June 23rd WTKA Club Race # 4 Report

First off, this is a first for Yaw Moment Racing....I am typing this race report from 30,000ft aboard a Delta flight to Virginia for a UVa buddy's wedding. Back to the racing - Joe, Stuart, and I raced our 125cc Shifter Karts with the West Texas Karting Association on June 23rd at Rimrock Raceway. It was blazing hot in Midland, TX last Saturday but our faithful crew member/pit bunny Ali made the trek with us. Given the 100deg temperature at 5pm when we arrived at the track, I decided to run one quick practice session on old tires as a shakedown. I was able to click off some consecutive 34.9s lap times which I was happy with given how worn my tires were (race tires from the SWRC last year).

At 8pm, the heat races (grid decided by pill pick) began and I raced on my MG Yellow tires from the May WTKA race that I won. Joe and Stuart ran a test day before this race while I was in Lincoln racing the Camaro and thrashed their May race tires so they bolted up some fresh sneakers. This would prove to be an advantage later in the evening. I drew Pole position for Heat 1 in our field of 5 shifter karts. After losing the lead after bogging at the start, I was able to slot back into P1 on Lap 1. Soon after, Stuart began to breathe down my neck on Lap 2. He gave me a little "love-tap" coming into the final hairpin which loosened me up and allowed him to sneak up beside me and take the lead into Turn 1. He checked out and went on the victory while I finished in a P3 after being passed by Joe on the final lap.

For Heat 2, I started in the 3rd position and was able to grab 2nd from Stuart at the start. I stayed there until the finish. My P2 and P3 finished put me in the P3 for the feature. The 12-lap feature was a fairly straightforward lead-follow race. Stuart started in P2 and we had a bit of a scrap on Lap 1 as I tried to pass him in several corners. I was not able to complete the pass and lost momentum which allowed him to build up a gap that he would not relinquish. Joe cruised to a comfortable victory with Stuart in P2 and me in the final podium spot.

I won't be able to race my shifter kart at Rimrock again until their September night race due to travel and SCCA racing conflicts. Hopefully, the San Angelo shifter kart racers can rack up some more victories later this year!


WTKA Website - Come out and race with us!

2012 Blytheville National Tour Race Report

Event: 2012 SCCA Blytheville Solo National Tour 

Date: June 10^th-11th, 2012
Car: 2001 Chevrolet Camaro Z28
Class: E Street Prepared
Tire: Goodyear Eagle RS (AC) 315/35ZR17
Driver (s): Dave Ogburn III, David Ogburn Jr. (my Father) co-driver

Combined Day 1&2 Results
Total Competitors:  203
Class Competitors:  6
Class Finish Overall: P2 (trophy position)
Delta to 1st Overall:  0.775s
PAX Index Finish Overall:  14

Day 1 Results
Class Finish Day 1:  P2
Delta to 1st Day 1: 0.792s
PAX Index Finish Day 1:  35

Day 2 Results
Class Finish Day 2: P1
Winning Margin: 0.017s
PAX Index Finish Day 2: 8^th (top production-based racecar)

Results Links
Overall Results: http://www.scca.com/solo/content.cfm?cid=51045

PAX Results: http://www.sccaforums.com/forums/forumid/9/threadid/430558/scope/posts

Satellite Photos of the concrete runway track at the Arkansas Aeroplex

Ali and I arrived in Blytheville on Saturday June 9^th after picking up the ESP Camaro from LG Motorsports in Dallas, TX. LG Motorsports performed a dyno tune on the Camaro and found issues with the previous tune. This alone inhibited my pace in Lincoln because I was significantly down on power, but I also wanted to improve the handling balance and reduce the vehicle weight before Blytheville. Before I ran any test n’ tune runs, I changed to a softer rear ARB, removed the 2-pt. subframe connectors, and installed a lightweight battery in the right rear corner of the trunk (20lb weight savings).

After some initial sighting laps on the test n’ tune course, it was apparent that the engine was much stronger than in Lincoln and that the handling was improved – better front/rear balance, improved peak grip, and much better power-on oversteer characteristics. I started with 30psi front and 28psi rear. Unfortunately, the test n’ tune course had limited hours so I was only able to run 3 shakedown laps and was not able to perform any tire pressure studies.

There were 6 competitors in ESP class at Blytheville including 7-time National Champion Mark Madarash. I started off the year at the Texas National Tour approximately 1s behind Mark on outright pace on a 60-70s course. My relative pace dropped in Lincoln due to the car issues so I was looking to improve my pace relative to Mark in Blytheville. He provides an excellent benchmark because he is consistently fast at each event and is the fastest ESP car/driver (by a large margin) in the country. Overall, Day 1 went well. I solidly positioned myself into P2 in class and finished 0.7s back from Mark in 1st. The ESP Camaro felt great and was well-suited to the fast and flowing Blytheville courses. I was having some trouble (especially on Day 1) with some mid-corner understeer especially in long, sustained corners. 

It rained over night which made for a green track Monday morning. Also, track temps were cooler which shifted my car's balance more towards oversteer. Power-on oversteer was still excellent but I was able to rotate the car more on entry and exit and modulate the car’s attitude with the throttle.  With this balance change, I was able to more accurately place the car on track and carry more speed through linked transient elements like off-set gates leading into a slalom. For the first time this year, I set top time for the day in ESP. My 49.913s 3rd run put me 0.017s ahead of the field. With increased tire temperature and adapting to the car/tire’s balance, I was able to improve my pace relative to the top ESP cars which I was very pleased with. Also, I was several tenths quicker than the fastest Super Stock (C6 Z06) drivers which is something I have not done at previous National Events. Another encouraging note is that my fast run from Day 2 was the 18^th 60+ second run on that set of tires which shows good wear potential for the Goodyears and that I may have been even quicker with new tires.

Overall, this was my best event of the year in the ESP Camaro. The improvements I made to my Camaro suited the Goodyear tires well. There is still pace to be unlocked from the Camaro through weight reduction and suspension tuning, so I will be working hard this summer to find a few more tenths for Lincoln in September. 

Onboard video from Day 2 fast run: 

Here are photos taken by Ali from my Heat:

Day 1: http://www.flickr.com/photos/yaw_moment_racing/sets/72157630170621596/ 

Day 2: http://www.flickr.com/photos/yaw_moment_racing/sets/72157630174872866/

Photo credit: Ali Ogburn

ESP Camaro Update - Engine Power is Back!

On the Road to Blytheville, AR This Morning

After my disappointing results at the Lincoln National Tour two weeks ago, I dropped the car off at LG Motorsports in Dallas for a dyno tune. I picked up the car yesterday on the way to Bytheville, Arkansas for the National Tour race this weekend, and am pleased (well this is good and bad, I guess) that we were actually down on power on Lincoln....not just going crazy and making excuses. We were giving up 25 peak HP at the wheels and lots of "area under the curve" especially at high RPM which is exactly how it felt on track. The silver lining is that I was still able to manage a 5th place finish with the poor setup and low power so there is much room for improvement.

Ali and I met my parents at the Arkansas Aeroplex today and I had some setup and car development plans for the car before we hit the test n' tune track. Based on my read on the car balance/performance the past two events, I decided to take a step back and "reset" the car's base setup and make an effort to reduce weight. My basic philosophy was the If I increased power from the dyno tune, reduced weight and improved the power-on  oversteer, I would improve my pace. Sounds logical, right? I started off by installing an 11.5lb Braille batter in the rear of the car. This is a 19lb improvement over the stock battery which I had mounted in the factory position. I then removed the subframe connectors and went to a softer rear ARB. I got to take a few runs on the test n' tune car afterwards and the car felt great with 28psi in the Goodyear Eagle RS tires. Transient balance was good and the car would rotate under the brake progressively and it was a monster power-on. Hopefully this translates into improved pace for the National Tour which starts tomorrow. We are running 2nd heat so wish us luck!

You can follow live timing and scoring here: http://sololive.scca.com/

We should be running around 10:30 tomorrow morning.

Pickup, Clag, Marbles, etc........

I brought some of Licoln Airpark's infamous tire pickup (I hate the term OPR and will never use it) with me back to San Angelo. I cleaned my race tires up last night to prep for the Blytheville National Tour and after about an hour with my heat gun, I had this pile to show for my efforts:

Solid couple of pounds off my race tires. Even if it doesn't affect grip, at least I cut some weight......

2012 Lincoln Spring Nationals Report: NECESITO MAS RAPIDO

Necesito Mas Rapdio....I need more fast. Well, the 2012 Spring Nationals are in the books. My results from the weekend were disappointing, but as always, I still had a blast racing with Ali, Lane and my parents. We had a great field of fast Solo drivers and racecars for the Lincoln National tour aka "Spring Nationals" aka "The Central States Championship." Whatever you call it, it was a great event with fast, flowing courses and it was a good barometer for Solo Nationals pace.....which tells me that I need more fast!

Ali and I rolled into Lincoln Saturday afternoon after staying overnight in Oklahoma City (San Angelo to Lincoln is a long tow!). The Spring Nationals was a full four day event with a ProSolo on Friday/Saturday and National Tour on Sunday/Monday. I did not have enough vacation to run both, so my Dad and I chose to run the Tour only as practice for Solo Nationals. We unloaded and setup the paddock quickly before heading to the EVO Test n' Tune which was a a separate course from the SCCA TNT. The setup was great and we got a lot of valuable seat time in the car. My Dad and I each ran 10-15 runs with our Goodyear Eagle RS tires. Sam Strano (10-time National Champ and builder of our ESP Camaro) was gracious enough to give us some feedback on the car and our driving. He seemed to be pleased with my overall driving and pace (we were running identical laps around the TNT course), but said I needed to look ahead more which is something that I have been trying to improve on.....but still need some work. Getting better in this area should help me gain valuable time on long, visually confusing National style courses by linking different sections of the course better. He enjoyed taking some laps in his old car and said the diff, setup, and tires felt good, but that the motor felt down on power from what he remembered. I was feeling the same thing unfortunately....our LS1 engine did not seem to be pulling quite as hard from before the ring/pinion failure back in March.

After some "seat time" laps, Lane and I did a pressure study on the tires. We had been running high pressures (42 Front / 40 Rear) in our Goodyear Eagle RS tires based on some feedback from SoCal Solo drivers.  This setup gave really good initial response and good transient response/balance, but seemed to give up some ultimate grip. We decided to try a higher mechanical grip setup and run much lower pressures. We kept dropping pressures until we settled around 28psi front and rear for both my Camaro and his Corvette. Dropping to 28psi yielded higher lateral and longitudinal grip at the sacrifice of gain (more handwheel angle required to make same corners) and initial response. It was getting dark and we ran out of air, so we did not have a chance to re-run our base setup of 42/40. We will need to do a more exhaustive study before finalizing our tire pressures with the Goodyears but for now, we are running in the 28psi range. We are also learning that the Goodyear tire likes heat so we will be tracking tire temps during our future testing/racing and using heat blankets to try and keep the tires in their best operating range.

I started Day 1 of the Tour on my tires from the Texas National Tour (so 12 total runs and two heat cycles). We had a solid field of 18 cars in ESP including most of the trophy winners from the 2011 Solo Nats. By Day's end, I was in P4 out of the 18 cars with a 62.135s run. This put me about 2s behind 2011 Champion Mark Madarash but only 0.2s out of 2nd place. The car still seemed down on power (seemed more like a stock LS1 than our modified/tuned LS1) and I was struggling with power-on oversteer on corner exit. I know that seems contradictory, but I struggled putting power down and then it wasn't pulling down the autocross-sized straights. I had switched to a stiffer rear bar for this event to help the car rotate on entry which it did at the sacrifice of corner exit performance. For Day 2, I decided to run the same setup (except for a new air filter) but switched to fresh tires. In hindsight, I should have switched back to the softer rear bar. I think that would have helped me gain more time on course from the new tires. I clocked a 66.804s run on my 2nd try which I could not best on my 3rd run. Unfortunately, a DSP BMW spun near the finish and took out the timing system for about 30 minutes between our 2nd and 3rd runs. Given how the Goodyears like heat, this did not help my 3rd run performance. My 66.8 dropped me back to 5th place and about 0.5s out of the final podium spot.

BMW Tangled in the Timing Wires

Overall, I finished in the trophies in the 2nd largest field at the Spring Nationals with a car I felt was under-performing. I know our ESP Camaro and it's Goodyear tires have much more potential than I showed in Lincoln so I will be working hard to correct this. The setup changes I have made to the car have been the wrong direction I think, so I will be focusing on weight reduction and having the engine output checked/increased. On the way home from Lincoln, Ali and I dropped the car off at LG Motorsport in Plano, TX for a dyno tune. As long as they don't find any issues mechanically, we will be picking up the car on the way to Blytheville, Arkansas for the next SCCA Solo National Tour (June 10th - 11th) on the schedule.

Here is onboard video from my fast runs:

Here are some photos from the Event:

Links to all of our photos:

ProSolo Day 2: http://www.flickr.com/photos/yaw_moment_racing/sets/72157629992050107/
Tour Day 1: http://www.flickr.com/photos/yaw_moment_racing/sets/72157630056936402/
Tour Day 2:  http://www.flickr.com/photos/yaw_moment_racing/sets/72157630000643731/


Photo credits: David Ogburn (my Dad) and Ali Ogburn