Team 's GRM $2k3 Challenge

Part 1

Grassroots Motorsports Magazine (GRM) will be hosting the $2003 Challenge April 4-5 2003 at the Gainesville Raceway in Gainesville Florida. As I write this, team ISOA has 121 days left to prepare the car for the fourth annual Challenge.

For our new readers, the object of the GRM Challenge is to purchase, prepare, and race a car without spending more than two thousand (and three) dollars. Cars are awarded up to 40 points for a 1/4 mile drag race, 40 points for an autocross (slalom course), and 20 points for curb appeal (concours). Team ISOA competed in last year's $2002 Challenge with a supercharged GT6+ running propane fuel. We were awarded an honorable mention as the team who best demonstrated the spirit of the event, and we received press coverage in Car & Driver and Hot Rod Magazine.

We spent about $1950 on the car last year so we had to sell off some unnecessary parts in order to have a budget for this year's competition. A large part of last year's budget was the "fair market value" of the electronic ignition system borrowed from my TR6 for the event. I returned the ignition system to my car and deducted it from the budget. This year we're using the original GT6 distributor (modified) and an old Heathkit CDI ignition box salvaged from our parts car. Our major purchase for this year was a set of used Hoosier DOT legal racing tires and rims which we bought from SCCA racer Andrew Stark. Phil Fox rescued a $50 GT6 Mk III parts car and, per the rules, we plan to recoup that $50 by selling a few unneeded parts at the Chicago British Car Swap Meet in February. So far the parts car has yielded a stiffer front sway bar, a better shift linkage, a better clutch, a high ratio differential, some rubber trim pieces (appearance counts!), and a working alternator. It also means we'll have a spare engine, transmission, and differential in case something breaks at the track.

We brought the car out of mothballs in October. One of the rear wheel cylinders had leaked while the car was in storage so we rebuilt the rear brakes. Our original exhaust system did not survive the last trailer ride so we built a new one using some 2-1/2" pipe and a cheap glass-pack muffler. After charging the battery we crossed our fingers and cranked the engine. It started the first time and the glass-pack sounded great.

Mike piled into the GT6 for a test drive. Since the car has no passenger Phil sat on the rust ridden floor (Flinstones, meet the Flintstones) while I followed in my TR6. We drove to NAPA Auto Parts in Highland Park (just in case) and switched places. I finally got to drive the car! The supercharger belt was slipping but the car still felt quick with only 5 PSI of boost. The glue holding the gearshift knob in place had deteriorated. The knob came off in my hand as I shifted but I got it back on without incident. I felt a fierce vibration from the rear as I reached 55 mph but we made it home in one piece.

At Mike's suggestion we adjusted the supercharger pulley and were able to get 10 PSI of boost. We're working on an improved belt drive, which should give us our target of 20 PSI. Phil dismantled the rear axle. To aid disassembly we used a piece of scrap rectangular tubing and an exhaust clamp to create a compression tool for the rear leaf spring. Irv Korey wielded the spring tool while Phil drifted the mounting bolt out as I watched from at a safe distance. Phil discovered many loose bolts on the differential flanges and a severely damaged rotoflex coupling on the right side. Fortunately the car's previous owner gave us a spare set of NOS rotoflex units. We borrowed one of the club hub pullers from Joe Pawlak (the other one is MIA- do you have it?) and plan to rebuild the rear next week.

We also stripped the car of unnecessary weight. We have to retain the windshield to comply with the rules but we're replacing the rest of the glass with lightweight plastic. We also removed the windshield wiper system, the hatchback hardware, the heating and ventilation system, all the carpeting, the window regulators, and both door trim panels. Each piece we removed was light but it adds up to a huge weight savings.

GT6 wheel studs have a 1/2" knurl and short 3/8" threads. These studs are not long enough or strong enough for our new racing wheels. The front wheel studs on a TR6 use the same 1/2" knurl diameter but they are slightly longer and have 7/16" threads. If you have any old TR6 wheels studs lying around please consider donating them to the team!

by Erik "Iceman" Quackenbush