I've decided i am going to aim for 350 bhp and as close torque with my uk classic then stop myself from going any further to keep the mrs happy!!! (apart from a gearbox if it needs one lol)

2.5 litre sti short block (brand new)
Standard uk classic my 00 head
nismo 550 cc injectors
warlbro 255 fuelpump
Fuel lab fuel regulator
FMIC (and of course K&N panel filter replaced with induction kit)
Stainless headers
Scooby clinic up pipe
Hayward and scott full de-cat system
Here is the decider i am currently running a vf 35! Is this going to hold or am i needing a td05 16 or 18g?
Eku-tec Map

Uprated exedy clutch, flywheel and pullies all ready on by the way.

Any thoughts would be nice before i take the plunge

cheers steve

 

Is there something wrong with your current bottom end? The standard one should be quite capable of handling that sort of power if its been looked after...

 

Isn't it a bit of a waste to go for a 2.5 block if you're just aiming for 350bhp?

Nice for torque, I suppose, but you could easily achieve the power on a 2.0 block also, surely

Also, is the fuel pressure regulator needed at this level? The 550's should flow enough for 350, I think?

 

As above, 2.0 block would surfice i`m sure, VF35 i`d say 340ish, what gearbox do you have at present, that might not hold out, especially with the torque being upped...

 

bottom end is fine, after speaking to tuners i have been told that uk pistons give way at 1.3 bar or around 330 bhp. So a rebuild would be needed with forged pistons and rods etc to reach a safe 350 bhp for standard gearbox, and this should be done properly with engine out and everything else checked out etc, been quoted around £2500 for this + Vat + mapping etc. £1500 gets me a brand new bottom end with sti internals which would easily handle the power. I plan on keeping the car for a while so i want safe reliable power and of course no future rebuild costs. Got a mechanic to swap the bottom ends it's just the map that would cost me.

oh the fuel reg is all ready on henrik, with the pump as i am on the standard 440's, scooby clinic recommended this when i had my vf 35 etc last year when i was mapped to 303 bhp

cheers

 

thats a load of crap as up to 400bhp can be achieved on standard internals wether its sti, uk spec or wrx, and this isn't coming from me its coming from andy forrest one of the most respected tuners amongst subaru enthusiasts, i myself am running over 1.3 bar boost on a standard wrx engine and its done over 80k miles and still going like a rocket! It all depends on your supporting mods and who maps it, heres what andy forrest has got to say....

AndyForrestPerformance

 

my vf35 made 357bhp/360ftlb, take it from me do some research and choose ur mapper wisely, like K18LLR said

 

cheers for that, i aint going to start mentioning the tuners who gave me that info but i will possibly look into keeping my bottom end instead of spending money then. you can see the list of supporting mods i have added so in theory it should be possible. It's just that i have listened to the advice of the tuners which say uk internals give way at 330 bhp?? i aint no mechanic i just drive the thing so you do take the advice of the professionals.

cheers steve

 

mapped CORRECTLY the 2.5 sti short block should be safe upto around 370bhp with ease.

 

I wouldn't want to run a standard uk or wrx bottom end at 400hp. it's been done, but it's not a recipe for long term reliability. But the question should really be, why are you chasing figures?

 

Doesn't everybody who uses their scoob as a hobby want to chase figures? Granted driveability is a massive factor when you use the car as an everyday motor (which i do). But if you are handing hard earned cash or the credit card over to a tuner who says buy this, buy that and we will get you x or y amount of power, the figure at the end of it, is the breath of fresh air and the thing which makes you smile when you have just handed over a few grand? Please stop me if i am wrong but surely you want the best and safest option for your money. I can't speak for everybody but when it comes to modifying a car you could go on forever i.e spend 100 grand and drive away with a carbon copy of this years subaru wrc car. Or say right, i'm happy with my car running 350 bhp on the road. When i get bored of that i might buy a 700 bhp skyline? But for now whats wrong with having a safe goal. And this goal can only come from tuners saying x amount of cash will get you 350 bhp if you are happy with that. Sorry for the essay, just wanted to get the point across.

Thanx for your input guys

Steve

 

ur very right, i chase figures myself lol

 

Hmm, I'm under the impression that you can get a safe 350'ish from the stock internals, but having said that, I'm just an armchair tuner At the end of the day, it may break at those levels, but I think it depends on how it's driven. It's possible to rag a standard engine to death, and the same probably goes for the 350bhp one (just that the 350 bhp one may die a bit sooner). My personal belief is that as long as you treat the engine / gearbox with some sympathy, you will be fine (but don't quote me, and don't send me any bills after the engine lets go )

I also think that it's not just about the level of boost you run. Some turbos will flow a lot more at any given boost rate, which means that you don't need the same boost pressure to achieve a given power with different turbos.

I'm also on the engine mod path at the moment, so will follow this thread with interest.

 

The Standard bottom end will handle 350bhp with problem IMO, mine has been above 300 bhp for quite a while now and is currently around 360bhp i would guess. I run 1.5 bar peak boost holding 1.4 bar tailing off at the top.

IMO you will be pushing a VF35 to get 350bhp, it has been done, but 330-340 is a more common figure.
I wouldn't say 350bhp is exactly a safe limit for your gearbox either, they have been known to break at less.

 

Well I'm after a new engine and this thread has made me re-think my options now:
Option 1:Rebuilt engine using forged pistons and steel rods,cost around £3k
Option 2:Brand new Spec C engine plus new management to control the variable valve timing,cost around £4k-£5k depending on which management and whether I fit myself or not.
Option 3:Buy second-hand wrx engine,drop it straight it in,hope it stays in 1 piece at 1.4 bar Cost around £500-£1000

Opinions please ?

 

I don't agree with the above and nor would any of the tuners I've spoken too! I have a VF35 stage two conversion from APi on my std MY99 and it's fine. The key is getting the right supporting components and top class mapping!

VF35 would not be the best choice for 350bhp though , TD05 16G would better.

Why 350 though, 320bhp and similar torque on a classic makes for a very rapid car, with excellent response and drivability, take my word for it.

Personally, I'd stick with the stock internals up to 350 with the right mods and a 1st class map, beyond that, yes, it's probably wise to replace the rods, pistons etc.. These are tough engines if treated and maintained well.

Ns04

 

IF treated and maintained well


couldn't agree more
my short motor came out after 18 months(14000 miles) of 350 bhp (MY00 UK)
and the mechanic commented on how good it was.

sold it to a lad with a blown 99 for £400

stick to around 320 - 330 and you shouldn't have any issues with reliability IF treated and maintained well

 

I'd consider axis power racing as well: AXIS POWER RACING- Services . The strong pound / weak dollar makes this quite attractive (well, it does to me)

Believe there's someone trying to organise a group buy at the moment as well

 

go to flat4online and order urself a 2.5 short block special deal OR speak to paul at zen performance, a few of my mates have had big power engine builds done from him at around £2500 inclusive of parts and labour search the threads for a something called "wizards of zen" everything u need to know will be mentioned..best of luck

 

I have spoken to David@Api and Paul@Zen Performance,both have been very helpful with me,they are both quoting similar prices for similar uprated spec.

The 2.5 block would mean having to buy another turbo as i've been told you can't run a TD05 with that ?

At the moment im leaning towards just dropping in a second-hand unit and hoping for the best.Even if that lets go,I can buy another unit and it'll still cost less than a rebuild !

Any ideas where to go for a good second-hand unit ?

 

why cant u use the tdo5? i know of at least 3 people using it with a 2.5.. another cheap option would be to get a low mileage wrx engine supplied and fiited by essex subaru breakers that im sure wud cost less than £1k

 

A standard TD05 ? Powerstation told me it isn't physically big enough to feed the engine and also the extra capacity of the engine will spin the turbo faster than what it's capable of doing ???

 

yep standard 90 degree TDo5 16g, i even know of someone thats running a 2.5 using a vf23 which is smaller than a TD05 16G turbo he posts on here by the name of R4LLY his car was built and mapped by zen

 

Just shows that you can't believe everything you're told

 

for all of u out there that need a rebuild read this.... 340 please pay particular attention to what turbo hes using lol


https://www.scoobynet.com/dealer-thi...zards-zen.html

 

Lad at work runs a td05 16g on a 06 2.5 wrx..... fitted and mapped by paul at Zen..... works very well

 

Also, I believe that the 2.5 WRX's even run a TD04 (shoot me down in flames if I'm wrong), which is even smaller than a TD05

 

standard fitment on 2.5 wrx is indeed a td04......

 

2.5 works nicely with a td05, it's never going to make lots of top end power, but it's a nice spread of torque with enough power for most people. You will need to port the wastegate on a td05 though to prevent boost creep.

 

Maybe they were assuming you wanted to run 1.4bar on your td05 still with a 2.5 engine ?

Don't know if that would make a difference ?