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Old 08-16-2013, 01:39 PM   #47
Fair
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Join Date: Nov 2012
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Project Update for July 13, 2011: Just some minor updates here, and last weekend's autocross report. Let's see, we had the car at an SCCA Texas Region autocross event last weekend, this time with some real STX competition again and a good course design.

Competitive drives put in by Brad Maxcy in his 328is and Chris Ledbetter and Brian Buchanan in Chris' 328is gave us some solid times to compare to. Costas co-drove the Mustang for the first time since April, blowing out the cob webs and trying to learn the new throttle mapping - with some other fun, new "challenges" to drive around.



I get to the event and unload the Mustang from the trailer (scraping both the nose and the tail on the trailer ramp - new 74" long Race Ramps ordered from SPS and should here by this weekend), go to set the shocks at our normal race settings, and... one of them is stuck. Damn! This can happen to any shock if its dropped, which might have happened last week when removing, reinstalling, or taking the shocks to be dyno'd (explanation why at bottom). This should not have been found while at a race, of course, and we had a talk about "checking all shock settings immediately after they are installed" in our Monday morning meeting at Vorshlag. So we've got a single rear shock stuck, either full soft or full hard. How much could that affect the handling? This sounds like a great test in the making.



It turns out, it affects handling a lot. Reinforces my "Shocks matter" mantra. Remember, this shock was still functioning properly, just with the adjustment stuck, as it turns out at full hard (stiff) in the Rebound range. The lateral grip was very different left to right, as a result. Made it a challenge on this somewhat tight autocross course today. Watching Amy and Costas drive through a particular offset compared to the 328is STX cars was dramatically different. Left turns were just a royal b!tch all day.



We also had a LOT of tire heat to deal with, especially Costas and me running back to back in STX class in heat 3. You see it was 100°F, and Amy ran in heat 2 by herself. She sprayed the tires after her 1st, 2nd and 3rd runs, to keep the tires within operating temperature for her next run. After her 4th run she was in 2nd place, a scant .053 sec behind Jen Maxcy, both running STX cars in the PAXed "W" class. She didn't spray tires - why would she? She was done for the day.



Immediately after her last the final run, heat (3) of the day started, and it was an abnormally small group. This meant that the 2 driver cars had little to no time between runs. Well the tire sprayer decided to die that day - it wasn't holding pressure and water just dribbled out of the spray tip. No jokes, please. So we started with hot tires and couldn't ever get the tire carcass or tread cool enough to even touch, and with just 2-3 minutes between 1st and 2nd drivers it was a thrash just to get the driver and numbers changed, much less splash a little water on the tires. So from our first runs on, we had boiling hot tires - especially the rears. Makes putting 392 whp through 265mm street tires on a sealed asphalt surface that much more impossible.



Costas and I both also heard some hideously LOUD noise in one turn, which spooked us both, so we had to investigate. We took a 1 minute "mechanical" to peek underneath, but we didn't see anything at the time. It wasn't leaking or obvious, so we drove thought the noise. Turns out we had two issues with things rubbing. First, a tire was rubbing on the inner fender well at full steering lock and full cornering load, which we saw in one corner only. No big deal. Second, the OEM end link bolts were dragging on the inner frame section at full droop, which was LOUD. The Eibach front swaybar we used was the 2005-2010 bar, so maybe the ends are slightly more inboard than the 2011? Whatever, we are fixing that in the shop now. And the steering shudder was ever present at any corner above 35 mph.

As you can see in the STX class results, I started out "in the hunt" after Run 1, just a few tenths behind Ledbetter and Maxcy. I found some time, but Brad Maxcy found a lot more (and PAXed #3 for the event), and had me by 1.3 sec at day's end. Ledbetter and his co-driver (2nd and 3rd in class) also got faster, and were in the same second as me after 4 runs, but still well ahead, PAXing 10th and 11th, with me in 15th in PAX and 4th class. Ugh. Costas was trying to learn the new throttle/power parameters of the car after 10 weeks away from autocrossing, and eventually managed to put in a time good enough for 5th (with a scratch time that was closer).

more below...
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Terry Fair - Owner at Vorshlag Motorsports - www.vorshlag.com - Plano, TX
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