Scoobypaul_mk

Hi all,
Been lurking for a couple of days (trying to gain some knowledge)
I have recently purchased a 96 import wrx, the only 'mods' it has are
1 - Panel Filter
2 - Afterburner Vortex back box and centre section.

Is a dump valve worth investing in?
If so - what are the differences in the 2? different types?
Any makes to avoid?
Any else worth changing that is cheapish? ie >£300
Soz for all the newbie questions,
Cheers
Paul

cefski

Hello and welcome.

With £300, I'd replace the catted downpipe, as this is the most restrictive part of the exhaust system. That said, someone here (i forget who) is selling a ScoobyECU on ebay at the moment and £300 might be enough to secure it. I'll send you a personal message with the link to it.

Dump valves have been discussed at length here (try doing a search). The one fitted as standard is a re-circulating one, meaning that the gas is recirculated to the turbo's inlet. A vent to atmosphere jobbie dumps the gas into the engine bay, giving off that Phhssshhtt noise in the process. Steve Breen (of IWOC fame) explains this better HERE, and explains the pros and cons.

Kev

Scoobypaul_mk

Thanks for the reply Kev, have now read the page you linked to - very handy info. Will have a look around for the downpipe - would i be right in thinking if i remove the original catted pipe i would probably have to but it back on prior to MOT?
Cheers for the info,
Anyone else got any tips to offer?
Cheers
Paul

cefski

Yes, but they're very tricky to get on and off if, like me, you aren't that mechanically minded. The centre section, on the other hand, is a ten minute job to replace, so it might be an idea to get hold of a catted one of these for MOT time. The car should pass the MOT with just this in place (provided the lambda and MAF sensors are working ok - but that's another story ).

Kev

New_scooby_04

iTrader: (4)

Woa, hold everything, before you do anything else, do you have a Knocklink installed?

Regards,

NS04

Delboy2

A knocklink as stated above should be considered as your JDM WRX will be set to run on Japanese fuel (100Ron) thus your car will be more susceptable to Detonation due our lower octane fuel - especially if also modified
A scoobyecu also stated above would be imho next if you can locate one - this will have modified IGN/Fuel/Boost to run Optimax plus give an increase in Hp/torque
Then a decat downpipe

Cheers

Scoobypaul_mk

NSO4 and Delboy2,
Cheers for the advice - no i dont have a knocklink installed, i have seen them advertised online - any recommendations on make or are they all pretty much the same.
Am now on lookout for ECU and will leave the downpipe till later,
Thanks for all the advice guys
Paul

New_scooby_04

iTrader: (4)

AFAIK The most commonly used one in the UK is available from BRD developements.

You are using octane booster on the car, right?

NS04

Scoobypaul_mk

Will check out BRD then, cheers
Octane booster - no im not, as ive read that it isnt particularly necessary:
http://www.sidc.co.uk/faq.htm#5.3
Cheers
Paul

Delboy2

For the sake of a few quid per fill up is it worth risking a 2k engine rebuild?
Knocklink is shown 1/2 the way down the page HERE

Cheers

Scoobypaul_mk

Thanks for the link Del,
Only reason i havent used the booster is because of what i read on the aforemetioned page -
2.4.1 Type of Fuel to Use

Many questions are often raised regarding the type of fuel needed for the Impreza. The sticker inside the petrol cap says use Super unleaded only, but this has different meanings in different countries. In the UK, the standard (or premium) unleaded fuel is rated at 95 RON, the same as the Super available in other countries such as Australia and the US. In the UK, Super Unleaded is rated at 97 RON (was 98 until 1999). In Japan, it is 100. Generally, in the UK, normal unleaded is fine. In countries where lower quality fuel is available, then the best advise would be to run on the Super (or Premium) Unleaded fuel. Beware of octane boosters, as many contain lead or lead-like substances which will damage the catalytic convertor and oxygen (Lambda) sensor..

Dunno what to do now
Paul

Delboy2

There are various boosters to choose from, NF imho is probably one the best though - available from stockists shown HERE

Cheers

cefski

I stand corrected. Having never owned a JDM model, the 100RON fuel problem has never been an issue and is not usually considered, but for Paully, it obviously should. So as above, a Knocklink, followed by a scoobyecu seems like the best plan, and will easily take care of the £300 (and the rest) that you have set aside.

Kev

TelBoy

Paul,

Everyone's opinion is different of course, but i run a heavily modified 97 import, and have never had a knock sensor fitted, ever. I run it on Optimax, and occasionally NF octane booster when i'm going back roads, and have never had a single problem mechanically (touch wood!).

Unless image is important to you, don't waste money on a dump valve - they impress certain factions on cruise nights, but do **** all performance wise. As has been stated here, get the downpipe changed. It really is the single best mod you can make, even though i know it's more hassle than a simple bolt-on accessory. There's no point looking at different ECUs with the standard downpipe in place. If you have any cash left, i'd look at getting a brake upgrade, to twin-pots at the front at least.

Scoobypaul_mk

Thanks for all the advice guys,

I am definitely on a steep learning curve at the minute
Cheers
Paul