JDM STI EJ25 can rev to 8000, why can't we?
 

I'm rather new to Subaru so forgive my question if it's overly easy to answer. I was watching some good 'ole Best Motoring shootout videos last night and one had the "new" STI wagon and an GD STI sedan vs some Evos and the like. I noticed that both STIs had an 8K redline and I wondered why Subaru stopped at 7500 with ours?

I think an 8K redline would have been a great marketing tool on it's own and possibly allowed for better 0-60 times as noted buy the guys who gained 500 rpm in a reflash.

*Note: I think I figured it out while typing this out. Both of those cars are STIs, ours is not. I'm assuming one of the selling points of the BRZ STI will be a higher rpm limit.

No use having higher redline if the engine isn't making power anymore. OEM can't really tune it the way aftermarket does either.

because engine tuning isn't as simple as increasing the redline. you need stronger components to support the increased load. imagine moving your arm in a punching motion; the faster you move it (increasing RPM), the quicker your arm gets tired. that's basically what the piston is doing.

the simple answer to your question is cost. stronger engine internals will cost more, which means the price of the car will increase.

because the JDM STI engine is 1998cc with forged pistons.

Yeah it's a 2L engine with heads with all of the parts needed to run up to a 8000 RPM redline.

The JDM EJ207 has been using cast pistons for years now.

Don from Accelerated performance is running 9K rpm with his Turbo kit.

I understand the principle, I've been building engines with my dad since I was 12. I guess I was wondering more about if there was something specifically boxer relayed that made revving high hard to do. The 23k Civic Si revved to 8K with their 2.0 and I would imagine out internals could handle 8k.

Don't most of the tunes raise the redline?

We can rev well past 8k, you just need the power up top to make it actually worth it.

Missed this, on my phone. Makes sense.

Something like that, and generally speaking, yes.

He has to - all that power from that BRZ 400 kit is up at the very top I would imagine. :) That said, while it runs on "stock everything", how long it lasts is another. Which is another reason why RPM is down - for longevity and all things equal, a shot at factory warranty. Besides, with the stock setup, you're not getting more power past 6500 - 7000RPM anyways.

My 2 cents...