Hi,

Ive recently bought a 2009 hatch sti. Im well aware of the problem that many have had with the 2.5 engines. Im looking to forge mine. Ive spoken to api and said thats needed is pistons, head studs and head gaskets. Will this be enough? What sort of power could the engine take with this mods? Ive seen peoples rebuild specs and the list looks endless.

Thanks Jamie

 

Im easily getting 440/440 on standard scdb, crank and rods.

Cap the boost at 1.5bar and keep the temps down and she'll be sweet.

 

rods are prob worth doing at the same time if your going towards 450 ish, you can get away with it but its pushing it and given the engine will be stripped down makes sence to do it.

your then into other options to do at same time, inlet pipe (sits under manifold), tg delete etc etc

 

Cheers guys. Well i just want to build a safe and strong engine as i know the standerd uk ones are weak. Id be happy with anything around 400+ but i know some builds can costs ££££'s and i dont really fancy that route. What else is there worth doing along with pistons, rods, headgasket and head studs.

 

Not chasing numbers are you Jamie ? :-)

 

who you gonna get to build it for you? best bet speak to them, see what they say cost/spec etc.

scoobyclinic built my forged 2.5 and i love it

 

Haha no maz! Just want a safe strong engine

Well i want to start buying all the bits over time and get dirk and powerstation to do it for me. Cant really afford to fork out a lump in one. Just need a rough idea what to buy etc.

Tidgy.. What spec is your 2.5?

 

Hi Jamie

Speak with Alyn@AS Performance or Paul Finch about the CDB insert and engine build.
If budget allow then I would go with CDB insert and Cosworth 11mm 260k psi Headstuds..

I've run on Open Deck Block 490BHP without the issue,this has been without the NOS,with NOS we are run above 500bhp and this has been on 11mm ARP headstuds and Open Deck Block

Jura

 

Cdb insert from ASperformance+cosworth pistons and rods= bullet proof at 400/450

 

That sounds decent. Can you explain the cdb please?

 

standard 2.5 odb, mahle pistons, uprated rods (not sure on make), arp headstuds, acl bearings, perrin intake pipe, sc46, 700cc injectors, 400lph fuel pump, sti top mount, wing mounted induction kit, sti inlet manifold, single avcs heads and ecutek map etc

ran 404/421 when it was mapped but pulled back slight on the road due to top mount not coping and now sat at 385/404.

 

cdb inserts are overkill for 450, standard will do that

 

Give me a shout for rods and pistons, my rods have been run at 650bhp I can do rods and Mahle piston set at £695 for sn members.

 

If i got mahle pistons, uprated rods, headstuds, acl bearings in the standerd 2.5 block. Would my engine be regaurded as strong/safe? Enough to cope with circa 400bhp?

 

Yes, the limit then would be the block, the general rule is 450 on a std scdb, there are plenty running much more but most of us would not recommend it.

 

Okay thats perfect. Other than that all i need is turbo, ecutek or something? Injectors?

 

What's the maximum power run on a standard 2.5 bottom end?

 

do it once incase u get a thirst for power
cdb/rods /pistons/cosworth gaskets/upgrade injectors and fuel pump and have a bullet proof 450 of each

 

This still impresses me, especially on the ODB. What heads were you using out of interest Jura?

Sorry to go off topic OP, although this thread does interest me also for the future forging of our hatch

 

the 2.5 engine is a different animal dont risk running high power without doing all u can to limit its weak points
the 2.0/2.1 odb can take more stick the 2.5 cant

 

For what it costs its worth doing in my opinion, and its then the ultimate block and like i said bullet proof, anybody considering building a 2.5 should get in touch with alyn i was shocked at how little this costs

 

Any one got any contact details for as performance?

 

Hi there

We are used JDM WRX AVCS heads with stock cams and stock valves/springs.

Many people run 2.0L OBD in excess 550bhp without the issue,OBD block is OK,if you are not looking to break 550bhp,2.0L block liners are thicker than 2.5L

But if you are thinking to run more than 1.8-1.9bar I would add 14mm headstuds,but at this stage I wouldn't consider OBD at all,probably i would rather go with CDB or CDB insert

Jura

 

It still won't make it bullet proof imho, I've seen first hand how thin the liners are and that's what will cause your problems. When put side by side with a new age 2.0ltr liner you see how thin they actually are, whilst the insert will help limit the movement it still won't cure it.

Was recently going to send an engine for the insert myself, only reason we didn't go with it in the end was down to the fact she is never going to run a bigger turbo to make use of that spec engine, so went the pinned route on a SCDB instead. I was very surprised at the cost as well tbh of the insert £450 plus carriage which i thought was very fair.

 

No doubt the 2 litre block is stronger, as far as the bullet proof phrase goes your right nothing is totally bullet proof, not even the 2 litre cdb but all you have to do is look at the afp car which is running well over 1000hp on an odb eg33 with an as performance closed deck inserts so i think that at 400/450 i can safely use the term bullet proof in this case, obviously they are different blocks but the evidence that the insert can do the job is clear to see