The ITB hype definitely showed how much interest there is in another NA option past the level of "simple" bolt-ons, but I think the result really fell short since it didn't address any of the big issues facing this platform.

Said issues (IMHO):

1. Lack of oil lubrication at high sustained G loads and/or also at high engine speeds
2. The huge drop-off of power at high engine speeds
3. The relatively low rev-limiter for a motorsports oriented application
4. The LOL torque dip (this one's pretty obvious)

Picture:
https://i.imgur.com/hnjGsQO.jpg

ITBs were supposed to address oiling and rev limit? Is this trolling, this feels like trolling.:lol:They didn't address the issue of lacking turbo either. :bellyroll:

That one more falls into the category of "general issues facing NA development of the FA20", while the rest are in directed towards the ITB shortcomings.

ITB's addressed the lack of eargasm the car so desperately cries for.

seems to me you just want to complain about other random personal issues with the motor.

This is a thread about NA development, hence why we're talking about NA development. I know people might be shocked to learn the FA20 isn't the 2nd coming of Christ, but it's still a decent engine with a lot of things to improve.

I'm racing in NASA ST5 (14:1) and really need more midrange without the expense of top end. The BMWs I race against have a powerband I cannot compete with. I have nothing for them in the straights, yet I run lower lap times. The latter does not mattter in a race, so I'm all in on extracting more from the NA motor.

Piper has had a few different camshaft profiles available for years now, unfortunately not much info out there on what results to expect.

Im not sure if its a true bolt in and drop in. but might you look at the 2.4 crank from the bigger FA motors, and then getting some hearty cam timing. something like a 270 duration should help over our puny stock cams.

that said you would have to check and recheck PTV clearances

New fa24 still uses a 86mm stroke crank like the fa20, the bore is 94mm. A new short block assembly from subaru is around 2k. https://parts.subaru.com/p/Subaru_20...0103AC95A.html
The question is what needs to be done to the fa20 head combustion chamber to match the fa24 bore, and possibly higher compression pistons if staying NA.

its one of those scenerios if i had alot of extra money. id love to check it out and play with it

its akin to sasha's 4.2 VQ motor for his Z. its so excessive but the fruits are glorious.

and id not mess with the cylinder head first. from favtory they are prety decent id worry about fueling and getting everything to work together and see what sort of power it makes and then go back in and give it more intake and exhaust and see about cam timing. compression is already phat

A good header will help auc on both sides of the peak. Aftermarket cams will introduce aftermarket problems imo.

Pretty sure the head would have to be milled to match the new bore of the cylinder walls and pistons. That would lower the compression ratio and need custom pistons. Also, our exhaust ports suck but they can be lightly ported. To be fair this has already been done on by Toda 2.3L, and Monster sports 2.4L.

Love this thread...hoping to contribute soon. Just finished removing the powerblocks(great for a stock car) and rescaling the MAF for a 3.5" Short Ram Intake. Car feels a ton better up top now, although still hard to figure the MBT without a dyno but hoping to get on one soon.

Mods:

Pump E85
HKS EL 4-2-1
2.5" Overpipe
De-Catted Front pipe
GReddy 3" Cat-back
72mm Grams TB (on the way)
Previously TRD intake w/GReddy front scoop

I think it all starts with realistic expectations.

In 2020 a N/A unopened K20a2(11.7:1 compression) on E85 still will churn the dyno to 220whp / 160wtq. That's really all we're going to get stock internals. Yes, I'm a bit biased as a Honda owner but we have to give it to them as far as all-motor R&D, limits being pushed etc. My High Comp(13.1) B20v that I'm building atm should give me around 240whp with the right cams.

It appears the FA is pretty stout, even when matched up the the JDM K20A(Crank 220hp/160tq @11.7:1). We're not far off. Subaru, Toyota, Yamaha put together a solid engine. What I would like our community to figure out is that solid "220whp setup."

I believe it'll come down to:
- E85(of course)
- 3"- 3.5" Intake
- 1st gen intake manifold
- Race Header(any de-catted will work but I think we could benefit from bigger primaries) 4-to-1 Might be ideal
- Full Exhaust(honestly, I think 2.5" will do it)
- Solid tuning

Just a matter of WHICH parts to use. We have a bunch of upgrades/parts that really just shift the power band around. Tuners like Bill have gave these things everything(witnessed when he came down to San Antonio to tune Justin's FRS). It's going to come down to the right parts application.

For example, with the Crawford Powerblocks and the 4-2-1, my Mid-range has been PHENOMENAL and a blast drive around from 2500-6500 but after that she turns into a pig, adding timing up top(2 degrees) helped a lot but (2) "mid-range power-adders" might be a bit much.

Rev'ing to 7500k puts us right at the threshold of a cast piston(4500 fpm) based on a 86mm stroke, we have to side with the engineers on this one. Getting power earlier is a good thing, we're just not getting enough air in and out & I wonder if we have anything left on the table in the form of VTC tuning. Granted, I have the turbo kit sitting in the garage(Garrett G25-550), I want to hit this damn 220, just something about scraping for every HP in an all motor setup.

I need some ideal plugs and gaps lol

The only thing that hasn't been very documented on this motor is cams and headwork. Ive only ever seen one example BUT iirc it made 200whp on 93oct equivalent gas. I think it was someone out of the UK. Important note it was running a standalone $$$$. Everything else you mentioned has been done good bad or indifferent.

Intake tracks larger than 3" aren't needed since we dont rev super high. RacerX tried it while prototyping their intake years ago.

Not sure why you chose the 1gen IM🤔 sir. In my personal experience with the black one compared to an extrude honed MY17, the red one was the clear choice.

I've run a 72mm TB in the past port matched to the IM. Easily more midrange and a little bit more top end. The MAFv increase was small enough percentage wise 3-5% in relationship to the larger area of the TB that I felt a bored over 67mm vs 65mm stock would net the same result soo that's what I currently have.

No surprise that slightly modded OEM parts are a better starting point than aftermarket I suppose.