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Old 01-03-2011, 09:36 AM   #1
mattmak
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Default Full Exhaust and Tune - 2010 2.5i Forester

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Old 01-03-2011, 09:52 AM   #2
GEE-OTTO
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Not gonna lie those are some NICE looking ELs for the 06+ N/A Subaru's
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Old 01-03-2011, 09:55 AM   #3
Bootzy
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If you cando it to a forester WTF stops us from doing it to a impreza! 30hp is a lot for a n/a car
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Old 01-03-2011, 10:10 AM   #4
mattmak
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not sure how to interpret those numbers. from what I'm seeing the increase is 13hp at the wheels.
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Old 01-03-2011, 10:14 AM   #5
GEE-OTTO
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Quote:
Originally Posted by mattmak View Post
not sure how to interpret those numbers. from what I'm seeing the increase is 13hp at the wheels.
LOL yeah 133 - 120 = 13

However those LaChute headers are at a minimum $850

And I would NOT use MagnaFlow Straight through muffler

BUT damn it sure does look good
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Old 01-03-2011, 03:49 PM   #6
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Looks like pretty standard gains for these cars really. Free up the exhaust and tune for premium puts anyone, old or new, into the same ballpark for power numbers.

I do like that the newer motors have been geared a little bit better for top end breathing. The older designs did have an issue with torque rolling off at the top which does limit peak hp a little bit.

Lachute's making the numbers look a little pretty by showing engine power (scaled to stock rating) which is fine as long as you understand that. Frankly, the numbers are normal and equivalent to what I've seen with my 02 with mods and tuning and just as others on this forum have seen with their own work. I do think that the car would benefit a little more with a tuned header versus what looks like a turbo header copy. I would also add a phenolic spacer on the intake manifold, not that it does anything specific for heat but because it strangely adds a rather significant bump to low end torque oddly, at least on the older engines. I can't say if it would do the same with newer ones given they run a different intake manifold design, but it's worth a shot at bumping up the torque at the bottom end. The other gain there would come from a real tuned header.
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Old 01-03-2011, 04:15 PM   #7
OrbitalEllipses
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With the plastic intake manifold, I'm not sure the phenolic spacer is going to do as much as it has done on the older cast manifolds.
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Old 01-03-2011, 04:34 PM   #8
GEE-OTTO
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True the revised Ej253 has the plastic IM BUT this is a 10' from 2009 so it still has the cast aluminum IM. I imagine there aren't definitions for the New EJ253 since it is back to DOHC, probably once they hit the Impreza's we will see the new Ej253 tuning defs.
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Old 01-03-2011, 09:19 PM   #9
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Quote:
Originally Posted by OrbitalEllipses View Post
With the plastic intake manifold, I'm not sure the phenolic spacer is going to do as much as it has done on the older cast manifolds.
It's not a matter of heat. Frankly even on the old motors it didn't do much for heat. There was still heat soak from just the engine bay air that gets it hot to the touch with or without the spacer. It's more a matter of changing how the air flows between the intake manifold and heads versus simply the gasket. Oddly, at least on the older motors, it adds a considerable amount of torque to the bottom end, on the order of 20-30 lb-ft around 2000 rpm. This is what I've experienced personally through data logging my car as well as separate dyno runs. I just can't tell you why exactly. I can't say if anything will happen with the newer intake manifold design though. It's simply an avenue to test based on historical results. It may do something. It may do nothing.
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Old 01-03-2011, 11:15 PM   #10
Wrencher86
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Quote:
Originally Posted by Back Road Runner View Post
It's not a matter of heat. Frankly even on the old motors it didn't do much for heat. There was still heat soak from just the engine bay air that gets it hot to the touch with or without the spacer. It's more a matter of changing how the air flows between the intake manifold and heads versus simply the gasket. Oddly, at least on the older motors, it adds a considerable amount of torque to the bottom end, on the order of 20-30 lb-ft around 2000 rpm. This is what I've experienced personally through data logging my car as well as separate dyno runs. I just can't tell you why exactly. I can't say if anything will happen with the newer intake manifold design though. It's simply an avenue to test based on historical results. It may do something. It may do nothing.

Increased air velocity= better cylinder loading= better torque at lower RPM


That's what I've always heard, anyway. That's why a lot of manufacturers use a "tuning plate/valve" system to change the length of the intake runners.

But, I could be wrong.
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