Hyundai’s 2.4L Theta II gets direct injection

hyundai-24-theta-gdi

Of all the GEMA manufacturers, the Hyundai-Kia Group has been setting the best track record in terms of extracting the most power and torque out of their engines. The current generation Sonata and Optima’s 2.0 litre GEMA engine (Hyundai calls them Theta, Mitsubishi calls them 4B11, etc) currently makes around 158 PS to 163 PS, which is probably one of the best in class when you’re talking about a regular engine with only variable valve timing and conventional port injection. The new “Passat CC-ish” Hyundai Sonata‘s 2.0 litre Theta II engine makes even more power, now rated at 165 PS at 6,200rpm and 198Nm of torque at 4,600rpm.

Hyundai is now taking the bar higher with the 2.4 litre engine option for the new Sonata. The 2.4 litre Theta II with variable valve timing on both the intake and exhaust now gains GDI gasoline direct injection and as a result, can produce 201 PS at 6,300rpm and 250Nm of torque at 4,250rpm. That’s some very good torque figures for a 2.4 litre engine.

Thanks to the lean burn precision that direct injection affords, compression ratio has been increased to 11.3:1. The engine also comes with a three-stake variable induction system. The variable valve timing system has also been improved, with a new drive system designed for silent operation and better durability. The block has also been reinforced, with improvements to the crank and piston design as well. For example, the piston now has a cooling jet under the piston crowd to get more oil onto the piston walls, helping reduce friction and improve economy/power.

Hyundai says conventional port fuel injection is limited in the sense that as the engine spins faster in terms of RPM, valve opening and closing times get shorter and shorter, reducing the time available for the injectors to injet fuel. A DI injector positioned inside the combustion chamber can inject fuel at pressures at up to 150 bar faster. The fuel travel path is also shorter and more direct, thus more control is available over the combustion process.

The Hyundai GDI system does injection in two phases. The first phase is called the pilot injection and ignition, which triggers the piston’s downward stroke. Then during the piston’s descent more fuel is injected and ignited. Hyundai claims this split-injection technique reduces load on the catalytic converter and helps reduce emissions. Optimal operating temperature for the cat is also achieve faster, which means better cold start emissions, a figure which Hyundai claims have improved by 25 percent.

The new 2.4 litre Theta II GDI engine will be available in the new Hyundai Sonata along with the high-powered 2.0 litre engine. No news yet when Sime Darby is bringing the new Sonata into Malaysia, but perhaps it might change people’s perception of Korean D-segment vehicles. Hyundai has also unveiled a 2.0 litre GDI Turbo engine before this.

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Paul Tan

After dabbling for years in the IT industry, Paul Tan initially began this site as a general blog covering various topics of personal interest. With an increasing number of readers paying rapt attention to the motoring stories, one thing led to another and the rest, as they say, is history.

 

Comments

  • Jimmy on Nov 18, 2009 at 3:43 pm

    I own both Hyundai and Kia cars. Generally good value for money. Just need to improve 2 things: suspension/absorber, and durability of certain parts.

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  • great!

    i own spectra5, so far no problem, decent performance for city use but heavy pickup

    ppl keep asking what car is that..

    proton should rope in a few partner for the upgraded campro engine

    sharing / supply engine

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    • Gordon Shumway on Jan 07, 2011 at 9:32 pm

      I don’t agree with you. Owned a Spectra5 too.Use weekly long distance travel .Great car, good performance and excellent pickup.no problem squaring off with Waja,Vios,Honda,Camry,mitsu,mazda,ford,mercedes can beat them anytime from stop start..people should get Spectra5.

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  • rexis on Nov 18, 2009 at 4:33 pm

    driven a rented spectra in Langkawi, I have quite a good impression about their auto gear.

    How about Campro II ^_^

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  • kalid on Nov 18, 2009 at 4:46 pm

    id love to see campro dual-cps, hehe

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  • alpha999 on Nov 18, 2009 at 4:46 pm

    next on the list….Campro CPS II

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  • NilsoN on Nov 18, 2009 at 5:01 pm

    huh?4B11?and Hyundai?

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  • Charger on Nov 18, 2009 at 5:40 pm

    I was expecting a higher torque figure out of the DI engine. Mana tau the compression so low for a DI engine.

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  • xenogearz on Nov 18, 2009 at 5:56 pm

    If I am not mistaken, the new Kia/Naza Forte which will be launched on November 24, 2009 is also equipped with the 2.0 liter Theta II engine. Am I correct Paul?

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  • Q? I do notice that is the max power @ ~ 6 to 6.3k rpm & torque @ ~ 4.3 to 4.5k rpm. Why the car makers (may not be Hyundai-Kia) wouldn't do or set the power come early ASAP? As most of these cars we gonna used it on road/city drive not track.

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  • Vbkcheng on Nov 18, 2009 at 6:35 pm

    Wah, 2.0 with 165Ps, not bad yah…. catch up Japanese lior…..

    Anyway, for normal daily use, power at RPM 2K to 3K is more important.

    Some car can be high output at high RPM, but it is not necessary the best for daily use.

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  • aksMs on Nov 18, 2009 at 7:38 pm

    Paul, I was told that Proton is considering to use GEMA engines for the upcoming Perdana replacement. Some says, Waja (Lancer) replacement will use it too. Any tip from the insiders? Where's si fu?

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  • Can't wait the new forte 2.0- Theta II engine 156ps

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  • scottloeb on Nov 18, 2009 at 10:42 pm

    Not just GEMA, it will be 4B series direct decendant from MMC. Jump in joy, you'll might get INVECS III CVT as well with the engine. Just pray that MMC will not screw P1 again (like it used to do). Hey, they are equal partners nowadays, remember?

    I was told although the Hyundai/Kia and MMC both use GEMA engines, 4B series is by far the better engines and more responsive. I might be wrong, as I've test both the Lancer and Rondo. Should wait for the coming Fortis I guess to get a better picture.

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  • shawal on Nov 19, 2009 at 3:06 am

    my family owns a kia preggio (its our 5th car , no commercial usage)

    and i'm telling you, the workers at the service centres are idiots and the spare parts are expensive!, if naza italia cn have italian ppl trainin the servicemen, y cant they employ real koreans to fix our cars…

    the kia coup looks nifty…, i like it yeah~!

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  • hyundai already got recognition in world market..since they have improve very much to compete with Japan counterparts..but not so good position in Msia..

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  • amiran on Nov 22, 2009 at 6:22 am

    Now the Jap must be really worried. Korean is overtaking Jap on both diesel & gasoline engine tech. Now they must improve on the assy & trim quality, build material is according to price segment.

    Compare the 2.4l output. It's far leave all pathetic Toyota, Honda, Nissan and Mazda 2.4/2.3/2.5l behind!!!

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