent to the displacement increase, which would put it at 246hp. But this engine is a full point higher in compression, yet still gets an 11% hp bump out of a 20% displacement bump? Doesn’t feel right; I thought specific output would go up, not down.

It's not, please re-read the official specs. They say 12.5:1.

The clearly prioritized the mid-range "fat" torque curve over peak horsepower.
And that was a pretty good decision, in my opinion.

Nice, I'd read somewhere awhile ago that it was 13.5:1 which might bode even worse for FI so I'm glad to hear that's not the case.


Regarding the tq curve: how is that emphasized when there's still a dip (albeit a smaller one) and even it's not a full 20% gain either? Just seems like this engine is all-around less efficient than the outgoing FA20.

Maybe I'm just grumpy because the other cars I've looked at on this search are just so much damn faster and I need to get over that, ha

Trust me, you're not the first one... :search:

It's not just more displacement, but also more air they suck in through the intake (possibly more losses?), the pistons have to be bigger (and heavier), connecting rods stronger (and heavier), the exhaust header still needs to go a weird way around the steering rack, etc.

They've put more stuff into basically the same dimensions and overall weight, so it's reasonable that they couldn't just simply achieve the same 20% gain associated with the 20% extra displacement.

It would be a different story if they created a boxer-8 FA40 by combining two FA20's together on a dyno stand :bonk:

215-220whp on pump without the car being too much louder than stock would be ideal

thats the power to weight of a E46 M3. 275whp/3400 lbs = 220whp/2800 lbs

In my defense, that 13.5:1 figure comes up A LOT in both Google and thread searches…I just didn’t read far enough through those threads to catch where it was debunked :bonk:


Re: that 220whp idea, I’d bet that will be pretty obtainable with a header and an E85 tune. If that’s your goal you should be in good shape staying NA. I don’t want to touch the exhaust and am looking for more like 260whp to match the 981 Cayman S’ power & weight, so I’m still pretty sure I’ll go FI if I get a new Twin.

Yeah, that was a Subaru PR fiasco :mad0260:

You shouldn't just go with PEAK power and PEAK torque alone.

The earlier engine sacrifices power and torque throughout the range for a couple of peaks over limited rpm ranges. Likely the new engine's cams have a bit less duration and overlap, hence broader less peaky power curve.

At hp *peak* of 7000rpm, the new 2.4 indeed only makes 11% more power vs. the 2.0 and not 20% more as displacement would suggest, all else equal. And the new 2.4's *peak* torque is only 18% more vs. the old 2.0's *peak* torque (close to but not quite 20%).

However, if you look at power and torque at the old engine's torque dip around 4000rpm, the new engine is making about 38% more power and torque there.

On average you're going to see ~20% more power and torque throughout the powerband. The peaks have been rounded off a bit, but the midrange trough has been massively filled-in. For sure they could have kept the same amount of peakiness and same power/liter, but at the expense of midrange. I would bet that actual overall performance is the same, but without the lull in the midrange.

Here's my plot of rwhp/torque of 2022 (scaled based on the dashboard readout) vs. 2017: