Doesn't fit an SLC so a non issue
We have one for mock up in a GTR for mark
We have one for mock up in a GTR for mark
2017 Audi SQ7 | car review @ Top Speed. . . 435hp twin-turbo 4.0-litre V8 diesel and 48V-driven 'Electrically Powered Compressor' combination to the 4.9-second 0-62mph time . . .
This is a properly rapid car. Not 'rapid for a diesel' or 'rapid for an SUV', just rapid full stop. Whatever it looks like and whichever pump it fuels from that's got PH merit.
Like the previous V12 TDI Q7 this is one of those 'all about the engine' cars that geeks like us can appreciate too. The cylinder count and configuration are a sound start but the addition of the Electrically Powered Compressor to the two exhaust-driven turbos gives it astounding punch. The EPC's job is to prime the induction charge before the turbos have spooled up, the way the boost gauge shoots up before you even deploy the throttle offering the first sense of what it's up to.
Suitably awoken, throttle response is razor-sharp, the V8's 664lb ft from barely more than tickover making a mockery of the SQ7's bulk. Acceleration is angry, quite frankly, and that sub-five 0-62 time feels a conservative estimate. Nor does that rate of progress abate either.
There's some really clever stuff going on here too. This is the first time Audi Valvelift System has been used on a TDI engine and it uses variable opening of the exhaust valves to control the sequential turbos. At low revs one exhaust valve remains closed, gases directed to the 'active' turbo as Audi has it. Above 2,000rpm and when the loads dictate the second valve opens to wake up the second turbo. Before any of this has happened, of course, the EPC has already been on the case.
And it sounds great too. There is a 'sound actuator' in the exhaust system but from the outside there's enough V8ness to suggest fakery plays only a supporting role. Suffice it to say even the tickover rumble inescapably signifies the SQ7's intent.
Engine: 3,956cc V8 twin-turbo diesel (with electric compressor)
Transmission: 8-speed auto, four-wheel drive
Power (hp): [email protected],750-5,000rpm
Torque (lb ft): [email protected],000-3,250rpm
0-62mph: 4.9 seconds
Top speed: 155mph (limited)
Weight: 2,330kg (unladen)
MPG: 39.2 (NEDC combined, on 20-inch wheels)
The Audi SQ7 is powered by a 4.0-liter TDI diesel that produces 435 horsepower and 663 pound-feet of torque. As you probably assume, the engine is turbocharged, but not in the way you think. This puppy has three turbochargers. Two are traditional exhaust powered units, while the third is electric. The two exhaust driven turbos are different in size. The smaller of the two works under lighter loads and lower engine speeds, the larger unit comes to life at higher engine speeds and heavier loads. The electric turbocharger works in coordination with both and is generally active at lower speeds. It runs on a 48-volt system and spools up almost instantaneously. This provides the boost the engine needs at low speeds without the annoying turbo lag associated with exhaust gas-driven turbos. As Audi put it, “turbo lag is history.”
n addition to this new electric turbo, Audi’s valve lift system (AVS) has also been integrated into a diesel engine for the first time. This system is rather creative and offers huge performance gains all the way around. Basically, each camshaft has two valve contours for each cylinder. For the intake valves, one contour is used for takeoff, in conjunction with the electric turbo. At higher speeds the second intake contour is optimized in filling each cylinder with air, providing more power at higher engine speeds. For exhaust operations, the contours are used to control the turbochargers. At lower speeds, one remains closed, preventing the larger turbo from operating. At higher speeds, the second valve is opened to allow the larger turbocharger to operate normally, and provide the power needed at higher engine speeds. In turn, this system provides exceptional torque delivery and response while offering, in conjunction with the electric turbocharger, excellent take-off performance as well.
The entire setup allows the SQ7 to hit the 62 mph benchmark in 4.8 seconds on the way to an electronically limited top speed of 155 mph
The most interesting part about this 4.0-liter is the reverse-flow setup of the intake and exhaust systems. On this engine, the intake is placed on the outside of the engine, while the exhaust outlets are placed between the two cylinder heads. This is opposite of most traditional engine designs, so expect to be thrown off a little bit if you’re someone who likes to perform your own maintenance.
That 435 horsepower and 663 pound-feet of torque is sent to the wheels via a redesigned, eight-speed Tiptronic transmission. The entire setup allows the SQ7 to hit the 62 mph benchmark in 4.8 seconds on the way to an electronically limited top speed of 155 mph. According to Audi, the SUV averages 31.8 mpg, which isn’t bad at all.