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For the Honda reference:
B18C: 87.2mm 8,900 RPM
K20A: 86mm 8,600 RPM
F20C: 84mm 9,000 RPM
I just sold my 2001 Integra Type R, so I definitely know what making power at higher RPM's is like. I shouldn't have let it go, but I had to make room for the S209!

I still have my 05 STi and I've never taken it past 6k, I just never felt the need.
 

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Discussion Starter #23 (Edited)
I just sold my 2001 Integra Type R, so I definitely know what making power at higher RPM's is like. I shouldn't have let it go, but I had to make room for the S209!

I still have my 05 STi and I've never taken it past 6k, I just never felt the need.
I hope that you got a nice amount for it! I miss the old Honda engines. I owned quite a few when I was younger:
'04 AP2 S2000
'95 Civic w/ K20a swap
'93 Civic w/ LS/VTEC turbo swap (JDM Type R head & LSD trans)

I always wanted an ITR, but knew that it was very likely to get stolen. I don't think that I could own one and just have it be a garage queen. They're way too fun to drive.

The S209 should be great, but I've heard rumors that MSRP will be around $60-65k.. and then dealer markups on top of that due to the limited production numbers. But if you have the financial resources then I'm sure you'll enjoy it!
 

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Another vote for the hatch -- my 2008 STI (minimal mods: Stage 1 93 octane map, Invidia exhaust, front and rear adjustable sways, alloy control arms, ACT clutch, etc etc -- no track time these days, only "spirited driving") is starting to rust out (sigh...New England winters will do that to cars that aren't garage queens). I'm holding on for another hatch, but if the 2021 isn't that, I'll have to consider jumping ship.
 

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For me i would like to see direct injection, bigger twin scroll turbo, ELH, active suspension, and exhaust valving. Basically an STI version of the FA24DIT. These are all really things that pretty much everyone else (other manufactures) is doing with their "performance" cars. Im indifferent about the car being a hatch or not but i would prefer a sedan. Either way, the new gen sti would have to be better and faster in all forms than my current stage 2+ GV sti for me to even consider it.
 

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Discussion Starter #26 (Edited)
Prime Motoring is swapping an Ascent FA24DIT into their Crosstrek. It should provide some insight into the FA24's capabilities for the future STI. The car previously had a FA20DIT swap with 380whp.

Prime Motoring - FA24DIT swapped Crosstrek

Mods that they've mentioned:
  • FA24DIT - oem long block w/ ARP head studs
  • STI drivetrain
  • Killer B IWG header (Equal length twin scroll)
  • FP XR Blue HTZ turbo
  • IBR TGV delete & BRZ intake manifold adapter (not yet installed)
  • Intake
They're still waiting on the IBR BRZ manifold adapter and have more tuning to do, but their baseline dyno was 462whp @ 20psi on E52.

They also disassembled another FA24DIT engine to inspect the components. Some of their comments:
We have done one clean pull with no change in tuning over the FA20DIT. 20psi made 462whp on e52 blend ethanol before we called it a day because it was getting late. Picked up power everywhere especially down low and mid range. More tuning tomorrow
[Subaru] used the FA20 as a building block to learn and grow. Every weak or inefficient point on the FA20 has been improved upon
The rods are still J shaped but way beefier
From what I can see so far, the future STI will be a great one. I was already a fan of the 2.0 but Subaru really improved on the weak areas. Also using FA24 cylinder heads and modifying them to work in an FA20 application. Only aftermarket part used was a set of ARP studs, everything else was new directly from Subaru. Goal of this is through trial and error, advance the FA platform further and give additional options to future customers. We will take it where no FA24 has been before and probably end up in many little pieces but this is the sacrifice we make for the future of Subaru performance
Keep in mind that this FA24 was designed to be the SUV version. An STI version would hopefully have more potential with stronger internals (rods, pistons, etc.), more aggressive cams, better head flow, etc.
 

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I hope that you got a nice amount for it! I miss the old Honda engines. I owned quite a few when I was younger:
'04 AP2 S2000
'95 Civic w/ K20a swap
'93 Civic w/ LS/VTEC turbo swap (JDM Type R head & LSD trans)

I always wanted an ITR, but knew that it was very likely to get stolen. I don't think that I could own one and just have it be a garage queen. They're way too fun to drive.

The S209 should be great, but I've heard rumors that MSRP will be around $60-65k.. and then dealer markups on top of that due to the limited production numbers. But if you have the financial resources then I'm sure you'll enjoy it!
I got a hell of a deal on it. I bought it for 10,500, had it for 6 years and sold it for 20k, cash.

I'm expecting 70k, knowing how shitty our dealer is her in Knoxville. My payments are gonna suck. I'm paying 550/month for my 19 Forester Sport right now. Not to mention I'm still paying on my 05 STi :lol::lol::lol:
 

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Discussion Starter #30 (Edited)
Did they baseline an ascent? Prime's dyno always reads high.

but the real question is how long will it last.
They didn't provide a baseline for an Ascent, but commented that they're using the same tune from their previous FA20 swap which made 380whp. I haven't found a detailed mod list of everything that the FA20 had, but it looks like that number may have been on the stock turbo.

It'll be interesting to see how long things hold up, especially given the larger bore/pistons (94mm vs 86mm). At least they'll find the weak point :)

Edit: Looking at some of their ethanol tuned FA20s, their dyno does seem to read a bit high.. maybe 10-20 whp (rough estimate) compared to some other dynos that I've seen with comparable mods. I've certainly seen much higher reading dynos though. Either way, it's an impressive number before any real tuning has taken place.

I'm mainly glad to see that Subaru improved the rods compared to the FA20 :) With FBO, stock turbo FA20s already pushing 350-400 whp on ethanol, I'm betting that we'll see the next gen STI push 400+ whp on the stock turbo with ethanol and minimal mods.
 

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if they put an vape-detector ejection seat that launched any clown vaping in their subaru, i'd pay money for that.

I'd also pay for bolt-on boobs.
 

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Discussion Starter #32 (Edited)
Update on Prime Motoring's 500+ whp FA24DIT build in their Crosstrek.

Mods:
  • FA24DIT - OEM Ascent long block w/ ARP head studs
  • STI drivetrain
  • FP XR Blue HTZ ball bearing turbo
  • Killer B IWG header
  • Stock WRX ecu w/ Cobb AP
  • Cobb Flex Fuel Kit (stock injectors & HPFP)
  • Cobb EBCS
  • Cobb FMIC
  • Cobb Intake
  • Invidia J pipe
  • Custom catback
  • IBR TGV delete & BRZ intake manifold adapter kit (not yet installed)
  • Non-power related: OEM STI 19" wheels, STI Type RA Brembos & Recaro seats
Tuned by JR: Made 502whp/484 lb-ft @ 22.1psi before they then ran out of fuel. They're still in the process of mocking up the IBR BRZ manifold kit. Next up, waiting on speed density & port injection tuning options.

Look at the monster torque on this thing. 300 lb-ft @ ~2800 rpm, 400 lb-ft @ ~3200 rpm, 480 lb-ft @ ~4000 rpm. Peak power (502 whp) @ ~6200 rpm (torque still at 420 lb-ft). I'm betting the IBR BRZ manifold kit will help carry the power a bit higher up. They commented that they limited the torque down low because they don't know the limits of the rods yet.



Prime Motoring; said:
Update on my FA24 swap. JrTuned and I have been working tirelessly these last 3 days etuning and figuring out little nuisances with this motor. Unfortunately we are out of fuel and at the limits of the MAF so we can not push further for now but happy to have hit the 500whp on a completely stock motor and only 22.1 psi. The most remarkable thing about it is i counted the amount of pulls we have made these last few days and this thing has seen 56 dyno pulls, in some terrible humidity ALL at 460+ whp & 460+ wtq and many with some very nasty break ups and misfires as he dialed in this thing. No break in whatsoever, right on the dyno, straight to ethanol, still on the original non synthetic oil, it has not left those rollers and has not skipped a beat. Tested after and 235psi compression & under 5% leakdown across each cylinder. Color me impressed with this engine. It has me looking very forward to the next gen STI. Now simply waiting on COBB Speed Density software and/or some port injection to further test the limits of the stock engine. IBR sent me mockup adapters for the BRZ manifold and they arrived today so all thats in the works. I want to see where we can take this stock motor to so we have a leg up come time the next gen STI is released. Exciting times ahead.

Mods again for those new to this. 2014 Crosstrek swapped as a 2017 WRX. FA24DIT ascent engine adapted in with stock WRX ecu. FP Blue XR ball bearing turbo, Killer B IWG header, Cobb Intake, Cobb FMIC, Cobb EBCS, Cobb Flex Fuel, Invidia J Pipe, Custom catback & STI 6speed transmission
This certainly looks promising for the next gen STI if it receives a version of the FA24. If not, just have Prime Motoring build you a FA24 swapped Crosstrek with the existing STI drivetrain :) You get a modern 2.4L engine, 6 speed STI drivetrain & the hatchback that everyone wants.

It'll be interesting to see how long things hold up, especially given the larger bore/pistons (94mm vs 86mm). At least they'll explore the limits and find the weak point for everyone else :)

Prime Motoring - Update on my FA24 swap. JrTuned and I... | Facebook

Subaru Ascent FA24DIT Swapped Crosstrek First Start! - YouTube
 

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Discussion Starter #35 (Edited)
Keep in mind that these are still rumors and specs for the JDM models. It's still possible that the USDM WRX will keep the FA20 and the STI will get the FA24 since both engines are already certified in the US. It would be like Japan getting the EJ207 and the US getting the EJ257 since Americans love torque and "bigger is better".

Even then I would expect the next STI to have between 310-341 hp. I don't think Subaru will immediately outdo the S209's power figure.

The advantage to the FA engine is that it has a broader torque curve (thanks to the EL header, twin scroll turbo, higher compression, etc.) and responds better to bolt-ons & ethanol. The WRX's FA20 already makes 320+ whp with a "stage 1 flex fuel tune" with everything else being mechanically stock (just an AccessPort, flex fuel kit & tune). I'm guessing an STI version will be capable of at least 350 whp with a similar setup.

Not to mention the improved fuel economy as an added bonus. I got better fuel economy in my '16 WRX running E50 than I do in my stock '19 STI :)

Subaru has the potential to make a great car.. only time will tell if they actually do..
 

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Discussion Starter #36
Aftermarket development for the FA engine seems to be advancing in anticipation that the next gen STI receives a better version of the FA20/FA24.

IBR has developed 2 new products:

A "stage 1" HPFP that replaces some internal components of the stock HPFP. IBR's stage 1 should add a bit more pressure and flow to push the stock injectors further and allow for more power. The injectors are the next fuel bottleneck. The stock HPFP and injector combination seems to run out of steam around 500whp on ethanol. Unfortunately, it looks like IBR is having issues with the pumps sticking. Price is $300 (when in stock).


A modular intake manifold that is certainly unique looking. The red portion adds plenum space over top large velocity stacks. The manifold provides "shower-style" port injection into the top of the bell mouth to get the most phase change and cooling benefits from ethanol for the intake charge. This should provide good gains over their BRZ intake manifold kit. Price is estimated at $1,499 (ETA is 2 months).

The shower-style fuel injection is popular in motorcycles and F1 engines. By injecting the fuel at the top of the the plenum it allows for more time to cool the intake charge and better fuel atomization (air/fuel mixing). The cooler, more atomized intake charge should provide better combustion, more power and less pre-ignition/detonation.







 
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