TypeR99

iTrader: (2)

Thinking about going 2.5 and have read up lots on what a 2.5 can/cant do, weak point obviously being liners, pistons and ringlands.

May have the chance to buy a 2.5 sti block with forged cp pistons, sti 9 crank/rods, standard semi closed block so wondered if this will sit happy at 400/400?

My standard sti v5 engine will be coming out soon so the heads will be swapped and I have most of the other ingredients. And yes, I realise my 5 speed box will probably not stay friends with me for long at that power, but my finances mean I can do the 2.5 and have options on a 6 speed at the right price.

I believe 400/400 makes a nice 2 door road car with the odd trackday so would be nice to know if the 2.5 i'm looking at is worthy.

merlin24

iTrader: (1)

Assuming you will be using at least a 11mm headstud kit, then the 2.5 with forged pistons will happily run 400/400 when mapped correctly.
In regards to the standard bolt type rods, you wont have a lot of headroom for further power and specifically torque gains in the future.
Ideally, you would have your Sti V5 heads chambered out to match the larger 2.5 bore.

Mick

TypeR99

iTrader: (2)

Thanks Mick, I dont propose to go higher as I know it wont take it so thanks for the advice

mickeymouse

As I understand it if you change the pistons, rods, gaskets, and arp bolts then the next weakest link is the block itself.. Being semi closed.. If you do those mods then it's commonly accepted that a semi closed 2.5 block will go upto 450bhp before it it needs closing.. Obviously their are exceptions as in any other modding.. I've seen semi closed blocks on a 2.5 at or just over 500bhp.

I myself am sitting around 450 with rods, pistons, gaskets, 11mm studs and a few other bits but I'm still on a standard block..i.e. Semi closed..

mickeymouse

Just to add.. If your going over 500bhp or your having the block closed then it would be smart/essential? To go 14mm head studs.

scoobyboy1

iTrader: (16)

If you was having the work done to go in a hawk/hatch etc then fine, but why put that 2.5 engine in a classic Type R, there are much better engines out there(built 2 litre or even stroker 2.1)

TypeR99

iTrader: (2)

If you can find me a built 2.0 or a 2.1 for £800 then let me know, because thats what the 2.5 forged is costing me. Its come out of a mates car, been run for over 3 years at around 360bhp on a vf43 but he needs the money, the cars got a blown gearbox and other issues and now he needs to move house. I've helped him in the past so he's letting me have it cheap.

scoobyboy1

iTrader: (16)

For £800 you cant complain, thought you was going to spend £4-5k having a 2.5 built. What heads are on it?? and what car was it in??

TypeR99

iTrader: (2)

wrx newage heads from a 2004 blob. 11mm arp's, cosworth gaskets. I dont drive my car on the limit everywhere, i just prefer the driveability of the 2.5 as I find it better than a 2.0 and you dont have to drive it as hard to put a smile on your face. Chances are i'll run similar power to what my mate was, I just wanted to know the potential IF my 5 speed dccd gives up and I go 6 speed.