Prime Motoring's FA24DIT 500+ whp build (stock block)

[WRXnick16]

Prime Motoring has swapped an Ascent FA24DIT into their Crosstrek. Their goal is to gain insight into the FA24's capabilities and get ahead of the learning curve for the next gen STI (assuming it gets a version of the FA24DIT). The car previously had a FA20DIT swap with 380whp.

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
• IAG AOS
• IBR TGV delete & BRZ intake manifold adapter kit (not yet installed)
• IBR HPFP (not yet installed)
• Non-power related: OEM STI 19" wheels, STI Type RA Brembos & Recaro seats

Tuned by JR: 502whp/484 lb-ft @ 22.1psi before they ran out of fuel. They're still in the process of mocking up the IBR BRZ manifold kit. They'll also be installing IBR's HPFP.

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.

https://i.imgur.com/3LgmgL1.jpg

They also disassembled another FA24DIT engine to inspect the components. Some of their comments:

Originally Posted by Prime Motoring;

[Subaru] used the FA20 as a building block to learn and grow. Every weak or inefficient point on the FA20 has been improved upon

Originally Posted by Prime Motoring;

The rods are still J shaped but way beefier

Originally Posted by Prime Motoring;

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

Originally Posted by Prime Motoring;

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

Keep in mind that this FA24 was designed as the SUV version. An STI version would hopefully have more potential with stronger internals (rods, pistons, etc.), more aggressive cams, better head flow, etc.

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

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[mamock116]

very cool, thank you for sharing.

[Schoat333]

Thank you to whoever wrecked that Ascent, or did they buy the engine from Subaru? lol

[alapilusa]

Originally Posted by Schoat333

Thank you to whoever wrecked that Ascent, or did they buy the engine from Subaru? lol

I think they used a wrecked ascent motor for mock up, but bought everything new from subaru for the one thats in the car now.

[WRXnick16]

Originally Posted by alapilusa

I think they used a wrecked ascent motor for mock up, but bought everything new from subaru for the one thats in the car now.

Yep, they disassembled the FA24 from the wrecked ascent to learn about the FA24 internals. They purchased a new engine from Subaru to install in the Crosstrek.

[jasonwrx86]

I want to see at least 350hp on the new STi with the 2.4L

[Stronkadonk]

Tbh might wait to build my broke ass car and see if the 2.4 can handle the power I want to achieve. 👀

[gn4rwhals]

Originally Posted by Stronkadonk

Tbh might wait to build my broke ass car and see if the 2.4 can handle the power I want to achieve. 👀

Just E85 the FA20DIT and call it good, then buy this when it comes out.

[WrightWRX]

That’s very neat. Looks like I’ll hold off on modding my FA20 more and wait to see what the FA24 can do.

[Straight6]

YouTube

YouTube

[blackseafleet]

sign me up. I was about to trade my wrx for a used crosstrek to fit my dogs. now I definitely want to.

[rexster]

Originally Posted by WRXnick16

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.

The block will most definitely be the same. A different turbo, intercooler and exhaust. Maybe revised intake and manifold, maybe some small valve train changes, but I doubt it. They’re not going to take the time to make forged internals or an 8k screamer engine for such a low volume car.

[WRXnick16]

Originally Posted by rexster

The block will most definitely be the same. A different turbo, intercooler and exhaust. Maybe revised intake and manifold, maybe some small valve train changes, but I doubt it. They’re not going to take the time to make forged internals or an 8k screamer engine for such a low volume car.

Agreed. Definitely no forged internals and probably a redline around 7k rpm.

[Stronkadonk]

Originally Posted by gn4rwhals

Just E85 the FA20DIT and call it good, then buy this when it comes out.

I already maxed & surpassed the stock block's limits 💀

[gn4rwhals]

Originally Posted by Stronkadonk

I already maxed & surpassed the stock block's limits 💀

Nice.

[WRXnick16]

Will update the original post shortly.

502whp/484 lb-ft @ 22.1psi and ran out of fuel. Still in the process of mocking up the IBR BRZ manifold kit.

Next up, waiting on speed density & port injection tuning software.

Originally Posted by Prime Motoring;

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 but happy to have hit the 500whp on a completely stock motor and only 22.1psi. 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 before and once again tested after, 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. @ibuildracecars 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.

[WRXnick16]

A lot of people have been asking them why they didn't go with an EWG setup and the Nostrum HPFP for more power.

Originally Posted by Prime Motoring;

The Nostrum pump does fit but we had bad luck with ours. It seized right out of the box.

Originally Posted by Prime Motoring;

No EWG - I still drive it often and hate the sound

[Straight6]

That's already 100 whp more than what FA20DIT can handle on stock internals and way more torque. These FA motors are a game changer. The next STi is going to be an absolute beast.

[2slofouru]

Direct injection is a major advantage.

[Joey B 18c]

this is awesome! thumbs up to Prime

[Stronkadonk]

Originally Posted by WRXnick16

A lot of people have been asking them why they didn't go with an EWG setup and the Nostrum HPFP for more power.

The FA20 HPFP has a different part number than the FA24 HPFP so that's the likely issue there.
As far as boost control, the internal option that comes with that turbo is pretty solid and has shown to hold up making even more power i.e. when Clark was testing out the Nostrum HPFP on a WRX. Maybe they just wanted to hold off for now since they're still testing everything out for now?

[WRXnick16]

Originally Posted by Stronkadonk

The FA20 HPFP has a different part number than the FA24 HPFP so that's the likely issue there.
As far as boost control, the internal option that comes with that turbo is pretty solid and has shown to hold up making even more power i.e. when Clark was testing out the Nostrum HPFP on a WRX. Maybe they just wanted to hold off for now since they're still testing everything out for now?

They experienced their issue with the Nostrum HPFP on their FA20. That made them hesitant to try it on the FA24.

[WRXnick16]

They'll be going with IBR's HPFP instead of Nostrum.

[dankor]

i guess this means i should keep my eyes open for ascent longblocks

[gn4rwhals]

Originally Posted by WRXnick16

They'll be going with IBR's HPFP instead of Nostrum.

Everyone should, the pump quality is highly suspect for what they charge for one.