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need some assistance - how to improve hp and tq

1655 Views 7 Replies 5 Participants Last post by  markinaustin
I'm new to the subi world and am happy to be here. i have a 06 Forester 2.5X and I am looking for ways to improve the horse power and torque. not quite sure where to start. any opinions?
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Laughing at oneself and with others is good for the Soul
@newbaru06 I see this is your first forum post, so welcome to the forum from Oregon! :biggrin:

There's not a whole lot of untapped, low cost, power to be found in the non-turbo engine. That doesn't mean you can't improve the handling, exhaust sound, audio system or appearance. :wink:

What are your plans for the Forester... on road, off road or both? That will dictate how you proceed with suspension & tire upgrades.

Start by perusing the "stickied" threads here: EJ25 - 2.5L Non-Turbo (1998-2010)


['07 FSXT MODding Journal] ['03 X MODding Journal]
Typical response is get the XT.. Really isn't much you can do with power. Concentrate on handling stuff.
@2.5x_sleeper I'm looking to have it for both on road and off road. I'll look at the thread you sent to see what I can do with it. also is normal for it to burn a bit of oil?
If you're going off road, you don't stiffer sway bars & you'll want tires that will work off road. Lowering or low profile tires might not be a good option for going off road. :confused:

As to your engine using oil. Assuming no issues with leaking or failing head gaskets, as the miles add up, the engine will consume some oil. if you're using the recommended 5W-30, you might move to a high mileage oil. They advertise more additives in high mileage oil, designed engines with a lot of miles. Some member also move to a heavier weight oil, but that can reduce your gas mileage.

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['07 FSXT MODding Journal] ['03 X MODding Journal]
Switch to 40wt or a mixture of 30/40. Since you don't list your location (recommended)..if you are in a cold climate use 5W-40
How much oil are you using?

Synthetic typically does not smoke so that you could be burning rather than leaking oil.

Above 150K Mi. on the car, burning 2-3 qts. in 5000 mi. might be considered "normal."

Check carefully for leaks - clean the motor when it is cold and clean your garage floor. Then check for leaks later.
Increasing HP and increasing torque are two separate issues. Torque increase for pulling a small trailer or boat takes a Stage I cam as the cheapest fix and it isn't that cheap. But it is completely streetworthy, doesn't require other mods, and works. Look at the thread:

When your cat has to be replaced you could replace your cat, pipes, resonator, and muffler with 1/4" larger inside diameter parts for a noticeable lift at highway speed, and some lightly improved MPG, but with an actual loss of low RPM torque!

Many recommend the mild cam + the mild increase in exhaust piping as the sweet spot in NA mods, bang for the buck, and because each can stand alone thus allowing budgeting over time.

If you have a MT5 a modestly lightened flywheel gets you more HP to the axles but takes getting used to as RPMs drop sharply every time you depress the clutch. This can be a standalone mod as well.

And if you go for bigger pipes, which are louder, think carefully about sound damping, a great DIY project with instant rewards in making your conversations and audio experiences notably more comfortable.
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