What mods are needed to hit 320-330bhp in a blob wrx ?

[Domo2106]

What mods would I need to hit 320-330 bhp I've already got a full exhaust system both cats have been removed but the standard headers and up pipe are still fitted would I be better off with a set of Sti headers and up pipe or just getting a decat up pipe

In the next month or so I will be fitting

A td05 18g or a vf35
A set of pink Sti injectors
Walbro fuel pump
Sti top mount or a front mount haven't decided which yet
K&n panel filter
And a set of irridum plugs

With a decent map will I get near 330bhp ?

[555_Si]

i'd go with top mount, much easier to install, no chasing boost leaks.

18g might be a bit much for a wrx lump, vf35 should hit 320 to 335 ish.

i'd go with a green panel filter personally.

got a set of pinks here and a nearly new walbro.

sti up pipe or a harvy up pipe, use standard or ported headers.

might be worth going 3 port boost solenoid if you get a chance before mapping. not essential but maybe a bit better at controlling boost. make sure you when you change turbo you have the restrictor pill in the boost control pipe still.

i actually changed the inlet manifold injectors as easier and this allowed to delete tumbler valves as well.

can sell inlet, pinks etc all together if you are interested.

[Domo2106]

How much mate ?

[555_Si]

walbro, inlet with tumbler deletes, injectors, £200. can throw in a silicon intake pipe as well as worth doing if swapping inlets.

[Ginola]

PFR-7B plugs
(WRX top mount will be fine to hit this power no need to change top mount)
VF35
Walbro 255
K&N or similar filter
Pink injectors - Butterfly delete on inlet manifold at same time (while your there might aswell)
remove standard up pipe cat. (STI up pipe will fine)
Sports cat downpipe or decat would be good too.

Hope this helps.

[Domo2106]

What is the butterfly valve delete I keep hearing about ?

[555_Si]

I think its the tumble valves I mentioned.

[SpecB]

If you go STI top mount you will also need the undertray to suit otherwise you only use the same amount of core as a WRX. For 330 - I'd say you're about right with the mods, 3 port solenoid as mentioned is a good idea.

The WRX has tumbler valves which restrict airflow and are there to reduce emissions at idle STI's never had them nor did JDM cars. They are in the cast blocks between the Inlet manifold and the heads and are where the injectors are fitted. If you are removing the inlet to change injectors turbo etc. then it's a good idea to remove the valves and port the castings. You will need new gaskets (inlet to tumbler) and tumbler to heads - Personally I'd fit a phenolic gasket with an O ring seal to the heads to reduce heat soak. Also consider a parallel fuel rail setup to further protect the engine while you have it all removed as the standard fueling system can lead to lean running on cylinder 3 (I believe).

[555_Si]

thought fuel rail issue was more on classic engines, only a problem on high horse power newage builds?

[SpecB]

The issue still exists (to a much lesser extent) on Newages and it's fairly cheap to get the kits these days so while it's all off it makes sense. If you're already going to the trouble of a tumbler delete then why not!

[555_Si]

fair enough, can you recommend any kits, was looking at RCM one, but thick end of £500.

already have a 3 port FPR.

[BIG"E"]

Surely the answer Is buy a WRX STI.

Which will cheaper in the long run and save a lot of head aches..

[scotty]

Originally Posted by BIG"E"

Surely the answer Is buy a WRX STI.

Which will cheaper in the long run and save a lot of head aches..

Nope its great fun fixing classics Si try Aeromotive kit from the states feck paying RCM prices .

[SpecB]

My kit is a custom setup from pennine Subaru as none of the cheaper options fit the Spec C manifold - the killer in the price is the Teflon hosing and the connectors! The rails are actually pretty cheap! Mine is fully fire sleeved as well to keep temps down and avoid abrasion. If it's a pure track car you could probably go for a standard hose which will reduce costs massively. The eBay rails are actually pretty good by all accounts.