Hi,

I have a 2004 Impreza STI Type UK with Prodrive performance pack.
I am looking to upgrade the turbo to a TD05 18G, what other supporting mods would i need to get the most out of this setup?

My list so far:

1: TD05 18G turbo
2: 3 port boost solenoid
3: Fuel pressure regulator
4: GT spec headers
5: 3" turbo back exhaust
6: NGK PFR7B plugs
7: RCM Induction kit

Thanks
Harry

You'll need a remap too

See my profile mate :D
Subaru now sold but was a great performer on the road

No need for the Fuel Pump Harry as it's part of your PPP. I'd also add a fuel pressure regulator to your lsit. Apart from that you'll have a nice setup. Should be good for 380ish Bhp maybe a bit more depending on the map

Thanks for the advice/info guys, I allready have a spare ECU that i will have remapped for this setup. I am collecting a turbo today.

Will the TD05 turbo fit in place of the original turbo or will i need to buy any hoses etc...?

I am looking to have the whole setup fitted and mapped within the next four weeks.

I was thinking of buying a set of headers from Andy Forrest or Zen performance. My current exhaust setup consists of the PPP cat and centre section with an unbranded 3" angled back box. I think it would be best if i changed to a full 3" system but i would like to have an angled tail pipe, any recommendations?

I thought the 20g was better suited to the six speed sti gearbox?

Hi Harry,

If you haven't purchased a TD05-18g yet, PM me for a great price :thumb:

Hi there, i have same car as you and am currently doing the same but opting for the md321h. to get the most out of this i was advised to get a set of 660cc injectors and to get rid of the standard air box and go for something like the rcm induction kit then this shuold see it good for 380-400 bhp. car already has ported/wrapped headers and flow matched u/p with 3" decat d/p k&n filter prf7b plugs and remap, this alone hit 350 bhp with nearly as much torque. So depending how far you want to run with this i would consider the injectors and air filter and it will give you more room for future improvements or tweeks.

Colder plugs (ie. NGK7's)
Cold Air Induction Kit

The rest you have covered. If in doubts, View my Scooby. :D

It really does perform well on the road. Well rapid motor.

Hi there, i have same car as you and am currently doing the same but opting for the md321h. to get the most out of this i was advised to get a set of 660cc injectors and to get rid of the standard air box and go for something like the rcm induction kit then this shuold see it good for 380-400 bhp. car already has ported/wrapped headers and flow matched u/p with 3" decat d/p k&n filter prf7b plugs and remap, this alone hit 350 bhp with nearly as much torque. So depending how far you want to run with this i would consider the injectors and air filter and it will give you more room for future improvements or tweeks.

I am aiming for approx. 390 BHP, I have been advised to fit an adjustable fuel pressure regulator by some tuners and others have advised me to fit 650cc injectors. I do not plan to take the car any further after this setup, I think i may change the FPR if it is suitable for my application to keep the costs down.

Most tuners are recommending ceramic coated headers but they cost approx. £800 :(, is it worth spending the extra money to have ceramic coated headers or will it be ok just to heat wrap the headers?

I will add the colder plugs and an RCM induction kit to the list.

I'd personally go for the APS 70mm CAI as it sits inside the inner wing and draws much colder air than the RCM which sits inside the engine bay

veiw mine. An 18g is great on a 2L sti with instant response

Does the 04 UK STI have side feed injectors?

I'd personally go for the APS 70mm CAI as it sits inside the inner wing and draws much colder air than the RCM which sits inside the engine bay

As above, plus it's easier to set up a cold air feed for it.

Harryr34; ported and wrapped headers will do the trick if you're not going further and will help the response. Check the banners at the top, Harvey and such do this. At around half the price of ceramic coated headers.

Gaz what size hose did you use on your cold air feed ???

I have ordered the following parts:

1: APS 70mm Induction kit
2: Kakumei GT Spec headers & up pipe (heatwrapped)
3: Kakumei 3" decat turbo back exhaust
4: Turbosmart 3 port boost solenoid
5: TD05 18G turbo
6: NGK PFR7B plugs
7: Dlow matched set of 650cc injectors
8: Walbro fuel pump
9: Apexi AVCR Boost controller (will use this instead of the 3 port)

I allready have a TD05 18G turbo and an Ecutek'd ecu that i will have remapped for this setup.

Thanks for the help!

No regulator needed if you go for bigger injectors which is why i went the injector route. I was also advised to go for the pump as it has been known for the uprated one not to be fitted when the ppp was installed. For the sake of £70ish its well worth the peice of mind to do it

Look at my scooby. I would go for the AVCR boost controller rather than the three port (Ive had both) as the AVCr gives a lot more tweaking capabilities for lower down the gear/rev ladder. Also you can have a low boost setting if you fancy saving some petrol every now and then.

Gaz what size hose did you use on your cold air feed ???

It came with the Pipercross kit mate. I think it's about 3" diameter.

They sell the kit at Halfords. (£25) You can split the kit with someone, as there's 2 trumpets and ample hose.

I just sold the other half.

I have ordered the following parts:

1: APS 70mm Induction kit
2: Kakumei GT Spec headers & up pipe (heatwrapped)
3: Kakumei 3" decat turbo back exhaust
4: Turbosmart 3 port boost solenoid
5: TD05 18G turbo
6: NGK PFR7B plugs

I allready have a TD05 18G turbo and an Ecutek'd ecu that i will have remapped for this setup, need to sort the fueling now!

If i fit a set of 650cc injectors will i need a fuel pressure regulator?

Is the PPP fuel pump good for this setup?

Where is the best place to get a set of flow matched injectors?

Thanks for the help!

Sounds like a great setup. :thumb: Interested to hear how the remap goes and your comments i wish i could go back and do it again. The car is a beastie. Quite a handful at the start, but you get used to it.

I would heatwrap the downpipe on the exhaust too.

No FPR needed if you go for the bigger injectors. I opted for neither and it ran fine on standard injectors. My injectors run at 94% duty cycle though. If i was modding further, they would be replaced.

Make sure you do have actually have the uprated pump. Walbro 255 (£80).

Try Lateral Performance & Roger Clark for the injectors.

Arghhhhhh! looks like my plans maybe on hold for a while as i placed an order with Flat4online for Kakumei headers, exhaust and an Apexi AVCR but no signs of any delivery. I requested a refund and was told read our term and conditions "we will offer a refund within 30 days"!!!

Is there anyway i could claim my money back sooner, i paid using a credit card!??

Should be good for 380ish Bhp maybe a bit more depending on the map

i doubt an 18G will make that without methanol TBH, my 20G just puts that out :)

i doubt an 18G will make that without methanol TBH, my 20G just puts that out :)

Octane booster. ;)

Is there anyway i could claim my money back sooner, i paid using a credit card!??

Buy the parts from someone else on the credit card and hopefully you'll have the others refunded before the payment is due. :)

That would be the impatient subaru modifier anonymous (ISMA) groups' answer.

Octane booster. ;)

what sort of boost levels are you guys running to make these figures on an 18G :)

what sort of boost levels are you guys running to make these figures on an 18G :)

1.63 peak, 1.4 constant IIRC.

1.63 peak, 1.4 constant IIRC.

aye thats quite high compared to me, im making 370 @ 1.3 on v power and 400 @ 1.45 on meths, maybe about time i got some more boost dialed in lol :lol1:

aye thats quite high compared to me, im making 370 @ 1.3 on v power and 400 @ 1.45 on meths, maybe about time i got some more boost dialed in lol :lol1:

Don't be shy. You know you wanna... :D

Don't be shy. You know you wanna... :D

it would make sense would it :D:D

Buy the parts from someone else on the credit card and hopefully you'll have the others refunded before the payment is due. :)

That would be the impatient subaru modifier anonymous (ISMA) groups' answer.

All sorted with flat4 i hope! Have been told the parts are due in next Monday. I got to be patient :lol1:

Is it worth spending the extra cash and going for a MD321H turbo instead of the TD05 18G?

I plan to have the car mapped on V power, what sort of figures am i looking at with my planned set up and both turbos?

Thanks
Harry