Hello everyone, just bought my first impreza yesterday and hope to be welcomed to the site and become an active member!!

Now i am quite mechanically minded and not too bad with cars, but have never had a turbo before. Previously i was a Vauxhall owner and completely modified my Mk3 astra from standard to the extreeme including an engine change.

The car ive bought is a 2002 model Bug eye Wrx uk spec in world rally blue. Its done 48500 miles and ive paid £9000 for it, Its got the quad headlight conversion and an adjustable sti rear wing. Gud deal??

First of all i would like to know what BHP the car should be running as there are so many different models about these days.

Then secondly, coming from a modifying background i wann start with this but only subtle mods. I would appreciate it if someone could tell me the best makes for the following parts that you recommend i purchase for my new baby!

Air filter (panel or cone?? Looking for more power rather than sound)

Dump valve (obvoiusly i must have one on my first turbocharged car! )

Exhaust (considered an Sti exhaust or have heard that hayward scott are a reputable make, again looking for power but nothing too loud - a nice purrr will do! )

Beyond this i will be looking for advice from u guys and gals as to where to go next or if theres anything you would recommend doing!

I dont wanna spend hundreds immediatly as i simple avnt got it but would like to progress slowly over the summer months!

Your adice would be much appreciated and i hope to meet some of you at some scooby meets or track days in the near future!!!

 

Welcome matey, dont worry a certain Mr Pslewis will be along soon to answer any questions you have .

MICK

 

Hello and welcome......

....I have put a panel (K&N) filter in mine, a cone will give you more but not really sure how much.
The real gains are to be had with de-cat or sports cats in the exhaust. I think your car has two or three and they are VERY restrictive. This will increase sound a little but there are big performance gains (upto 30bhp for a full de-cat).


Cheers



Oh please don't put a dump valve on it. It adds nothing and takes away a whole lot more..............

Oh and put MORE money aside, once you start it just does not stop.

 

Hi Mate
I have an as new ITG pannel filter for sale in the "for sale general section", I want £20 for it, includes postage, well below 1/2 price and is a quality high performing bit of kit
As regards dump valves, it's your car so do whatever you want, as long as it makes you happy thats the main thing.
BTW, welcome to Impreza ownership, one of the best decisions you ever made !!!
ray

 

Welcome to ScoobyNet

The 1st thing would be to upgrade the brakes (Brembos/AP) and suspension(AST. Steins etc), then look at power.
Panel filter every time. Cones/Induction kits just wreck the MAF.
De-cat is essential - when I had mine, I had a H&S ScoobySport system. Nice, and not too loud.
DV - Subaru's one is fine. You'll be branded more of a Chav if you change it!!

Apart from that, have a look around the projects forum. You can upgrade the turbo, FMIC, headers etc..... kinda depends on how much money you want to throw at the car......

Enjoy ScoobyNet, but seriously fine-tune your BULLSH1T filter - there's plenty of it on this site!

Dan

 

225 bhp for an unmodified 2002 WRX IIRC.

Panels seem to be the option most people prefer. Green, K&N, etc... it's up to you.

This is a contentious issue on Scoobynet - most people think they're undesirable to say the least, but if you must...

An STI backbox doesn't sound any better than the WRX one. The only Subaru option that improves the sound is the Prodrive backbox. Other than that you're looking at other aftermarket ones - Magnex, H&S, Ninja, Vortex, etc. It's a must in my opinion, and I really don't understand why Subaru think people buying Imprezas would want them to sound like a Mondeo or something...

 

I swapped my standard wrx backbox for an STi one and I think there is a subtle difference. It is slightly deeper with more burble, especially at low revs. No performance gain though, but I think it looks better than the standard twin pipe.

 

I have also swapped my wrx back box for an sti one. Dont know or care about the performance, but it does burble more

 

Oh, I agree it looks miles better. I never had a WRX so can't compare, but I found the standard STI one very quiet. Changing it makes a massive difference to the exhaust note, but of course this depends on personal preference.

 

First of all thanks for the warm welcome!

Bit gutted at the power tbh, got told they started at 267 bhp but, that just means i will have to spend more money quicker then to get it up there!!

The car has upto three cats?? i can understand how that will be very restrictive! Are they all in line or in different sections, i suppose what im trying to get at is can i just purchase a single de-cat pipe or do i need to stump for the full system straight away??

I thought the panel filter would be more beneficial, its what ive found in the past, would a cone be better if the car was chipped though, because you could remap the ecu to let in enough fuel to cope with the increase in air??

And about the dump valve, im sorry guys but i think i maight just have to have one for a short while! i have always wanted one for a while but having only ever driven one car with one in the past i can imagine it might get a bit annoying after a while. I have hear that you can get ones that you can open and close manually on a switch or summot?? So you can be sensible one minute but turn into a big kid every once in a while?

Thanks for your help so far people. Im sure it wont be long before i get up to speed with all your help!

 

I assume you are aware that there is already a perfectly good dumpvalve fitted as standard to your engine? It's amazing how so many people seem unaware of this? The valve vents back into the induction system which is why you don't hear it. Replacing it with a vent to atmosphere type is for noise and nothing else. For want of a better phrase, it's a boy racer thing! Honestly, spend your money on something useful to actually improve your car.
JohnD

 

Its just the noise thing! Im gettin the impression its not the best thing but thats why ive suggested an open/close type that ive heard of. Ill consider it......

 

been looking on ebay at stainless steel decat downpipes and decat centre sections from someone called '2fast2cool'? Anyone had any experiance of this company and their products? They seem quite good and have a vast range of exhaust parts for sale. Is it also tru that i should see a 30bhp gain from the downpipe and 10bhp from the centre section?

If so i think its well worth the £200ish to get these parts and fit them.

I have also decided to go for a panel filter for the scoob, probably a k&n which seems to be getting the best rating.

After fitting these parts is it advisable to get the scoob remapped? Wheres the best pace to get this done and how much am i looking at?? Im based in Wrexham, North Wales, so if anyone knows any reputable companies??

Thanks in advance!

 

Do a search on here for dump valves mate, you'll see this thorny issue pops up almost every week on here! By fitting a VTA (vent to air) dump valve you've effectively altering the mixture the ECU is expecting to get in the engine - by dumping out some of the air that's been metered. As a result most people (if they're honest) find the engine runs worse after fitting one. Generally you can get uneven idle, poor throttle response, and sometimes worse problems.

I've had 3 impreza's, the 3rd one I bought had a VTA dump valve fitted (i think it was a Bailey) which had been fitted by the previous owner. I honestly couldn't believe how much better it ran when I'd changed it for a brand new Subaru recirculating valve a week later, it felt like i'd fitted a whole new engine!

Seriously mate, have a decent look around on this site and see what people have said about them. In particular look for posts by "Greasemonkey" or "Bob Rawle" about this issue. It'll probably convince you to save your hard earned to spend on something else.

Personally, what i'd recommend as a first mod which will make the biggest positive difference to the car, would be to take it to somewhere like Powerstation and get the droplinks and anti-roll bars changed for uprated ones, at the same time get an anti-lift kit fitted, and have them set the wheel geometry up properly for fast road use. It's the best £500 i ever spent on any of mine and made a MASSIVE difference to how the car felt/handled.

 

Yes it's possible to get these sort of power increases, but only after removing the cats and getting the ECU remapped to compensate. Without a remap you'll just get slightly more power and faster turbo spoolup, but the engine will run much leaner than it's supposed to - and will eventually melt your pistons. Remapping will allow more fuel, more turbo boost, and more power without damaging the engine.

Also if you start modding you'll lose any warranty you have left on the car. Maybe an idea to consider the Prodrive PPP kit which Subaru sell, it's more expensive than getting it mapped yourself but won't devalue the car or affect your warranty.

 

Whats included in the prodrive ppp kit?? and how much are we looking at? I was under the impression this kit is rather expensive.

Got any recommendations as to where to get it remapped and how much am i looking at.

Looking to spend around £500 initially so that allows me to get the exhaust and filter sorted and hopefully a remap if im lucky but not sure??

I only have a 3month warrenty on it from a local garage, so by the time i have spent the money, got my hands on the bits and got round to fitting them the warrenty will probably be dead and buried by then

 

First of all I think you may find your car has a bit less power than others have stated. IIRC bugeyes were 220PS which is about 216BHP. Blobeyes from 03 on were 225PS.

Definately get a panel filter as I/K's can actually reduce power by inducing hot engine bay air, obviously increasing induction and charge temps unless you isolate it well and supply a good cold air feed. Green, K&N or JR Racing are good, ITG have a jaded history. I/K's also have a history of killing MAF sensors due to excessive vibration unless well fitted and bracketed.

A dump valve will only give one gain, the noise. However, there are downsides to them from poor running and jerky gearchanges to potential engine damage. If you want to hear the OE recirc DV (albeit about half as loud as a chav valve) then do a search on here for resonator removal. It takes about 20 minutes to do and costs nothing, but will make spool-up, induction and dump more audible. A guy with a VTA DV who drove my car yesterday is now considering replacing the OE as he couldn't believe how much smoother it ran, even though my car has 50k compared to his 12k.

Look at getting a decat centre pipe and a good BB which will free up the burble and some ponies. The Prodrive BB is good, but expensive, and similar can be had cheaper. It's worth keeping an eye in For Sale as people often upgrade from PPP and have perfectly good stuff for sale at reasonable money. Only Decat the down-pipe if you're prepared for the potential hassle of refitting a cat when the MOT's due, and aren't bothered by roadside checks and rectification notices. Some have fully decat'd and pass these (just) but not all.

When you've got all the mods in place get the remap done to get full benefit from your investment.

However, I can recommend an alternative route. Better suspension and brakes can make the car just as fast, and sometimes faster in real world driving as power increases. There's no point having 400bhp if you can't control it around a corner and can't stop it in an emergency. I have the Powerstation Type 20/25 AST coilovers with Whiteline ARB's and links, along with slightly uprated brakes and can embarrass many much higher powered cars on A and B roads. The Whiteline 22mm adjustable rear ARB with solid links is a must no matter what, along with a very good geometry set-up. I used to have Prodrive settings but have since had a bespoke set-up done by a very experience race suspension technician which moved things on a level.
I also firmly believe that driver training is much more beneficial than any power mod. I have been taught by international rally drivers and Police pursuit drivers and can honestly say that they have made me not only considerably faster, but much safer too.

Welcome to SNet

 

First off, welcome to scooby ownership!

You'll get/read a lot of people saying your car is the ugly one, but beauty is in the eye of the beholder. (and yes, i think it's ugly )

Sounds like a good price, lOOking at the current market and sales.

Air filter (panel or cone?? Looking for more power rather than sound)
A panel filter will suffice unless you want to go into the wild mods. A K&N or Green comes recommended.

Dump valve (obvoiusly i must have one on my first turbocharged car! )
I had to get one on my first turbo'd car too In fact, first 3 turbo'd cars. lOOk in the Parts for Sale section, there's normally quite a few in there. Do a search on BOV/Dump valves to find out the one for you as some are louder than others.

Exhaust (considered an Sti exhaust or have heard that hayward scott are a reputable make, again looking for power but nothing too loud - a nice purrr will do! )
This is personal preference. Some can be too loud whereas other are only loud on full boost. Make aquintances with people on here and go listen to their cars. And yes, H&S are a reputable make. A backbox will do for now, just to release the scooby rumble. See scoobworld.co.uk for exhausts like the Ninja too.

Beyond this i will be looking for advice from u guys and gals as to where to go next or if theres anything you would recommend doing!

I dont wanna spend hundreds immediatly as i simple avnt got it but would like to progress slowly over the summer months!
I'm sorry to dissapoint, but if you're on here, you're guaranteed to spend hundreds/thousands. It's a drug and this place is like a dealer, it tells you where/when/how/why. I've spent thousands in months of ownership, thanks to comments on here, but it's been money well spent!

Your adice would be much appreciated and i hope to meet some of you at some scooby meets or track days in the near future!!!
Enjoy!

 

corradoboy- Thanks for that, i am starting to learn slowly more about my car and others. I will be purchasing a panel filter tomorrow before it goes for its service.

What other parts that are changed in the full service would you recommend upgrading to peformance parts?

Filter - K&N probably
Spark plugs? or are they coil packs these days?
Brakes - Will probably leave for now but when changed will prob go for black diamond D&G discs and fast road pads

Anything else??

With regards to the dump-valve, obviously the only benefit is the sound but i have also been told that the gear change is acutally smoother at higher revs with a DV, not the other way round. It is a very contraversial topic over these DV's aint it. Sounds good what u suggest with the OE DV thats fitted tho! Might have a go at that.

The cars come with 12months MOT so i dont mind swapping the Dwn pipe over next year so i think i will stump up the cash for a complete system from dwnpipe back, only trouble is i dont want an OTT tailpipe, summot like a 3" slash cut like on Sti's will do fine. I hate the look of those 5" tunnels!!

Ive been told about the chassis upgrades and will be carrying them out slowley, just wanna release a few more ponies first!

Cheers for this mate!

GAZ - Again thanks and personally i do agree with your ugly opinion but the car does have the quad lights fitted that do look much better!

And i understand the modifying bug, i had it on my mk3 astra which was totally modified to the extreeme. Only i wont be making the stupid body kit mods this time!

Keep the advice coming guys!!

 

K&N is fine
Pulgs - Yes they have coil packs, but they still have plugs. I believe the popular ones on here are NGK PFR6B or 7B if more modified. Someone please confirm as I've never bothered with researching these.
Brakes - Stay away from drilled discs as they fracture, grooved are OK but the OE solids are up to the job really. The OE 4 pots are fine with just some braided lines (Goodridge £45), DOT5.1 fluid (Ferodo or similar £10) and some better pads (Ferodo DS2000 (may be called DSPF now), Mintex 1155 or Pagid RS4.2.1 Black, I don't rate EBC, at all).

Best cheap mod for a noticeable difference is the Whiteline 22mm adjustable rear ARB, although hardly anyone ever adjusts them so you may as well buy a fixed one. I had mine fitted, like most, on the middle setting and was satisfied with it, but only just. After a coupe of weeks I switched it up to the stiffest setting and the difference was awesome. In retrospect I should have just got a 24mm fixed rate, but if you're unsure or like to play with the set-up then the adjustable is superb. Solid (steel, alloy are much dearer and just for the bling) drop-links finish this mod off by removing the initial flex of the plastic OE units.

 

Where can i get one of these ARBs from, either fixed or adjustable and how much am i looking at??

 

Sorry if this is hijacking the thread a little but........

What is a anti-roll bar, what does it do for the suspension and how much to buy/fit?

Cheers

BEAT ME TO IT!!!!!

 

When you lift off whilst on boost the DV releases metered air from the induction chamber. The OE DV feeds that air back into the induction piping to slow the turbo in a progressive way and limit overfuelling. A VTA DV releases that air out of the induction system completely, thus ceating a sudden and significant drop in pressure which can stall the turbo. The MAF and AFR have measured the air and metered the fuelling accordingly. When that air is lost the fuel is still injected without enough air creating a rich partial burn. Some of the unburnt fuel can be pushed past the piston rings removing the lubricating oil film (borewash) and some makes it to the sump, thinning the oil over time, although regular oil changing removes the risk of thin oil leading to bearing damage. Much of the unburnt fuel however gets pushed out into the exhaust where if it doesn't explode, it contaminates the cat. If it does then you get what is affectonately called pops and bangs. This is appealing, but is just a new term for the less appealing backfire. These backfires can shatter the cat and cause negative flow pressures in the exhaust system spoiling valve motion. All these factors combine to make the car run erratically very briefly at every on-boost gear change. But they do make a pleasing silly noise which will impress the 11 year olds at the bus stop.

Cue all the "I've had a VTA fitted for xxxk miles and it's been fine" comments. I prefer the ones that say "I've just refitted the OE and can't believe how much better the car runs".

 

Ok u have persuaded me, how do i go about removing the resonator in the induction then??

Dan, dont worry about hijacking the thread, ur not changing the subject too much and lets face it, were all here to learn!! I know the basics of the ARB but i will leave it up to someone who knows more about what theyr talking about to explain more!

 

CLICKY

Scooby's understeer by default, everyone knows this, and it is designed in to try and make drivers who aren't particularly skilled realise early where the limits may be. By stiffening the rear ARB, during hard cornering the front alignment stays in a much more ideal geometry to the surface of the road, and thus the tyres stay in better contact maintaining more grip, and reducing understeer.

 

Scoobs understeer! thats another wrong asumption by me, always thought they overstear a little, or is that the Sti which has a different diff set up?

So hiow much and where dya recommend then mate? Is it simple enough to fit myself?? I would assume so?

 

WRX understeer badly, STi's a little less so due to the Suretrac diffs. They can be provoked into oversteer, again the STi is better due to the diffs making it much more adjustable on the throttle.

Whiteline rear 22mm adjustable ARB should be IRO £90+vat from Demon Tweeks, solid steel links maybe £40. It is a DIY job. The front is much more difficult so someone like Scoobyclinic who supply and fit at a good price is worth it in that instance.

 

Just to reiterate what has already been said...

Your car has three cats - middle,up pipe and down pipe. I removed the middle cat and changed the back box. Just doing these two made a MASSIVE difference (in reality only 18bhp). Felt like there was a power band at 4,500 rpm. Try and get a decent back box - I found a NUR Spec on here for £200 which really released the burble

If you want to remove the other two cats, you MUST get a remap to make the most of the greater air flow. I've substituted the downpipe cat with a sports cat as I'm worried about the approaching first MOT...This makes the car feel as different again (and really helps the economy). The car comes alive at 5,000rpm (although I am using a bigger intercooler...don't know what good that does).

Oh, and always run it on good fuel...

Enjoy and welcome

 

Welcome. Your scooby already has a DV- but it's a recirculating one that helps to keep the turbo spinning up- if you put on an atmospheric DV you'll get the full chav whooosh, but it wont help proformance and will shorten the life of the turbo.

Go for panel filter- I use a Green Stuff one- great air flow plus you get a bit of induction hiss without screwing the MAF.

Power gains- get rid of one of the cats! Go for stainless decat downpipe, centre section and hi flow back box- give you some bhp (10-15) and still get through MOT, because you are still keeping the first cat. REplacing the first cat as well will give you the 30bhp you mentioned but wont be street legal and wont get thru MOT (unless you use pure methanol whenn you MOT it, but you could easily burn ut your valves).

Ultimate power gains- remap ECU. Sensible remap and you wont need to change much elseCan be costly, esp if you go above 300bhp- you've got to then start thinking about uprated clutch, gearbox, brakes, suspension; then valves, pistons, cams etc if you go 400+ . good luck

 

That would be the STi.



Some good advice coming through on this thread!