MightyArsenal

Hi all,

New to the site and Subaru's as a whole, been the owner of a 2007 hawkeye STI now for around 5-6 months, currently running around 310/320bhp with uprated clutch, lightened flywheel, front and rear strut braces, CAT back 3" exhaust, upgraded panel filter, just purchased some EBC BlueStuff break pads yet to be installed.

Looking to increase the bhp and car as a whole, in an ideal world I'd like to reach around 400bhp (achievable with the stock turbo from other posts I have read) any ideas on where to make a start on would be greatly appreciated.

Been looking at Headers, Up/Downpipe, Front mount etc etc before being remapped.

again any ideas and help would be greatly appreciated.

sorry in advance if there's a thread already on this, i did have a look around but couldn't find anything in particular.

Cheers

poolio74

In a nutshell mate, I wouldn't be going anywhere near 400 on a standard engine. Your probably pushing your luck as it is. Sorry to **** on your parade, so to speak.

MightyArsenal

ahhhh ok mate, thanks for the reply. so really if I'm looking at going any further I'm looking at more internals than anything forged pistons etc etc.

poolio74

Definitely mate. Speak to a decent specialist i.e Engine Tuner, Finch Motorsport, API etc etc. They will point you in the right direction.

Gambit

iTrader: (6)

350bhp/400lbft is usually the safe limit on std internals and std vf43 turbo. Any higher and ideally you want forged pistons. Std headgasket can go at any bhp!

MightyArsenal

thanks guys, I think I'll start looking more into the internals then. any recommendations e.g. forged pistons , connecting rods, cranks etc ?

Bez300

iTrader: (2)

The good this if you go forged, for a bit more money, you will see close to 500/500 with std position gt3076
On a built 2.5 you will have a fantastic road car

Bez

beefoss

iTrader: (2)

Don't know if this would be much help but it has been known for the standard intake and STi intercooler to be adequate for reaching up to (and above in some cases) 400bhp.

mickeymouse

My head gasket let go at 340bhp..they are really a ticking bomb...

If your going to forge the internals then I would forget about power figures for awhile and just do the internals.. By that I mean pistons, rods, oil pump, head gasket, oil pick up, bearings etc etc..I would also suggest that you get the block closed and go for 14mm head studs.. I never done the closed block or head studs and I bitterly regret it..!!

Know your limits, don't kid yourself or bullsh1t yourself.. We ALL say 'I want around 400' etc but at the end of the day we nearly ALWAYS want more... So if you do All the internals first, then it doesn't matter what figure you really aim for.. The standard semi closed block is only good for around 450bhp give or take..

Even if you have to wait another year or so to get the add on likes turbo, front mount etc.. Then this is the route I would take.. Basically beacause you won't have to break open the block again,, which is where the costs start to mount with labour charges..

So....

Research..
Plan..
Ask plenty of questions..

And personally I wouldn't have a figure in mind... Because you'll only end up breaking it!!!

mickeymouse

Oh and as a side note... don't forget about brakes and handling.

jazzyjembreaze

iTrader: (11)

Was a pleasure reading that post #9
Mickey

MightyArsenal

Looks like internals is definitely the route to take, appreciate the posts fellas.

Time to start some research on what to go for!

FlatoutDave

Doesn't matter what you do the problem you've got is that weak 2.5 engine, I'd do an engine swap and put a JDM 2.0 litre twin scroll in probably cheaper than forging. You'll get easy 380bhp and 400 lbs of torque, it might **** 2.5 owners off but the 2.0 is so much stronger fact

MightyArsenal

Ahh right. Think I'll stick with the 2.5 and start looking into the internals like Mickey suggested. I'm thinking it be better for me to source the parts instead of doing it all through a tuner but like before you probly know more than me haha

mickeymouse

plenty of websites to look at parts.. but youll end up going blind!!! have a chat with a few tuners close to you and see what they do as a package.. you really domt want to source your own parts only for one or more not to fit when the guts is open..


http://rogerclarkmotorsport.co.uk/
http://www.enginetuner.co.uk/home.htm
http://www.apiimpreza.com/
http://www.scoobyclinic.com/
http://www.subaru4you.co.uk/
http://www.lateralperformance.co.uk/




have a gander at those ^^^


they do parts aswell as fitting..


im sure other sites exist..but those they will give you some reading material.

MightyArsenal

Cheers mickey. Massive help mate, I'll have a browse and speak to a few local places like you suggested. Top man

The Pink Ninja

iTrader: (23)

Not as easy as that, Budget for a new ECU(syvecs) that will run it too, Cam sensors are different

scoobyboy1

iTrader: (16)

I ran 380bhp 412lb/ft on the standard hawk STi engine, but I was aware that it could be on borrowed time, as long as you know this and are prepared for the worse, otherwise your better off having the engine forged and at least future proofing it for any other mods you have planned.

wms-racing

I'm building more 2.5's than anything at the moment, as long as they are built with decent rods, pistons, arp headstuds and decent gaskets they are fine at 400-450bhp, more than that and CDB conversion is the best option. Give me a call or drop me an email if you want some ideas on the cost.
Andy 07917204738
wmsport@yahoo.co.uk

fat-thomas

iTrader: (4)

do you know what you are talking about???

utter b0llocks

firstly the jdm engine will be twin scroll and therefore need a twin scroll turbo and pipe work.

secondly i doubt very much its cheaper to source the engine and associated bits needed than it is forging the existing poo.5

Bez300

iTrader: (2)

I have run a scd 2.5, this is the graph
1.5 bar of boost GT 3076 std position on a top mount intercooler,,yep top mount

This has done a lot of miles and track miles, still going strong

Then I had a 2.5 cdb
This pushes your eyes into the back of your head
1.8 Bar of boost GT3582 Owens race spec turbo




The 2.5 are by far a much better road car,
Both these had a rev Limit of 7800 rpm, which is good, but not as high as 2.0 2.1 2.2 2.35s
But the power comes in lower down,

I have also run Nos on both these engines, boost comes in 500 rpm lower

No mater what any one says,
When you are getting 500 plus bhp from a 2.0 upto a 2.5 and driving it using all the power, eventually it I'll let go

Bez

mickeymouse

very very nice who closed your block?? I assume you had 14mm studs aswell do you also have an aftermarket ECU??

InTurbo

iTrader: (3)

Just incase your not ready to go forged yet.
Adding a fuel pump, decat down pipe and remap to what you already have will make for a very good road car with high torque levels.
I wouldn't bother with headers as this tends to lower spool times on the vf43.
There best fitted with bigger turbos.
You can fit a front mount but the oem one is good for just over 400bhp

Think that anything more than 1.3bar will definitely start to lift the heads so don't be greedy.
Some people have got away with more and some have gone on standard engines, just down to luck I guess.

I had a 06 hawk Sti and the HG went at 18k after being mapped to 1.35 bar and when rebuilding it had signs of early ringland damage.

Now have a 07 Sti that has 26k and had been running 350bhp for 3 years when I brought it.
I rebuilt the engine before adding any more mods and the Pistons were perfect and not a sign of HG problems.

So like I said all down to luck.

Bez300

iTrader: (2)

It was Alyn at AS performance who closed the Deck, yup 14mm bolts were used
And Alkatec ECU

Thanks

Cpt Jack Sparrow

iTrader: (14)

Totally agree with that well said

ditchmyster

iTrader: (7)

I bet it does, Jesus H Christ that's not even a curve, must feel like your going to the moon.