Report: BRZ STI Model Already in the Works, No Turbocharger

[Stigmaru]

250 HP and 2700 lbs. This definitely fills the hole left by the S2000 and then some.

[Corey]

I'm waiting

[serialk11r]

Originally Posted by Soravia

Power adding can be done easily with aftermarket stuff like Rotrex supercharger. I don't see a point of paying $35K (WRX STi price) for CF roof and a few other suspension bits that can be bought better with same money from aftermarket. This will just be a halo project with sale numbers like S2000 was, the real deal will be with the base model. There's nothing exciting about these news, really.

But the fact that it'll be a quasi-S2000-replacement is exciting, because the S2000 is out of production.

It'll also make badge/status whores happy! (we all have it in us after all)

[Levi]

Even 300 PS on FA20 without FI is possible. But here were are takling about a car that should be road drivable. The torque cuvre is so flat, almost 200 Nm @ 3000-7000 RPM. Move that higher for worse daily drivability, you'd get about 230 Nm @ 5000-8.000 RPM with power about 250 PS @ 8.500 RPM. It should be doable on keeping 2.0l displacement. Increasing stroke would be better for torque and city driving, but the engine would be less rev friendly. I am not sure is there is place for increased bore.

Stroke 86 x Bore 86 = 1998 ccm
Stroke 86 x Bore 90 = 2188 ccm
Stroke 86 x Bore 92 = 2284 ccm
Stroke 86 x Bore 94 = 2387 ccm
Stroke 86 x Bore 96 = 2490 ccm

IMO 10 mm increase in bore is the max possible, but even this I doubt, is would mke the walls 5 mm thinner.

[Blitz]

Jajaja@ M-17. Anyways I probably would like some extra torque inestead. Or a good distribution of HP/Torque. Maybe an extra 20bhp, and 20Tq. Btw, they might have ment or "speculated by the journalist" 50bhp to flyweel...

[cleethree]

I'm going to guess that it'll be a 2.5L.

[Redback]

Originally Posted by Levi

Even 300 PS on FA20 without FI is possible. But here were are takling about a car that should be road drivable. The torque cuvre is so flat, almost 200 Nm @ 3000-7000 RPM. Move that higher for worse daily drivability, you'd get about 230 Nm @ 5000-8.000 RPM with power about 250 PS @ 8.500 RPM. It should be doable on keeping 2.0l displacement. Increasing stroke would be better for torque and city driving, but the engine would be less rev friendly. I am not sure is there is place for increased bore.

Stroke 86 x Bore 86 = 1998 ccm
Stroke 86 x Bore 90 = 2188 ccm
Stroke 86 x Bore 92 = 2284 ccm
Stroke 86 x Bore 94 = 2387 ccm
Stroke 86 x Bore 96 = 2490 ccm

IMO 10 mm increase in bore is the max possible, but even this I doubt, is would mke the walls 5 mm thinner.

I think you're just about right.

Take the FA20 stroke out to 90mm and the bore to 94mm (which gives it the same dimensions as the FB25) and you get 2498cc.

Assume the same specific power output for this larger "FA25" motor and you have 250hp. Not really rocket science.

Cheap, easy to do, almost no increase in weight, no exotic forged internals, no screamingly high red-line and a nice fat torque curve.

Modify the valve-timing, fit a freer exhaust and tune it for a slightly higher red-line and you'd probably get another 10-12%, - 280hp!

That's a 40% increase in power without forced induction and all the accompanying weight/heat/cost issues. Sounds pretty good to me!

[Stigmaru]

Originally Posted by Soravia

Power adding can be done easily with aftermarket stuff like Rotrex supercharger. I don't see a point of paying $35K (WRX STi price) for CF roof and a few other suspension bits that can be bought better with same money from aftermarket. This will just be a halo project with sale numbers like S2000 was, the real deal will be with the base model. There's nothing exciting about these news, really.

The point is that it's NA at 250 bhp

[switchlanez]

Wow just because the author speculated 250hp, people get fixated on boring the engine out to 2.5L. Atake only said there will be a "faster version" and only hinted at a more developed intake. With some weight reduction as well, it will be faster.

I'm not too familiar with Subaru's engine practices but is it common to make a bored out version of a base engine for mass produced cars among Japanese automakers? I would think the FA20 is set at 2.0. If they wanted more displacement they would start with a displacement figure then build an engine system around that number. It's a more sound engineering practice for an OEM.

Edit: s2k 2.0->2.2L

[old greg]

Originally Posted by switchlanez

is it common to make a bored out version of a base engine for mass produced cars among Japanese automakers?

It's very, very common.

[Lonewolf]

Originally Posted by old greg

It's very, very common.

Why would they change the bore if the whole point is the 86's lineage and history? I don't see them doing that, unless they want to slap Toyota in the face...

[OrbitalEllipses]

Originally Posted by Lonewolf

Why would they change the bore if the whole point is the 86's lineage and history? I don't see them doing that, unless they want to slap Toyota in the face...

Marketing. It's a square engine, there's room for improvement: oversquare.

[Jordo!]

Originally Posted by daiheadjai

Correct me if I'm wrong, but if there is to be a higher-strung NA version tuned for even more bHP/liter, wouldn't it make more sense to come from Toyota's engineers rather than Subaru?

Toyota does have some experience in making NA high bhp/liter engines (i.e. 2zz-ge and the LFA engine via Yamaha), but Subaru does not (traditionally more inclined to FI).

That being said, whoever does it, it would still be greatly appreciated.

And out of curiosity, while I wouldn't be surprised if the FA20 has variable valve timing, what about something like VTEC or VVTL-i?

Yamaha.

[switchlanez]

Originally Posted by old greg

It's very, very common.

Can you provide any Subaru or Toyota examples?