Tim(e)

I recently swaped my Renault Sport V6 Clio (LHD) for an 04 WRX STI Black Mica.

Loving it but at that stage now I want to tinker but don't know much about turbo tuning etc

I have a friend who may be giving me his Greedy Boost Controller.

The car has the second cat removed with a straight through pipe and custom rear silencer.

What would folk recommend? Panel filter or Induction kit and a good remap? Who does the best mapping?

What about dump/blow off valves?

Anything else I should consider?

How easy is it to get my car which should be sitting around 290bhp to 320 say? Will a remap and panel filter do that or maybe more?

What is the Walbro Fuel pump everyone seems to go for?

Cheers

Splitpin

Don't bother with the boost controller.

Panel filter plus remap will probably get you straight to 310-20. No advantage (and a few potential disadvantages) in an induction kit. Full decat or sports cat will get you another 10-15bhp bduring the remap.

The standard dumpvalve is the best one you can get, anything you could swap it with will make your engine run less optimally.

Walbro 255lph pump improves fuel supply at high outputs but may or may not be necessary - find a good/local mapper and start having a chat with them about ways forward. There are a number of good ones, start reading the forum a bit and you'll soon learn what's what (and where people are).

Petey1985

iTrader: (1)

I have asked the same question about my 05 Sti as I want some info about tuning. It seems there are many ways to get more power but the most important will be the custom map.

Walbro 255 is uprated tank fuel pump that allows for larger flow of fuel which is needed before any power upgrades are undertaken. The O.E fuel pumps seem to be a weak link.

Tim(e)

Why is an induction kit of no advantage over a panel filter? Is the OEM cold air feed good design? It looks to be good with the ram air feed but the bottleneck into the resonator in the front wing can't be good. The straighter the flow of air to the throttle body the better I always thought?

What is the general view on the best panel filter to get? I have heard Green are good? Is the standard STI one no good?

K&N, Blitz, HKS..?

wrx9181

iTrader: (2)

from what i gather it effects air flow so upsets the maf and if the maf s not happy your car wont run properly

milliemoo

i reverted back to the oe airbox on advice from splitpin and although i lost the 'arousing' noise lol i found the engine ran so much smoother.i did fit a green panel and im more than happy with that.

joz8968

iTrader: (13)

You're correct Tim in what you say.... but on the Impreza, the OEM inlet tract ONLY represents a resrictive bottleneck at around 350bhp. So only needed to go to a IK/air filter pod for bhp goals after this, and/or when swapping to a FMIC, due to lack of space for the airbox, etc. (includes mapping obviously).

The OEM WRX paper filter is very effective at trapping tiny dirt particles plus its surprisingly free-flowing. It only adds a 2% restriction to the air that it can flow, as tested by Autospeed some time ago.

Aftermarket panels can't really appreciably improve on the OEM re flow/filtering - other than you don't have to replace them as often. So represent good value for money in that respect. To this end, K&N, Green, Apexi and Cosworth ones are considered good ones. The STi one, strangely, fairs badly in comparison...

TonyBurns

iTrader: (3)

The uprated STI panel filter is the best of the lot when it comes to extra power and filtration (as proven on a proper sti on a rolling road ) but unlike the rest it is actually a service item and requires replacing at regular intervals.

The standard air intake is also very good, better than most people expect

Tony

joz8968

iTrader: (13)

Weird. There always seems to be conflicting "views", all things Impreza.

Re the STi filter - I read it elsewhere on this forum some some time ago so, indeed, could well be another "myth".

Splitpin

Correct. It only becomes a bottleneck in the 350-400 region.

That's a theory, but in practice the differences can become so marginal as to be non-existent, and have to be weighed against other variables. The resonator does some cool stuff, not least acting as a water block and getting rid of a degree of turbulence from the inlet air. IME car runs better with than without it, unless, as above, you are at the point where it is actually impeding.

There's very little difference between the good ones, primarily because, again, this isn't an area where there are significant difference. K&N, Green or Cosworth would be recommended without hesitation.

Tim(e)

Cool replies! Cheers boys!

What about HKS, Apexi or Pipercross. The HKS is the cheapest. There's probably not a whole lot of difference between one over another?

My friend has a boost controller by Greedy on is WR1 and there is some thump of the car when he changes gear. Running 1.4 most of the time. He says this still needs mapped but gives more boost and therefore more power than a remap?

Tim(e)

My filter defo is not an STI one if it is supposed to look like the one in Scooby world or scooby parts...? Mine is a standard cream coloured paper element with an orange seal?

How much is an STI one?

Tim(e)

My filter defo is not an STI one if it is supposed to look like the one in Scooby world or scooby parts...? Mine is a standard cream coloured paper element with an orange seal?

How much is an STI one?

Splitpin

In this area it's worth going with a good recommendation. IIRC some of the ones you've just mentioned are either metal gauze filtes, which aren't as effective, or quite heavily oiled, which can damage the airflow meter (and in turn damage your engine). Buying one of the alternatives just because it's a few quid cheaper could cost you a lot of dosh if it blows your engine up. And speaking of which...

Lol at the typo. There's a degree of unintentional irony there!

Your friend is basically wrong, and his bravado may end up costing him. The bottom line is that a well executed remap will give you as much power as your setup is safely capable of delivering. D*cking about with third party devices like that can take the engine (and ECU) into performance scenarios it is not properly mapped to deal with, and the consequences of that will be the failure of the weakest link at some point in the future.

The bottom line is that a properly mapped car will almost invariably outperform some sort of bolt-on solution, and even if it doesn't, the car running the piggyback will almost invariably be the first to blow up.