Re­vamped 2.0-litre en­gine adds both sweet­ness and spice

Wheels (Australia) - - Contents - ASH WESTER­MAN

Iconic sportscar gets power boost and at­ti­tude ad­just­ment

THE YEL­LOW ad­vi­sory signs with the squig­gly lines pro­vide the of­fi­cial con­fir­ma­tion of what we al­ready know. We’re deep in Gold Coast driv­ers’ coun­try, but still the lum­ber­ing Hilux in front of us holds his course. The lush hin­ter­land ramps up to­wards Mount Tam­borine, beck­on­ing us in. Still we wait. Fi­nally, mer­ci­fully, old mate sticks two wheels on the verge and al­lows us space to pass. Snap, the sixspeeder’s beau­ti­fully tac­tile short-throw lever is flicked back to sec­ond and the throt­tle squeezed to the floor. This is it, our first real chance to ex­tend the MX-5’S heav­ily re­vised 2.0-litre Sky­ac­tiv-g en­gine and see to what ex­tent it re­ally changes the char­ac­ter of our 2016 Car of the Year win­ner.

In­stantly ob­vi­ous are an ex­tra level of zingy ea­ger­ness to rev, and a mid-range that feels es­pe­cially sweet. The ben­e­fits of mov­ing to a dual-mass fly­wheel seems most ev­i­dent in the crisp­ness of the throt­tle re­sponse, with any sense of slight low-rev dough­i­ness now re­placed by a sat­is­fy­ing im­me­di­acy of re­sponse of tacho to pedal. The slight bump to the torque curve also surely con­trib­utes to this – it’s up 5Nm to 205Nm, de­vel­oped 600rpm lower at 4000rpm.

Any­way, the ex­tra 17kw Mazda has ex­tracted from the ex­ten­sive raft of re­vi­sions re­side at the top end, ob­vi­ously, so you need to keep your foot planted. The old point of peak power – 6000rpm – is now spun past with a dis­mis­sive sweep of the nee­dle, the ex­haust note har­den­ing to an in­sis­tent yet cul­tured rasp. Just shy of 7000rpm was where the old en­gine would stut­ter up against the lim­iter; that fig­ure is 500rpm short of the new red­line. So even though power flat­tens off past the peak at 7000rpm, it doesn’t drop off a cliff, and driv­ers who en­joy wring­ing out ev­ery­thing their car

can of­fer will ap­pre­ci­ate the ex­tra head­room pro­vided by a lim­iter that now doesn’t call time un­til 7700rpm. On the roads of our test route, we of­ten held sec­ond or third gear at the top of the rev range, rather than force a waste­ful up­shift only me­tres be­fore the brak­ing point for the next bend.

If you’re a fan of all the fas­ci­nat­ing oily bits of in­ter­nal com­bus­tion, the changes to the 2.0-litre make in­ter­est­ing read­ing, not be­cause they’re rad­i­cal, more be­cause they’re ex­ten­sive. The goal, Mazda’s en­gi­neers are happy to ad­mit, was to give the 2.0-litre en­gine a char­ac­ter more like that of the sweet, rev-happy 1.5. Fact is, the mer­its of the 1.5 ver­sus the 2.0 were de­bated at COTY 2016 with the sort of fer­vour that would be nor­mally re­served for Aus­tralia’s an­nual change of Prime Min­is­ter, or vanilla snot-blocks ver­sus cus­tard tarts. The 1.5 is the purist’s en­gine (an ir­refutable fact, be­cause that’s what our sum­ma­tion in Show­room says), its out­put deficits ac­cepted as the price you must pay for its more free-spin­ning char­ac­ter and sweeter tonal good­ness.

The new 2.0-litre suc­ceeds in mak­ing that a mostly moot point. To achieve this, first came a weight re­duc­tion to the ro­tat­ing assem­bly, with new, short­er­skirt pis­tons each trim­ming 27g; slim­mer rods and new bolts cut a fur­ther 41g each. The crank, mean­while, had to cop a slight weight in­crease due to the eight re­vised coun­ter­weights needed to keep it vibe-free at the higher rev limit.

Breath­ing im­prove­ments go fur­ther. On the in­take side are a bet­ter flow­ing man­i­fold (that also cuts charge tem­per­a­ture), larger valves, re­shaped ports, and new in­jec­tors that spray fuel more ac­cu­rately. Up­grades to the ECU al­low a more tai­lored three-stage in­jec­tion strat­egy that varies ac­cord­ing to en­gine speed.

On the ex­haust side, both lift and du­ra­tion of the re­vised cam have been in­creased, open­ing larger ex­haust valves that flow into re­shaped ports. To cap­i­talise on the im­proved ex­haust flow, there’s now a new man­i­fold with larger in­ter­nal di­am­e­ters. So noth­ing rad­i­cal here, yet there’s some­thing sat­is­fy­ingly old-school about it all, in a turbo era where more power and torque al­most in­vari­ably come via a soft­ware change to the ECU.

As for the other im­prove­ments, they ad­vance the MX-5’S safety cre­den­tials, and ad­dress the sort of is­sues that clearly ir­ri­tate own­ers. Of the lat­ter, the ad­di­tion of tele­scopic col­umn ad­just­ment is the most sig­nif­i­cant. Okay, it only moves by 30mm, but in a cabin as snug-fit­ting as that of the MX-5, it’s like hav­ing your high­rid­ing trouser cuffs let out by that amount. For my six-foot frame, it al­lows the wheel to come in for a more bent-el­bow, straight-legs po­si­tion. Pity the hand­brake lever still makes con­tact with my left

knee, but it’s still prefer­able to an elec­tronic but­ton.

As for safety, the up­dates amount to im­proved AEB to bet­ter recog­nise pedes­tri­ans and cy­clists, a re­vers­ing cam­era mounted dis­creetly in the re­vised rear bumper, and traf­fic sign recog­ni­tion.

Prices are up $750 across the board, but what hasn’t changed is the MX-5’S chas­sis tune or han­dling bal­ance. The high­er­out­put en­gine makes it eas­ier to ex­tract the MX-5’S best, but do­ing so still re­quires that the con­di­tions are in your favour. Slow traf­fic in hilly ter­rain can spoil your flow, and an ex­tra 17kw/5nm can’t over­come that. Nor does it mag­i­cally bring an ul­tra-planted front end that begs you to wail on it. No, the MX-5 re­mains very much a fin­ger­tips car that tele­graphs its lim­its early, and, via its rolly set-up, brings the rear into play al­most be­fore you’ve fas­tened the seat­belt.

So not for every­one, but for the fan base, any ag­o­nis­ing over the 2.0-litre’s power ver­sus the 1.5’s sweet­ness has been com­pre­hen­sively re­solved.

02 01 03

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