So last August my dream since I was a kid to own a Impreza came true. Problem is I am far from a petrol head, really enjoying the car as it is, but feel I need to do some bits to it.

















Don’t get me wrong it’s had a lot of time and money already spent on it before I got it. First thing I did was a new timing belt kit. But that’s all I’ve done so far.

Full blue suede STi interior
Hayward and Scott heat wrapped ceramic coated centre pipe
Hayward and Scott back box
de-cat treated down pipe
Walbro 255 lph fuel pump
cosworth panel air filter
uprated large top mounted intercooler
high performance boost hoses
ASH vacuum hose kit
HKS purple magnetic sump plug
New MAF sensor fitted genuine denso
lightened flywheel and clutch 15k miles ago
and a few more cosmetics.

so my problems first:

When I’m below 1/4 tank of fuel I get serious power loss when accelerating (hard) and of course being AWD you get throw forward. It feels like the engines being starved of fuel, all I can think is the pumps fitted wrong or is this normal?

my intercooler, as big as it may be. It’s not fixed down, it doesn’t line up with the anchors, I can adapt it does this need addressing sooner rather then later?

i don’t seem to have a air intake funnel. After a bit of research I can’t seem to find a definitive answer if I need one or not (In pictures above) I like the look of the carbon fibre funnel, worth fitting?

my header tanks leaking near the lid. Repair or replace? Easy fix or not worth it?

So that’s the problems I have at moment I just want a few answers to, now for what I should do next.

I want to kill M3’s basically. Another favourite car of mine but just not as cool 😎.

the cars never been remapped with what’s been fitted. Previous owner was a mechanic and said all he was gonna do was de-cat the up pipe, uprate the turbo and add a heat shield then re-map.

I feel like there’s more to it then just adding a few bits, I feel a remap is gonna make the world of difference, as I said before I am no petrol head. I’ve never had a nice car. So nows my time to play.

So before I go for the remap I wanna get done what needs doing to smash an M3, surely it’s possible right? but in the long run making it an even more thrilling exciting, nail biting drive. Main aim is 300-350bhp

In a nut shell TLDR

What do I need to fix
How can I improve before remapping

thanks if you still here, and in advance for any answers.

 

I know that it gets old on here because it is said a lot of times by members,but in all honesty you should of started with a STI.I am not saying that you cannot tune a WRX to embarrass a M3 but it will take ££££...as when you start to increase the power on a WRX it becomes much more essential to upgrade the supporting mods that come as standard on a STI i.e brakes gearbox etc...as 350hp is not really going to trouble a M3 when the new models are pushing 420BHP+.SJ.

 

thank you,

bit late for that unfortunately 😂😂. This isn’t going to be a ‘I need it done by summer job.’ Will be a long ongoing project. So willing to make it my own in reality. Brakes I already plan on doing with new wheels. Other bits I suppose il learn about being here.

Just went for a drive and something ‘went’ 😭😭 got engine light and liquid in engine. Great.

 

When you say smash an m3 do you mean the newer ones? If so then forget it.
They have 430bhp in non competition model with a ultra fast DCT gearbox, a simple remap and decat will see them with well over 500bhp and 500ftlbs. Yes you MAY get off the line quicker but that's where it will end for you.

I had a wrx that I went down the power route and it was a waste of money. To even get an sti to embarrass an m3 would cost huge amounts.

350bhp is yesteryear power I'm afraid,these German hatches/m3's etc have nailed it because they stayed ahead of the competition.........something subaru didnt do.
450+ Bhp is the new 300bhp if that makes sense.

Even a lardy 530D with a remap will show its heels to a tuned sti.

Sorry to **** on your chips but that's the way it is, hence why I'm seriously considering an F10 m5 as a simple remap with no other modifications will see 700bhp and around 650ftlbs.

 

replace header tank with a new one , see if supporting arms for the i c can be bent to work if not replace them , a 1/4 of a tank in a straight line should not effect acceleration , is gauge faulty so it’s less than a 1/4 of a tank , not good pushing it hard with a lack of fuel as can cause det which kills an engine , sounds like fuel pump or connection issue ?? assuming the tank is not low , fuel pump is fairly easy to get to , it’s under an access panel by rear seats , and yes it needs a map , my thoughts are if i changed i c i would have mapped it for that on its own , your power issues could be around mods done and a lack of remap , i think i’ve answered most of your questions regards the thread , i do second the idea of should have got an sti , especially regards the gear box if you are looking for more power , it could be a m3 bearer if was an older school m3 , sports cat will help reduce lag which they tend to suffer more from v a 2.5 turbo engine

 

Thats what you call tough love Loool,it may hurt but it's the truth.SJ.

 

No point sugar coating it lol.

The subaru will get off the mark quicker,probably handle better,sound better and look better (in my opinion) but it will not compete with the performance German market of today. Subaru didnt evolve where as most of the others did.

I'm not saying the germans are the better cars,I have a soft spot for the impreza and I love how much attention it gets and all the compliments it gets But I am dangerously close to grabbing an f10 m5 competition pack................

 

To the OP I don't want to end your dream though,as it can be done as I destroy M3's on the road and trackbut my car has had thousands thrown at it plus I am an experienced driver especially with Subarus owning and modifying mine since 2003...I love Subarus and in all honesty every time I think of selling up I change my mind and find another modification to put on it,Subarus can be a joy to live with and always can put a smile on your face theirs not much affordable cars these days that can do that, my advice is just enjoy your car and modify it sensibly when you can afford to,just take your time getting use to it...all the best.SJ.

 

If it's your 1st fast car then yes it can be made to be very fun.
if you can fully de cat it and then get a remap it will transform the car into a rapid car.
my 1st Subaru was a bug wrx and the thrill of driving it home after a remap was fantastic.
Full de cat though and my 1st turbo car.
Just forget about the m3......unless its wet and not on the motorway.

 

Thanks all that’s replied. I don’t expect it to beat modern technology it was more of a wish than a reality.

its fun now can only imagine what it would be like with the right mods and remap. Getting 300-350 bhp is my goal. It will be a slow process because of ‘life’ but excited to see what it can do.

as for cosmetics that’s last of my agenda need to get it running right.

I would have gone for an STi but my budget was a bit less then what I could afford at the time. Il do what previous owner said. Get it remapped. Plus some other bits and see what I can do with it. Don’t expect it to be beating 69 plate cars but il a damn good go 😂😂😂

 

off a standing start my fsti and an m2 there was nothing in it , plus up to motorway speed still nothing in it , he was definitely trying and clearly surprised to still see me there , i reckon an m3 catch it napping a bit and that would be interesting 😁 , it’s only had a remap exhaust fuel pump other mods are handling

 

figures are 330 bhp v 364 bmw,1450 kg v 1625 bmw , so the advantage is more different gearing and auto boxes , buying cheapish v 65000 £ bmw , running costs cheapish normally v ££ bmw 🤣

 

I agree...but a lot of different variables still come into it,I have already said to the OP he needs to get use to his car so to give him more experience when it comes to the limitations of the Subaru WRX model...because when driving his car he will soon realise that he is probably setting his sights a tad high especially against the new BMW M3 models as the standard brakes,suspension, are not up to much when you start upgrading the engines horse power and will definitely have to be upgraded first.SJ.

 

It does seem a bit pointless doing all them engine mods on a wrx with rotted out rear arches (and most likely rear suspension turrets as well)?

 

Sorry I forgot to answer these questions
When I’m below 1/4 tank of fuel I get serious power loss when accelerating (hard) and of course being AWD you get throw forward. It feels like the engines being starved of fuel, all I can think is the pumps fitted wrong or is this normal?
Its not normal definitely sounds like a fuelling problem maybe fuel pump I have had that exact symptom on a bad batch of fuel ...also what fuel have you been using and do you usually allow your car to run low in the tank before topping back up?

my intercooler, as big as it may be. It’s not fixed down, it doesn’t line up with the anchors, I can adapt it does this need addressing sooner rather then later?
Simple answer "YES"... in all honesty mate it looks like you have purchased yourself a bad one as it just seems that the modifications that he has done have been thrown together without no care taken to proper fitting So yes I would definitely get the intercooler secured correctly.

i don’t seem to have a air intake funnel. After a bit of research I can’t seem to find a definitive answer if I need one or not (In pictures above) I like the look of the carbon fibre funnel, worth fitting?
Revert to the answer above!...I just think that it has been modified badly, that induction ram intake funnel is to draw in cold air from outside into the factory airbox in conjunction with a wheel arch snorkel u bend component, what I think the fella that sold the car to you has done is fitted a aftermarket induction kit set up i.e K&N filter and before he sold the car to you he took it off and put the o.e filter set up back on minus the induction ram intake funnel "SPECULATING"...which if you still decide to use the o.e set up, you really should be reinstalling so as to have your factory air filter function just how Subaru intended it to....or take the o.e air box out and purchase yourself another performance induction setup.SJ.

 

Totally agree with the above, but you will still have alot of fun. For me, the most important thing would be to take it for a custom map and health check all round at a Subaru specialist. No proper mechanic would decat a car and not correct the changed fueling etc; especially on a 17 year old car.
Other thoughts are; tmic is aftermarket, and unless it's one of the ££££ ones like Process West or Grimspeed, it is probably worse than stock. An sti one would be better, and a direct fit. Alarm bells ring for me with that one, especially if it has fitment issues.
Your air box will be sucking in hotter air without the "snorkel", so pick up a second hand one, along with the top coolant tank.
Re rust, as has been pointed out, if there are bubbles externally, it will be much worse out of sight, so check under the boot lining/carpet on the arches and top mounts.
It may be boring, but I would be spending on polybushing, replacing suspension and a brake rebuild/upgrade to maximize what made your car great back in 2003. That is having a fast b road blaster, rather than a dual carriageway M3 eater. It's the wrong car for the latter.

 

I may be a bit behind in the Subaru world these days, but I do have a classic a bug and a blob

But this car has a full decat after market top mount and a walbro fuel pump and no map

I thought the fuel pump would be over fuelling as IIRC they are 255l/h and higher rated than standard, without a remap surely its overfuelling (which is not good) as the ECU will still think the standard one is there

I would do as others have said

Get an STi Intercooler, it will be a straght fit ( you dont need to remap for just an intercooler change unless going FMIC)
Get a second hand air box funnel and get the air flow back to how it should be

Get some decent wheels

 

exactly 😂😂 plus scoobies are far cooler and the sound 😍😍😍

 

Exactly what I plan on doing.

This has given me exactly the answers I needed thanks all.

I’ve had a long hard think and I’m going to restore it. The rusted arch’s I knew about and it’s on my to do list. So this is going to turn into a project.

definitely going to change the intercooler and get a funnel.

strip her down de-rust, even thinking of changing the gearbox to a 6 speed STi, with male arms new drive shaft, brembos and decent wheels. The different colour engine bay ‘bugs’ me to no end. So engines coming out and going to get a respray. I didn’t pay a lot for the car and it’s on my bucket list to do something like this so why wait. I have got surplus income now which I can throw at this. So a crazy as it sounds it only being a WRX I’m gonna get it to a nice enjoyable sweet spot and maybe purchase a blob/Hawkeye STi at a later date to race track spec it up.

I may have messed up but I don’t ever plan on selling it. So can make it my own. The mods been done I agree seem a bit odd reading through some other posts. So here we go with the (expensive yet satisfying) process. What I’m going to do yet, totally I’m unsure. It have a very good friend whose willing to help and he knows performance cars. But asking you guys was the confirmation I needed for the restoration.

 

If your going to spend that much it’s well worth pricing up some sti , my bugeye was a sti jdm wagon it was around 6500£ fairly low mileage very good nick

 

Ryan the engine bay colour is the original colour that comes as standard on Subaru’s,it’s a very good indicator to tell if a car has been damaged before and repaired as the colour in the engine bay will usually be changed to gloss to match the panels colour.SJ.

 

The injectors determine the amount of fuel into the engine. Changing the fuel pump won't make any difference. If you fit bigger injectors to supply more fuel, you need a bigger pump also but a bigger pump with standard injectors won't cause overfuelling.