OK, not posting under my usual username for obvious reasons.

Here's the scenario-

MY03. Full decat (apart from up-pipe). APS top mount. Hyperflow cold air kit. Ecutek re-map.

What next?

I reckon there's some more to come from it as is, as it has a standard de-cat map in it, and isn't mapped for the induction or intercooler (doesn't seem to run lean though).

So, primarily, I need to find someone in the North West with a good reputation for Ecutek maps. Any ideas?

Then I would like to go further. Was thinking turbo (which one?) injectors fuel pump and reg (and remap again).

 

Have you had the car on rollers yet? Just curious as to whether you're making much more power/torque than a normal decat/ecutek with the intercooler and induction kit.

Anyway, IMHO, do the fuel pump and reg anyway. Also consider headers (either porting your OEM ones or something like the Gruppe-S, but different headers seems to suit different turbos), and replace your inlet hose if you haven't already done so. Injectors - the STi ones will probably do the job within the power/torque limitations of a WRX gearbox. After that, with a suitable map, you're be at the limitations of the TD04, and probably getting noticeably over 300bhp on the more "optimistic" rollers.

At all times with these sorts of bits, consider where you're eventually going - no sense e.g. getting headers that work with the TD04 but aren't that clever with your new turbo

When it comes to turbo's - depends on how much power matters and how much you want early spool up. You'll get a fair bit more poke and early spool with a VF34, and maybe up to 340-350bhp. Probably slightly slower spool with a FE TD05, a bit more power. A TD05-06 or equivalent hybridded TD05 will give close on 400bhp and still pretty resepctable spool up. May well also give enough torque to seriously endanger your gearbox and/or clutch..

That's all IMHO, but I haven't gone the whole way down that road myself (yet?!) - there will be others who have done a lot more