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Discussion Starter #1
Faster Acceleration???

The reason why there is so little news from SOA is that they are facing major difficulties trying to make the 2.0 liter engine run under US gas emissions (especially CA). The problem comes from the gasoline being too different here (compared to Japan and EU).

They are looking at the option of building a 2.2 liter for the "US STi" version that would develop around 275HP.
 

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I'm not trying to be funny or condescending but isn't the WRX engine 2.0 liters. I know the WRX and STi engines are different but are they that different? Also the WRX engine is pumping out 227 HP stock but we all know it's capable of more and on US gas at that. Couldn't they just throw in another cat and bump up the boost to keep things even?
 

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With the increased boost, you risk detonation. To avoid detonation, you spray in more fuel. You spray in more fuel, you get more unburned fuel. Slapping on another cat and adding more boost is counterproductive. I can believe that to get the big HP numbers, they'd try to use a 2.2L engine. The American public is not concerned with how well a car handles, they like big sexy HP numbers, low 0-60 times, low 1/4 mile times, etc. I just hope they don't ruin the car with the extra weight in the front.

-WRCFocus
 

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It seems realistic to me as well. In other words, I wouldn't be completely shocked if SOA uses something larger than the 2.0L engine in the STi. Since US emissions are based on the displacement of the cylinder block, getting large HP numbers out of a relatively small engine AND staying emissions complient gets very difficult.

Assuming 275 HP and a 2.0L engine, that equals 137.5 HP/Liter. That's an insanely high number. That would be higher than any US production car ever (including cars like Porsche Turbo and Audi TT Roadster). Take 275 HP and a 2.2L and you get 125 HP/Liter, which is about what the TT does.

Just like WRCFocus said, the more HP you try to squeeze out of an engine the more leftovers you have coming out the tailpipe. It's easy to make the WRX get more than 227 HP. It's not easy (or cheap) to do that and pass emissions.
 

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Other ways to speed up turbo

WRCFocus said:
.... I just hope they don't ruin the car with the extra weight in the front.-WRCFocus
I don't belive there is any additional weight to the equation. Isn't a 2.2L just a punched and stroked 2.0L engine? Pls correct me if incorrect!
 

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I certainly hope you're correct Albert. That would seem to make the most sense, too. It seems odd to build a 2.2L engine, figure out how to shoehorn it in, redo the plumbing, etc.

-WRCFocus
 

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Even if it is a different block, the 2.2L engine would still fit pretty easily. The Impreza RS has the same size engine bay and the 2.5L engine.
 

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I don't think they would just punch the block bigger. Would they not need to modify the block to accommodate the stresses which are greater than those in the WRX and likely not a heck of a lot lower than in the current STi. Additionally, there's more moving weight (the bigger pistons), so would a driver in this most finely-calibrated machine notice it more than the driver of an RS?
 

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More on hybrids

You can get to 2.2L without changing the bore. If they increase only the stroke, like with a different crank, there's no need for bigger pistons. All the aftermarket "stroker" kits out there do it this way, even if they may have a very slight overbore to accomodate their own pistons. If they bore it out, cylinder wall thickness decreases and stress will increase.

Using a longer stroke won't make the engine any heavier. What will happen is you'll probably get a significant boost in low-down torque, moderate HP increases, and you'll lose some potential for really high rev limits. (The Dahlback Golf was actually destroked from 2.3 down to 2.1 because the thing can spin faster when the piston doesn't have to travel as far. The result: a 10,500 redline. Same deal with F1; low displacement, ridiculous RPMs.)

But I wouldn't mind at all. A bigger engine can accomodate a bigger turbo for a given level of lag. More power potential, baby!

Chobos
 

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a mirror

I'm still confused about how you'd get more low-down torque if you don't change the bore. With a longer stroke, you need to put the piston's point of contact further out from the camshaft, no? Increasing the distance to the torque's axis means you get a lesser force.
I know that the cams are just bumps, so they'd have to be more pronounced, right? Would the steeper slope on the cam's profile not make it harder to push up on the piston's butt end?

Also, a greater stroke at a given rev speed means more friction in the cylinder, so what effect(s) would that have? More heat?
 

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You're getting increased torque from the increased displacement. It doesn't matter how you get there (bore and/or stroke). For each revolution, you're simply pushing more air/fuel.

TiTaNiuM sAMuRai said:
With a longer stroke, you need to put the piston's point of contact further out from the camshaft, no? Increasing the distance to the torque's axis means you get a lesser force.
I know that the cams are just bumps, so they'd have to be more pronounced, right? Would the steeper slope on the cam's profile not make it harder to push up on the piston's butt end?
This has nothing to do with the cams. We're talking bottom end only. It's the crank that gets modified, and maybe the length of the connecting rods.

Also, a greater stroke at a given rev speed means more friction in the cylinder, so what effect(s) would that have? More heat?
Perhaps... but a greater bore at a given RPM gives you the same issue. The bigger piston has more surface area. And to some extent, the advantages would be offset by the fact that you're pushing heavier hardware.

Chobos
 

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Discussion Starter #15
spec c type ra

I think I rather have the 2.0L engine with less horse power. Then the sti will pass emission, but still have the potential to extract savage hp(just get some stock jdm parts). I mean, who the hell is going to leave a sti stock anyways, people now a days put at least a intake kit in their car regardless what the hell their car is. Most importantly, less hp = lower MSRP :lol:
 

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Discussion Starter #16
I have been reading all of these topics for weeks now. I was considering buying a wrx, but I see myself modifying it within a short time of owning it. What kinds of parts will violate emission standards? People tell me that the up-pipes wont pose a problem, but they also say its illegal to modify that. Nobody here (Delaware) checks under the hood of your car. I'm wondering if such modifications will fail emissions checks. Does anyone here have any related experience?


227 is NOT bad in a car that is agile enough. I'm more concerned with the handling than reaching 60mph in 3s. I agree that Americans are too concerned with big HP and 1/4 mile times. I want to see what those Camero's do when they have to bank left in the rain!

Another question... what kinds of extra wear do these modifications do to the engine/drivetrain? Do we destroy engine lifetime by replacing certain parts? 8:1 compression is actually pretty low for a 4cyl.


thanks
jeremy
 

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Emissions regulations really vary state-to-state and even station to station. It all depends on what your state regulates and what you feel you can get passed. The up-pipe, which is a popular WRX upgrade, is technically illegal in most states because it removes one of the cats from the system. Almost every up-pipe is sold with a disclaimer that says, "For off-road use only". Does this mean that no ones uses them on the street? Of course not. But it is something you can get nailed on if your state is more stringent or your inspector is on the ball.

Generally speaking, anything that effects emissions cannot be removed legally. This includes cats, smog pumps, breathers, etc.

Also, any performance mod will put more strain on the engine and will technically make it wear faster. How much faster is determined by the extent of the mods and the engine you are starting with. Most Subaru engines are pretty well built and can be modified without too many problems. However, poorly thought out or mismatched mods can detroy even the best engine. The key is using reputable sources and engineered kits that are designed to work together. The reason the WRX has a low compression ratio is because of the turbocharger. The lower pressure helps prevent detonation and excessive wear. All turbocharged vehicles have lower compression as compared to their normally asprirated counterparts.

Hope this helps.

J.B.
http://www.wrxtra.com
 

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Discussion Starter #18
Yeah, thats helps me out, and makes a bit of sense. I've never owned a car that was worth driving. I want to buy a WRX really bad. Modifying it just seems natural for this type of car. I couldnt imagine what 265hp would feel like in a car that small and with AWD.... I just could not imagine.


jw
 

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No Way

Ok, I know in Europe emissions are pretty tough. If anything they will easily be able to use the EJ20 engine even in California..they just might have to decrease power in CA or through out all of the states. Speculation of not offering the 2.0 liter is ridiculous b/c what else would they use? a 1.8, a 2.2??

We'll get the 2.0, but we may(probably won't) get the 276+ hp in JDM form. My guess is right at 270. I figure the Euro STi has 261 hp..their WRX has 218. The 227 from our WRX minus the 218 from the Euro-WRX is 9hp. Add 9 hp to the 261 current hp on the Euro STi..voila..270. Of course, I, myself am also speculating..

:lol:
 
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