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I have a 2008 Subaru Impreza 2.0R - normally aspirated. I do a lot of miles and the car has been good. One problem though - It doesnt have much in the way of performance. Not that I expect it to be like a turbo model, but it seems very dead. It goes ok at around 2000-3000rpm but below or above that, nothing happens. Sluggish most of the time and a bit frustrating. Think its just the way the engine management has been set up. There is also a delay between when you put your foot down and when things actually start to happen. (Only when you start with small throttle opening - like in stop-start traffic). This has nearly gotten me into trouble a couple of times? Any ideas how to make the car more responsive / nippy / powerful?
Any ideas or advice will be appreciated.

Is it an auto?

The thing about NAs is they arent really "performance" engines.. I wouldnt go in lenths spending money on an NA for performance wise apart from exhaust... Is that an Impreza?
Cheers
AP

Hi - yes it is a manual Impreza. As far as the "NA" - I know the Subie turbo engines are the designated "performance" engines, but one should surely be able to beef up a NA one too? I know that VW engines for example (Older Golf and the like), can be greatly improved and souped up. Just by - as you said - exaust and chip / computer. I'm not expecting turbo type power at all, but any improvement would be good. I think that the engine management has been set up so the motor runs very lean - maybe to try to improve fuel economy or something. The cam timing is also variable, as in a lot of other modern cars. I think all the important bits are there. It may just be that the computer is not very powerful, or the mapping etc is just crappy.
Thanks for your feedback so far.

One thing I've heard of is "resetting" the ECU (I dunno how you do this without removing the battery) - then drive it like you stole it for a week. Those that do it reckon it works.

Otherwise do a search on the forum for "supercharger" - one of the member's on here got a supercharger kit for his RX liberty 2.5 ltr and swears by it.

Otherwise not much I can think of other than running a higher octane fuel - like BP Ultimate/Shell Vortex etc.

Cheers

Bennie

El_Freddo wrote:One thing I've heard of is "resetting" the ECU (I dunno how you do this without removing the battery) - then drive it like you stole it for a week. Those that do it reckon it works.

Otherwise do a search on the forum for "supercharger" - one of the member's on here got a supercharger kit for his RX liberty 2.5 ltr and swears by it.

Otherwise not much I can think of other than running a higher octane fuel - like BP Ultimate/Shell Vortex etc.

Cheers

Bennie

im pretty sure you can reset the ecu like this

first warm the car up to normal running temperature

turn the car off and remove the ECU fuse and disconnect the battery.

press the brake so until the brake lights dont come on (drains any small amount of power throughout the car)

leave the car for five

replace the fuel and battery start her up and drive like a p plater!!

should make the ecu believe the car needs power over economy

im pretty sure anyway
never did it on my suby

hope this helps

El_Freddo wrote:One thing I've heard of is "resetting" the ECU (I dunno how you do this without removing the battery) - then drive it like you stole it for a week. Those that do it reckon it works.

aussie_bob wrote:im pretty sure you can reset the ecu like this

first warm the car up to normal running temperature

turn the car off and remove the ECU fuse and disconnect the battery.

press the brake so until the brake lights dont come on (drains any small amount of power throughout the car)

leave the car for five

replace the fuel and battery start her up and drive like a p plater!!

should make the ecu believe the car needs power over economy

I hate to be the bearer of bad news, but no this doesnt work.

The ECU is always adjusting the ignition timing and the fuel mixture as you drive in closed throttle mode (general cruising and idling). Open loop mode (occurs generally anything over about half throttle) is derived from permanent load maps and cannot be changed.


Unfortunately your engine is designed to be economical and is already making good power for 2.0L engine. There is practically nothing you can do (except for forced induction or extensive NA race fuel tuning) that will make a difference

Run Subaru upper engine cleaner through the engine and clean the throttle body with the same product.

Have used the product many many times on problem cars with similar complaints.

I have a 1997 Sportswagon with an EJ20.
Removing the resonator, K&N filter, service, and 98 fuel has made a difference-that was 3000km ago.
I've got a hole in my exhaust now so I'm going to whack a 2.25 catback on it, and probably decat and chuck some ebay headers on not long after.

I'm pleased enough with the gains so far, and happy to have a go at performance exhaust, but realistically, as soon as I get off my P's I'll be hunting down a 98-2000 Wrx/Sti anyway, so not much point spending too many $$$ on it.
Pretty impressed with the fuel economy with what I've already done, 600km to a 50 litre tank.

Bradenrm wrote:I have a 1997 Sportswagon with an EJ20.
Removing the resonator, K&N filter, service, and 98 fuel has made a difference-that was 3000km ago.
I've got a hole in my exhaust now so I'm going to whack a 2.25 catback on it, and probably decat and chuck some ebay headers on not long after.

I'm pleased enough with the gains so far, and happy to have a go at performance exhaust, but realistically, as soon as I get off my P's I'll be hunting down a 98-2000 Wrx/Sti anyway, so not much point spending too many $$$ on it.
Pretty impressed with the fuel economy with what I've already done, 600km to a 50 litre tank.

ebay headers are junk and moreover 0 difference.

Your mods to date are very sensible - only suggestion would be handling from here.

Back to the OP, the 2lt NA engine is perfect for what is designed to - it is already engineered to near maximum efficiency by the good people at FHI. If after a decent service you crave more power, sell, and buy a RS/WRX etc