Less stress to be honest, depends how far you wanted to push the engine really.

 

I believe the WRX pistons are more dome shaped compared to the STi and this give the slightly higher comp ratio. Also the WRX block is the ej255 open deck where as the STi is the ej257 semi closed deck. So the wrx and sti short motors are not the same. The reason for less wrx failures is due to less boost and power than the sti.

 

That was my suspicion, so in other words if you remap the WRX to STI levels you are just as vulnerable?

Ive just done a gocompare search. The WRX comes up at £1475 whereas the B200 Turbo (which has simlar performance) comes up at £515 o it looks like my hope in returning to Subaru may be a short lived, especially as tax is double as well.

 

Having never had one of these units fail on a wrx I'll hold my hand up I was always lead to believe they were the same short motor in the newage 2.5's & only the non turbo 2.5 was open deck with the domed pistons hence the higher comp ratio for normally aspirated.
I know there all made from the same Hyper cast materials to run really tight piston to bore clearances.

 

The ej255 is semi closed block as mine has been out not to long ago

 

£1475 ins on a WRX. Do you live in Beirut?

 

Then what's the difference between the ej255 and the ej257?
There was a discussion here a while back on the differences between the wrx and sti short motors. On the ej engine wiki page it stated the blocks were the same with only the piston shape being different. One of the very respected engine builders who frequent this forum pointed out the wiki page was wrong and the the ej255 block used in the wrx was open deck and the sti's ej257 was semi closed. It was said this was the only difference between the 255 and 257 blocks.

 

Close...Bradford!

That's with 12 years driving 6 years NCD. No points or accidents.

 

Apparently the WRX piston is more robust, if you put the 2 next to each you can see the difference. The WRX has a larger skirt, etc.
Anyway, this is what I was told by the guys that rebuild the engines. I would most certainly fit forged parts.
The precise reason as to why they fitted WRX pistons, I don't know. I assume it was cost.

I never went through this excercise, so I can't put my head on the block about it.

If it's just the same or differs, I couldnt really be bothered. I just thought it was worth mentioning, as it ties in with WRX not failing to the same degree that the STI does/used to.

 

Pudsey here and 600 for an sti 2011

 

We are dragging up old stuff lol.

Ok so ive trolled the forums for 2 years owned both cars and this is my view
Pistons aint great but not the cause, forged would help but any piston under the wrong enviromentals would blow, yes forged may survive extreme explosions det combustion but may still blow.

The diff in the wrx was the ecu and map, subaru made a mistake on the new 2008 hence why they patched it later on, subaru were learning this new ecu i think, and got it wrong from the off, over time they seem to have nailed it and we dont have any issues at all on the new ones.
basics were something that map did on the 2008 caused the piston to die if put under high revs and lean conditions.

I mat still be wrong but i dont actually think its all down to the chocolate pistons, it may not have been so apparent is subaru fitted forged but i also think they would have blown also.

It was 2 fold, i think before the 2008 the hawks ran the same engine etc but indeed had diff pistons and an older differant ecu and map

What you thinlk ?

 

I fully agree, it is a 2 fold issue, but mainly because of detonation. Here the hawkeyes broke down even more than the hatch that came in 2008.
In SA the conditions are worse for these cars, due to a low octane (95Ron) and high altitudes above sea level.
I have heard of a few new engines that have gone ( post 2010. the saloons), but I dont know why, maybe older spec maps, ECUs or soft pistons.
I don't know of anyone that bought a STI in the last year. It so damned expensive to buy one here.... 45 000 pounds! I think people stopped buying them, news got out of the ringlands.
A BMW 135i is much cheaper and problem free...and I guess guys opt for that instead.

 

Lucky you. I could only dream. I can only assume that you have an LS postcode. Insurers see that postcode as part of the UK whereas the BD postcodes is completely alien and has its own highway code.

For example;
Traffic lights are there only as a precaution, if its red but with less than 10% chance of killing someone then go right ahead.
One way streets only apply when there is no car coming that you can see.
Undertaking on a single carriageway, half on the pavement is fine as long as your car is less expensive so the other person will yield.

A few examples of what I had to negotiate on my last trip into the town centre.

Fortunately I wasnt involved in any crash for cash scams, maybe Ill get that chance next visit.

 

lol

 

The Hawkeye engines still suffer the same ringland issues as the Hatch, but at a higher mileage normally, as far as i am aware they run the same piston design.

Also i do know of a couple of Hatch engines fitted with forged pistons, otherwise std, still breaking ringlands, wether they had not had any ecu flashes / re maps i can't comment on, as they were dealer retro fitted, so the answer is not all piston design related, any piston will fail under the wrong fuelling/ign parameters over time.

Also it was mentioned about compression ratio difference between WRX & STI Hatch engines, the difference is combustion chamber shape not piston crown.

 

Srs check out that new amg merc a45 I think due out 2013 firt quarter I'm sorely tempted

4wd 330 bhp

 

Would the extra height in the piston mean a better ability to withstand the heat and not so likely to fail (more metal)? Or is it just the result of the sti map being totally crap and the wrx map being better sorted?

 

When the cars are remapped over there do the mappers knock back the new maps so they can run on the low octane fuel? I never have understood why Subaru would sell the car in SA with a map that needs 97 ron when the fuel is not available. Total madness in my opinion especially given the rate of failures on highr grade fuel.

 

Hi Vince

As far as i understand the standard map goes off and a new custom map goes on. the car in repeatedly dynoed and so the new map takes shape.
The throttle response is immediate and the car is set to run much richer to combat the detonation.

Subaru SA is not part of Subaru Japan, I was told, it's just a company that buys the cars from Subaru Japan. SO they do no R&D on the cars in local conditions, they simply pull a parallel between Australia and SA and slap a 95 RON sticker in the filler cap.
Australia has 98 RON I believe, available freely.

When I initially found out about all this detonation issues, I asked the exact same question as you just did. It's really amazing how they simply ignore the facts.

 

You need to shop around. I have a MY03 JDM STi modified, 9Yrs NCD, 6 points 40Yrs old and it is half what you are being quoted! Postcode BD22. I did have Greenlight on here refuse to touch BD codes.

HTH.

 

the ej255 has different heads and valvtrain to the ej257. I have had my engine out twice to two different engine builders and both confirm the ej255 is semi closed

 

You have some kind of problem Keith, or just getting stuff done to it?

 

Thanks, that gives me hope.

 

guys a bit off topic, but I read this on a thread.

Am I right in thinking the older Blobs only got 200 to a tank ? and this 2.5 in the hawks lifted the bar slightly.
I get about 250 to 300 outa mine which is good, and acceptable. I can see why scoobys got a bad name for guzzling if the older cars only did 200.

anybody know ?

 

hi Ted

Mileage i dont't know about, but those 2litre engines were tough. they didn't break, even here in africa with this diluted garbage excuse for petrol.

 

Well the first time it was at Ali Burrows for a forge build about 2 year ago and short while back it was at Micheal Whites for syvecs ecu and mapping with lots of other things incuding a cosworth HD

 

do you guys in the UK often hear about guys stroking their ej25 motors to a 2.7 liter , when going forged?

 

Thought about it with my own but if I was I'd be fitting sleeves to it. The other option is to de stroke it use a 2.0 crank & +2mm rods. Make the bitch rev easier. Makes it a 2.35

 

This is Scoobynet, what else do think they do?! Hell, they'd take them to bed every night if they could! Whilst dribbling. Uncontrollably.

 

lol