October 3, 2009

Lamb, Piel, Witcher Memorial Race

Changes since September 26th race: 

Last weekend stunk -- we crashed Friday night and nursed a sick engine on a tire eating 'rubber down' track on Saturdary night. I hate rubber down tracks due to the follow-the-leader racing and the destruction of about $350 worth of tires! However, the rubber down was exactly what we needed to diagnose our engine problems. Remember my constant complaints about the engine popping, hesitating and inconsistent power? When the rubber goes down on a dirt track, the grip of the track increases; thus, the engine labors much harder. The increased stress on the engine showed me that we had a major electronics issue that was costing us big time horsepower. The engine often sounded like a diesel, spit blue flame out the exhaust and backfired. LET THE DIAGNOSTICS BEGIN!!!

Special thanks to Mike Gigot of Scorptec -- he talked with me on the phone for a substantial amount of time on Monday diagnosing our problem. We concluded that the Cam Sensor and the Crank Shaft Sensor are getting out of time (losing synocronization) during heavy engine load. The MoTeC computer showed that the sensor sync was within their limits, but just barely -- we were walking a tightrope.

Let me explain sensor sync. The Cam Sensor is triggered from a single tooth rotor mounted on the exhaust camshaft. The Cam sensor tells the computer the position of cylinder #1. The Crank Sensor is triggered using a 12 tooth rotor mounted on the crankshaft. Remember - 12 teeth means each tooth is 30 degrees apart and remember that for each camshaft revolution you have two crankshaft revolutions. The MoTeC must see 24 pulses from the crank sensor for every one pulse from the cam sensor. Timing these sensor pulses is CRITICAL for proper engine function - if you get too close to the next pulse, the MoTeC will fire the injectors and ignition 30 degrees out of time. That is what was happening to our engine intermittantly!!! That is why we were down on power (retarded ignition timing) and why we were 'popping'. The situation gets worse as the engine wears (especially timing chain stretch) and since we are now on our 12th race - the sensor sync was inconsistent.

At this time - I must also give a HUGE thanks to my friend Robby Johnson in Hastings, Nebraska. He also runs a Honda engine / MoTeC setup. His sensor settings were the EXACT opposite of mine and we really didn't know why. We spent an hour on the phone probing our MoTeC wiring harnesses looking for a reversed wire, but we never found one. His engine runs awesome and mine stinks, so I went with his settings. This forced me to pull the valve cover off and remove the cam sensor rotor off the camshaft. We use the factory cam rotor, but cut off two teeth and slot the two bolt holes so we can rotate the rotor to achieve proper timing. It turns out that my cam rotor is rotated counterclockwise and his is rotated clockwise. I grind new slots on mine and rotate it clockwise to match his. I fire the engine and the syncronization is dead on!!! The engine has a sweet, throaty sound and idles a ton better. This may be it!!!

Hot Laps: 

The track is narrow and tacky. The car runs pretty well. Engine feels strong and we gain on the cars running in front of us. NO POPS, no loss of power!

Changes before the Heat:

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

Tightened the car:
Changed RR tire to reduce stagger and 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 6th / finished 5th) 

Started on outside third row - engine runs good, but I have a massive push entering the corner. It takes me a lap to pass a slower car and move the top wing forward to reduce the push. I then hold my own against the rest of the field.

The engine never missed a beat, but I can tell that my fuel map is a little off. We have been making all of our adjustments to an engine that was going out of sensor syncronization; thus, we will now be correcting my past fuel map adjustments.

Changes before Feature: 

Starting 7th:

Reviewed the data logs and sure enough, we are LEAN all over. I richen the entire fuel map by 5% and since this is the last night - decide to experiment and turn on Lambda Control. Lambda Control is where the MoTeC computer uses the oxygen sensor to automatically adjust the fuel mixture as I race (just like your passenger car). I program the MoTeC to adjust the mixture a maximum of 5% richer or 5% leaner as needed to maintain a predetermined air/fuel ratio. This did not work well earlier in the year when we were running the Yamaha Throttlebodies -- I hope it works with these new throttlebodies!!!

Track is sealed over (slick) and wide with a cushion pushed wide - the cushion is usable, but the A-Class feature was won using the bottom of the track! This could be real interesting as I start behind the top 6 in point average (fastest cars).

Tightened the car:
Changed right rear tire to a lesser grooved RD12 compound with a 5psi bleeder.
Set RR and LR shocks to #2 compression position to start the race and put more clicks into the rebound on both rear shocks (12 total clicks).
Changed to big sideboard wing.   

Feature: (started 7th, finished 1st) 

Started on the inside fourth row behind the top point cars. The car makes an awesome move on the first lap and I get by the 5th starting car. I then go to the middle of the track (in the black) and pick off 5th and 4th by lap two. The leader then begins to slow and we all pass him. I am now in third behind Tim Koch and the 2009 points champion Stan Kreisel. Tim and Stan are racing each other hard and over drive turn four -- I dive below both of them and take the lead --- CAUTION FLAG! Dang it - back to third for the restart and now they know I'm here! On the restart, I work on Stan into turn one and get a run on him down the back straight, Tim slides high off of four and I get beside him. I cannot clear him into turn one and I know that he is going to take my nose off and run me to the infield berm; thus, I hit the brakes just as he chops across in front of me. He now knows I am trying to pass him on the bottom -- the perfect setup! I run nose to tail with him down the back straight and he shoots to the bottom entering three - I stay on the thottle and drive above him (right in the black-slick), pull even at mid corner and pass him coming off of turn four. What an awesome racecar! We quickly pull away and put a 1/2 lap on second place by lap 15.

The caution (red) flies and I have a couple of lapped cars between me and second place. On the restart, we pull away again, but another caution flies at lap 20. This time there are no lap cars between me and second place (Tim Koch). Tim beat me on a resart a few weeks ago -- that isn't going to happen again now that my engine is hitting on all four cylinders! On the restart - I hug the restart cone and protect the bottom groove through turns one and two. Over the last ten laps I pull a 1/3 lap lead and we win our fourth race of the year!

Wrap-up: 

This win is sweet for many reasons:
1. We passed the top points cars to earn this win.
2. It is always good to end the season on a high note.
3. We fixed our engine problem that has been plaguing us for the last month.
4. Our experiment with Lamda Control worked beautifully.
5. This was the Lamb, Piel, Witcher Memorial.
I have wanted to win this race since it's inception. I never knew Ron Piel, but Don Lamb was a close friend of my long time sponsor Lee Cromwell of Lemco Performance. I cannot remember a time that Don Lamb was NOT having a blast at the race track - the guy was always smiling and seemed to be having the time of his life. I was in the grandstands the night Don passed of heart failure while racing at SSMC. I remember the sick feeling as Teresa and I watched the ambulance crew work on Don. I remember displaying the circled #71 memorial sticker on my car (I still have that arm guard on display in my shop). I also remember Wes and Haley Witcher pitting next to us when they were first starting Jr. Sprint racing. You could see the love of a father for his daughter and it came to the forefront one night when Haley flipped her car. Teresa and I could tell she was frightened, but she still wanted to race. We never saw Wes put any pressure on his daughter - if it was still fun for her, he seemed to fully support it. I remember the final race night of Wes's final year of life - the night he strapped himself in Haley's Restrictor Class car and took a number of laps. I believe we all teared up that night and I am tearing up as I write this. That is why this trophy means so much to me. Oh and by the way - that seemingly frightened little girl of eight years ago WON her first Restricted Class race at SSMC a few weeks before the Lamb, Piel, Witcher Memorial of 2009. Awesome memories!!!!

Our car is amazing through the slick part of the track - that is our advantage that we will continue to work to improve for the 2010 season. Time to reflect on what we learned in 2009 and look to 2010.

Look for my 2009 review and 2010 preview blogs coming soon. No video this week, it was TOO COLD (44 degrees).