Matt grb sti

Hey guys running a standrad sti 2.5 at mo gunna star put some money in to it wondering has anyone used the sivec ecu or simtec?? and how much to fit new pistons all in cause my cadburys ones aint gunna last obviously with exhuast and mapping usual stuff??

john banks

Save your money and start with a different car IMHO.

Matt grb sti

Charming whats wrong with my hatch sti??

IggyRB320

iTrader: (9)

If your hatch engine & internals are standard, I don't think you'll get the benefit from an uprated ECU, as your pistons or HG with give up the ghost very quickly!!

Matt grb sti

Screw it ill just go to a decent tunner chuck money at them tell em what i want and make sure it dont go bang

john banks

That is a nice idea on the face of it, but when you spend that much you'll want the power to justify it, and then you'll realise you're just polishing a (rather wobbly) turd of an engine.

Hence starting with another car...

chopperman

Just be clear what your targets are before spending. It's better to have a target then stick to it when building the engine. For a road car around the 400-450 bhp forged pistons, arp studs and acl bearings should be enough. If your after power upto and beyond 500bhp you will need far more.

chopperman

Not everybody is in a constant search for more power. Some people have a target that suits their style and usage and stay with it.

john banks

At nearly every level starting with an EJ257 they would be better starting with an Evo in terms of reliability vs price. Having a factory unopened engine for your daily driver is a very good thing IMHO for longevity, scuffing, oil usage, noise, future emissions testing success etc. Some conversions go well, many don't. I would not run a rebuilt engine as my daily driver unless I wanted a needy project.

topshot

iTrader: (4)

Whats wrong with a rebuilt engine? I ran one for 70k miles (not a subaru but still) and used it for driving all over the UK with no issues. If a rebuild is neccessary then get it done right first time, its when cutting costs that issues start to arise.

john banks

The issues I mentioned are common reasons why many who have had built engines wouldn't have another on their daily driver. Your individual satisfaction with 70000 miles from a non-Subaru engine may encourage you, but when you consider the issues across a wider sample it is a different matter. Aftermarket testing is nothing like OEM testing and it is pot luck whether your engine will last 70000 miles. I'd suggest that was the minority of built engines.

Alan Jeffery

Absolute twaddle.

chopperman

Glad you said that because i was thinking it

jef

iTrader: (13)

had exactly this in my classic - new block ect, worked very well - but not a daily driver tbh
was around 430/430 and a great road car - the old simtek ecu was all that required attention to get a nice stable idle.

chopperman

I think most peole with "built" engines dont use them as daily drivers is because most "built" engines are also quite highly tuned.
Many after market parts used the the engine builders have had years of R&D and testing. Take Mahle forged pistons, firstly these have been developed in many forms of motorsport including F1, They also make about 80% of the worlds pistons including OEM. ARP studs and ACL bearing are tried and tested . What parts are you actually referring too? Most built engines that are unreliable are due to DIY or tuning to beyond some parts design brief.

john banks

Alan, a better quality reply from you which might attract custom from the original poster and would change my opinion (not generally about EJ257 builds, only about yours) would be for you to provide independent data on the long term reliability and customer satisfaction of your EJ257 builds, along with details of how your testing is superior to that of OEMs.

Hawkeye D

popcorn time!

john banks

How much of the reliability is related to the part selection and how much due to other factors (excluding the two you mention which are DIY and tuning)?

Why should I trust a built EJ257 from x supplier because they happen to use Mahle pistons?

I have a distinct preference for factory engines for my daily driver due to the OEM standards to which they are constructed and the testing/certification that goes into them, combined with my own and the bitter experience of others. Others have had more success, but there are are a lot of engine build horror stories that get hushed up from the forums.

Engine builds on a slower car are a very poor financial decision IMHO if you can start with a better platform to modify and leave the engine intact. Of course those busy making a living off the unreliability of some engines will disagree

Pramas

Not going to get involved to much, but i forged my 2.5, simply due to the poor design and head gasket problem, chocolate pistons ain't to good either.
However i now have a fully pinned and forged engine and believe me i know its not going to do 100k, it prob might need a refresh every 20-25k if driven hard, however it wont be.
Now i have the peace of mind every sound i hear in the engine it isn't about to give up, either way its down to the consumer to choose there path, this is the path i choose

chopperman

I wasn't suggesting you use a builder because he supplies Mahle pistons, i was just pointing out many of these after-market component makers also supply oem parts and have had extensive R&D.
Also i think its far to say car manufactures no longer build cars with after-market tuning in mind. To single out the Subaru ej257 in standard form as not the best platform for tuners after high power i think could be said about most modern engines. Everything is built to a price these days.
Your last point about Engine builds on a slower car are a very poor financial decision. Well i would say that depends on the value of the car. It maybe a poor decision if your not looking to tune much and your car is only worth a few grand. But take the op's car. Its a hatch so quite a new car and worth several thousands. Spending a few K so the car can now be driven hard with confidence maybe seen as money well spent.

chopperman

If the engine was built properly using quality parts. If you used high grade oil and change regularly and use 99ron fuel i cant see why it will not achieve high mileage. Like anything it comes down to quality of parts,care in assambly and mechanical sympathy.

Pramas

well i did see a post once from api saying an forged engine needs a refresh if driven hard every 20k, but i can understand that, a f1 engine gets rebuilt every few races and they don't last anywhere near that however iam no lewis hamilton nor do i drive way, id expect 50-80k off mine

LeeP

iTrader: (7)

Its not usually the "forged" motors that need refreshing because of the components though is it? It's down to the mapping pushing for numbers which usually results in cylinder temps and pressures bigger than normal / design, bore wash issues with cold start maps etc etc

A well built, reasonable mapped and well serviced build should last every bit as long as an OEM build.

Pramas

ideally yes, although iam just quoting an old api post saying 20-25k forged engine requires a refresh if driven hard which i can understand, i have to say i found it refreshing since not many builders will put that info out there

APIDavid

iTrader: (4)

Nothing wrong with Mahle pistons, we use them when we have to - with no issues. Our in house pistons are made by Supertech from California, been using them now for a number of years. They have one quality; the best. They have very strong tool steel piston pins and are remarkably quiet in a bored engine [ not a 2.5 I hasten to add ] NEVER rebore a 2.5, the block won't take it .

The other stuff like Wiseco, JE, Ross, CP, Manley, etc., etc have caused problems in the past - mostly about inconsistency of shape. How a CNC machined article can come up with 4 pistons in a box, all different sizes is beyond belief. NOT just from manufacturing, but quality control at the packing process. Surely it's not diffcult to select 4 that are the same size and put them in one box ??

Omega and Cossie are the best, no doubt, but in my opinion, the slipper piston type is not ideal for long term road use and we only use them when high horsepower and severe track use requires it. Otherwise the Supertech's fit the budget for life and strength and consistency of shape. AND most sensible horsepower targets for road cars.

Once you get above 450-460 hp it does become a bit of a trial as a road car and the happy medium is somewhere mid 400's for build cost, running cost, reliability and durability.

The point about refresh at 20,000 - 25000 miles is when you are running 'high' power Say above 480 hp [ on a 2.5 ] The block flex starts to become a problem and oil consumption is just around the corner. The only cure is a new standard semi closed block.

We have any number of 2.5's running around in the 430 - 460 range that have done significantly over 25,000 miles with no problem Daily drives and track used cars. One in a GC8 Vers 5 + MD321T making a solid 430 hp and 460 something torque is well over 50,000 mile and not causing any concern. never uses any oil above a drop between services and works hard to and fro work every day.

People talk about pinning and closed decks and liners and Darton sleeves conversions. I have never seen any need to do that and frankly if any of them were a solution that us engine builders KNEW would work every time [ and be reliable ] [[ and cost effective ]] We'd all be yelling it from the rooftops.

No one is .......................................

The solution for the OP's upgrade is a simple build with forged pistons, head studs, Sump baffle, latest original STI hatch head gaskets and a careful build with multilayer crank bearings and Hey Presto! instant power and reliability [ up to 450 ] Very affordable too.

David API

IggyRB320

iTrader: (9)

So your saying a forged EJ257, will only have a life of between 20k to 50k miles?

Would that be the same for a forged 2.35 build on a daily runner?

Whats the cost for a safe 2.35 build running 450/500?

APIDavid

iTrader: (4)

A 2.35 is the most expensive to build as you need the 2.2 cdb as a base and that immediately adds £1000.00 for a block casting before you start any processes. We do not recommend a high power 2.35 for a daily drive. It will be OK at 450 - 460, of course it will, but there are cheaper ways to get there reliably.

I know, I know, others do use and recommend 2.35 ...... APi doesn't for road use

NO, a normal up-to-450 hp 2.5 will run as if stock, built carefully. No reason why it wouldn't, essentially the engine is as built by Subaru, but with better quality pistons and better quality head clamp pressure.

A highly stressed 2.5 running close to or over 500 hp will have a reduced life and no matter whose kit you use, the internal engine dynamics are the reason. Apart from the previously mentioned crankcase flex problem.

The Subaru EJ257 is massively ' oversquare ' meaning that the bore is much greater than the stroke length and whilst that is not uncommon in many modern engines, there is a ratio that it is unadviseable to exceed. Piston speed, and piston crown loading come into play and in simplistic terms that is why " a 2.5 won't rev " That is an overstatement, but they are less than happy at over 7000 rpm and will start to creat all sorts of other stresses that leads to engine life expectancy being shortened.

AND of course when you see the dyno traces, there is no need to rev its brains out, as the torque and power curves are long since on the downslope.

Above 7000 on a 2.5 all you are doing is making a lot of noise and wearing out a whole bunch of parts inefficiently.


Horses for courses is the mantra here.

David APi

01926 614333

Alan Jeffery

Call me old fashioned, but when I detect a sweeping generalisation passed off as fact, I'm inclined to be abrupt.

The OP has already been in touch, and we discussed our 100% Hatch success rate.

There is no reason at all why a carefully engineered engine build should be inferior to OE, particularly considering the poor quality of some OE products. I'm not just talking Subaru!
Example? The Nissan 350z "Rev up" engine, which had a habit of burning oil in a terminal fashion.
A customer of ours had a brand new one sieze up on him after 8000 miles, before the first service in fact, when it ran out of oil. Nissan's take is that 800 miles per litre of oil is just fine! They refused a warranty claim, saying he shouldn't have let it run out of oil.
We collected the car in pieces. We rebuilt it, despite having never worked on one previously. We had pistons made, as you couldn't buy them. We reassembled the motor, and it didn't use a drop of oil from that day on.

Subaru have found their engines wanting in plenty of areas. The only really reliable one, certainly after tuning, has been the new age 2.0 STi.
When we rebuild Scooby engines, we often have to carry out corrective machining due to poorly manufactured blocks, the EJ22 often being the worst culprit!
Once done, these engines can be tough enough, as long as every other engine killing issue is sorted.
EG a EJ257 we built five years ago, still winning in competitive motorsport.

This is how I see it.
Forged engine components do not show any signs of increased wear relative to stock parts.
Stock parts won't cut the mustard, ergo you have to do something with it, or just be satisfied with the stock product.
It isn't the forged parts that are the big problem, it's what people choose to use the car for! It's perfectly possible to just spend your time poodling to the shops in a 500 bhp car. It'll last for ever doing that. There is no compulsion on anyone to rag it about. If you choose to do a spot of weekend motorsport that's fine, just bear in mind that reduced life of all the car's parts is the price you have to pay when you do.

john banks

All good points, it sounds like your are confident in your hatch recipe that you can apart from small random failures resolve all the predictable issues with this engine at a given power level. Do you feel you have a large enough sample of hatches over a long enough time with sufficiently hard use that you've "cracked it" and if so at what power level? The question then remains whether it is value for money and a wise investment?

Matt grb sti

Im new to this i really appreciate the feedback from everyone espically the professionals opinion but i think everyone agree all performance cars aint good value for money or a wise investment the only reason we buy them and have to tunned is passion for love of fast cars