| Hylton |
04-21-2009 10:32 PM |
Heard exhaust of L99 tonight - OMG!!!
Some of you have heard the exhaust from my V6 and V8 videos I did last month. Basically they were of the cars sitting still and being revved up. All you folks who have been around performance cars know that the sound of an exhaust is very different when the engine is under load and that is really when you want to hear what the stock exhaust sounds like.
Anyhow, I had the opportunity to go check out an L99 tonight. When things were wrapping up, I explained to the person who had the car how much work was put into fine tuning the sound of the exhaust on these cars and that the only way to truly hear the fruits of the project teams labor, was to turn the traction control off and let her rip out of the dealership.
I have heard a lot of exhaust sounds in my life but I have NEVER heard a stock exhaust sound like that. There was about 10 of us watching/listening and the first thing I heard after the car could no longer be seen, was a Z06 owner saying "oh yeah!" as he nodded at me, clearly impressed. It's not only loud but it's a big tubular sound. Sorry to tell all you guys with after market exhaust plans - you will not want to change the exhaust.
Whoever hears the exhaust will not believe it is stock. When you have the opportunity, stand about 30 feet behind the car and listen to it drive off away from you at WOT - you'll be just as shocked as when you first saw the car. Whoever has met me knows I don't get impressed easily but to be honest, I'm still in disbelief.....I did not expect that!
For those who have not read up on the amount of effort that went into developing this sound, here's a few pics and a recap from an older thread:
http://www.camaro5.com/forums/attach...1&d=1225484691
http://www.camaro5.com/forums/attach...1&d=1225484803
Quote:
Getting an Earful
How Do We Make the Exhaust Sound Right?
It goes without saying that the exhaust character of a pony car is vital to the success of the vehicle. The engine note is central to the Camaro's very being — it's part of the reason for buying the car in the first place.
We will not have done our job correctly if it comes out sounding like a turbocharged vacuum cleaner.
So just how do we decide what the Camaro needs to sound like anyway?
The process, like all of those that we do with GM Engineering, is reasonably simple but very complex. First, we identify a number of vehicles (some are usually competitors' vehicles and some of our own product) that we think sound good. We measure them with a tool affectionately known here in Melbourne as "Helmut." It is a very sensitive set of microphones attached in a facsimile of a human head that is carefully calibrated to accurately simulate the human hearing spectrum.
Helmut usually sits on a box in the passenger seat of the vehicle and goes for a ride with the driver as he or she performs various maneuvers. We then repeat the same procedure for all of our test vehicles to give us a comparative set of sound recordings for the cars. These recordings can be used later by the induction and exhaust development engineers to calibrate their parts to the intended sound pressure curves on various test benches and dynamometers. Incidentally, we also measure the cars from the outside to simulate what an observer is hearing as the cars drive past them.
We process the sound recordings using a fast computer and break them up into their constituent frequencies (this is called Fourier Transformation — named after the French scientist who invented the mathematics behind it), graph them, and document the portions of the sound which are pleasing and those which are not. These are then put into a virtual melting pot; we use some parts of one recording and other parts of another to create a master file, which is a composite of all of these recordings and sounds exactly the way we want it to.
We're all ears
We usually convene a cross-sectional group of marketing and engineering people in a soundproof room once the master file is done, play all of the files one after another through very sophisticated headphones, and come to some consensus on the new composite.
Typically, we then throw this composite file in a drawer somewhere, forget about it, and decide to copy the car that sounded the best in the first place. Simple, really.
One Final Step
Oh yeah, there's one last essential step. We all go out to the track and burn some serious rubber in the original test cars, just to make sure we made the right decision — and to remind ourselves how cool our jobs can be.
— Andrew D. Holmes
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To everyone on the Camaro team who participated in this activity, THANK YOU! A grand slam! :clap: |
