New_scooby_04

iTrader: (4)

IME it's not Subaru's manufacturing that's the problem, it's the people who drive em!

It's a great engine, which habitually tolerates much higher outputs than it leaves the factory with as long as a) the modifications and mapping is done correctly b) it is driven with some degree of mechanical sympathy and c) it is maintained correctly.

Problem with this marque is too many people think: cheap performance and, in reality, there is no such thing: one way or another (be it the cost of the mods, the running costs etc) - you play, you pay!

Mus

iTrader: (2)

took the words out of my mouth but i still think they could of done better with standard transmission

got a 2.5 no mods to the block 500+bhp lots of mixed driving and no problems at all

New_scooby_04

iTrader: (4)

I'm one of the fortunate ones who have the std 5 speed that appears to be coping fine with about 350 ft/lbs torque.

I think it's very much a case of how it's been used previously and your own driving style though.

Ns04

Shaun

So true..... I see a few "drive in, drive out" conversions at high power levels, that have no where near enough ancillary changes made. It is more than just about an engine build. People wonder why, when they take the car on track, or thrash the **** off it on the road, and they start to have problems. Do it once and do it right.

There are suddenly a lot of big bhp (500+) builds happening nowadays.... let's see how long some of them last, with use other than going down the shops with the kids in the back and polishing it. I'm not saying engines will let go, but a dyno figure is one thing..... keeping it together is something else.

I know for a cast iron fact, of a number of higher profile cars that have had all sorts of engine problems..... but alas they are never admitted to in public.

Anyway... I digress.

ALi-B

iTrader: (1)

Gearboxes is another thing; My driving style used to be quite hard on gearboxes. But I learnt the hard way, and now my driving style is more sacrifical on the clutch (a new clutch is cheaper! )

Tidgy

03 is a 2.0 isn't it?

STi Singh

In the USA there are many owner's running 450-500 on standard internal's on the 2.5 with rotated setup's. Some are with & without additive's.

Peanuts

iTrader: (15)

a standard mondeo makes about 450whp in the USA

53

iTrader: (41)

Black-Hawk

iTrader: (4)

dito

Mus

iTrader: (2)

i would of agreed with you till i saw a few videos on youtube.

Anders_WR1

iTrader: (8)

Not sure i get the Ferrari Analogy. If a standard 2.5 STI is circa 270bhp, pushing the power to 500bhp is nearly double. Try running a 100 Ferrari blocks with 900bhp and see how many fail.

Anders

helm

my 2.5 570hp no problem at all ever

lunar tick

iTrader: (2)

Yes, but still manufactured by Subaru if my memory serves me correctly

Alan Jeffery

We had one that suffered a totally unexplained inlet valve failure. It parted company from the stem at a steady 3500 rpm, datalogged by the Motec.
Can't blame the block for that! Naturally we fixed it. It now runs well over 600bhp like it did before. It isn't the one we posted a graph for this week, which is still running well two years after we built it with no block problems.
This one is running well after a year of track days and hard road driving.

MartynJ

I am sorry Tidge, but sadly all the 2.5s in standard form have cast pistons, be they WRX or STi, none of them are forged are anything like it.

The earlier 2 litre STi did have hypereuretic pistons and these have been proven time and time again to take in excess of 450bhp reliably.

STI_Baly

iTrader: (23)

Alan if you don't mind me asking was the valvetrain upgraded on this motor? if so could you tell us what was done?

Alan Jeffery

It used upgraded valve train materials throughout. The supplier took a huge amount of trouble over the subsequent investigation, and an arrangement was reached that adequately dealt with the aftermath of a valve head rattling about. The engine is now restored, with the same component specs, and is running perfectly. Fantastically in fact.

mikepaul

I agree, some people on the Ford Forum blame the Volvo engine for going pop on modified ST and RS's. But think its more likely cheap backstreet mods and rally mode pilots. My cousins STi is a gem with no issues, gosh even trim rattles seem a thing of the past with the new hatch.

STi Singh

USA is the home of horsepower. 450hp is considered very slow in the states, its like owning a UK spec.

Also i have a 2.5 STi block in my Type R mapped at 430.3hp/459ft with standard internals. Its been good for the last two years, with many track days

Peanuts

iTrader: (15)

No doubt

But, horsepower in the usa is measured differently to Brake horsepower in the UK.
American horses are smaller than ours

Tidgy

tbh its all down to personal opinion, i can show you people who have posted with destroyed blocks and you can show me people who havn't. thats the whole point its where do you class the safe limit as? Its not a definative this is the mark.

havn;t you had one of your 2.5 self destruct alan that was pished over 500? not sure what the casue so might not be the block, but theres alot of folks who take an ej275 above 500 and they let go for various reasons, siome of which are block failures. So you could also argue that of a reliable 500+ ej257 is much harder to achieve than say a 2.33 closed deck then y would you want to stay with the ej257 and take the risk?

as far as the analaogy with ferrari, there 500 as standard so designed to run like that all day, so compare a scoob at 500 and you will get that sort of results. thats the whole point, the design of the engine takes into account that, the subaru engine wasn;t designed for that much power. Its only after customising it gets there which is way way above design specs.

Shaun

Tidgy,
I really do understand what you are saying, but you must at first realise how these failures are happening. Failures need to be put in to context, anything else just causes confusion. The fact of the matter is that there are not than many REAL 500+bhp Scoobs out there, compared to the number of that are not. What you highlight is that it IS easier to achieve 500bhp and not so easy to keep it all in one piece..... regardless of block.

500+bhp is still virgin terrority in the grand scheme of things. Everyone that passes that kind of level is themselves testing. Things are improving and so is knowledge.

Nothing is full proof at this level, but a decent level of research in to what causes 2.5's to fail would be a good starting point. Too many people get sucked in to so called facts, without knowing the detail. Before you know it, it becomes the defacto!

I have even heard through the grapevine that some little rumours are about that mine has never run 500+bhp. Thus the reason why my case has never split. How many RR's do I have to go on to prove that one! Also mine run's as it is for any of my dyno runs.... road, sprint or track! I have NEVER ran a dyno map/fuel mix/boost level etc to make it look good for a dyno run. What you see is what you get for any use. However, through constant development I actually make more power now at less boost, than I have ever ran. This block used to be regulary hit with way over 2bar of boost, but that level is just not needed anymore (at the moment ).

Fai17

iTrader: (2)

Spot on Shaun....if we heard all REAL the horror stories out there then we would never be modifing our cars.

I had a linered EJ257 and through faults of me own i managed to split/cracked/damaged 2 of the liners.This was done when i was in my early days of modifying and having a lead right foot and no patience(sp).I gave it too much boost and not enough fuel...car was flying(as they do before they go bang).Lesson learnt and now sitting here waiting for my current build to finish.Heres hoping that everything will work out and i will take my time to make this car run correctly.

Fai17

iTrader: (2)

Alan and Martin.

I always read with great interest on how yous get on with your customers build.Have heard many a good comments on customer service and big builds
Yous sure do have a great results on 2.5L builds and long may it continue.

Peter

cptcaveman

Just add me to the unlucky ones. 2006 sti, no mods, always allowed to warm up and cool down, already had the head gasket replaced once, and now I have just had it done again, along with a now cracked piston. I'm sure a built engine is brilliant, but I have a sneaking suspicion, mine is actually made of some type of chocolate, more specifically one with a really low cocca content, like the stuff you get in cheap advent calendars..... I had a lot more faith in my last 2 litre one, that was driven in exactly the same manor as this one.....

Mus

iTrader: (2)

sadly it happens and mainly down to what kind of history the car had what oil was used was it abused before or maybe your just a little unlucky

ALi-B

iTrader: (1)

Head gaskets are more down to lack of coolant changes or correct coolant type/concentration than what oil has been used.

Also warming up and cooling down does squat all if air has found its way into the cooling system, say from a tiny weap on the water pump shaft seal or a pinhole in the radiator that wouldn't be big enough to show any puddles under the car when parked. All it needs is a bit of air lock or localised boiling in one of the cylinder heads and pop goes the gasket.

Rule no.1 of head gasket failures; find the root cause of the gasket failure. They can often fail due to some underlying problem elsewhere.

dynamix

iTrader: (3)

Maybe it shows how easy 2.5's get to the 500 mark with a good turbo too.

As Shaun rightly says those that have been amongst the early pioneers at this power level are doing the research and the testing - finding what works and what doesn't. Sure there are going to be some issues and failures but it was the same when people were going for 400 or 300. It could never be done people were told or they would just destroy themselves.

Shaun's has held together perfectly barring a head gasket issue - but that is a relative small thing caused by use of very high boost. My own would have held together if it was a road car but as it is used in anger on track (which brings into play lots of other issues such as oil surge) other issues got the better of it and had to have a rebuild. But it has since done 5000 miles with no issues.

Again, I don't do maps on mine for dyno's - I can't see the point. I get it right for the road/track and measure that on the dyno if I get time. Unfortunately it hasnt been on the dyno since just before the engine went but it will be soon to fine tune the map and to measure what it has been running.

Lots of issues don't make it to the public domain from very well known places (my god I can't believe I am agreeing with Shaun 3 times in one post !) running 2.0 to high levels.

500+ is not a place for true road cars really and we are talking about more than double the OE power and torque levels (they are exactly double on mine) - it is never going to be as reliable as it leaves the factory ... fact. But there are lots of things that can be done to help protect it.

Is the 2.5 a weak engine ? I don't think so.

StickyMicky

The **** waving in this thread is immense , bunch of gayers

The way i read the original post was this.....


The OP has just bought a car, i assume with a stock engine, and suspect he wants to know if his stock engine is going to last? now we have the meat-sabre warriors swinging the pink oboe about ,trying to prove some other kind of point.

Taking engines apart and changing things may not be what the OP was asking about.

SN at its finest

Stock 2.5 = Weak piston ringlands, headgasket performance as expected, crank good.
Built 2.5 = nothing to do with this thread really>? but pretty bullet proof considering.