CLASS 7

NOTES FROM THE LIGHT RACING LR-2 CLASS 7 CHEVY S-10 CIRCA 1987 - DRIVER LARRY RAGLAND

CHASSIS (SIDE VIEW) - Drawn by hand in half scale - we needed 3 large drafting tables and would put a different view on each table (front - side - top). The grid lines were critical since you had to transfer a lot of dimensions between drawings. The extra cabs were relatively new back then and we loved the ability to scootch that driver back and give them some more room. Note also the high point on the roll cage over the rear axle. I had proposed (to GM) designing our own custom length shocks which would have required a high mounting point. That cost add was around $100 grand (back then) for engineering and building custom shocks and Bilstein was paying $50 K to use their parts ... a $150 K swing in the budget! So ... GM made us stay with the Bilsteins and that drove the design of the "Grasshopper" rear rocker, allowing 21" of travel with modified off-the-shelf 14" travel shocks (the longest available at the time). The Class 7 rules stated "No remote mounted shocks"! So ... we made sure one end was attached to the axle.

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CHASSIS (TOP VIEW) - The detail drawings for the shop to build the frame and all of the components were all done in full scale. This allowed the fabricators to literally trace out some of the plates that needed to be cut by hand on a band saw ... pre-laser cutting days! These full vehicle half scale drawings were used primarily for design layouts.

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COIL ADJUSTER NUTS - Hand drawn

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REAR LEAF SPRING SHACKLES - The SCORE Class 7 rules back in the day required the vehicle to be supported by leaf springs (stock length) in the rear per the production truck suspension type. However there was no rule yet that said you couldn't have other control links! LR-2 used a complete 4 link system for superior axle location control for the 21" of rear travel. Since the axle is normally located by the leaf spring system ... the added 4-Link system would be redundant and result in competing locational forces. This was solved by using articulating tension shackles at both the front and rear leaf spring eyes which greatly reduced any conflicting load paths. This allowed the weight of the vehicle to be suspended by the leaf springs, but the suspension not precisely located by the leaf springs. Note also the 4130 sheetmetal double thin-wall outboard shackle mounts.

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REAR LEAF SPRING UPPER SPRING CLAMP - Modeled and drawn by hand in 2D and made from 7075-T6, this lightweight, multi-function mount on the rear of the Larry Ragland Chevrolet S10 accommodated four U-Bolt nuts, three lower shock mount bolts, and one rocker drive link bolt.

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FRONT COIL SPRING STACK COMBINATION CHART - CIRCA 1988

All of the 2 stack combos were mapped out in the chart shown here for easy reference out on the track during testing.

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SHEET METAL TRUSSED REAR AXLE HOUSING

When is the first time you saw a 4130 Chromoly sheet metal trussed rear axle housing? This high modulus light weight construction used largely .063" and .050" sheet, flared holes, and capped double thin wall - double shear link mounts. Used on the Chevy S-10 Class 7 driven by Larry Ragland. This truck won it's first race (1987 SCORE/Riverside Off-Road World Championships), was SCORE/HDRA Class 7 champion in it's first season, won the 1988 SCORE/Riverside Off-Road Class 7 Championship, and finished every race mile of every race entered as a GM Chevy factory entry.

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RIVERSIDE OFF-ROAD WORLD CHAMPIONSHIPS - CIRCA 1981

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The first of 6 SCORE Riverside Off-Road World Championships in Class 7 that we were involved with. In 1981 we were a part of the student group of the Society of Automotive Engineers at Cal Poly SLO when we convinced Roger Mears to drive our student built Toyota Hilux in the famous venue. Originally slated to drive the Jim Conner Olympia sponsored Nissan (Datsun back then?), and after an initial test run, Roger agreed to drive our Cal Poly truck in the race. Jeff MacPherson then took over his ride in the Oly Datsun, and ironically was the only truck to beat Roger into the first turn after the traditional land rush start. However Roger wasted no time in overtaking the leader in the S-turns and then led the rest of the race for the victory!

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The Cal Poly Toyota in the Mears Gang pits at the 1981 SCORE Riverside Off-Road World Championships. In those pre-wrap days, most of the graphics were air brushed on the vehicle for each race as needed. Our student built motor was to go up against the other competitors professionally built motors. We spent countless pre-race hours and all-nighters in Roger's shop and in the race pits working out a few issues leading up to the race ... but come race time, it didn't miss a beat and all the hard work paid off!

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For the 1981 Score Riverside Off-Road World Championships we built a custom short course fuel cell for our Cal Poly Toyota Hilux that weighed much less than our regular desert race cell. In those days, everyone in the truck classes would simply run their desert trucks in the occasional short course races during the busy desert race season. Not many competitors went through the trouble that we did to make our truck lighter: notice also the aluminum rear bumper and the holes in a lot of the brackets ... not common at that time. The relatively heavy trophy in this photo was not there during the race.

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I remember years later Roger told us it was still one of his favorite wins ... I believe because he made it happen and made a huge impression on an underdog bunch of hardworking college kids who were overjoyed at the outcome and stamped forever with the impression of the experience. Jack Auld, Mario Santellan, Al Bodey, and Bryan Kudela (Lanternmark Industries) all ended up working in the off-road space for Cal Wells at Precision Preparation Inc ... and onward with many others. Rick Sturckow went on to become a pilot for the Marines, a top test pilot, and eventually flew 4 space shuttle missions, 2 as a Pilot and then 2 as the Commander. And some of you may recognize Alan Roach as the founder of Baja Designs ... all from that era at Cal Poly ... to name a few. HAPPY CAMPERS to say the least!

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