Hi guys, just picked up an '03 Impreza WRX, and I love it! But it does feel a bit sluggish compared to the 280bhp MR2 Turbo I just sold...

i have about £1000 to spend; the car is on 125k miles with FSH and completely standard bar a Prodrive backbox, so should I save for a head rebuild or start modding? It drives really well but just need a bit more powah :P

I've heard I should go for exhaust system, fuel pump and remap? But what exhaust sysems work well but aren't deafeningly loud? A full decat would be fine if it's cheaper

Any suggestions welcome, I'm new to this so any help appreciated!

Thanks
Ash

I have a Bugeye Wrx and just had the following done to mine
Decat Downpipe £80, backbox (quiet one and was already on) decat uppipe (already on)
Panel air filter £35
Fuel pump no required for this power.
Remap by Andy Carr, now producing around 277bhp using factory td04 turbo.
So for your budget i would think you could get a bigger turbo etc.

Hi Fella.
Mines a blobs wrx 2005, I spent around 1000 quid, I'm running at 285bhp. Mods I did-
Ppp rear box
Ppp sports cat, £100
delete centre cat £40
silicon intercooler pipe £40
sti uppipe £35
225 walbro fuel pump £80
green sports filter £30
3 port solenoid valve £45.
Custom map £350
Cost to fit exhausts £200
These are the prices I paid, but you can see it's easy to spend.... lol
You could go decat if want to, but I wanted no issues at mot time. Also 3 port not really necessary but helps the mapping and holding boost.
Best bang for buck would be a remap and a performance filter/intercooler/centre pipe delete and you will still have 260 bhp or similar as above post and get a fuel pump for safety as yours has done over 100k.
If you want more power.... add on another 300-500 notes for bigger turbo/intercooler from an sti.
Cheers Phil

easiest and most cost effective way of more power will be to follow the path:
http://andyforrestperformance.co.uk/58901.html

I would say fuel pump and boost gauge are #1 mods - then move onto producing more ponies.

A pro map will take a big chunk of that budget - so do all your mechanical mods first then get the car mapped to suit. Or pickup an openport cable and start with an XPT map or something from romraider (openport is about 120 - XPT map is around 50-80 dollars and is an easy way to get going). The cable also serves as a handy diagnostic tool if anything starts messing about.

Steer clear of super giant mega ultimate ebay #1 racing pod suction suppliers, stick to a decent panel filter and put the money somewhere else (like decat up/down pipes).

Personally I wouldn't bother with a 3port on a TD04 - if the car and turbo is healthy they will make the needed boost without issues. If your struggling to make boost then it could be a leaky exhaust or the turbo's on it's last legs.

Also check out the traders on here, sometimes cheaper than ebay - mattybr5 is the king of bubblewrap and anything i've had from him has always been as described.

Thanks a lot for your input guys! Definitely gonna keep an eye out for a decent used exhaust system and STI intercooler got a Subaru specialist local to me and had a chat with them too. Will the standard brakes be ok with this power setup? They feel pretty shoddy but probably have standard pads and I'm used to EBC.

standard brakes usually have a sticky piston or two so just have them checked out. decent pads/disks should be capable until you get into big mad turbos and whatnot. The brembos are just better all round plain and simple - see if anyone can take you for a spin in their STI and you'll see.

If your going for the STI intercooler, make sure and get the STI undertray to match, otherwise your WRX scoop undertray will be blocking airflow to the STI intercooler and you'll be worse off than before.

Thanks, yeah I've bought an STI intercooler and need to keep an eye out for an undertray and scoop! Expensive mod! What benefits will it bring?

just makes the charge a little cooler so you can run a little more boost or a little more timing. You can look at chopping up your existing tray if you can't find an STI one but if your a blob then there should be tons of them kicking around!

Yeah I've seen a few undertrays for sale for around $£50 but gotta find a scoop now too! I'd like a carbon one or used black one as they're pretty expensive new

TBH, on the standard TD04, the boost levels will be such that, any gains from an STi I/C will be neglible. Sure, every little helps but upgrading the I/C at modest boost levels would be the last mod I'd consider doing.

Consider the cost, it's the worst value mod, bang for buck. Only if it cann be demonstrated that the inlet temps are such that you are losing noticeable power, would I consider one. You are far more likely to notice the increase in lag than you are from any power gained.

The standard WRX I/C should be fine. I'd consider selling it and putting the money towards the decat, up-pipe, fuel pump, filter and remap. They are the main mods required for appreciable gains (in fact, even the up-pipe is questionable but sensible given how cheap they are).

thanks for your input dude! It does seem like it's "bang for buck" is nothing compared to an exhaust or remap, even a set of coilovers! I've bought it now but it'll probably be up for sale soon!

I spent about 750 on mine, taking it from standard power to 290bhp. I added a kn panel filter, full turbo back decat, 3 port boost control solenoid, walbro fuel pump and remapped the ecu. It was an amazing difference as I installed everything the day before and had it remapped the following day. Don't decat it before remapping mate as it will det

+1 on that

I've heard a lot about these 3 port boost solenoids, are they easy to fit? Don't cost too much... Ok so best idea is to fit the exhaust system then remap as soon as possible? Makes sense

Yes mate easy to fit, but get the mapper to fit it on the day not before. As said before not really necessary unless you go for a bigger turbo. I only got one fitted because I wanted to squeeze every ounce of boost out of my TD04 turbo

Ok cool I'll probably leave that then :P I've found a PPP sports cat and STI up pipe... Are these what I need? Would I get similar gains from the sports cat as I would a decat?

Thats not an sti up pipe, not a standard one anyway. The standard sti one looks very similar to the wrx one but without a sensor on it.

my car came with one of those non-standard flexi uppipes and it was leakling all over the place. solid pipe like the STI one in the second picture there is the way to go. It's the same pipe on a classic impreza as well so check your local breakers for something cost effective.

PPP sports cat will be fine at your power levels and still get you though an MOT too.

The prodrive sports cat won't get you to 290-300bhp. It will get you around 260-270bhp. However you will pass your emissions test. My mate has an MOT centre so mines a bit of a wink and a smile to pass 😁

I saw the ppp downpipe on ebay too ;-)

It said it needed a spacer to fit on an a wrx due to the different turbo, I've not heard that one before?

"will fit most Impreza's (Newage) 2001-2007.... WRX's will need a small spacer due to the divider in the mouth that splits the wastegate pressure from the actual turbine exhaust pressure.... see pics or google it :-)"

you can also grind a little off the divider to make it fit more snugly - it's basically just a little too deep for the exhaust housing on the turbo.

Ah ok well MOTs aren't an issue for me so if I'll get more out of a decat I'll do that :P just a nightmare finding one! I've seen the japspeed full system is pretty cheap new, but I hear they have a reputation for being deafening?

You really need to monitor oil pressure and oil temperature, as well as a boost gauge.

Not tarring you with this brush, but, the light on the dash isn't there to tell people that the oil level is low. It signifies low oil pressure. Or on a Subaru, if it comes on when you're driving, it's the "Your engine is probably fucked" light.

I do believe my PPP WRX is pushing out 291bhp currently but I think that be all I'm getting out of her without some exhaust decatting related modifications...

A standard wrx would be around 225, with a ppp package it should be 250 bhp plus.
Phil

A Standard Blob WRX is 225, knocking on 250 with PPP (unless it's JDM then 250 is standard).

With the mods mentioned 270/280 is easy and will make the car completely different to drive. It will probably achieve better fuel consumption because of the added torque and will be more "driveable".

The brakes can be an issue but I did a refurb on my 4 pots with stainless pistons, some Automec SBF lifetime and the problem is instantly solved (https://www.scoobynet.com/1018042-we...-really-4.html - post 110 onwards). Uprated discs and pads will be more than enough.
The other issue to address maybe suspension, ARB's etc to get the power down and not lost due to a poor set up.

A lot to do but you'll enjoy it.

A bugeye STi undertray fits perfectly inside a Blobeye WRX scoop, and is the perfect size for the STI intercooler.

had the same setup on my bug as well, standard WRX scoop, STI intercooler, STI tray and fitted like a glove!

Dammit, why did no one tell me this before I bought a blobeye STI undertray haha, typical!!

Looking in to the three port boost solenoid, any one in particular? Seen a SWRD one on scoobyworx, good enough?