SCORE Journal - The Official Publication of SCORE Off-Road Racing
Issue link: http://read.uberflip.com/i/501768
all day long and that kills the valve job," says FAT's Aronson.. "You run the next 700 to 800 miles, then a complete overhaul. So within the full SCORE schedule, you start fresh, run the San Felipe 250, tune it, then run the Baja Sur 500, tune up again, and run the (Bud Light SCORE Baja 500 or Bud Light Imperial Valley 250) Plaster City 250. Then you do a full rebuild for the SCORE Baja 1000. With this program we can supply championship power for the whole season." Under the SCORE rules, a 5/1600 needs to start out with a VW series Type 1 engine from a U.S. model sedan using the same components and dimensions. However, when it comes to camshaft duration and compression ratio, there are no limitations. So you can turn up the compression ratio and run racing fuel if that's the route you want to take. And most competitors do. If you are going to run a higher compression ratio to use 110 octane fuel, forged pistons are recommended. Camshaft manufacturers, engine builders, and race parts suppliers will give you all the help they can in making the right selection of components. So if you are building your own, these people are more than willing to mentor you to some degree. But the learning curve will be all on you. Transmission Choices Best practices usually compel race teams to run a purpose- built desert racing four-speed 091 VW Bus transmission. Like the engine build, this is an area where specialty shops have technical expertise and efficiencies to build a stock bus transmission with all new and strong components to survive long, grueling, desert racing. You can expect to invest anywhere from $4,500 to $6,000 for a race- ready VW 091 bus transmission transaxle for your 5/1600 car. There is a good selection of companies, shops, and individual transaxle builders you can go to for your transaxle build. Shops such as J&G, Power Box, and Weddle Industries know how to build within the rule book, and will steer you in the right direction for parts and advice if you are going to build your own racing transaxle. Either way you go on getting your transaxle setup there are lots of racers and builders who will help you get the information you need. For advise on how to keep your race transaxle healthy and reliable enough to run a full season, Ron Weddle, COO, of Weddle Industries weighed in on this critical topic. "For the utmost in reliability we recommend service after every race. That doesn't always fit in every schedule or budget. Some racers try to push it to two or three races for a mileage that comes close to 1000 miles, based on the trans making it through the SCORE Baja 1000. We don't recommend this. Cars tend to get driven harder in most short sprint races than longer races like the SCORE Baja 1000. As with any off road class, the suspension on these cars is getting better which translates into going faster. Bumps at higher speeds equal more stress on the driveline." To keep the 091 transmission in good shape during the season, Weddle recommends regular maintenance that anyone can do. "At minimum, we recommend and oil change with a magnet check in the trans for debris. The shift shaft can be checked for side play, same with the drive flanges. Look over the trans for leaks. Check the operation of the clutch linkage/ slave cylinder. It's difficult to check or adjust anything externally. That's why we recommend a tear down and inspection. While the car is still drivable, listen for odd noises and check to see if the trans shifts smoothly." Rules require use of a stock VW Type 1 or 2 transaxle housing. Although the stock transmission case is used, the internal parts will largely be aftermarket performance parts. "A typical build will take 8-10 (hours) once all the parts are pulled and cleaned," Weddle said. For example, a Weddle Industries Ultimate 091 Bus transaxle will be loaded up with their heavy-duty ring and pinion, bearing thrust plate, spider gears, Chromoly pinion retainer, steel cage needle bearings, shot-peened 1-2 slider "Building a 1600 off-road race engine is more detailed than some of the big motors we build."-- Greg Aronson, owner of FAT Performance. 054 SCORE JOURNAL SCORE 101