JAJ
Well-Known Member
- Joined
- Apr 9, 2016
- Threads
- 4
- Messages
- 2,011
- Reaction score
- 1,714
- Location
- Vancouver BC
- Vehicle(s)
- 2016 GT350 Track Pack
The exhaust flap valves open automatically at high rpm and WOT, presumably to protect either the engine or the exhaust, and if this auto function is not working, the ECU throws a code and shuts down all of the performance enhancing stuff, like launch control. That's why the exhaust flap valves are cycled at engine start - you can hear it happen. It sounds like your valves are not working properly.We had a track day with the BMW club on Sunday. First time getting the car out with the new front bar and FP springs all the way around, as well as dialing back the camber from -3 on the front to -2.9, and the rear from -2.3 to -2.0 on the rear. Also, while it might sound like nothing, I wore gloves for the first time ever (Admittedly "Mechanix" gloves, but grippy none the less).
The FP springs and sway bar were a massive upgrade. And my times show it. Last event, I was ~1.7 seconds off the leading CAMC Mustang, which has had a lot of weight saving done. This event, I was .5 seconds off one of the drivers, and .9 off the other driver. After reviewing the video, I can see that .5 seconds in my driving. And then some. Long story short, I think the leading CAMC car is now within reach with this new suspension, and more importantly, better driving. The car felt much more composed, and flatter through all sections. Transitions from right to left were much more controlled and smoother. There was one high speed section with a transition where with the old springs, I would have had to let off, but was able to stay on the throttle this event.
There was one downfall of less body roll and flat cornering. The rear of the car did not get loose. And that resulted in the fact that I couldn't buy a clean lap. There was also some cones being called that should not have been called, and cones put onto the wrong drivers. My wife was there, and said she didn't see me hit any on my fastest lap, but apparently I hit one. Regardless, this event was more of a test and tune session for me, to get read for the SCCA event in two weeks.
Here is my best run, a 34.010 (Supposedly a cone...). Top time was a 32.6, in a C4 Corvette, and a masterful driver.
AND, as you can see in the foregoing video, the organizers did not set up a particularly safe course, setting the finish at a corner after a long straight that has a ramp right prior to dropping into the corner, and the corner leading right into the paddock, or if you don't get a good bite, a treeline and fence. I almost lost it myself. Here is that video.
One other thing that has long plagued my car. For whatever reason, it has a little electrical demon, that randomly shows up with no ability for me to predict when or where. I start the car, and usually within 2 minutes of starting, sometimes the active exhaust status will pop up on the display. Then it keeps flashing on and off. I also notice the Launch Control turn on and off along with the active exhaust. I do not know why it does this, I cannot replicate it, and when it does this, it is apparently turning on and off a different drive mode. It did this on my first run, and the "service Stabilitrac" light came on, which killed my power, and obviously the TC was on, not allowing me to fully push the car. When I got to the paddock, the service light turned off, but the flickering continued. I turn the car off, and turn back on, and it acted up again. So I turned the car off, and back on, and the issue never came back.
If anyone has ANY ideas on what is going on, I am all ears. I first thought it was an active exhaust sensor issue, but the LC turning on and off lead me to check the LC button. When the issue arises, the LC button does not work. But it does work when the issue isn't happening. I keep the battery on a trickle charger, and the battery has tested good multiple times. So not battery. Last night I disconnected the battery, and will hook it back up tonight. I am hoping maybe a hard reset will fix it. One other thing. Granted yesterday was the first time it's been hot here, it seemed to do it a lot more than normal. Usually I get the issue, then have 10 starts where the issue never happens. I have cranked down all the ground wires I can find, but if there is a secret one someone knows about, please let me know. Like I said, I cannot replicate the issue, and it usually resolves itself if I turn on and off.
As for Stabilitrac, that sounds like a wheel sensor issue. They're easy to access, so take the tires off, clean them up and that'll probably keep it from happening again.
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