PIECJ STi

What would be needed to get a version 4 sti to around 320bhp ?

Full Exhaust system (what make recommended? Cost ?)
Downpipes ? (Make & Cost ?
Air Filter/Induction Kit ? (Make & Cost?)

how do i remap a version 4 ? as im sure ive read i cant ecutek it as i would a version 5 or 6.


many thanks
Carl

gpssti4

iTrader: (6)

I think there maybe some tuners who can remap it (as I was told), otherwise it's a new ECU.

rmtypeR

I got 322.9bhp on my STi V4 with the following:-

Full turbo-back decat exhaust (Hayward & Scott, approx £500)
Apexi Power FC (supply, fit and map is about £900)
Oh, and an uprated fuel pump, although that may not be strictly necessary (Walbro £80)

The standard air filter will be fine.

Gear Head

iTrader: (2)

I got 313bhp on my old sti4 with just a full decat and panel filter.
I had the fueling checked and it was spot on.

Mocom Racing

iTrader: (2)

remapping of the v4 is in the pipeline but for the time being you'll need a mappable ECU cheapest being the Power FC, fuel pump, plugs and exhaust (decat or sportscat).

mozzaITA

I was told you need FMIC too for 350 bhp??

Mocom Racing

iTrader: (2)

The post was for 320bhp, 350bhp you would need a FMIC, WI and a suitably large turbo

mozzaITA

So you would have to ditch the v23 then? i was told it would be sufficient for this.

Sorry ive hijacked the thread :-(

i want 350 lol

PIECJ STi

keep going nice to see whats needed on shopping list for next stage lol

DevilHimSelf

i have 350+ coming out of my TSL tuned 00 classic, no front mount.

So i think that statement may be slightly asque!

MartynJ

Hayward and Scott exhaust , headers from RCM or Lateral , SimTek ecu and a decent panel filter K+N or similar...
These should see any easy 320bhp on the topmount if your car is a good one...

harvey

iTrader: (48)

My STi 3 Wagon on a VF23 made 335 bhp 333ft lbs. on a Dyno Dynamics RR on several occassions This was with a GBE valve lifting boost to 1.4 bar mid range, Walbro 341 fuel pump, my own ported headers and up-pipe, Revolution down pipe and 3" exhaust system and aftermarket pannel. However the O/E Subaru pannel is just as capable. NGK PFR 7 B plugs. The car was also on O/E ECU, injectors and TMIC. Relevant parts including the headers, up-pipe, D/P and turbo exhaust section were heat wrapped.
The turbo was at the limit of its performance and I was measuring ACTs which could rocket past the guage max scale of 69.9 C in a sprint 0-100mph from normal operating temps.
I would think that 320 bhp or thereabouts is easily achievable with similar mods in line with rmtypeR's achievements but you will need to have AFRs carefully checked to be safe.
ACTs on any Classic will rise alarmingly beyond 300 bhp and more so on earlier cars with the slanted TMIC.
Tubular headers would be a retrograde step until you were flowing much more air, certainly 450 bhp upwards, perhaps more.
DHM. Nobody doubts you can produce 350 bhp with a TMIC but what are your ACTs on WOT?

Skoobie Dhu

iTrader: (3)

My V3 wagon managed 326 bhp with a full decat and k&n (+ bottle NF race). There were 20 cars there in total and the standard V9 STi's were producing bang on the mark. RR operator wouldn't accept it was virtually standard and was impressed at max power @ 7,500 rpm

Mocom Racing

iTrader: (2)

Care to elaborate with the exact spec including turbo?

This is what can happen to a VF23 when pushed................

Tidgy

speak to Scooby Clinic | The UK's Largest Independent Subaru Specialists | 01246 590 807 - Chesterfield S42 6QX, they can now map early classics

mozzaITA

so mocom you would suggest a turbo upgrade for a 350bhp spec?

rmtypeR

Just to respond to your question to Mocom from my own experience...

My car was mapped at 1.2 bar. At that point the injectors were running at over 95% duty at the top end of the revs - so for more power they would need either replacing with larger ones (550cc maybe), or if you fit an adjustable fuel pressure regulator you can increase the fuel pressure which let you get a bit more power out of your standard 440 injectors.

As I understand it (although I could be wrong!) the std turbo isn't worth taking much over 1.2 bar as this just results in it heating the air up too much. It can be increased mid-range to maybe 1.4 bar which would give you more torque but not much more peak bhp.

I'd say it's best to either:-

a) be happy with about 320bhp,

b) or go for a new turbo, injectors, and intercooler which could get you approx 400bhp (anymore and the engine internals would need looking at). But then of course, the clutch would probably not be able to cope, and the gearbox may not last long either).