2014 SUBARU WRX STI REVIEW
What’s Hot: Super-sharp steering, performance and body control
What’s Not: Still a bit understeery
X-FACTOR: A genuine track weapon: rear wing aside, it's almost as practical as a family sedan.
Vehicle Style: Performance small sedan
Price: $49,990 (plus on-roads)
Engine/trans: 221kW/407Nm 2.5 turbo petrol 4cyl | 6sp manual
Fuel Economy claimed: 10.4 l/100km
It’s fair to say that more than a few of the 300-odd WRX STI sedans Subaru expects to sell this year will find their way onto a racetrack.
How could they not? For a sub-$50k retail price, you get 221kW of power, 407Nm of torque and a sophisticated AWD system to harness all that grunt.
And don’t let the identical bodywork fool you: under the skin, the STI is worlds apart from the $38,990 WRX.
It's also a very different animal to the previous-gen STI despite the carry-over powerhouse under the bonnet.
The body is more rigid, the steering is tighter, suspension re-tuned, torque vectoring has been added and forward vision has been improved.
Wakefield Park was the venue for this outing, and it’s the perfect crucible to put a rally-bred machine like the WRX STI under the blowtorch.
There are mid-corner elevation changes, off-camber bends and short straights that demand much of the engine.
The layout looks simple, but it’s a challenging track.
The STI, however, took it all in its stride.
ON THE TRACK
You've only got to rocket out of pit lane, any pit lane, and you'll immediately become aware that Subaru’s approach to the new STI’s engine is “if it ain’t broke, don’t fix it”.
The engine carries over with identical power and torque numbers, and no changes to the way either is delivered.
Boost starts to build from 3000rpm; the STI's EJ25 2.5 litre boxer four doesn't have the low-end flexibility of most modern turbo petrol engines.
It does, however, have masses of midrange and top-end thrust.
Peak torque arrives at 4000rpm, and peak power at 6000rpm. Stray out of that 2000rpm gap between peak torque and peak power and performance is blunted.
Gear ratios are also unchanged, though the shift linkage has been tightened up to give greater precision when rowing through the six-speed gate.
Keeping the engine in the meatiest part of its powerband would necessitate more frequent shifts were we at a faster circuit like Phillip Island, but at Wakefield most corners are easily dispatched in third gear.
Straights here are short, but the STI can carry race-car mid-corner speed for very rapid exits. We were nudging up to 170km/h at the end of the main straight.
But speed is nothing without handling.
Thanks to a vastly stiffer chassis (40 percent more torsionally rigid than before, with 30 percent more bending rigidity too), the new WRX STI features much firmer suspension settings that help it corner flatter and extract more grip from its tyres.
How much firmer? The front springs are 39 percent harder, while the front dampers are 10 percent firmer in rebound and 20 percent firmer in bump.
The front crossmember and bushings have also been reinforced, and the alloy lower control arm cuts unsprung weight.
At the rear, springrates are up by a huge 62 percent. Rear dampers are 20 percent stiffer in rebound and 50 percent stiffer in bump to match, and the rear subframe also gains reinforcements.
Some rubber bushings in the rear suspension have also been replaced with more rigid 'pillow ball' bushings, and the front and rear swaybars measure 24mm and 20mm respectively.
Helping that firmer suspension put the power to the ground is the STI’s familiar Driver Controlled Centre Differential (DCCD) that allows drivers to play with the front-rear torque split, now augmented by brake-based torque vectoring.
And then there’s the steering.
The rack ratio has been quickened to 13:1; Subaru reports it benchmarked the Porsche 911 for steering response.
Turn-in is super-sharp as a result. And thanks to a tighter rack, on-centre response is alive and very alert.
Rack rattle is still plainly evident. Not such a big deal in a racetrack environment, but even Wakefield’s relatively fresh tarmac managed to get the rack moving in its bushings.
Push hard, and if left to its own devices, the WRX STI can be its usual understeery self. Enter a corner too fast (and we frequently did), and the nose washes wide.
Try to counter it with power - as you can in a GT-R or Evolution - and the result is more understeer. It seems Subaru’s interpretation of torque vectoring isn’t quite as clever as that of its Japanese competitors.
It can be corrected a little by flipping the DCCD toggle to the rear to bring up a rear bias to the torque split, but the best result comes from stabbing the “DCCD Manual” button and dialing it most of the way to the rear.
The STI becomes transformed in this mode. Steering angles can be adjusted with the throttle, the nose doesn’t push under power and the car is far more entertaining - and satisfying - to drive as a result.
It also puts less strain on the front tyres. In Auto mode we found the front tyres were overheating after just a few hard laps, but with a rear torque bias this became much less of a problem.
Granted, these benefits only come into play when accelerating.
Torque vectoring and torque split changes only have an effect when the engine is actually producing torque, so entering a corner with neutral or no throttle will still see the STI understeer.
Solution? Slow-in, fast-out.
And when it comes to slowing down, the car’s big Brembo brakes make light work of reining in the 1525kg STI.
Measuring 326mm at the front with four-piston calipers and 316mm at the rear with two-piston calipers, the STI’s stoppers are powerful, resistant to fade and have a progressive and firm feel through the pedal.
In fact, with the mechanical package so capable and adjustable, we reckon the only great limitation on the STI’s performance is its tyres.
The Dunlop SP Sport Maxx RT tyres (245/40R18, for those interested) are not lacking for grip, but after the strain of sustained fast lapping they do tend to heat up rather quickly.
For road use they’re hard to fault, but keen trackday enthusiasts may want to invest in more specialised rubber.
TMR TRACK TEST VERDICT
It’s a hell of a package, the new WRX STI. The handling is so much sharper and focussed than the old car, yet it’s still got that typical STI hallmark of fantastic midrange torque.
It’s still an understeery thing, but much of that can be eliminated via the clever DCCD system.
And as a car that you could drive every day yet still have fun with at a racetrack, the WRX STI is virtually without peer.
It’s got a spacious interior for a small car, plenty of mod-cons, a fairly comfortable ride (yes, despite that massively stiffer suspension) and a huge boot.
Practicality and performance need not be mutually exclusive.
And with the new STI’s pricing, Subaru is bound to find more buyers for this generation of STI than it did for the previous model.
The bang-for-buck quotient is through the roof.
PRICING (excludes on-road costs)
- WRX STI sedan manual - $49,990
- WRX STI Premium sedan manual - $54,990