2009 Subaru Impreza 2.5i Sport
Rear Wheel Drive Conversion


How To guide to Disable Daytime Running Lights

Can I modify my car to get more horsepower from the Subaru 2.5 liter normally aspirated engine?

Most auto enthusiasts want more power from their cars. In the past, there was some pretty easy gains to be made with better air intakes, better exhaust systems, camshaft changes, and other items. However, today's vehicle engines are pretty much optimized from the factory. There may be some small gains to be had but it is a lot harder now. And in some cases, the aftermarket systems actually reduce power. Granted, forced induction (turbo and supercharged) motors CAN get significant power gains with relatively low cost modifications.

In the case of the Subaru 2.5 engine, if you want more power, than the best approach is to buy a WRX. The turbo WRX makes much more power than the plain old 2.5i and it can be modified to make a LOT more. So if you want lots of power: sell the normally aspirated car and get a turbo car.

So can anything be done to make the normally aspirated Subaru's faster???

Yes, you can make the car faster. Since getting more power from the engine itself not practical we need another approach.

And that is:

Make the car lighter!

Making the car lighter:

Making the car lighter is an all around good thing. Will it ever be as fast as a WRX? Not accelerating. But it will stop quicker and handle better than a stock weight WRX. Of course, a lightened WRX will be even faster! But a lightened normally aspirated car can be faster than stock, more fun to drive, and save gas.

So what can be done to make it lighter? OK, some ground rules.

There is also an important consideration as to what weight is most beneficial to lose.

Any weight that can be removed from rotating parts is the *MOST* beneficial.

This is because not only are we reducing vehicle weight but also making the vehicle drive-line more efficient. And while this doesn't actually add horsepower to the motor, it DOES allow more of the motors power to be transmitted to the road.

Reducing rotating weight has a dramatic impact on the overall performance of the vehicle.

This page will be updated as I make changes to the weight of my 2009 Impreza Outback Sport. Some items will be simple and free while others may be complex and more costly. I will weigh the items to get exact savings whenever possible. I received this car in April of 2013 and it was 100% stock.

May 2013.
Removed extra un-needed items from car.
Owners Manual
Rear Rubber Mat
Extraction Hook (located under the rear hatch cover).

Installed Light Weight Battery.

Subaru Stock Battery

New Battery:
Shorai Battery


Shorai INstalled in Subaru IMpreza

More coming:

Lightweight Wheels.
Lightweight Crank Pulley.
Rear Wheel Drive Conversion.