imfomation on impreza turbo upgrade on gc8

[whatchain]

hi, my car is a v4 sti type r and it currently has a vf24 turbo. im looking to spend maybe around 2000 on upgrading the car to make a bit more power. would like to get some feedback or suggestions on what to do. 2 things i want to ask.

First: i reed from a few fourms saying that the vf24 turbo has a max power output of around 325hp. is there anything reason why i can't just raise the boost to increase the power? what would i need to modify or improve to reach say the 320hp mark? only related mods i have atm is a 3" catback exhaust and a dual stage boost controller.

Second: also can can any1 tell me what other vf turbos can be directly bolted on (vf34 perhaps)? I haven been on trademe looking at a t3t4 and tdo5 turbo, just wondering what do you guys think of those turbos. would it be a good option?

[MercuryFree]

Most VF's will bolt on, including the 'big ones' ie. vf22, vf23, vf30 and vf34.

You can raise the boost to increase the power, however this is not infinite and is limited by a number of factors including turbo sizing, turbo efficiency (vs rpm band etc), injector sizing, intercooling setup, ecu, tune etc.

[Timmah]

Buy a Link, get a tune.

[Guest]

What are you using the car for and what do you want out of it? The hp figures on VF turbos are a crock unless theyre fly power. From dyno sheets Ive seen VF24 max out 180-200kw atw I think? To max out a VF23/22 you need to get a walbro or equivalent too. Anything bigger than that will need custom work unless its subaru flanged and you will run out of 2g fast. You may be better to just get a possumlink if you arent planning on big mods later otherwise G4 seems preferred.

Id do possumlink 300-600, tune 600-1000. walbro 120, split rails 50, rear swaybar 200ish.

320hp is a bit of a dream tbh unless youre talking flywheel power.

[G-unit]

with a vf22 i got 216kw @ wheels on 16psi with aftermarket ecu. link G4 would be easiest and safest way, but what psi are u running now?

[whatchain]

hmm interesting comments..

 G-unit said:

with a vf22 i got 216kw @ wheels on 16psi with aftermarket ecu. link G4 would be easiest and safest way, but what psi are u running now?

It's 2 stage set at 10psi and factory boost which is around 16-17? i know the link would be best option but i will looking over $3000+ to get it get one and tuned. just wondering would fitting a bigger turbo $500, front pipe $300-400 and tune $1000+ would be a better option. like i said im not looking to push it too hard. but just not sure would all the other component eg. injectors, intercooler, fuel pump be up to the task.

[G-unit]

yup 16-18 is stock, go the usual route, bigger vf turbo, walbro and try for a tune, most cant tune the stock ecu tho

[whatchain]

 G-unit said:

yup 16-18 is stock, go the usual route, bigger vf turbo, walbro and try for a tune, most cant tune the stock ecu tho

so what would be a gradual step up from a vf24? the bigger the number the bigger the turbo?

[G-unit]

http://www.clubsub.org.nz/forum/index.php/topic,1569.0.html

have a read there bud, vf 22 is decent, but no the larger number doesnt mean better, i have vf 28 and the 22 is bigger

[whatchain]

nice. just what i wanted to see... so it seems almost all the turbos are can be bolted on and have the same HP ratings. if a vf24 really is good for 325whp as stated. wouldn't it just be a waste of time n money to replace the turbo? might get more out of it just from effectively a good tune or maybe upgrading other components? just wondering how much difference would a bigger fuel pump and front pipes added to the already existing catback exhaust give after a tune.

[Timmah]

 evowrx said:

To max out a VF23/22 you need to get a walbro or equivalent too. Anything bigger than that will need custom work unless its subaru flanged and you will run out of 2g fast. You may be better to just get a possumlink if you arent planning on big mods later otherwise G4 seems preferred.

Id do possumlink 300-600, tune 600-1000. walbro 120, split rails 50, rear swaybar 200ish.

+10000 this.

Also, I don't think anyone can retune a Subaru ECU older than V6.

[G-unit]

wrc development in napier can do ver5/6 ecu reflashes

[whatchain]

mines a v4 tho :'( ... r u guys 100% sure the v4 can't be tuned. because one of my mate said it might be able to.

[Stoffa]

if I had my time again I'd just buy a link g4 and get it tuned on a factory set up, you'l probably get 220kw atw

[Ninja8)]

 whatchain said:

mines a v4 tho :'( ... r u guys 100% sure the v4 can't be tuned. because one of my mate said it might be able to.

Definitely cant tune a factory v4 ecu. If you are interested i have a VF34 to let go if the offer is right. Pm me for more details when you are ready

[boon]

 Stoffa said:

if I had my time again I'd just buy a link g4 and get it tuned on a factory set up, you'l probably get 220kw atw

220wkw seems to be about the limit of a VF23, and that's at 20+ psi. Dunno if a VF24 would quite stretch that far.

There is no way a VF24 will do 240wkw (that's ~325whp) without running E85.

I got 231wkw from a VF34 and that was with pretty much every possible stock-location mod done.

[pedro]

220KW@Wheels would be at the limit of the standard rods i would think..That is assuming a reasonable life for the engine.

[Stoffa]

sweet put a P20 housing on it then

[whatchain]

i was reading one of the threads on here and apparently on the NZEFI website under dyno tuning, it says the Subaru WRX/STI V1-4 factory ecu tuning can be done? http://www.nzefi.com/services/dyno-tuning/

[Timmah]

 whatchain said:

i was reading one of the threads on here and apparently on the NZEFI website under dyno tuning, it says the Subaru WRX/STI V1-4 factory ecu tuning can be done? http://www.nzefi.com/services/dyno-tuning/

Yup, if you saw the reply they sent me, they can be tuned. Didn't say prices though.

[whatchain]

just went to nzefi today after seeing their post in christchurch section. they reckon with my current set up, yellow injectors, oj afm, catback exhaust and boost controller i would get around 220kw atw tuning the factory ecu. for $1400 that seems like shit all power. what else can i do to get the maybe a higher out put? would like to get the most out of the engine and turbo within a safe limit. has anyone got a higher power output with a vf24?

[chappell943]

 whatchain said:

just went to nzefi today after seeing their post in christchurch section. they reckon with my current set up, yellow injectors, oj afm, catback exhaust and boost controller i would get around 220kw atw tuning the factory ecu. for $1400 that seems like s*** all power. what else can i do to get the maybe a higher out put? would like to get the most out of the engine and turbo within a safe limit. has anyone got a higher power output with a vf24?

I imagine that is near the end of the turbos efficiency, also the 440cc injectors will nearly be maxed out at 220wkw (depending on AFR's), not saying upwards of 220kw isn't possible, just suggesting the extra 10-15kw might not be worth it.

[thorpy]

I wouldnt say its shit all power , should be circa 350 fwhp

Although at a guess the 24 would be well at its limit and creating temp issues.

[whatchain]

one of guys i know said he tunes a subaru with over 400hp with yellow injectors and orange afm. so maybe it won't be an issue? $1400 for 15hp is shit all not worth it one bit. hmm, prety much out of options at the moment. unless i get one of those shitty chinese td04 bolt on turbo on trademe or something, promises to deliever over 350hp??.... but thats probably a shit option?

[Guest]

 whatchain said:

one of guys i know said he tunes a subaru with over 400hp with yellow injectors and orange afm. so maybe it won't be an issue? $1400 for 15hp is s*** all not worth it one bit. hmm, prety much out of options at the moment. unless i get one of those s***ty chinese td04 bolt on turbo on trademe or something, promises to deliever over 350hp??.... but thats probably a s*** option?

You do realise that its a lot more than a 15kw gain? Stis being 206kw is a flywheel figure...besides if you change stuff in your setup then dont tune you will never reap the rewards. Ive talked to a few tuners all said around 200-220kw atw safe tune. Thats sti v6 VF23, fmic etc.