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MotoIQ: DRIVEN – 2012 McLaren MP4-12C

by Billy Johnson

We spent two days with the McLaren MP4-12C on the street and hot lapped it around Buttonwillow’s 13CW configuration to see if the 12C really is the best supercar that you can use as a daily driver.  Is it a modern day NSX in this regard?  Did it turn the fastest production car lap at Buttonwillow?  Read on to find out…

Our test car is a 2012 McLaren MP4-12C which was updated to the current 2014 software programming that bumps the power output a little, improves the suspension programming and completely revised the entertainment system.  More on that later.  But first we need to take a look back to see how the 12C came about.

As two of the greatest motorsport powerhouses of all time, McLaren and Ferrari have been going at it in Formula 1 for nearly 50 years. For the majority of this time, the rivalry didn’t take it to the streets since McLaren was not a street car manufacturer like Ferrari, but that would change in 1992 with the launch of McLaren Automotive and one of the greatest street cars of all time: the McLaren F1.

 

McLaren F1

The father of the McLaren F1 was none other than McLaren’s Formula 1 Technical Director, Gordon Murray who owned a Honda NSX and viewed it as inspiration for a reliable supercar that you could actually use every day.  It was also his ride quality and performance benchmark.  Prior to the 1990s supercars were inconvenient, uncomfortable, unreliable, and while lust worthy; were only enjoyable for short periods of time or on weekends, like a supermodel. We can credit the NSX for raising the bar and showing the world that with proper engineering, a supercar can be reliable and actually driven every day.  While it took Ferrari nearly a decade to catch up to the NSX in this regard, McLaren was able to execute this feat on their first attempt in a production car with the F1.

As an engineering firm, McLaren spared no expense in producing the F1.  From its unique central driving position and 3-seat layout, industry-first carbon monocoque tub, down to its 24-karat gold engine bay lining; the F1 is a packaging masterpiece built to be the ultimate supercar. While McLaren’s Grand Prix cars were powered by Honda at the time, it was BMW who stepped up to the plate to supply the F1’s 621HP, 6.1L naturally aspirated V12 engine which had a 7,500rpm redline and propelled it to a 243mph top speed, which stood for 15 years until it was dethroned by the 1,200hp Bugatti Veyron.

 

McLaren F1 and 12CWhile separated by nearly two decades, the 12C’s DNA is unquestionably McLaren.  The greenhouse is proportionally similar to the F1’s

It took McLaren 13 years to make another production car, and in the meantime Ferrari was improving their product line developing the 348 and 355, to the 360 Modena and F430, to recently make a big jump to the 458 Italia.  While Ferrari has taken the stereotypical Italian route with a passionate and sexy, high-revving, naturally aspirated V8, and ultimately making the amazing 570 HP 4.5L V8 that screams to 9,000rpm; McLaren took the engineering route and had a little more foresight of the industry’s shift to lower displacement forced induction engines.

 

The 12C is powered by a 3.8L twin turbo V8, which has a 93mm bore, 70mm stoke, 8.7:1 compression ratio and a 8,500rpm redline.  McLaren boasts this powertrain masterpiece as having the highest horsepower to CO2 emission ratio of any current production engine, while delivering 24.2mpg combined driving to avoid the gas guzzler tax.  All of this without direct-injection no less.

McLaren took a stillborn Indycar engine program and completely re-engineered it to create the M838T, a 3.8L HP flat-plane crank V8 with twin turbochargers to produce a whopping 616 HP (up from 592 after a 2014 update) and 443 lb-ft of torque and weighs a mere 330lbs.  Their brand new MP4-12C street car was not intended to be a replacement for the F1, but rather a more affordable supercar aimed directly at Ferrari’s 458 Italia.  McLaren’s P1 Hybrid is more of a F1-replacement and squares up against the LaFerrari in the hypercar segment.

 

12C side intakesThese massive side intakes cool the longitudinally mounted radiators as well as the A/C condenser and transaxle coolers.
12C side window inletWhile the McLaren F1 had a roof-mounted scoop that fed all 12 throttle bodies, the 12C uses these inlets at the rear of the side windows to feed the two turbochargers with air.  I think the McLaren engineers and designers worked very well together to make form follow function.
 
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Comments
Wrecked
Wreckedlink
Thursday, January 15, 2015 4:38 AM
Thanks for the in depth article. So if I understand you correctly, the McLaren is a faster track car but the Ferrari is a more satisfying drive?
BJR
BJRlink
Thursday, January 15, 2015 8:21 AM
Hi Billy - be careful with the stock 12C Corsas - the fronts can cord and delaminate on the center tread at the speeds you drive - Pirelli fixed that in the 650S version of the tire.

Happy lapping.
rawkus
rawkuslink
Thursday, January 15, 2015 8:23 AM
Question for suspension gurus. Because of having the Z-Bar, does that require increased roll resistance?
Mike Kojima
Mike Kojimalink
Thursday, January 15, 2015 2:56 PM
The Z bar acts like a 3rd spring. Makes for interesting shock tuning I bet.
ginsu
ginsulink
Thursday, January 15, 2015 4:38 PM
"The Sequential Shift Gearbox developed for McLaren, as you may be aware, takes the dual-clutch transmission to a new level by allowing the driver to pre-select the next gear and load it onto the second clutch before engaging it, reducing shift times to practically nothing while engaging the driver in a way lost on many paddle-shift transmissions." -from Autoblog
ginsu
ginsulink
Thursday, January 15, 2015 4:46 PM
"This is what they call a "z-bar" or "heave spring", and it's not something you see outside of high-level racing. And by high-level I mean high levels of aerodynamic downforce.

A stabilizer bar is u-shaped (albiet a wide U), so it does nothing when both wheels compress together. Its job is to resist body roll, to dampen the suspension from being fully independent, in effect, when the wheels are moving in opposite directions, such as they do in body roll.

Because one leg goes forward and the other aft, a z-bar (or heave spring)is exactly the opposite animal. In corners, it does nothing to inhibit roll. If one wheel hits a bump, it's not going to put up much of a fight. Butwhen both wheels compress together, as they might when a huge wing is creating a ton of downforce, the z-bar becomes a spring that counteracts that force. This allows the coil springs at the wheels to be relatively soft for good mechanical grip and drivable comfort.

You don't see this often because not many cars make enough downforce, either because they don't really have a big rear diffuser or wing, or because they don't go fast enough. The MP4-12C goes fast enough, and it's got a real, functional diffuser. The rear downforce is significant." - from Edmunds.com

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ginsu
ginsulink
Thursday, January 15, 2015 4:47 PM
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rawkus
rawkuslink
Thursday, January 15, 2015 10:11 PM
I am aware of how the Z-Bar works, but because of its design, it would work the opposite of a sway bar, increasing roll. So does roll resistance have to increase to overcome that affect? If so, does that mess with anything else?
Mike Kojima
Mike Kojimalink
Thursday, January 15, 2015 11:22 PM
That is too general of a question be be answered simply.
ginsu
ginsulink
Friday, January 16, 2015 12:21 AM
@rawkus - Yes, I would imagine you would have to change parameters to account for the z-bar. The roll resistance in the 12C is controlled by the computers so I'm certain that they tuned the rear with the Z-bar factored into the equations.
BillyJ
BillyJlink
Friday, January 16, 2015 10:31 AM
@rawkus - The Z-Bar has no effect in roll, the 12C controls roll with its swaybar-less interconnected hydraulic suspension via computer-controlled accumulators and valves.

The Z-bar itself (I assume) has no pre-load on it at ride height, and as the suspension compresses with aero load, it twists the Z-bar to add vertical rate (like a coil spring) to resist this compression. On the other side, past ride height in droop travel, the Z-bar would also twist (assuming no preload at ride height) so the Z-bar would add a force that opposes the coil springs from letting the car go to full droop.

This is the major difference I can see of the Z-bar over simply adding stiffer springs since in compression, the Z-bar would still give a harsher ride that's just as independent as choosing stiffer springs.
SM_Clay72
SM_Clay72link
Tuesday, March 01, 2016 2:13 PM
If the links that the Z bar mounts too where were fluid cylinders with pistons and their reservoirs where linked then you could transfer fluid from one to the other in roll situations and reduce its roll enhancing character.

If you did it hydraulically (or hydro-pneumatically) with a bit of cleverness you could also avoid the anti-droop character passively.

In this case it looks like they just used solid links that can be neutralized for static ride height, and they just adjusted around the peculiarities the Z bar adds to the suspension system.
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