HomeImpreza WRX Impreza STi Oblivion 


Meridian's Impreza STi

This on-going saga starts at the bottom, here; news at the top is the latest.



Currently the car has: MD321H turbo, HKS EVC6 boost controller, Bosch 650cc injectors, Hyperflow front-mount intercooler, Samco turbo inlet hose, Full Hayward & Scott 3" sports cat exhaust, GT Spec 2 unequal-length ceramic-coated headers and up-pipe, Hyperflow induction, GoFastBits lightweight pulley set, Walbro 255 fuel pump, Roger Clark Motorsports V7+ Group A oil catch can, Hyperflow fuel surge arrestor, Hans Kummerehl air deflector. Zen Performance remaps by Paul Blamire

Whiteline 22mm rear ARB and Whiteline alloy rear drop-links, Performance Friction front brake disks, Goodridge braided brake hoses.

Currently the power is 410bhp, and torque is 348lbft.


The diary

2 May 12 

The best laid plans of mice and men and all that...

Well, I've still got this car. I was all set to replace it when the government decided to destroy my job. I leave work soon, and still don't have a new job, so this car is still with me. In all fairness, I'm also struggling to work out what to replace it with. I like the new hatchback STIs, but they are a bit wider than the Bugeye, and I need to see if one will fit in my garage or not: like most British garages, it's too small for an actual car. I looked at a good STI at Westaway, but they weren't willing to let me drive it home to try it out (too far apparantly) so no deal. If they are too big I will have to think again.

Anyway, the car has been running just fine, with no problems to report except one: a spurious Engine Management warning light. This first came on last year, lasted a few days and got reset by Zen Performance. It came back again over the winter, and again had to be reset. The exact fault code is: "Lambda Sensor Overtemperature" or words to that effect. The car has to Lambda sensors, one in the headers (you can see the fitting in the pictures of the new headers below) and one in the exhaust after the cat. This is the headers one. The problem is that the exhaust gasses are much hotter than the system expects due to the higher power, and also the the better (ceramic) insulation on those headers, so the sensor overheats. After a discussion the eventual solution was just to reprogram the ECU to ignore that warning. This was a little easier said than done, as there are hundreds of things that can be turned on or off in the ECU software, and eventually Paul had to talk to Ecutek, who gave him the correct code. So far, touch wood, the warning has not repeated.

The car will be ten years old in about three weeks.

7 April 2010

This may well be my final entry here, as I've come to the decision not to do any more modification on the car, and I figure that my six faithful readers don't want to read about routine maintenance and such. The problem is essentially one of economics: the car is worth about 6000-7000. I could spend, for instance, 2000 getting a really good suspension setup; and I seriously toyed with the idea of spending about eight grand to get up to 500bhp. But in both cases the car would still be worth 6000-7000 and I'd be a lot of money down. And in the case of the 500bhp setup, I'd be eating into the otherwise faultless reliability quite considerably. So instead I'm saving up for a newer car. Not a new one: someone can pay the first two or three year's depreciation. I did debate getting an M3, but BMWs are pretty common these days, even if not in M3 guise. Currently the plan is a hatch version STI, but it won't be for a while yet either way. In the meantime, thanks for reading.

27 August 09

The car was back in today for the 60,000 mile service. This means that the brakes have to be drained and the fluid replaced, so I took the opportunity to get Zen to fit Goodridge braided brake lines:

The front disks were also pretty worn, so they got replaced with Performance Friction disks (along with Performance Friction pads):

And here one is, fitted to the hub:

Other than that, it was a standard service. I did also got Paul to check why the engine management light had come on a month or so ago while I was overtaking someone. The answer was, the MAF sensor had hit its limit. The combination of the big front-mount intercooler and the larger turbo means that the MAF is running at the limit of its designed capacity. Under some circumstances, it can therefore exceed that capacity. It has only done this once so far, but if it does it more often then I may need to look at either another MAF, or running without one.


20 May 09

Lord, is it really that long since anything significant was done? Anyhow, I finally bit the bullet and had a front-mount intercooler fitted. I know a lot of people will have being saying that I should have done that ages ago, but I just wanted to see how far I could take the standard STI7 top-mount. The new FMIC is the Hyperflow one (the standard one, not the "Monster". I also had a Samco turbo inlet pipe fitted at the same time, after a recommendation from a fellow ScoobyNet member (thanks Stu). There was a minor panic at about 5pm however, when Paul (Blamire) came in and said that the fuelling was running way to lean at higher revs. He went off to investigate and an hour later reported that the issue was a faulty fuel regulator. Essentially it was not varying pressure at all in response to demand, so that the car was over-fuelling at low revs and under-fuelling at high ones. He swapped the regulator out for a spare one, and went back to mapping. Working (as usual) way beyond the call of duty, he came back at 8pm with the graph below - we'd finally got the car over 400bhp.

Torque is down, and will need investigation. There seems to be an issue with compressor surge, which is limiting the boost which I can run at: currently 1.70 bar peak, dropping to 1.50 bar.

Anyway, here we are:

I then had to do a couple of chores: change the enlarged scoop for the original one, and move the number plate up a bit to get it out of the way of the intercooler. That and the fact that the force of the air against it was twisting the bumper, as the plate was mounted pretty near the top, and only supported now along a narrow strip - the rest of the support part having been cut away to fit the FMIC. Needless to say, it wasn't quite that simple. Two of the bolts on the scoop had become free inside the fibreglass and they rotated freely when I tried to undo the nuts on them. Eventually I had to resort to chiselling the fibreglass off the bolts until I could rip the scoop off. Then it was easy to undo the nuts. The only problem with the plate was my inability to remember a measurement, so I drilled one hole 5mm too high and had to drill a second hole.  I still need to get a grille to protect the new intercooler as well.


25 June 08

Following the lower-than-expected power run in May, I went back to Zen for uprated headers and up-pipe. The headers are tubular GT Spec 2 jobs similar to the RCM ones. Both headers and up-pipe are ceramic coated: effective, but d*mmed expensive. Of course in the modding game, nothing is simple. And everything is more expensive than you expected... For a start, Tim discovered an oil leak, eventually traced to a broken o-ring in the front left drive shaft. So that was more time and a new lot of gear-box oil. Next up, the Lambda sensor wouldn't come out of the old headers - and they are expensive. I was lucky here: while it wouldn't come out in situ, once the headers were out the extra degree of brute force which could be applied got it free and into the new headers. So here are the old and the new:

and the new ones fitted:

Next up, it was time to find out what was causing the power to be lower than expected - and also an obvious dip in output just after peak power. Paul put the car on the rolling road and found the problem after about half an hour: the neutral position sensor was not always working. When the ECU fails to detect neutral it does some odd things: like refuse to engage the variable valve times system which would hit power quite badly. Once found the problem was fixed relatively easily: Paul pinched the sensor out of the Zen race car because that machine doesn't use the sensor. Then the car was tweaked a bit more and finally we had a figure:

As you can see, the headline figures are 372bhp, and 356lbft torque. Lower than I had hoped, but not bad. The red lines are new figures and the blue ones are from before, with the old headers and the faulty neutral position sensor. In particular, the dips in output are down, and the torque is way up. But it's not enough, and this seems to be as far as the current setup will go, so it looks like I may yet end up with a front-mount intercooler. I've been avoiding it deliberately, trying to see how far top-mount I/Cs will go, but it looks like the answer is: about 372bhp on an STI 7.

And now, for those who've never seen it, the Zen Performance workshop and the happy team at work:


14 May 08

The car was due in for an MoT, so I also got Zen Performance to to fit a Whiteline 22mm adjustable rear anti-roll bar and alloy drop-links, then check the alignment. Ever since I got the mud-flaps fitted I've noticed the body-roll, because if I hit a bump while cornering hard I can hear the front mud-flaps scraping on the ground.

Sorry about the poor quality of that last picture, but I think you get the idea. I'm not the greatest driver in the world (except in the sense that all men are...), but I can detect at least some difference on hard cornering. And I do take roundabouts hard enough for my front tyres to be wearing differently on inside and outside edges. Body-roll definitely seems less, but it does seem a little "floaty" at the edge. That may actually be due to the tyres (Goodyear Eagle F1 GSD3s), as they have a fairly progressive loss of grip, and it may be that I'm now pushing hard enough to notice it.

After that I asked Paul to put the car on the new rolling road, so I could see what power I had now with the higher boost.

At things point things went downhill fairly rapidly. After one run at 375bhp, but with the engine detting fairly seriously, Paul was forced to tweak it down to 363bhp. After a couple of hours he had got no further, although I had spent yet more money on some NGK PFR7B Platinum plugs! We discovered that on the 1.3 bar "girly" second map it ran at about 350bhp, which is about what should be expected for the hardware fitted. But adding 0.4 bar caused loads of det, which in turn made the ECU retard the ignition quite markedly, and this the tiny gain in power. There wasn't time to work out what was causing the det, so it will be back to the drawing board next month. New headers may be a possibility, and we also need to test a) the effect of a different exhaust, and b) the power at different boosts. If I'm really lucky it's just a duff batch of V-Power, but knowing my luck it's a bit more serious.


20 February 08

The car was in for its 50,000 mile service, which means a cambelt change. I took the opportunity to get Zen to fit a Go Fast Bits (yes, really) light-weight pulley set while they were at it. In practice that's just two pulleys for crank and alternator, because you can't get the power steering one off. The new ones are in a tasteful shade of black and do absolutely nothing for performance, but look good:


27 November 07

Had the EVC6 fitted today at Zen. Paul then mapped for 1.75 bar maximum boost on map B, with a more conservative 1.3 bar on map A. Apparently that's for when I let someone else drive the car. As if...

Here's the control unit, which is a bit less than 10cm long.

The controller is currently fixed at the bottom of console just below the ashtray: I don't plan to touch it very often, if at all, so it's fine down there. Here's the other half of the system, the three-port boost solenoid (stepper motor actually):


10 October 07

The best-laid plans of mice and men etc...

I was supposed to be going in to Zen today to get an HKS EVC6 boost controller fitted, and get a new map done, plus a couple of odd jobs: get the drain pipe for the catch can connected, and get the intercooler water spray wired up so that the Auto switch actually worked. Unfortunately all that came unstuck on Monday when I realised that the clutch was slipping in sixth gear. So I had to phone Paul and change the appointment for a clutch change. On the way over to Zen the clutch started juddering in fifth as well, a sure sign that it was pretty dead. Sure enough, once removed it was clearly very worn. The worrying bit is that it was an Exedy up-rated clutch, which meant that the previous owner had replaced it during the thirty thousand miles that he owned the car. Which meant I had probably wrecked it in about twenty to thirty thousand miles - the car has currently done forty-eight thousand miles. Anyway, Paul fitted an AP Racing organic clutch, which should handle any planned torque increase:

and here it is in place:

It's a bit brutal compared to the worn Exedy, but I'm sure I'll get used to it. I did stall the car the very first time I used the new clutch though...

As I said earlier, I also got the drain pipe connected up for the catch can - Paul had the wrong connector part when the can was fitted in July. The new pipe is a fairly solid (and expensive) bit of hydraulic pipe:

At least it won't wear out any time soon.


23 July 07

While at JAE over the weekend I bought a couple of carbon fibre bits from Scoobyparts to bling up the engine bay. So I present: the new fuse box and pulley cover covers (you fit the CF part over the OEM one)

20 July 07

A couple of small bits of work done today: an RCM V7+ Group A oil catch can and a Hyperflow fuel-surge arrestor (actually supplied by TSL). The catch can didn't go entirely to plan and currently the drain hose is missing - but blanked off, so don't panic! It's a matter of debate as to whether the car really needs one, but it's not that expensive, and better safe etc.

The fuel-surge device was to try to counteract the bad fuel surge I get if I accelerate hard after a big right-hander. For those that don't know, the scoob fuel tank is a bit like a letter "B" on its side, rounded bit down, and with the "saddle" over the transmission. The fuel pump is in the front right corner. That means a big right-hander - like a roundabout, say - throws all the fuel into the left half of the tank. There is a pipe connecting the two halves and fuel soon goes back, but for a couple of seconds the fuel pump cavitates because the high demand due to the acceleration overwhelms the pump's ability to supply fuel without a full head of petrol over the filter bag. The effect hits once the tank is only half full, and slowly gets worse - by the time you hit a quarter tank-full you have to drive like a grandad to prevent the car kangarooing up the road like a learner with disco-foot in his left leg. I've not had a chance to test the new toy though.


31 March 07

I left the car at Zen Performance over last weekend for Paul to do some work:

That's mine on the right...

The big job was the turbo upgrade, from the standard VF35 to a Lateral performance MD321H:

To support that, I also had Bosch 650cc injectors fitted, along with a Hyperflow induction kit, which was fitted into the driver's side wing through the hole that the air intake used to use. The original air intake system came out.

This is what the empty area looked like once the old turbo and intake were out:

In goes the MD321H:

and with the pipes all connected, it looks like this:

Last in was the intake kit. Doesn't look very interesting as the business end is hidden inside the wing in front of the wheel arch though:

It leaves the engine bay looking a bit bare on the driver's side:

Because the induction doesn't come in through the slot at the front of the bonnet any more I refitted the air deflector, which had been removed during the last remap as it choked off air intake.

Anyway, with bits in an connected, and nothing leaking anywhere (fitting new injectors can be a risk here) it was off to LSV to do the mapping. On arrival, I was greeted by this slightly frightening view:

It wasn't anything serious: during the work, coolant had got spilt on the turbo piping and was now being cooked off. After about fifteen minutes it all went away, but there's still a slight smell of cooking coolant even now. Anyway, Paul put the car onto the rolling road:

and began the initial mapping. He spent about ninety minutes on the rollers doing the initial tweaking, before a final run to get a "headline" figure. Which was 388.7bhp. Later testing suggested that this figure may well have been pretty inaccurate. I'm going to have to disregard it for the time being.

Now I had set out to get 400bhp, and Paul was fairly certain we could get there with these mods, so this wasn't brilliant. But you need to bear in mind that by the time this run was done, the car had been on the rolling road for well over an hour, having the the guts thrashed out of it. You also need to know that the LSV rolling road has a big blower for the radiator, but it doesn't get any air into the bonnet scoop. And finally, I still have the top mount. All of which adds up to big a heatsoak problem I suspect. I'm off to a rolling road day at Powerstation in May, and they do have a scoop blower, and I'm hoping that I will get over the 400 figure there. If not, the next step is lagged tubular headers and up-pipe. If I'm forced to, I will change over to front-mount, but I really don't want to: I'm determined to show that getting an STI to 400bhp on top-mount is not only possible, it's not even particularly difficult.

Of course, nothing is simple in this game. On my way home on the Monday I was giving it some along a private road and had hit about mubblety-mumble miles an hour when the fuel-cut kicked in and the engine management warning light came on. Overnight it reset, but serious welly the next evening had the same effect, so it was back to Zen. Paul tracked it down to the maximum boost, and dropped that a little, while leaving the constant 1.45bar main boost intact. Some more, er, testing, suggests this has cured the problems. While I was there though, I got him to fit some mud-flaps I had picked up second-hand from someone on Scoobynet. So now it looks pretty. Apart from the dirt, cleaned off since this pictures were taken:


14 November 06

I've now done the first part of the next batch of mods: replaced the rest of the exhaust. If you could be bothered to read all this page you would know that I used to have a Hayward & Scott combined down-pipe and cat pipe (with sports cat) tapering from 3 inches to 2.5 inches, and joined to a standard resonated centre section and a TSL firestorm backbox. I've now had the centre and backbox replaced with more H&S parts to give me a full 3 inch system, ending in the rolled-tip backbox:

The new pipe is as loud as the old, but with a deeper note. But it doesn't rise as much in volume with increasing revs as the Firestorm did. That was slightly wearing on long journeys above 3000rpm, whereas this is not as intrusive - but still rather louder than the original Subaru system.


26 April 06

Took the car back to Zen to get an STI panel filter fitted, a couple of minor map tweaks, and finally the rolling road, done over at Linden Special Vehicles. The biggest problem there is that the fan used to cool the engine doesn't sit high enough to blow into the intercooler scoop, and they don't yet have a shroud to force the air in. The first couple of runs were a bit low (315bhp) until Paul remembered to spray water on the intercooler. The result was this:

326bhp, and about 320lbft of torque. Not bad for what are, after all, fairly minor mods.


24 April 06

I took the car over to Zen Performance for Paul and his team to do some work. The original down pipe and cat pipe were removed and replaced by the one-piece Hayward & Scott unit mentioned below. As usual with scoobs, things didn't go according to plan and rather a lot of banging and sawing was need to get the heat-shield off the turbo so they could get at the down pipe bolts. More work was then required to get the heat-shield back on again, but they managed in the end. While that was going on I also had the OEM fuel pump replaced with a Walbro 255 unit. Finally, and much later than planned, Paul did a remap. That took about two and half hours on its own, so the work took pretty much the whole. Unfortunately it was late in the evening when Paul finished so I couldn't get a rolling road run that day.


24 March 06

I've just had a set of Defi Gauges installed by Xtreme Scoobies, out in the wilds of Essex. Hard enough to find their place, even harder to get away from it: rather like Alice in the looking-glass garden I went round in a big circle on narrow (but fun) country roads for ten minutes and found myself back at the end of their road. But the second time I set off I worked out where I'd taken the wrong turn. Anyway, here they are:

along with the control unit, in its subtle and unobtrusive location:

And here are the gauges at night:

All part of that general red-and-green theme:

That's now most of the work I need doing before the remap: just the fuel pump and new exhaust bit, and both will only go in just before the mapping is done.


14 March 06

Out with the old:

and in with the new:

Yes, I know it doesn't do anything for performance but it looks good.


6 March 06

I've been out and taken some more pics. I still can't get a perfect shot, mainly because I'm not a very good photographer, but here they are:


And I've bought myself a new toy: a single sports cat pipe to replace the current standard catted downpipe and cat pipe. Courtesy of a Group Buy at Scoobynet from Hayward and Scott. Only took about a week from when I ordered, and it's made to order. I haven't unwrapped it yet because there isn't any point until it's ready to fit; and that won't be until the car is ready for remapping. So here it is wrapped in bubblepack:


21 January 2006

Another year, another mod... OK, it's a small one, but here it is:

If an air deflector. Basically it's the same as the "Cool Deflector" that Zero Sports make and sell for about 48, but in this case it was made by another ScoobyNetter who sells them for a lot less. The idea is to stop air coming in through the grille simply going over the top of the radiator, and instead force it through the rad.

I've also had Paul at Zen Performance (better known as "Pavlo") give it a check over before the warranty expires. The good news is that the impact which broke the alloys hasn't damaged the suspension. The bad news is that whatever accident or accidents the car was in before I got it has results in several parts of both front and rear suspension being replaced. And it looks like the front bulkhead may have been slightly displaced as well.


20 November 05

First of all, the car is back from the bodyshop. I used Notley's in Huntingdon, but I can't link to them because they seem to be the last business in the Western Hemisphere with no web page. Anyway, they've done an OK job with the paint and dents, but I'm not happy about some of the panel gaps. I discovered when I took the car in for the quote that it had been in at least one previous accident in pretty much the same areas: the front left wing (replaced by Notley's) was already a replacement one, and there was signs of work on the front RH door and the RH side of the rear bumper. The combination of the two accidents (assuming that there have only been two...) is that msot of the front panel gaps are uneven. The bonnet sits slightly high, the gaps around the headlights are different for each side, etc. If I planned to sell the car anytime soon I'd be pretty ticked off, but I'll probably keep the thing for a few years yet. But that time any minor prangs won't effect the insurance so much.

 Second of all, another slight upgrade: a new backbox. This wasn't a planned upgrade, but I saw someone on ScoobyNet selling a TSL Firestorm, and I bought it.

The default STi box is better than the default WRX one, but it's still a bit muted. This one is loud. Not mind-numbing "Oh God, my ears are bleeding" loud, like some I've heard, but impressively loud. At tickover it's just a rumble, but even at 1500rpm the noise starts. But 3000rpm and boost the noise is a roar which just builds up as you go through the rev range (which doesn't take long on an STi...) until it acquires a slightly strained note at about 6000rpm. I've got an idea that I'm going to find it a bit annoying after a while (although not as annoying as my neighbours might find it after a couple of 2:30am call-outs) but it's OK for now. The long-term plan is for a full 3-inch pipe with sports cat anyway, so this is just a temporary fix.


5 October 05

More bad news - last Saturday my car was collided with (yes, I know that's not correct English, but it's a pretty good description) and scraped/dented down the left-hand side. I can't say too much until any claims are sorted out, but the damage looks like this:

As you can see, there is a big dent along the leading edge of the wing, as well as a second dent on the trailing edge, plus scraping on the bumper. The wing has actually been pulled back about 5mm, and has dragged the headlight with it. I'm hoping that the wing can just be replaced, and the headlight mounts aren't damaged. Because the scoob's wheel arches flare out so much, the next point of impact was towards the rear of the back door. Look carefully, and you should see a shallow dent:

as well as scrapes on the rear wing. I'm awaiting a quote from a local body shop to forward to my insurers.


12 September 05

After the little accident mentioned below, I was forced to buy some new wheels. I would have liked some genuine PFF7s, but the 250 each asking price was a bit steep. My local dealer was doing a set with tyres for 1200, but they were in Bright Flitter, and Rally Blue scoobs are required to have gold wheels by law. So I bought a set of replicas from David Hendry cars in Wiltshire. They are marketed by Zero Sports, but I'm not sure who actually makes them. They arrived just two days later - thanks guys - and today I got them fitted, along with Goodyear Eagle F1 GSD3s:


5th September 05

I've changed the side repeaters from smoke to blue since I last updated this page, but last weekend was rather busier. And not a lot of fun...

First of all, my garage door broke again. I know I need to replace the thing, but it's a low-priority item, and at least 600, so currently it's bodged back into working order again.

Then on Saturday afternoon I set about fitting the STI version 8 scoop I'd bought from Milsport a couple of weeks ago. I'd like to have installed it when I bought it, but the useless shower that is Royal Liverpool Victoria/Frizzell wouldn't insure the new version. 1600 of new wheels for instance wasn't a problem, but no, I couldn't have a 180 scoop. But my policy with them lapsed and now I'm with the nice people over at Keith Michaels who actually understand this sort of thing. Anyway, the old scoop came off easily (five nuts and three plastic clips),

and on went the new. I'd put sealing tape around the edge, but it turned out to be too thick, so I took it apart and tried without any seal. I wasn't happy with that so I tried to take the scoop off again. No such luck: one of the screws secured in the GRP of the scoop had come loose and was rotating with the nut. Guess it will be without a seal then... Looks OK though, although I'll admit this picture is really from the wrong angle to do it justice:

Then it was off to Wellingborough to meet some friends. On the way I ran into a partly exposed paving slab at about 70mph (no, really 70mph). The story is long and complicated, but it was essentially my fault, although the bloke who changed lanes in front of me as I was overtaking didn't help. But the result was this to the front wheel:

and this to the back wheel.

This morning I phoned the garage to find the cost of replacements - 360 EACH. That is actually over 100 more than PFF7s or P1 wheels. If the factory wheels are more expensive than PFGF7s, why the hell don't Subaru put PFF7s on instead? They're far better looking of a start. I'm now going off to fume again...


30th June 05

Now de-tangoed. The replacements for the reflectors are the ones sold by TSL, but I don't know where the smoked indicators came from as I bought both items as a set second-hand. I originally planned for blue indicators, but the smoked ones look OK - they even have a slight blue tint, probably reflected off the paint.


7th May 05

Bought the first toy for the new car: a Prodrive gear knob. From Little Acorns and all that...


The saga starts here. For the latest news, go to the top.

19 February 05

I've just sold the WRX, and upgraded to an STi: 30k miles, three years old. This is a proper Impreza: right colour, big spoiler, gold wheels. Chavs everywhere will be jealous....