Race Date: 4/2/2016
– Class: 1st/13
– My FTD: 66.614 sec.
– Class FTD: 66.614 sec.
– The FTD: 51.982 (2009 Top Kart Speedy TM K9b)
The Central Carolinas SCCA chapter returned to zMax Dragway for round 2 of their 2016 autocross season, and the day started off cool and wet. The field was large again with 182 total entries and nearly two dozen novice drivers. I began the day in the 2nd run group, and the track dried just in time for me to turn my first lap. The goal for today, in addition to getting my autocross legs underneath me, was to evaluate the Harry’s Lap Timer App for the iPhone and it’s efficacy at reviewing each run in preparation for the next. A full write-up on my impressions of the app will be posted here. Read on for more of my impressions from the event:
And check out the video of my fastest time by clicking here:
Learning to Autocross:
For this round, I opted not to have an instructor ride in the car with me. I noticed feeling distracted with the instructor in the car with me, and my nearly 2 second improvement from my last “instructed” run to my final run of the day, without instructor, was enough to prompt this new strategy. I would still recommend having the instructor for your first event, but I was happy to go solo this time around.
Before the runs began, I walked the course and marked the start and finish locations by GPS in the Harry’s Laptimer App. The app would automatically begin and end recording data and video at these locations. Reviewing the video was quick and easy, and I believe it enhanced my ability to process the previous run and pick out improvements much more effectively. The biggest complaint was that the screen on my phone wasn’t big enough to review the video comfortably. A bigger screen, like a tablet, would make it easier to review the video in more detail.
Feeling the Car:
The delta between my first run and fastest run was much less than my first autocross with CCR. I was able to push the car right out of the gate because I had more confidence in my understanding of the car’s behavior. Over the course of my five runs I was able to feel the car’s response to my inputs and to the track surface. The zMax Dragway parking lot is gently sloped from inside to outside and front to back, and due to the course configuration there were several off-camber turns that proved to be very difficult. One tight turn in particular made it clear that the car would ride on the very outside edge of the left front tire as it slid away from the apex and towards the outside of the turn. Feeling the tire tread after each run confirmed that the outsides of all four tires were much warmer than the insides: no temperature measurements required.
Another vexing condition was the vehicle body roll. Riding on the stock suspension, the WRX has miles of ground clearance compared to it’s better prepared contemporaries. This leads to weight transfer that takes ages to complete and makes the high speed transitions of the track tricky and time consuming. Keeping the laps smooth was difficult as the powertrain could easily outpace the suspension, which would induce a desire to give rapid steeting inputs. Reminding my hard learned, prior lesson of, “slow is fast” was the key to keeping a good smooth pace, and this showed with nearly a strong improvement from my 4th to 5th run.
The practice of recording and reviewing the runs was one that I plan to continue. I was better able to remember the run in it’s entirety and pinpoint areas for improvement. In order to improve the car’s handling ability I’ll start with increasing camber. The car is set to the factory recommended alignment because I wanted to make sure I had a true baseline for the car. The camber can be increased with the factory hardware, but it seems likely that camber adjustable strut mounts will be necessary. In addition to increasing camber, a reduction in CG height could greatly improve the handling by lowering the weight transferred from the inside to the outside wheels. Less weight transfer means a better load distribution between the four tires and the their respective contact patches, which allows the car to grip the track better. The next autocross will be on April 30th, so the goal is to make the most out of aligning the stock suspension and re-evaluate afterwards. Although CCR will be competing in May, I will not be able to attend due to a prior engagement, however, that will give me plenty of time to tackle to larger tasks of dropping the car and adding negative camber.