September 19, 2009

Changes since September 12th race: 

Not much - we did our normal weekly maintenance and preparation. I also checked and re-checked that all four spark plugs were tight! I didn't pay much attention to the engine data logs since we know that a spark plug was loose last weekend. No use trying to retune the engine knowing that the ignition system was not at it's full potential.

Hot Laps: 

The track is slimy, so we start with right rear air pressure at 8 psi and leave the right rear spacing in tighter than we normally run hotlaps. The car runs pretty well. Engine feels pretty strong and we gain on the cars running in front of us.

Changes before the Heat:

Track is getting slick, but it really isn't widening out as much as normal.

Tightened the car:
Dropped RR air pressure (6psi)
Moved top wing back.
Started with the shock compressions at: LR and RR set to #3 position I also added four clicks of rebound to both rear shocks to hold the rear end down coming off the corner.   

Heat Race: (started 7th / finished 6th) 

Started on inside fourth row - engine runs OK, but I still hear the same raspy sound that I heard in the feature last weekend. I struggle with the handling, but finally get going in the last four laps and start gaining on the lead cars.

The engine is pretty good, but I can tell we have some rich areas in the fuel map as the throttle response is not crisp. We'll analyze the data logs and try to work on the fuel map.

Changes before Feature: 

Starting 14th:

Reviewed the data logs and sure enough, we are RICH. I lean the entire fuel map by 5% and then lean some key areas another 5%.

Track is sealed over (slick) and wide with a cushion pushed all the way to the turn one wall and about 3/4 of the way up the track in 3 and 4. - no one's going to win on the cushion in this race!

Tightened the car:
Changed right rear tire to a lesser grooved RD15 compound with a lot of siping and a 5psi bleeder.
Set RR and LR shocks to #2 compression position to start the race and put four more clicks into the rebound on both rear shocks (10 total clicks).
Changed to big sideboard wing. Took 1/2 turn out of the right rear torsion bar.

  

Feature: (started 14th, finished 1st) 

Started on the outside seventh row - and the seas parted! The car JUMPS on the start and I drive right up the middle of the sixth and fifth row. The car sticks in the black and I continue to pass cars down the back straight. For the next eight laps I work the middle and bottom passing cars every lap. I catch the lead car going down the front staight and pass him around the top through turns 1 and 2. We then run into heavy lap traffic. The car is awesome everywhere on the track. It jumps off the corner when I run low (on the berm) and sticks like a slot car when I run through the black slick middle. A caution flies and I have four lap cars between me and second place. On the restart the engine pulls HARD and we quickly stretch the lead out again. A caution again flies on lap 25. I have a three lap car buffer back to second place for the restart. We again pull a straight away lead in the last five laps for our third win in the last four races.

Wrap-up: 

Wow, we passed a lot of cars tonight (25 started the feature). The car was the best it has been and was easy to drive fast! Working lap traffic is a blast when you have a car that handles this good! I had a smile on my face the whole race -- Man, that was fun!

I still hear a strange warble in the engine, but it made great power. It still sounds ignition related, but it doesn't seem detrimental to performance. I figure it is one of four things:
1. Spark Plug is weak.
2. Ignition Coil is weak.
3. Intake Valve is tight (not closing all the way)
4. Resonance (sound) back through the new throttlebodies and I am just not used to the sound yet.

I will replace the coils, spark plugs and check all ignition wires. I will also check the engine valves for proper clearance this week. If I don't find anything - we'll just continue to run her as she is.

This was a special night since two of the three people who designed and built this car were on hand. I am proud of the fact that this race car is ONE of a KIND! We built it from the ground up with only a few components store bought. We didn't just write a check and have a turn key car delivered from one of the major chassis builders. We drew this thing up and built it! We also designed and built the intake system, wing system and the exhaust headers. There is nothing better than winning with a car you designed and built. Many thanks to Richard and Jack Canaday of Canaday Chassis and Jerry Whitworth of Mirage Chassis. We have built one hell of a race car! Also, a BIG thanks to Mike Gigot of Scorptec - he talked me into the MoTeC engine computer, continually works with me on tuning and guaranteed that building our own headers would be worth every penny (or thousand dollars in this case).

Once again; Becky Hand video taped the feature.

http://www.youtube.com/watch?v=a2PRgTRuZh4