I don't think that we were meant to find the suspension the most impressive aspect of the car, but that's what really blew us away. Sure the power was damned strong - there aren't too many 12-second street cars that you drive around with blasé indifference - but it was the way in which the Rex put down its power and just sprinted through corners that had us totally rapt.
Why? Cos it always sat just so flat and confident - even while the enormous power was simply overwhelming the bitumen backwards. This wasn't a car that skated sideways with a brush of the right-hand pedal; nope, instead the g-forces built and built, the tyres clawing at the bitumen until g-r-a-d-u-a-l-l-y either the front or back started to develop slip angles that told you adhesion was being inexorably lost. But no, not 'inexorably'. A tiny lift of the accelerator was always enough to restore grip, and then again you could explore the ability to make the blacktop disappear behind you faster than damn' near any other car on the road... Tromp the loud pedal with a total lack of subtlety and you could have understeer or oversteer just as you wished, the on-demand choice making the car feel more like it had a Torsen centre diff than a humble viscous coupling.
We had ChipTorque's Impreza WRX for three days; at times we laughed aloud with the sheer delight of a package where warp speeds could be achieved even between just traffic lights. But it was the ability to simply spit out corners with absolute stability and safety - and sheer bloody grip - that really opened our eyes.
Lachlan Riddel is the chief honcho at ChipTorque, a chip re-programming company based on Queensland's Gold Coast. The company car is also the development hack - it has been thrashed hard enough that the survival of its (standard) turbo has been a constant source of company wonder. The point? If WRX go-fast parts that ChipTorque sell are gonna break engines, they'd rather it happened on their own car first. So what sorta parts? The powerplant upgrade consists of a polished stainless steel 3-inch exhaust ($2080 fitted), front-mount intercooler with polished stainless plumbing ($2700), a cold air intake to the standard airbox ($155), a blow-off valve ($379) and a re-programmed chip ($995 without a dyno). The turbo stays the same (pretty small) beast that's fitted to late model cars, with boost supposed to be around 22 psi. (We'll come back to that boost level later.) This package is good for 143kW at the wheels on a four wheel drive dyno and the car has run a 12.6 second quarter mile with just these mods.
But - as you can see - this car hasn't stopped there. The wheels are Largo seventeens wearing ultra-grippy Falken 215/40 ZR GRBRS Tune II's. And the suspension that wowed us so? Pretty simply really. The shocks are STi (off an RA import) matched with lowered progressive rate King Springs. That's it - no coil-overs, no fancy bushes, no adjustable thicker sway bars. And this is a car that rides better than a locally delivered STi and outhandles it to boot! Helping the handling is the far better than standard throttle control that comes from the lower gearing achieved by new 4.11 diffs. While the engine's revving hard at cruising speeds (3000 rpm at 100 km/h - the same as the Aus-spec STi), the trade-off is well worth it. Through the gears it's braaaap - braaap - braaap; the sort of car where you can feel your eyes widening and nostrils dilating as your brain goes into the hyper mode needed to take into account all of those eventualities that are about to happen as you rush through the scenery.
The lower gearing - and the chip re-programming - give the car unusually good tractability for a WRX. The latter is needed as most EJ20 turbo engines - RS Liberty, WRX - have appalling low rpm torque. They're usually the sort of car where you'd like to go back to first gear when you find yourself slowed in a carpark - but you're worried to do that because engaging first on the move isn't the sweetest effort with the grouchy Subaru gearbox. But low revs in second - or even third - are no problem in this car, with zero signs of engine misbehaviour and excellent throttle response even below 1600 rpm. But what of higher revs - especially at full noise?
The turbo feels very 'unwastegated' in the way that an aftermarket system that closes off the wastegate until peak boost is reached also feels. The turbo spools up at part throttle; with load you can see full boost at as little as 3000 rpm. And how much is that? Here's where the only downfall of the ChipTorque car occurred. And it's a big one. The WRX had the worst boost control of any turbo car we have ever been in. Peak boost in first gear was 22 psi, in second just the same, and in third gear also 22 psi. Great, so far. But select fourth or fifth at low revs and then floor it, and the boost went mad. How much do you ask? Well 28 psi, 30 psi, 32 psi - you name it, depending on the temp of the day, it simply rocketed to frightening heights. However, if you rushed up through the gears - 1-2-3-4-5 - then boost sat nicely at 22 psi.....
As a development vehicle, the car was running the combo of a chip designed for a top-mount intercooler together with the front-mount core. But still, we can't see the cooler intake air temps adding 50 per cent to the boost value... The variable behaviour of the boost - depending on the rate of acceleration, engine load and so on - also suggested that here was a problem of a different origin. Lachlan Riddel claims that his 'customer' WRX's never behave like this, but the obvious question remains - why was the car given to us with this occurring, and how much testing of boost levels in upper gears had been carried out? (We returned the car complaining of this problem, and the car was checked and the chip replaced. Exactly the same problem continued.)
After that initial exploration, whenever boost rose above 22 psi we were quick to back off - the engine was obviously unhappy at these stratospheric boost levels. But then when we realised that driving quickly through the gears gave decent boost regulation, we started to explore the immense torque that was available. First gear is short with these diffs; it's second gear that's just an absolute killer. The shove in the back is simply mind-boggling, with third a touch disappointing - until it's time to change into fourth and you realise that what you thought had been a bit slow had actually been catapulting you straight into lock-you-up territory. Away from the boost gremlins, the engine management was completely well-mannered, giving good part throttle and full throttle control, that excellent tractability, decent fuel economy and a lack of detonation.
Throw in some luminescent white-faced gauges, a short-shifter and the standard WRX's excellent seats, steering wheel and gearknob and here is a package that is extremely liveable. To be totally frank with you we were just so disappointed with the boost behaviour - on the first day we didn't see the boost problem and so we were infatuated with the car, on the second day we saw 32 psi and so were wary, and on the third day we simply drove around the boost problem by fanging through the gears absolutely everywhere...
The third day was the best!
www.chiptorque.com.au
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