Jay Leno's E85 Corvette Shows Powerhouses Can Go Green
May 1, 2008 4:05 PM
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Whether it's a high-tech wind turbine, a vintage generator that runs on coal gas or a restored steam engine, I'm fascinated by alternative power sources and fuels. I'm also interested in powerful cars that are fun to drive. Hey, I'm a car guy first, environmentalist second—what can I say? There's grease in my veins.
Take my 2006 Corvette Z06. Thanks to Pratt & Miller Engineering, a New Hudson, Mich.-based performance shop that specializes in designing and building fast-moving rides for the road and racetrack, the Vette now develops 600 hp, has a top speed of 208 mph and runs on a homegrown alternative to gasoline—cleaner-burning E85 ethanol. Now that's a fun-to-drive car.
But why a Corvette? Why turn a perfectly good high-performance vehicle that's already thrilling to drive into a muscle-bound, flex-fuel speed demon? The answer is simple: It's exciting and sends the message that an alt-fuel vehicle doesn't have to be a slow, boring econobox whose only claim to fame is that it emits fewer greenhouse gases than a car that burns gasoline alone. Reducing harmful emissions is a wonderful thing, but it's not very interesting on its own. A car like this, on the other hand, makes people stop and say, “Wow!” It demonstrates that going green doesn't have to be dull.
Even if it's just an engineering exercise, I hope building a high-performance flex-fuel vehicle like this will open more people's eyes, especially enthusiasts', to the idea of using alternative fuels. If it inspires just one engineer to think up environmentally friendly solutions to the future-fuel issue that preserve the excitement and driveability of cars, this project will have been well worth the effort.
The transformation from mild-mannered Z06 into a C6.R Le Mans race car for the street—P&M calls it a C6RS—began with dropping in a new powerplant from Katech Performance, the folks from Clinton Township, Mich., who build engines for the Corvette C6.R racing program. Milled from a solid block of billet aluminum, the new 8.2-liter small-block V8 has 1.2 liters more displacement than the stock engine. The one-off reciprocating assembly includes a forged-steel crankshaft and connecting rods, and forged aluminum pistons. It churns out a tire-melting 600 lb.-ft. of torque (130 lb.-ft. more than a stock Z06).
Power from the mighty V8 was originally routed through a strengthened T-56 six-speed transmission and a high-performance Centerforce dual-friction clutch. But P&M reworked the electronics, turning my Vette's T-56 into a sequential shifter. For me, this setup is the best compromise between electronically controlled paddle shifters (which I don't like) and a full manual (which I do like). My left foot is happy to do the work instead of delegating it to a bunch of circuits. Now, shifts are lightning quick—bam, bam, bam!
I know ethanol isn't the only answer to our fuel needs. But it's a start. The more alternatives to gasoline we have–you know, cars that run on E85, natural gas or hydrogen fuel cells—the less foreign oil we will consume in the long run.
Ethanol-enriched fuel, however, does have some obvious advantages in the high-performance arena. Not only does it address all of the important environmental issues (it produces less carbon monoxide and hydrocarbon tailpipe emissions than gasoline), E85 has a very high octane rating (100 to 105), allowing engine builders to run higher compression ratios—producing more horsepower. Ethanol also combusts at a lower temperature than gasoline, which means the engine runs cooler. Thus, a smaller radiator and fan can be used, which will significantly reduce a vehicle's weight. And although decreasing harmful emissions usually doesn't directly affect performance, engine parts like pistons and valves tend to stay cleaner. Unlike gasoline, ethanol burns 100 percent, so it leaves behind no nasty residue. Without any leftover gunk to clog these key components, E85-powered engines tend to operate smoother and require less maintenance. Now you can see why Indy Cars run on E100 and the American Le Mans Series runs on E85. Ethanol helps clean up racing without sacrificing any performance. So ends the sermon for this issue.
By Jay Leno
Published in the May 2008 issue of Popular Mechanics.