morpheus1870

I have owned only one Scooby in my time which i sold a year and a half go (wish i kept it) which was a 98 JDM wrx and had been looked after religiously by the previous owner (afr module, bump steer mod, mapped to uk fuel etc etc) and was the most reliable car I have ever owned.

I am now looking to purchase my second impreza looking favourably at an import classic STi, but have been told by a number of people that the Sti engines are in much more risk of going POP compared to say wrx models or uk spec cars....as my knowledge of the impreza is quite limited im not sure whether to concern myself with these comments or ignore them.

Common sense makes me think that as long as the car has been serviced regularly and mapped to UK fuel the Sti engine should be as reliable as any of the other models.

I'm looking at the Sti version 2: is there any issues know with this model i should know about, consider or watch out for.

Apologies if this question or topic has already been answered in previous threads...semi-newbie needs your knowledge!

The Chief

From what i've been told (and read) STi's are more robust if anything due to having forged pistons and rods.

I've got a UK classic turbo and my big ends went - i got an STi short block and had that fitted.

Mo

The STi is no more prone to failure than any other model if operated under the correct conditions; as they come from Japan the ECU is configured to run on 100RON fuel which has a far greater resistance to detonation than the 97RON super unleaded we get here and it's this that can cause failure. If the ECU is expecting 100RON and is run on a lower quality fuel you are asking for trouble but use of an octane booster such as Millers or NF should see you OK, alternatively and recomended is a replacement ECU like the Apexi PFC mapped for the fuel and conditions you will experience here in the UK.

RB5_245

imo it's mistreatment that kills them. If the maintenance is kept up to date with, and proper warm up - cool down followed they'll last forever.

I think a lot of the trouble was that when they first became really popular (sti4-5) the sort of people buying them didn't really know how to look after them. 95ron fuel with no re-map, thinking once the water temp was up that it was warm.. not cooling down after a hard run. This gave them an un-founded rep in certain circles, but I think you see less and less 'blown up' threads these days compared to a few years back.

I stopped a lad in a petrol station once putting 95 in his type R. I think importers rarely bothered, or knew to say.

morpheus1870

thanks all, much appreciated...all the best!

morpheus1870

What is a good ecu to purchase?
How much would it cost for the ecu and remap apprx?
Where would you reccomend on getting this done from?

thanks again

GC8

The STI V2 'Wagon uses a Z4 ECU; which has an excellent map. It'll happily run on Optimax and it was used by Prodrive for Classic (early) PPPs!

Considering that most engines lose number 3 piston; Id assume that the failures were caused by low fuel pressure rather than by poor fuel.


Simon

edited for clarity

coulty

Nope it uses a 6k ecu actually. Also the sti had the early heavier forged pistons if you were lucky (some didn't cause of the factory's ability to throw whatever they had at the time into the engine bays) and most had open deck blocks also.

Stuart

Prince_of_Tokyo_RA

APPARENTLY stI'S BLOW UP NEAR TOP END DUE TO SHODDY FUEL OR OIL PUMP...

GC8

The GF8 STI V2 'Wagon uses the Z4... I drive a 'Wagon remember? As an aside; the C2-Series Type-RA and STI-Type RA both use the Z5 which is very very similar.

Simon

dsmith

MY03 WRX. Serviced by Main Dealer. No Mods. Just over 40K miles.

Now sat in the dealer with suspected big end failure.

*AL*

My MY03 with 34K 'died' earlier this year with big end failure.Now had a complete rebuild.

To be fair i have no idea how the car was treated for those 34K.

marmski

I may be wrong (and i am new so i can be ) but...

I believe with the Subarus (STi included) if you change the smallest of things (like the airfilter and/or exhaust) and dont get a re-map you are likely to run the car lean and it will do the big end.

Also from what i understand all newage Imprezas were designed to run on 97+RON fuel only, anything below and you were risking big end damage again causing owners to really have the only choice of Optimax or in extreme cases 95 with Octane booster. (this was also stated inside the fuel cap)

The only reason i know this was because my friend had a bugeye STi which went bang even when he ran purely Optimax (i believe this was down to Exhaust / Air Filter upgrade from standard without a re-map) but his fuel cap stated 97+RON fuel. My new 06 Blobeye STi states inside the fuel cap 95RON fuel leaving me to assume that all new Type UK Imprezas are being re-mapped to our poorer quality fuel.

Obviously im using 98+RON only and the car runs smoother on it, but even the dealer was adimant that the car was designed for 95 now and not 97 like they used to be.

I may be wrong, im just talking from my experiences and what i have noticed from friends Imprezas. Please can someone with good technical confirm? (maybe Bob Rawle since i understand you really know your stuff)

ramsden1

I think if you have auk car put in specified fuel rating stated in user handbook or petrol cap. But a good quality petrol not cheap stuff but the specified octane. on an import Tesco 99 or optimax should be ok without Booster if your not thrashing it constantly, its a lot to do with the way you treat them.

RB5_245

Could just be bad luck, but unless you've owned it, or known the owner since new you can never be sure. It may well have been driven off the driveway straight on to the main road and up to 5500rpm every morning.

In my experience very few people allow their cars to warm up properly.