Building an Impreza for Road Rallying

[mejamj]

PARTS AND ADVICE NEEDED...

This may sound like sacrilege to many impreza heads as Im building a NON TURBO, REAR WHEEL DRIVE impreza, but please read on and hopefully you will see my reasoning..

The car is being prepared for next years welsh road rally championship (WAMC) road ralling rules state that non turbocharged vehicles must be used and to a maximum of 4 cylinders.

The Legacy 2.5 naturally aspirated engine seems the obvious transplant for this build as im hoping the install will be successful with only changing the ECU and maybe some wiring, as i haven't found the donor car yet I am open to suggestions or anyone out there with parts.

So I acquired this impreza from a friend for all it owed him which was very little, I am competing currently in the welsh championship in a front wheel drive car and finding it great fun, but cant help noticing that the mk2 escorts still dominate the top 10 on nearly every event. So here is my cheaper modern option a RWD scooby.

I am aiming to build it as 4x4 to get it running as currently it's missing.. Engine box etc, rad, fuel pump.. it's basically a rolling shell. So once its driving and legal, i just know the 170bhp is not going to be enough power to throw it flat out in the technical stuff where critically understeer in dominant in the impreza.. allas the RWD will give oversteer on tap and increase the pleasure factor by a few i'm sure.

Finally is there anyone out here who knows the best way to maybe get the power output up into the 200's without going mad on the spend?

[stum450n]

I've driven a RWD Impreza sport on a Tarmac sprint track (standard 127bhp 2.0 engine though) and it was phenomenal!!!! One of the most fun cars I've ever driven!

Set up correctly I would put money on that being quicker on gravel than most factory STis!

Best thing for performance in a sport is a lightened flywheel - can rev higher and decelerate a lot quicker after. Factory breathing isn't very restrictive so a 2" decat exhaust and uprated air filter do the trick there. You can get beyond 200bhp in a later GX but you'll be looking at silly money for porting, polishing and reprofiling cams etc.

[stum450n]

Oh, and the ECUs on the sports can't be mapped so if you go down that route you'll need a piggyback ECU

There's also the 3.0l legacy H6 that could be worth a look - can pick them up from about £900 - scrap that, just saw your note about 4 cylinders! Oops!

[mejamj]

I've driven a RWD Impreza sport on a Tarmac sprint track (standard 127bhp 2.0 engine though) and it was phenomenal!!!! One of the most fun cars I've ever driven!

Set up correctly I would put money on that being quicker on gravel than most factory STis!

Best thing for performance in a sport is a lightened flywheel - can rev higher and decelerate a lot quicker after. Factory breathing isn't very restrictive so a 2" decat exhaust and uprated air filter do the trick there. You can get beyond 200bhp in a later GX but you'll be looking at silly money for porting, polishing and reprofiling cams etc.

I am liking your response, the rwd sport you drove, how was the conversion done? I have heard it can be as simple as removing the front shafts however the sensible option being to strip down the transfer box and welding the planet gear or replace the front drive with a bypass (kinda mini prop i guess?) transferring power directly to the rear.

[stum450n]

I am liking your response, the rwd sport you drove, how was the conversion done? I have heard it can be as simple as removing the front shafts however the sensible option being to strip down the transfer box and welding the planet gear or replace the front drive with a bypass (kinda mini prop i guess?) transferring power directly to the rear.

In all honesty I'm not sure - the cars are at the Subaru Rally Experience centre down at the Haynes motor museum in sparkford.

I've done a little research since (been tempted to do it to my sport) and your suggestion coupled with a rear LSD seems to be the best approach - the strongest route as well!

Keep us posted yeah?