2009 Subaru Impreza 2.5i
Sport
Rear Wheel Drive Conversion
Articles:
How To guide to Disable Daytime Running
Lights
(THIS TOPIC UNDER CONSTRUCTION)
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:
- Increases acceleration.
- Decreases stopping distance.
- Improves Handling.
- Increases Fuel Mileage.
- Reduces wear and tear on
brakes, tires, and everything else.
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.
- It is not a good idea sacrifice safety to make the
car lighter. Sure, removing the bumpers would make it
lighter but also make the car less crash worthy.
- We don't want to make the car look stupid.
Removing body panels would make it lighter but would not
look too good.
- We don't want to sacrifice too much comfort.
Taking the air condition off saves weight but, to most
people, not worth the sacrifice.
- We want the cost to somewhat reasonable.
Carbon Fiber drive-shafts are lighter but is it worth 1000s
of dollars on a street car? Probably be better to
spend the $ on a WRX!
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.
- Savings 5 Pounds.
Rotating Weight 0.
Owners Manual
Rear Rubber Mat
Extraction Hook (located under the rear hatch cover).
Installed Light Weight Battery.
- Savings 25 Pounds.
Rotating Weight 0.
Stock:
New Battery:
Installed:
More coming:
Lightweight Wheels.
- Savings 28 Pounds.
Rotating Weight 28.
Lightweight Crank Pulley.
- Savings 5 Pounds.
Rotating Weight 5.
Rear Wheel Drive Conversion.
- Savings BIG Pounds.
Rotating Weight BIG.