Opportunity Cost | What Did We Miss-Out-On Because of the GT350's FPC 5.2L VooDoo V8?
A few months ago I was talking to a former Ford employee who spent a little time at SVT. He was around when the team was developing the Shelby GT350 Mustang, so naturally our conversation started to drift towards that topic. I’m always interested in hearing the thoughts and theories behind why certain decisions are made during the development process, and the GT350 certainly has lots of details to explore. Eventually our conversation turned to the Flat Plane Crank (“FPC”) equipped 5.2L VooDoo engine. That’s when he laid a bit of knowledge on me that I wasn’t quite prepared for. He told me just what that FPC program cost the Ford enthusiast community.
How's this for a 'before and after' shot? The mystical 5.2L Flat Plane Crank.
It’s no secret, thanks to Ford’s marketing team, that the VooDoo is essentially a miracle engine that defies the laws of physics. At 5.2L it was larger than production FPC V8 ever attempted by any manufacturer. The SVT engineers really took this as a opportunity to shine and flex their grey-matter for all the automotive world to see. You see; FPC V8’s tend to have some nasty vibration issues that only get worse as the size of the engine, and the weight of the rotating assembly, increases. Essentially that crank configuration turns a large V8 into a paint shaker.
A fantastically machined combustion chamber.
So in order for this engine to not rattle the rest of the car to pieces SVT had to find some creative ways to mitigate the vibrations. If you’ve ever been underneath a GT350 Mustang , somewhere other than the sidewalk at the exit of a car show, you have undoubtedly noticed the numerous mass dampers strewn about. Each of those heavy little jewels were placed just so by a highly educated, and decently paid, NVH engineer just so owners could enjoy their new Hi-Po Mustang with their fillings intact.
Speaking of 'machined', check out the CNC work on this factory exhaust port.
All of that time a material spent engineering around the laws of nature has a cost, and that is really the purpose of this article. I don't want to get into specifics, but the NVH mitigation accounted for over 15% of the cost of the entire program. According to my friend, if they engine program had spent the money consumed by NVH mitigation on the valvetrain we could have been enjoying a standard Cross Plane Crank (“CPC”) 5.2L V8 capable of spinning to 9,500RPM. I don’t know about you, but the mere thought of a factory Ford V8 turning to that high of an RPM just brings a smile to my face. Seeing as I have never really fallen in love with the VooDoo engine, that bit of news was a bit of a gut-punch.
Sure would be nice if those cams could spin just a little faster.
Supposedly the SVT engineers were benchmarking against the Lexus LFA's V10 cylinder head, which I consider a good thing. That engine has a 9,000RPM redline with fuel shutoff occurring at 9,500RPM. I'm told those were the exact figures SVT was aiming for. Supposedly the valvetrain configuration required to hit those marks was tested in computer simulations, but never made it beyond that. Reportedly it was going to take some trick F1 style valve springs to go much farther.
Not a typical view. This gives you an idea of how much stuff is moving around in a 4V valvetrain.
You may have heard that the main purpose of building a FPC V8 engine is its ability to spin-up/rev faster. That is a benefit smaller displacement FPC engines enjoy over their CPC cousins (due to less rotating mass), and it was planned to be the case with the 5.2L VooDoo. However, the one-piece aluminum flywheel that was originally planned to be part of the build would not pass Ford's durability tests. It simply would not live behind 5.2L FPC engine. In its place we got dual-mass steel flywheel that wiped out any rotating mass reductions the flat plane crank would have gotten us.
The GT350 clutch and flywheel setup ended up being much heavier than originally intended.
Sadly, to add even more insult to injury he let me in on another little secret. SVT had tested CPC 5.2L engines with the VooDoo heads, intake manifold, headers, cams specs, etc. and found some very interesting results. After all the dust settled, the FPC engine managed to just ekk out four more horsepower than its CPC counterpart. It was determind that the meager difference was due in large part to the different firing order of the two engines. All this really made me question whether the entire endeavor was worth it. Then I remembered another SVT vehicle that a lot of people questioned the value of, the Ford GT (both generations and the original GT40 if you want to go even further back).
Something a little spicier could have resided here if not for all the vibration mitigation.
The Ford GT was built as a statement. It was a message to automotive world that Ford engineers can compete and win in any arena they care to enter. It used to be a saying during the early years of SVT that their actual purpose was to “polish the Oval.” Essentially, make Ford look good through superior engineering. No matter how you slice it, the 5.2L VooDoo engine certainly does that. While a Coyote engine screaming at 9,500 RPM would have been impressive, it would have basically just been another in a line of great engines from SVT (Trinity, Terminator, Petunia, etc.). However; building something that had never been done before, and that most believed wasn’t even possible, is of the things from which legacies are made. I believe that is how history will view the VooDoo. Not as the engine that cost us a 9,500 RPM Coyote, but as the engine no other manufacture had the balls to build.
I'm still trying to convince Ford to give me one of these Cut-Away Engines to use as a coffee table.