Twins Exposed! The McLaren MP4-12C
by Khiem Dinh
Khiem Dinh is an engineer for Honeywell Turbo Technologies at the time of this writing. All statements and opinions expressed by Khiem Dinh are solely those of Khiem Dinh and not reflective of Honeywell Turbo Technologies.
Everyone should know by now about the McLaren MP4-12C, the next supercar from one of the most successful Formula 1 teams. If you’ve been reading our forums, you’ll have already seen details of the suspension bits. One of the questions I had surrounding the car was the engine setup and the potential for power upgrades.
To power their new supercar, McLaren developed a 592hp, 443 lb-ft, 3.8L V8 with twin turbos. What? Twin turbos? Yup. I’m sure many of you, like me, are afflicted with an illness that when we see the word ‘turbo’, we instantly conjure up thoughts of turbo upgrades and more power. My only problem up to this point has been trying to find good pictures of the turbos. There have been a few photos from a distance, but nothing focusing directly on the turbo setup.
Due to the magic that is known as Cars & Coffee this past Saturday, I got an up-close and personal look with the McLaren’s top off, literally (please excuse the crappy phone pics). McLaren was kind enough to bring out a rolling chassis sans body to show all the important guts of the car.
McLaren naked! There’s not much in the way of a muffler, so don’t expect any large horsepower gains to be had here. Upstream of the muffler before the bends, a pair of catalytic converters can be seen.
The major surprise to me was the very simplistic design of the exhaust manifolds. They’re what I would call an advance log manifold. Why would McLaren use log manifolds? There are many good reasons with a very important one being durability. These manifolds are strong cast pieces most likely made from a grade of stainless steel; they’re never going to crack.
It’s a relatively simple log manifold, but I consider it an advanced design for a log. Notice how all the runners are nicely angled to direct the exhaust flow as best as possible towards the turbo. The turbo connects to the manifold using studs and nuts.
Another reason is for quick transient response. Log manifolds have minimal volume which means less space for the exhaust gases to fill. That translates into the exhaust gases getting to the turbo faster for faster spin up.