GM Details 3.6L LF3 Twin-Turbocharged V6

[FenwickHockey65]

Cadillac’s Twin-Turbo Kicks Turbo Lag to the Curb
Efficient air flow delivers better torque response for CTS Vsport, XTS Vsport
General Motors

2013-07-26

DETROIT – Turbocharging increases power and performance with efficiency, but the delay in the delivery of power – known as “turbo lag” – has historically been its key limitation.

That’s about to change.

Cadillac’s first-ever Twin-Turbo, available on the 2014 CTS Vsport midsize luxury sedan and XTS Vsport full-size luxury sedan in the U.S. this fall, kicks turbo lag to the curb with a unique combination of smaller turbochargers, top-mounted throttle body and shorter air pathways.

The Cadillac Twin-Turbo V-6’s patented air flow design, which eliminates circuitous heat-exchanger tubing, makes the most of engine packaging efficiency to improve torque response time over other air flow designs.

Rated at 420 horsepower in the all-new 2014 CTS Vsport and paired with Cadillac’s first eight-speed transmission, the Twin Turbo is one of the most power-dense engines in the midsize luxury sedan segment, rated at an SAE-certified 420 horsepower (313kw) and 430 lb-ft of torque (583 Nm).

Air flow routing volume is reduced by more than 60 percent when compared with a conventional design that features a chassis-mounted heat exchanger. The water-to-air cooler system achieves more than 80 percent cooling efficiency with only about 1 psi (7 kPa) flow restriction at peak power for fast torque production.

“By creating a very short path from the turbos to the throttle body, the compressors are able to draw air directly from the inlet box and send pressurized air through the intercooler immediately,” said Richard Bartlett, Cadillac assistant chief engineer for the 3.6L engine. “This gives the driver a more immediate feeling of power on demand.”

Using two smaller turbochargers rather than a single, larger turbo also helps ensure immediate performance because smaller turbochargers spool up quicker to generate horsepower-building air pressure that is fed into the engine. An integrated charge air cooling system also contributes because the compressors blow through very short pipes up to the intercooler.

The single, centrally located throttle body atop the engine controls the air charge from a pair of turbochargers after the temperature is reduced in the intercooler. This design fosters more immediate torque response and reduces complexity by eliminating the need for a pair of throttle bodies.

Together, smaller turbochargers, top-mounted throttle body and shorter air pathways help sustain peak torque over a broad range – 1,900 to 5,600 rpm – for a confident feeling of power in almost all driving conditions, such as accelerating or overtaking traffic on the highway.

“The Cadillac Twin-Turbo intercooler design builds on our experience with the 6.2L supercharged engine used on the current CTS-V Series,” Bartlett said. “That means more performance for drivers without sacrificing efficiency.”

[King Sun]

Man this engine gets better and better everyday

[SS 376]

Is this engine going in the ATS-V too? I feel like I read that somewhere. Maybe I'm making it up. I really hope this motor finds its way into a Chevy product too.

[FenwickHockey65]

It'll probably be the ATS-V engine.

[big hammer]

poor ecoboost.

[Bhobbs]

Originally Posted by FenwickHockey65

It'll probably be the ATS-V engine.

You think they will tune it for more power in the ATS-V or leave it as is? If it does end up in the ATS-V, they should go for power instead of mileage.

[TheReaper]

That's impressive for an American made V6.

[King Sun]

Originally Posted by big hammer

poor ecoboost.

yeah ecoboost is looking real flabby and sick atm

[dorfmac]

What are the chances one of these would drop right into a Camaro v6?

[newmoon]

Buick Grand National please!

[Number 3]

Originally Posted by SS 376

Is this engine going in the ATS-V too? I feel like I read that somewhere. Maybe I'm making it up. I really hope this motor finds its way into a Chevy product too.

I would say I doubt it only because Cadillac needs something exclusive.

Originally Posted by Bhobbs

You think they will tune it for more power in the ATS-V or leave it as is? If it does end up in the ATS-V, they should go for power instead of mileage.

The Epsilon architecture has always had an issue with exhaust routing under the front of dash that chokes off power. My guess is the ATS in a North/South configuration will just make more power from breathing a little bit better.

[DGthe3]

The Assistant Chief Engineer for that engine was on Autoline After Hours last night. Haven't watched it yet, but skip ahead to around the 20 minute mark to see what he has to say about it (the first part of the show covers recent automotive news)
www.youtube.com/watch?v=X_kYGY7ZMNA

there should be a podcast version of the show available at the following link sometime soon: Autoline After Hours

Originally Posted by Bhobbs

You think they will tune it for more power in the ATS-V or leave it as is? If it does end up in the ATS-V, they should go for power instead of mileage.

420 hp out of a 3.6 isn't exactly an economy tune. They could go farther, sure. But I'd say they are already leaning towards the power side of things with this engine.

Originally Posted by dorfmac

What are the chances one of these would drop right into a Camaro v6?

Ask the people that have done LS9 swaps into their SS, I don't think it would be too different in terms of overall work involved. But that said, there are much better ways to get 420 hp out of your V6 -just as there are better ways to get 640 hp out of an SS than dropping in an LS9.

[camaro2lt]

I Plan on putting this engine in my car in a couple of years.

[Apex Motorsports]

That is going to be a lot of fun to play with.