2.5L with lower revs/more torque, or 2.0L with higher revs?

[lickitysplit]

Originally Posted by diss7

Because 250hp is too much for a rwd platform to control?

(Its not)

The point, you missed it.

[jamesm]

2.0l with high revs, boost for the torque. Best of both worlds . My experience with 2.5l subaru motors suggest they're like a Chevy small block in that they're powerful, but lazy and sluggish feeling. Like a truck engine.

[ZDan]

Originally Posted by jamesm

2.0l with high revs, boost for the torque. Best of both worlds . My experience with 2.5l subaru motors suggest they're like a Chevy small block in that they're powerful, but lazy and sluggish feeling. Like a truck engine.

You've been driving the wrong Chevy smallblocks...

[diss7]

Originally Posted by lickitysplit

The point, you missed it.

No; you're making out we were talking about something else.

We're talking about 250hp. Not zomg moar power!!!!1111!11one

[radroach]

Originally Posted by jamesm

2.0l with high revs, boost for the torque. Best of both worlds . My experience with 2.5l subaru motors suggest they're like a Chevy small block in that they're powerful, but lazy and sluggish feeling. Like a truck engine.

Agreed you guys want something that sounds like an outback but even more tickkety sounding with direct injection and has slower revs?

[mad_sb]

8500 rpm 2.2 liter but i doubt it would ever happen.

[jamesm]

Originally Posted by ZDan

You've been driving the wrong Chevy smallblocks...

i know (and even said) that they make great power, that's not the problem. the problem is that, on the street, they feel sluggish. lots of power until about 4k then it just tails off to nothing at redline. makes it feel lazy. i drove a c5 corvette for a while, it was good fun, but nowhere near the experience of hitting boost in a 400+whp 2.0l 4-banger.

it's just a whole different experience. i prefer the 'pulls to the moon' feel over the 'could pull a house off it's foundation' feel.

there is one exception: the new mustang coyote engine. test drove one, it has the torque AND pulls to redline like a banshee. if i had all the money in the world, i'd pull the turbo and put one of those in the fr-s

[DarkSunrise]

Effect of the extra 0.5L displacement on weight, weight distribution, and CG? More hp or same?

[Anaxilus]

Originally Posted by Turdinator

A high revving 2.5l 4cyl would require a new engine. The Subaru FB25 has a stroke of 94mm. That is not a good start for a high revving 4cyl. Now a 2.5l 6cyl could have a nice short stroke and could be designed with a better rod:stroke ratio. I wonder how hard it would be to de-stroke the EZ30 bump the comp to 12.5:1 and add D4S injection...

^ Now you're talking. I've been wanting a destroked version of that 3.0 H6 for awhile, increase breathing and you're there. Increased displacement and increased firing cycles = Win-win. I'd be willing to pay a nice premium for that motor in an 86.

[sato]

Originally Posted by LeeMaster

I had a decade old 2.4 liter Honda engine with an RSX type s head that revved up to 8,100rpm. So obviously I choose wisely a 2.5 with more torque(That can be lego into an FA20 head or other better future aftermarket head for higher RPM).

Winner winner chicken dinner

If I remember correctly, they also used Hondata to raise the stock KA24 Rev limit from 7000rpm to 7500rpm. They use ECUTek to raise ours to more than 7400rpm... why should it hold us back from getting a 2.5L to at least 7400rpm, as the 2.0L.

[DJCarbine]

Originally Posted by sato

If I remember correctly, they also used Hondata to raise the stock KA24 Rev limit from 7000rpm to 7500rpm. They use ECUTek to raise ours to more than 7400rpm... why should it hold us back from getting a 2.5L to at least 7400rpm, as the 2.0L.

These have been reliability concerns with revving a K24 to the K20 red limit and beyond... 7400 seems safe though

There are plenty of people that go to 8K rpm with a K24 frank, but there are also cases of the bottom end giving up and I would be concerned about reliability if you rev to 8K or higher every day with a k24 bottom end

K24 spinning at 8K rpm has a piston speed of ~5200 feet per minute
K24 at 7400 rpm is at ~4800 feet per minute
k20 at 8K rpm is only going ~4500 feet per minute

The K20 has the same bore as the FA20, so piston speeds should be idendtical

Don't know what the weak point of the FA20 is though.... is it the bottom end or the valvetrain

[Admiral Ballsy]

Originally Posted by jamesm

it's just a whole different experience. i prefer the 'pulls to the moon' feel over the 'could pull a house off it's foundation' feel.

Did you even look at the dyno chart?

With the exception of the LSA, the LS engines are top-end engines; I ran into the rev limiter (6000) on my LS1 Camaro all the time. My LS7 is still pulling at 7000.

The last GM V8s that ran out at 4500 were the TPI engines last seen in 1992.

[Sonolin]

Originally Posted by Admiral Ballsy

Did you even look at the dyno chart?

With the exception of the LSA, the LS engines are top-end engines; I ran into the rev limiter (6000) on my LS1 Camaro all the time. My LS7 is still pulling at 7000.

The last GM V8s that ran out at 4500 were the TPI engines last seen in 1992.

Is that dyno with a procharger kit or something?

I keep toying with the idea of buying a used LS1 camaro and strapping a procharger kit for the drag strip. I have a lust for power that the frs doesn't satisfy, and I don't want to destroy my car getting there lol...

I'm just not so sure its worth the money & hassle thinking about it. Camaro would cost me ~7k, procharger ~8k, and supporting mods would be pushing the project close to 20k which I could've just bought a used vette or something. Decisions decisions...

[Admiral Ballsy]

Originally Posted by Sonolin

Is that dyno with a procharger kit or something?

He doesn't specify what the engine is (at least that I see); the peak speed - about 6600 - matches an LS3/LS9. LS7s go to 7100, and that's about 60HP stronger than a stock LS7.

LS3s do about 390 to the wheels, and the spin - and pull - to 6600. LS7s do another 50-60 and 500RPM on top of that. Anyone who thinks they're sluggish either hasn't driven one or DDs a Bugatti. The LS3 matches the Coyote everywhere on the curve, up to redline.