1980 Jeep CJ-7 - The World's Quickest JeepPosted in Project Vehicles on August 15, 2007 Comment (0)
The title says it all. You're looking at the world's quickest street-driven Jeep. With a quarter-mile time of 8.87 seconds at 151 mph, Greg Zoetmulder's supercharged CJ-7 is a screaming example of horsepower's ability to overcome absolute aerodynamic inefficiency. Not only does the small-block Chevy 400 pull enough snort to send a brick down the 1,320 in less than 9 seconds, but with the exception of the fiberglass hood and fenders, the body is all steel, the lights all work, it still uses the stock Jeep leaf springs, and the open cockpit effectively creates enough drag that Greg may as well have a parachute following him down the track. The fact that it can muster less than a 12-second time is good-a sub-9-second pass is just flat-out amazing.
As stated above, Greg's '80 CJ-7 essentially sits on the original suspension. The stock front and rear leaf springs have been de-arched by Spring Alliance in Palitine, Illinois, to lower the ride height. Even the shocks are the factory pieces. Out back, a set of slapper traction bars put the snubbers to the forward spring eyes when the slicks hook, keeping pinion climb down and increasing tire bite. The factory CJ-7 frame has been marginally reinforced and benefits from a little stiffening, thanks to the front- and mid-engine plates that solid-mount the engine to the chassis, but otherwise, it's just as it left the factory.
Up on the front frame horn, a factory manual-steering box puts the turn to stock Dana 30 knuckles. The centersection was cut out, converting the rest of the Dana 30 to a full-tube front axle. That's right, folks, this Jeep is for haulin'-not crawlin'. Other sanctioned items for the track include the use of a driveshaft loop in case of U-joint failure, a tranny shield, and a set of genuine, no-foolin' wheelie bars out back.
Let's just get right to the meat of the matter. It takes a lot of reliable, repeatable horsepower to do what Greg does with this Jeep. While nitrous used to be the weapon of choice, Greg has since ditched the funny gas in favor of a ProCharger F2 centrifugal supercharger with an air-to-air intercooler. To keep an engine alive with such a brutal induction system, a bunch of stout parts went into building the engine.
For starters, Anthony Schroeder of Automotive Engine Specialties (AES) in Elk Grove, Illinois, took a Dart Iron Eagle 4-bolt block and filled it with a billet crank, 6-inch Crower billet rods, and Forged CP pistons with Hellfire rings to bring the compression to a blower-friendly 8.0:1. A set of fully CNC-ported Dart Pro-1 220 heads received 2.10 intake and 1.60 exhaust valves and were topped with an Edelbrock Super Victor high-rise manifold. A Cam Motion solid roller camshaft with 260 intake and 272 intake duration at 0.050-inch lift and 0.629 intake and 0.640 exhaust lift moves a massive volume of air.
To top off all this intricate engine work, a Carburetor Solutions Unlimited (CSU) 1,000-cfm carb specially designed for blow-through boosted applications was fitted to the intake. Along with the cog-belted F2 blower, a ProCharger race blowout valve was fitted to the intake plumbing and ensures the engine and Precision Turbo 1,200hp intercooler won't be overboosted. The fuel system is a full tilt MagnaFuel ProStar 500 with a boost-referenced regulator-that means as the boost increases, so does the fuel supply. A set of 171/48-inch primary tube Kooks headers feeding into4-inch collector mufflers and side pipes shatter eardrums.
Backing the brutal engine is a TH400 built by DRC Performance Transmissions in Elk Grove, Illinois. The tranny employs a Precision Industries 3,800-rpm stall converter, a Hibsters transmission brake, and a huge TCI cooler. A B&M ProShifter toggles the gears.
Moving backward, a 3.5-inch-diameter driveshaft connects to a fully braced Motive Gear Ford 9-inch. The Strange Engineering centersection is loaded with 3.73 gears, a spool, and 31-spline Moser axleshafts. Wilwood four-piston calipers are juiced by the stock manual master cylinder and pull the Jeep down from speed without locking thanks to a Wilwood proportioning valve.
A set of Weld Drag Lites 15x5 front and 15x10 rear hold the Mickey Thompson tires. In case you're wondering, the rears are 28x10.5 and don't rub anywhere.
Body And Interior
On the inside, a pair of Jaz bucket seats provide a place for the M&R harnesses to rest. Aaron Stapleton of Fast Forward Race Cars did the 10-point Funny Car cage out of chromoly and installed a parachute (not seen in photos above). The driver's seating position gives a full view of the Auto Meter Silver Light Sport Comp gauges and puts the controls within easy reach.
Outside, the factory steel tub and grille were on the $800 Jeep when Greg's dad gave it to him over 15 years ago. The body was cherried out, fitted with the fiberglass fenders and 5-inch cowl hood from glasstek.com, and a pair of '95 Wrangler doors were hung before the Standox teal green paint was sprayed by Eric Pasternak in Island Lake, Illinois. The graphics and tribal flames were then added by Greg's company, Sicker Dude Designs in Lake Zurich, Illinois.
Good, Bad, & What's It For
Although it's a bullet on the track, Greg does drive the CJ-7 on the street around his hometown. Granted, with only an 8-gallon capacity in the Triangle Engineering fuel cell, he's not going far, but it's nice to know he can cruise to the ice cream shop if the desire arises.
Although the 8.87-second e.t. at 151 mph Greg cites is impressive, keep in mind those are old numbers. Over the long, Midwest winter, Greg addressed some fuel-starvation issues he was experiencing that held the horsepower output to only 770 at the rear wheels.
With the installation of the aforementioned ProStar 500 boost-reference fuel pump and larger CSU carburetor, right off the bat, the Jeep dyno'd at 750 rear-wheel horsepower. Adding larger jets to the carb brought the power up to 777 rwhp. Even more carb jetting brought the power up to 798 rwhp. With the fuel-delivery issues apparently cured, the crew threw some timing into the ignition. Advancing the timing brought it up to 813 rwhp. If some is good, more should be better, so even more timing was dialed in for a final total of 870 rwhp. With 100 hp more than last year and more consistent performance, Greg fully expects to break into the 8.60s with a big jump in his trap speeds. We'll just have to wait and see.
Why I Featured It
As a former car guy and drag race aficionado, I know how difficult it is to turn in a fast quarter-mile time. Keep in mind that a really fast production car like a Corvette or Viper will probably hit low 12s or high 11s with a lot of aftermarket massaging and a really good set of tires. If you've ever watched a car that runs in the 10s launch off the line, it's just violent. It looks like it's being slung out of an aircraft carrier's catapult. Back even 10 years ago, it was pretty uncommon for a streetable car to dip into the 9s. The fact that Greg's Jeep is surpassing those numbers with zero aerodynamics, very little use of weight-saving materials, factory leaf springs at all four corners, and with only 400 ci is just plain astounding. I'm all for it. Go get 'em, Greg.-Christian Hazel
'80 Jeep CJ-7
Chevrolet 400 ci
Solid-tube Dana 30 (front), Ford 9-inch (rear)
15x5 (front), 15x10 Weld DragLite (rear)
26.0/4.50-15 Mickey ThompsonET (front), 28x10.50-15 MickeyThompson ET Street (rear)