driven: MINI Cooper S JCW

September 16th, 2005

Our first drive of the Mini Cooper S the day it hit dealer stock left us cold. The exhaust was boomy, the gearing too long, the powerband asthmatic and the suspension overdamped and skittish on 16s, underdamped and bouncy on 17s. The car would snap from power-on understeer to trailing-throttle oversteer in a heartbeat. Since then, we’ve actually preferred the normally aspirated Cooper’s low speed response, rising rate powerband, and more BMW-like suspension (it better evinces two adages that MINIs should embody: “it’s more fun to drive a slow car fast than a fast car slow” and “speak softly and carry a big stick”)

Revision to the ‘05 MCS solved all but the motor’s feeling a bit winded before reaching 6,000 rpm and the exhaust boom – if anything the note has grown more prominient with time; changes were instututed for more pops and burbles on the overrun. Revised gearbox ratios and shock damping make for a car that claws its way forward and keys to the surface like the ‘04 and earlier Cooper never did. (The recently added limited slip differential should only improve matters).

We recently had the opportunity to put an ‘05 Cooper S with the JCW engine kit and 18” wheels through its paces, and it wasn’t at all what we expected.

Walking up to the car you eye the exhaust and the 18’s and think “this is going to hurt.” But once underway you find that the exhaust is less prominent and boomy at small throttle openings yet more melliflous at high revs. Even more of a shock, the combination of lightweight wheels and 18” Dunlops are less leaden than the stock 17s. You’d expect the 18s to throw impact absorbtion out the window, but they unsettle the car less than than the 17” wheels and Pireli eufori@ run-flats or Dunlop 9000 DSSTs. Only the sharpest square edged ridges elicit a metallic whack from the suspension. As an added bonus steering gain is less abrubt than with the eufori@s and more linear than with the 9000s. Back to back drives with the 115hp Cooper on sport (rather than sport plus) suspension showed the ostensibly smoother car to be the rougher riding of the two. In the MCS on 18s it feels as though the kid in the seat behind you is misbehaving, in the Cooper it feels as though the tires are are as round as medicine balls. Go figure.

There’s no question the engine kit does what’s claimed. The car now pulls strongly right into the rev limiter, something that’s more easily enjoyed with the ‘05 and later car’s revised ratios. The flexibility is such that you can pull cleanly in the upper ratios with less than 2,000 rpm on the tach (the standard car deosn’t wake up til nearly 3,000). In the standard model 6th is for cruising only – in the JCW it can be used for passing as well. The added urge gives the S motor what it should have had all along – zeal. As evo pointed out in Dec. of 2004, “immediately the throttle response is cleaner and more decisive, while the supercharger’s whine has less drone and more zing.”

If we have one criticism of the 2006 model, it’s that the engine kit is bundled with a limited slip differential and the JCW brake kit. While this saves you money should you want all the ‘upgrades’, we preferred the flexibility of ordering a la carte.

The LSD and suspension kit we’ll take, but those bigger front brakes add unsprung weight and rotational inertia while requiring 17s which add more of the same. The unsprung weight forces you to slow down over lumy pavement while the rotational inertia menas the car is steered less with the palms than the forearms – you have to wrestle the car into the turn that much more. The inertia also dulls some of the JCW engine kit’s extra shove – you notice the reshaped power curve more than you feel your neck snap back as you crack the throttle. Plus the 18s miss the point of the MINI somewhat; the car trades some of its stealth quotient, its indifference to surface conditions, and its playful eagerness to wag its tail for a fair amount of texture dependent tire rumble, which quashes more of that BMW level refinement. For the track-day junkie the brakes will be a Godsend but for a (U.S.) street-driven Cooper they opening something of a Pandora’s Box.

Many armchair reviewers say you can get more bang for the buck via aftermarket modifications, but before you talk yourself out of the added cost of the JCW equipment, find a way to try a JCW equipped Cooper S for yourself. It’s an experience you simply can’t put a price on or express in numbers. The effect of the upgrades is greater than the sum of its parts and would make the late John Cooper beam with pride.

UPDATE: We recently sampled an 03 MCS with the JCW engine kit. Like the all of the pre-05 MCSs, the gearing is just too damn long (to reduce wheelspin in tighter corners?) but the JCW kit does make the engine pull more cleanly – esp. from a stop – and ensure that you don’t get blown off by the bog standard Cooper sitting next to you at a light. (Well not unless he’s on smaller, lighter wheels…)

The moral: if you don’t think you can afford an ‘05 or later S, save more pennies. (If the JCW engine kit can’t overcome the gearing and make the car feel as alert as something bearing the Cooper name should be, nothing will…)

UPDATE 2: Today we had the opportunity to compare a Cooper S (on 17” S-lites and Goodyear RS-As) to an ‘06 JCW kit equipped car (on 17” Web Spokes and Dunlop 9000s).

Once again the JCW exhaust proved less tiring and more mellifluous, speaking up only under larger throttle openings and singing with a less raspy voice. The increased in gear flexibility and broader powerband improve drivability and give the engine the same big motor feel at freeway speeds that 3 series car with 3.0L sixes enjoy.

The 17” web spokes and Dunlop 9000s had a similarly large effect, the reduced unsprung mass leading to a less disjointed feel over bumps while the 9000’s softer steering response caused the car to bend into corners rather than dart into them – the tradeoff being less zig-zag motion when trying to go straight. Compared to the 18” wheels we had sampled previously this combo wasn’t as sharp in the steering but the tire noise was significantly lower. The flinty metallic report you get from the 18s over larger bumps wasn’t apparent either.

Finally the limited slip device works exactly as advertised: feed in more throttle in a corner and the car first feints that it’s going to run wide – ignore this and squeeze further and you’ll feel the nose sniff towards the inside shoulder. Coopers have always been at their best near the apex – LSD only improves matters.

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