morpheus1870

I have £1000 to spend on increasing the power on my 03 sti PPP. I have already set aside a budget for the mapping so the 1k is for mods alone. Handling has been taken care of with the aid of some pro drive springs and Whiteline bits, whilst Mintex pads cover the breaking.

What do you guys suggest I should invest in and the gains you would expect to be achieved?

Thanks in advance.

Rob Day

iTrader: (78)

Assuming you have standard exhaust I would look at changing this to a full 3" cat back, you could probably make do with 2.5", but as there is little money difference I would go 3". Set of Tubular/ported headers and up pipe, Walbro 255, CAI, and maybe even look at running on a splash of meth if you getting mapped anyway (so free power, no extra cost there). Keep the VF35 and you should have a failrly lively motor, somewhere near 370bhp+ with a bucket load of torque. Should have plenty change if you search on here

HTH
Rob

morpheus1870

CAI?

Rob Day

iTrader: (78)

Cold Air Intake

jura11

iTrader: (7)

Cold air induction kit


Jura

morpheus1870

The car is currently supporting the ppp exahust, what kind of power is this good for as a maximum? Also don't want to run meth, just Vpower.

Summary:

full 3" cat back
Uprated headers & up pipe
CAI
Bosch pump (not happy with the walbro)

Can people suggest makes and suggestions? I have previously bought all my sti's already moded, this is the first time i'm doing it myself starting with a good base.

dazdavies

iTrader: (22)

Not sure why you're unhappy with the walbro. Mine managed 450bhp without issue.

GT Spec headers (RCM, Lateral, Scooby Clinic)

APS CAI is pretty good.

Revolution 3" exhaust system is supposed tobe pretty good.

morpheus1870

My previous walbro had problems during a mapping session. The specialist told me he was seeing more and more cases of the walbro's failing. I know that there might be isolated cases however from my own personal experience I also advice from someone much more in the know i thought to go with the Bosch.

Thanks for the advice, any other alternatives?

jura11

iTrader: (7)

OK with your setup,which you have you will be looking at 330-350bhp(350bhp is rare,but possible)

3" is not necessarily,your 2.5" is OK if you are looking for 350bhp,,just buy decatted dp or sport cat.

Headers and up pipe, suggestion is Harvey set is best bet.

CAI,your OE panel filter is OK,i would go with OE airbox,OE airbox is OK up to 400bhp,i would go with CAI,if you are looking for FMIC at future.

Walbro pump are OK,if you are buying from dealers,not eBay(AS performance,Lateral Performance etc),if you arte not happy with Walbro i would suggest HRC 340lph(i'm using this on 500bhp),this selling JAutos and highly recommended guy and very helpful.
Just remap and you should have nice 330-350bhp STi.


God luck

Jura

Rob Day

iTrader: (78)

From my experience of getting to 400bhp, I went:

3" Exhaust, had a few, now got Miltek
CAI, again had a few, now HKS with Maf fitting
Original TMIC
Original Injectors
Walbro 255
Hayward and Scott headers, and up pipe.
Sard FPR

GT30 Turbo
76mm Samco

So if you add the VF35 to the above if you staying with the standard turbo then its within budget. If you add a 2nd hand 20G then you'll get closer to the 400bhp marker. It all depends what you plan on doing going forward. I knew that 400bhp would bore me so let margins by fitting 3" zorst and some decent headers, and as things panned out I went FMIC with Methanol and maxed out my injectors

Im still not happy with the car, but know that im now not in a good position to continue, I need to upgrade the injectors, change the ECU and finger crossing push the 2.0 bottom end to its unknown limit.

Rob

morpheus1870

So currently my car has a ppp, what does this consist of then in terms of exhaust system?
what part of the system should I change and what should I keep?
I take it the ppp is a 2.5 system?
Does this mean it is 2.5 diameter throughout the entire system?
Does this mean any additional parts I add need to be 2.5?
I want to retain the cat as the mot is due in a few months.

I want to be running around the 360-370 mark, my previous sti was 340 whilst my last car eve 6 tme was ruining 385.

morpheus1870

Hey rob thanks for that. I want to run stock turbo yes budget won't allow for a 20g. In terms of future upgrades nothing power wise but do want some ap 6pots, lightened flywheel, coil overs etc.

Would be more than happy with 370-380. Can I achieve this within my £1000 budget though (not incl mapping, fitting). Don't plan on a fmic so think will do without the CAI (did however love the sound my hks mushroom made on the evo).

jura11

iTrader: (7)

You have one cat in DP,which can be replaced with Decatted dp or Sport cat(this will pass MOT)

Yes you have 2.5" exhaust all way through,you will need replace DP with sport cat or Decatted dp(downpipe)

For this power you will need at least 20G or 18G with some methanol will do this bhp,VF48 claimed will do this bhp..


Jura

morpheus1870

Thanks Jura, how about if I change to a 3.0 system? What about the headers and up pipe what dia are they? Can I keep the 2.5 and upgrade the headers, up pipe, down pipe with sports cat, pump, remap to achieve better figures than 340-350

jura11

iTrader: (7)

Without the changing turbo,you will be still limited by your turbo there.You will need add there turbo,because with VF35 you will struggle without the methanol make more than 350bhp.

Headers and Up pipe have still same diameter,just don't buy cheap headers please,GT Spec or Harvey headers with Harvey up pipe which will bring spool down,if you want laggy car you can leave Up pipe,i rather change Up pipe for Harvey Up pipe,which is proven by mappers and customers.


Jura

Rob Day

iTrader: (78)

A decent Panel filter will be fine, and you certaintly dont need a FMIC. Have a word with whoever is mapping the car in advance for his suggestions on mods to get you to 370-380.

Me personally I would remove the whole PPP exhaust system in place of something more free flowing, but thats me. You will definalty need to upgrade the Fuel pump, leave the headers and up pipe alone for the being and go for a remap, this will cost you only £300ish for around 350, then go from there. If you really want to spend all you £1000 then headers, up pipe too, oh and lets not forget 3 Port, but then I think the PPP came with a 3 Port boost solenoid

Rob

morpheus1870

Right so good headers and up pipe is needed as deff don't want a laggy car if I went for a better turbo what do you suggest, 20g? Also would the headers still be suitable for the new turbo?

dunx

iTrader: (3)

FroSTI had a set of Harvey's ported headers for sale recently...

dunx

jura11

iTrader: (7)

Headers to 400 you should go with Harvey ported headers and Harvey up pipe best for buck.
If you can find cheap GT spec headers,there i also suggest Harvey up pipe.

20G will do this bhp,18G will be have better spool i must say,this turbo generally will make 350-370bhp with nice spool on AVCS heads(which you have)

Yes your OE headers are suitable for any turbo(bolt on,not rotated),but if you are going up to 400bhp+,you will need at least GT Spec headers


Jura

Rob Day

iTrader: (78)

Hey Dunx,

How's the car going, or not as it seems (no slang intended) you and update, or a thread?

I cant find FroSTI on the search for some reason

Rob

morpheus1870

Ok long term plan is 400bhp however I know this will come at a much later stage once all the handling and break mods are complete. So all the bits I fit need to have that longer term goal in mind.

So GT headers and up pipe; Harvey, Haywood, RCM etc
Uprated fuel pump walbro/Bosch
Stock fmi and injectors
Stock air box with green cotton or k&n
Down pipe?
20g 18g turbo.

If I ditched the whole ppp exhaust for a 3" what would be a good replacement??

jura11

iTrader: (7)

Good exhaust which not cost too much is Cobra exhaust UK or Revolution.

Jura

Carlh

spend it on petrol and have a LONG weekend, FAR FAR away!

Rob Day

iTrader: (78)

If you source on here 2nd hand parts you may still be able to do this on budget, but you will need to under take the work yourself or find some whom is cheap on labour. Some of the jobs are very simple and you require minimal knowledge and tools, but as for changing the turbo, up pipe and downpipe, well you need good resource in my opinion as some of those pesky nuts and bolts can play very stubborn.

So GT headers and up pipe; Harvey, Haywood, RCM etc £400 ish
Uprated fuel pump walbro/Bosch £70 ish
Stock TMIC and injectors £0
Stock air box with green cotton or k&n £30 ish
Down pipe? £70 ish
Exhaust £180 ish
20g turbo (AF or Harvey type) £400 - £600 ish

Totals around £1250

Obviously products and prices vary hugely, and you could probably get a full 3" exhaust inc DP for £200 if you look hard enough on here, or you are prepared to wait for one to come up. Same with all the parts really, I mean these were a steal , but you missed out. https://www.scoobynet.com/subaru-par...c-up-pipe.html

HTH
Rob

dynamix

iTrader: (3)

It is dangerous to get shopping lists on here ....

If it is PPP then it already has the sports cat in the downpipe so you dont need to buy one.

Also, if it is PPP then it already has the walbro pump so again you dont need to buy one.

Simply change the centre and backbox to an exhaust that produces the sound you need and will flow a little better. 2.5 inch system will be fine.

Headers and uppipe would work but tbh you will get a better bang per buck by fitting a fmic, which along with just a remap will get you over that 350 bhp level IMO.

Rob Day

iTrader: (78)

Duncan obviously you are far more qualified have more experience than I will ever have, so i take everything on board that you are saying, but its listening to proffesionals like yourself that leaned me to my comments earlier.

I was told to buy a Walbro for 02 Prodrive just because it was knocking on 9 year old, and for £70 and 20mins work it worth doing to be safe

This was my point, and if he decides to go 3" he may aswell change the whole lot inc DP for something more free flowing.

I have always been told that FMIC's are pointless under 400bhp unless you track the car or you are often stood in traffic, and if he does go FMIC then he would definatly need an induction kit as the airbox would need to go.

Rob

morpheus1870

I didn't really want to change the entire system so the mid section and back box replacement sounds a good option.

Definitely want to retain the TMIC and original air box so will do the headers and up pipe instead.

New fuel pump is a deff as the current one has been in there for some time and for the cost of £70-£140 for a bosch/walbro it's worth it i think.

Carlh

nice new seats

morpheus1870

jura11

iTrader: (7)

Everybody have different approach to what is best and what is worst.

I would go first

Fuel Pump(HRC/Walbro or Bosch)
Panel Filter(K&N or Green cotton)
Exhaust depends on your feeling and what you want
Turbo choice is from 18G-20G or VF48
Harvey Ported headers with Up pipe or GT Spec headers with Up pipe
Remap and you should have nice 370-400bhp

Jura