What differences between 2006-7 Stock Impreza and WRX?

[Jeff818]

I had my heart set on a stock 2006 or 2007 WRX, but there seems to be way more non-WRX Imprezas out there at way lower prices.

So if a stock 2006-7 Impreza presented itself at a low price, what parts would be needed to make it a true WRX...
Of course we're only talking about the parts needed for an 818 build.

First we'd need the turbocharged 2.5L engine (EJ255) and I'm guessing the ECU, wiring harness, and maybe certain different exhaust parts associated with the turbo.

What about the clutch, and the 5 speed transaxle... are they the same?

Brakes are upgraded on the WRX, but can I buy WRX or aftermarket brakes... and are the spindles the same so that they will just bolt on?

Axles... are the splines the same, control arms, CV joints?

What about the wiring harness, instrument cluster, and anything else I forgot????

In other words.... is it more hassle than it's worth trying to buy a WRX one piece at a time or could this approach really save money?

[papajon1000]

First of all: Are you looking for a damage free, clean title car? Do you plan to drive this before you convert it to the 818?

It is usually more of a hassle sourcing the rest of the parts rather then spending the extra money up front. Unless of course you can get the impreza for cheap.

With the engine you would also need all of the little parts, such as intake, turbo inlet, turbo, intercooler, throttle body, intake manifold, tgvs. The list goes on. I'm not saying it is impossible to get a fully dresses engine, but usually you will get just the long block or short block. As far as the exhaust, the base NA exhaust is very different from the turbo exhaust.

I do not know about the transmission but I am pretty sure they are different. I do know the clutch is not the same.

I can keep going but like I said unless you got one super cheap....

[PhyrraM]

As a educated guess, I would say that at least 50% of the parts that get transferred to an 818 are different.

I'll try to come up with a more comprehensive list when I have more time.

[Jeff818]

First of all: Are you looking for a damage free, clean title car? Do you plan to drive this before you convert it to the 818?

This requires a whole different discussion... and I don't want to hijack my own thread, but I live in Massachusetts, so all of the salvage inspection issues arise?

Someone who has recently (post grace period) titled their car in Massachusetts.... please start another thread about this important topic.

[papajon1000]

This requires a whole different discussion... and I don't want to hijack my own thread, but I live in Massachusetts, so all of the salvage inspection issues arise?

Someone who has recently (post grace period) titled their car in Massachusetts.... please start another thread about this important topic.

I was just curious what cars you are looking at now. Are they running and driving still or are you looking for one just for parts?

It is important to your statement about how the base imprezas are a lot cheaper than the wrx. I have looked at wrecked cars and the price difference is reasonable.

[Xusia]

From what I've seen, yes the NA Impreza is cheaper, but once you add on the price of everything you are talking about, you'll likely have spent more than if you just bought a WRX to begin with. To say nothing of the extra hassle that route imposes. Unless of course you find a STELLAR deal on a NA Impreza. I've seen them, so I know they are out there. But so are stellar deals on WRXs. IMO, you are better off spending your time & energy looking for the stellar deal on a WRX. If an Impreza or STi fall into your lap, well of course jump on it! :)

[Mechie3]

A WRX will have more things that will command a slight premium over NA impreza bits as well when selling stuff off.

[PhyrraM]

Here is the list of parts that are being used currently on the prototype:
• Front spindles with full brakes and front lower control arms - Brakes are different
• Rear spindles with brakes and e-brake handle/cables - Brakes are different, spindles are different for some brakes
• Steering rack, tie rod ends, and upper steering column assembly
• Pedal box and throttle pedal - Gas pedal is different if going to 'fly-by-wire' motor
• Master cylinder and brake booster, and clutch master cylinder
• Engine with turbo and intercooler (if WRX model) - Very different, of course
• Exhaust manifolds, O2 sensors, and down tube - All different, even differently routed
• Transmission - Basically the same, minor differences. Only will matter if you try to 'mix-'n-match'
• Rear lower control arms, toe links, and CV joints
• Front seats, front seat belts, and gauge pod - Redline on cluster will not be correct for the turbo motor, some don't have the tach in the center like most WRXs
• Fuel pump - Different, and different pump controller
• Radiator - Different
• Wheels and tires - Same on 2.0 WRXs, different on 2.5 WRXs
• Door hinges, front w/ latches,strikers, and inside door handles
• Side view mirrors, left and right
• Rear view mirror


This list doesn't mention the harness, but it will also need to match the motor.

There are also more, but this covers the list the FFR has released so far.

Some things are functionally the same, even if the parts are different. Such as the brakes.