Tigges Talk - How It All Started - Part 2

Back in the pits, it was all business for between round service. Doug on the front of the body, Pete and me on the rear quarters, the body was lifted off the chassis and set behind the trailer. The chassis was rolled forward, then the front was raised by two of us using a pivot jack. The rear of the car was lifted using a floor jack, then supported with a chassis stand. Mark downloaded the computer data only to find unusable corrupted files. I worked on the left side of the hot engine, unstrapping the blower restraints, disconnecting the puke tube & spark plug wires, removing the valve cover nuts, then the spark plugs and finally the valve cover. Pete did the same work on the other side. As soon as I cleared the area, Fred and Pete started checking and adjusting the valves, cranking the engine by hand via the supercharger pulley and a long ratchet. All the needed tools were in a tool rack setting on top of the engine.

Meanwhile, Doug & Mark removed side and bottom chassis sheet metal, the driveshaft, Lenco planetary transmission, titanium bellhousing with clutch pedal, input shaft, three disc clutch, floaters and pressure plate. Every part was being analyzed… the plugs showed little color, the discs and floaters were not as hot as normal. At the back of the car, I drained the puke tank, then each upper front frame rail into a small bucket. Pete dropped the right side chassis sheet metal and diaper then drained the engine oil into a large plastic container.

With the valves adjusted and rocker lock nut torque checked, the valve covers were placed back on and each side was re-assembled. Order is important, spark plugs 1, 3, 5, 7 front to back on my side 2, 4, 6, 8 on Pete's side, installed first, so if you accidentally drop a valve cover nut it can't fall into a cylinder. Then the valve cover nuts, started by hand, then snugged up in an alternating cross pattern center to outside, then tightened using a 'T' handle wrench, then checked again. Finally, plug wires, puke tubes & blower restraints were put back on.

With no computer data to look at, tuning decisions were made based on past experience, expected track and air conditions, condition of the parts during teardown, the incremental timeslip numbers and Fred's feedback from the driver's seat. The trick was figuring out what to change of many variables to get improvement. How much static clutch pressure should there be? Which clutch discs to use… the old ones that grip better or the new ones that are smoother acting or a combination of the two? What jets to use where, what about the timing of the fuel curve given the corrected air density? What about the ignition timing or transmission ratio? Will it be cloudy, or will the sun heat the track surface? It is like being halfway through a chess game with both players using the same color pieces.

Clutch decisions made, Doug cleaned the floaters then assembled the clutch with the selected discs. The pressure plate static pressure was set and checked with vernier calipers and changes to the counterweights to increase or decrease pressure and clutch lock-up timing were done. Everything was checked and torqued. Like the top end work, all the clutch service tools were in one box ready to go.

The Tigges have a very well organized way of doing things which makes it really easy to observe and learn. Still, I managed two mistakes in this service, dropping a spark plug due to going too quickly, and discarding the oil Phil had drained when it should have been analyzed for methanol content and re-used. Slow down, ask more questions.

While Pete refueled the car with five gallons of methanol, refilled the drysump tank with oil and checked the tightness of the intake manifold nuts, Mark set the pneumatic fuel volume timers and made any jet changes he had decided on. Any change affects the other systems, so the balance between all the decisions needed to be well thought out. The computer cover was removed, showing the tire shake had disconnected several connectors. When re-connected, the computer still did not record properly. The car was fired on the stands and run for about ninety seconds, checking all the system functions and looking for leaks. Soon enough the track radio called 'alcohol funny car to the lanes' and it was time to go up again, hoping to improve. Somewhere in there we found time to eat lunch.

At the starting line, safety is always on your mind. Never stand behind anybody's tow vehicle. Don't watch a burnout directly behind the car. Wait until the car moves forward after the burnout before stepping behind it. Be aware of your job and keep an eye out for broken routines. All our pre-prep was done in time to watch 17 time TAFC champ Frank Manzo make an event best 5.53 / 261 MPH pass in front of us to go to the #1 qualified spot. Our 5.73 / 252 moved us up to the top half of the field into the #7 position. In the truck, heading to the top end, the replay of the run on the jumbo screen showed Fred's car bouncing and skidding down the shutdown area, the useless parachutes tangled behind the car. Fred got the car slowed down and made the turn off, much to our relief.

Fred was out of the car at the top end, smiling about making the turn off. The top end dance involved raising the body, attaching the body pole & strap, hooking on the tow strap, replacing the coil shorting wire & fire bottle safety pin and gathering up the tangled chutes. Fred got back in the car, and we towed up to get the timeslip which shows incremental times… 60 foot, 330 foot, half track with MPH, 1,000 foot and quarter mile with MPH. Next stop was the scales, where the car was weighed with the driver, followed by a fuel check, then we were back at the pit.

Mark can tell you five minutes of information watching five seconds of run from behind the car. If the car shook, how much it shook, how much wheelspeed did it have early in the run, when the clutch started to lock up. Was there enough or too much RPM, did Fred short shift intentionally, what did the exhaust flow tell about the fuel flow, and the list goes on. With the computer still not providing data, his experience set the plan for the next day's qualifying.

During teardown, excess oil and methanol in the puke tank called for a leakdown test. Cylinder #1 showed excess leakdown, so in addition to the normal service work the supercharger, manifold, and left side cylinder head were removed. Pete dropped the oil pan, removed the #1 rod cap, and pushed out the piston and rod. Fred inspected it, found minor piston damage and determined the top ring was leaking compression. A fresh piston & rings were fitted to the rod, slid through the ring compressor and re-torqued to the crank journal. I helped Pete re-assemble the oil pan and cleaned the solid copper head gasket then the head, intake & blower went back on. With Saturday's third qualifying run scheduled for early afternoon, we called it a night, pushing the car into the trailer to be completed the next morning.


Chris Saulnier - Team Tigges
Mechanic Falls, Maine

 

I hope to someday be able to give 5 minutes of debrief after a pass. That and the tuning decision proficiency is what I revere the most.