Probing the LS9’s Potential

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Is It 1970, All Over Again?

It's a much agreed upon statement that 1970 was the high watermark for the muscle car era. GM, Chrysler, Ford, and even AMC had some pretty stout performance cars with a lot of red meat left in them for racers and speed freaks to extract. Most of us are familiar with the story from '71 to '75. It seemed that everything suddenly ganged up on the muscle car party – reduced compression for lead-free gas, insurance surcharges, increased safety regulations, tighter emissions, and even sound limitations. By the mid-'70s, most of the muscle car packages were gone and those that managed to hang on were sadly stripe and decoration packages. Even America's only sports car, the Corvette, was hobbled.

Stump-pulling, sub-6-second 0-to-60 performance didn't start to make a comeback until the arrival of the C4 ZR-1. Through the '90s and '00s performance just kept getting better and better. Before we knew it, a mildly tweaked C5 could easily walk away from almost any big-block thumper from the old days. Now lets fast forward to December '07 when Chevrolet unveiled the new C6 SUPERCHARGED LS6 ZR1.


The most powerful engine to ever come out of Detroit.
"Powerful enough to blow your head, CLEAN off!" - Dirty Harry


What? "Supercharged" you say? The initial press release threw a lot of us because it said that the new LS9 engine used a "root-type" supercharger. For all of us old drag racing hounds, we were all wondering, "where's the huffer? Shouldn't the supercharger be sticking up out of the hood?" Ah, those crafty Bow Tie guys stuffed the huffer in the lifter valley of the all-aluminum LS9! Initially, Chevy said that the LS9  had 620-HP. That's a quantum leap over the already fierce 505-hp LS7 that powers the C6 Z06. After everything was settled, the official power number for the LS9 stood at 637-hp and 604 ft/lb of torque. WOW! The LS9 currently stands as the most powerful production engine to ever come out of ANY Detroit car maker. And remember, this engine not only makes copious amounts of power, it passes durability, AND emission tests.

So here we are, forty years after the peak of the muscle car era, we've hit another performance high-water mark, and dark clouds are forming and moving in fast. But this time, we're looking at the worst economic recession since the 1930s and GM is on life support. In the last 10 years, GM has shed Oldsmobile, Pontiac, Saturn, Saab, and Hummer. What's also bearing down on Detroit are dramatically increased the CAFE (Corporate Average Fuel Economy) averages over the next ten years. And Detroit MUST comply.

Have we hit another performance plateau? Perhaps we have, but people will always want to have cars with extra grunt because it's fun! Fortunately, the LS3, LS7, and LS9 engines are likely to be with us for some time. GM recently announced that the LS9 would be available as a crate engine. GM's current LS-series engines are powerful and overbuilt for durability. That means that if you have the where-with-all or a fat wallet, there's more juice left to be squeezed from the latest generation of performance engines.

Lingenfelter Performance Engineering (LPE) dished up an example of how much potential the LS9 has. In December '09 their mildly messaged ZR1 thundered down the quarter-mile in just 9.813-seconds at 145.74-mph! The astonishing thing about LPE's ZR1 was that; 1. the engine wasn't tweaked that much – a smaller supercharger pulley to spin the supercharger faster, a ported throttle body, a revised air-intake snout, and increased capacity for the intercooler. 2. First gear is only slightly taller for more off-the-line scoot. 3. Mickey Thompson 345/35R18 ET Street Radials (almost slicks) were mounted on the back and skinny 185/50R18 tires were used up front. and 4. The tank was filled with 109-octane racing gas. Aside from a sharp LPE dynotune, that's it!

Now, about the rest of the LPE 9-second ZR1. The car was NOT tricked out as a drag racer. The car was not lightened. No creature comforts were removed or disconnected. The car was not running open headers, it just had its exhaust flappers on "open." The car was essentially "stock" and completely streetable. On the LPE dyno, the car generated 739 rwhp and 739 rwtq!

Back in the olden days of the '70s, we had the likes of Grumpy Jenkins, Richie Zul, and others blasting the 1/4-mile with their big-block Pro Stockers running in the mid-to-high 8s. John Greenwood was hitting over 225-mph with his maxed-out ZL-1-powered IMSA Corvettes. Compared to the LS9, the old Mark IV big-blocks as as sophisticated as a boat anchor. While it remains to be seen where performance will go as we move forward, GM's LS series of engines will no doubt power many ruthlessly fast race cars and street machines.

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Imagine that, a ZR1 Corvette doing a wheelie!
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This article was written by K. Scott Teeters, an editor for Alex Schult of www.SmokinVette.com and a freelance columnist and artist with VETTE Magazine. His monthly column, "The Illustrated Corvette Series" has been running consecutively in VETTE since 1997 and can be found on the very last page of every issue. You can find reproductions of his Corvette art at: www.IllustratedCorvetteSeries.com