Sonoma Trackday Video (spinout included)

[jonnyozero3]

Mind if I armchair quarter back for a minute?

Caveat: I'm a track noob (about a dozen days under my belt), and I've had a beer. I'm just very curious and want to learn.

Looking at the two laps, the biggest differences I see:

Lap 1:
4th Gear @ ~4900rpm
71mph

Lap 2:
3rd Gear @ ~6800rpm
76mph

- Lines look similiar, and G's on the G-meter looks close.

My guess..you had your foot in it about the same amount, but were carrying additional speed (5mph) and putting down about 30% more horsepower because of the different gears (roughly the same throttle input). The turn dips into a slight bowel, giving you some traction circle leverage, but as the turn levels out, you cross a couple pavement creases that suddenly make it slightly off camber.

I'm guessing with the additional power on the tires, you were about max performing them, but that little bit of off-camber-ness destroyed your immediate correction and lifted the back around around you. Kind of a super quick perfect storm.

That, or the little tree at the corner is a jerk and it pissed on the course.

Any thoughts?

[rice_classic]

Nice editing... but um, I think we're gonna need to see that spin from at least another half dozen angles!

[orthojoe]

Originally Posted by jonnyozero3

Mind if I armchair quarter back for a minute?

Caveat: I'm a track noob (about a dozen days under my belt), and I've had a beer. I'm just very curious and want to learn.

Looking at the two laps, the biggest differences I see:

Lap 1:
4th Gear @ ~4900rpm
71mph

Lap 2:
3rd Gear @ ~6800rpm
76mph

- Lines look similiar, and G's on the G-meter looks close.

My guess..you had your foot in it about the same amount, but were carrying additional speed (5mph) and putting down about 30% more horsepower because of the different gears (roughly the same throttle input). The turn dips into a slight bowel, giving you some traction circle leverage, but as the turn levels out, you cross a couple pavement creases that suddenly make it slightly off camber.

I'm guessing with the additional power on the tires, you were about max performing them, but that little bit of off-camber-ness destroyed your immediate correction and lifted the back around around you. Kind of a super quick perfect storm.

That, or the little tree at the corner is a jerk and it pissed on the course.

Any thoughts?

Thanks for the eval! I think what you say makes a lot of sense. I didn't think about the difference in gear position, but that totally makes sense. I was still trying to figure out the best way to drive the course, so I was trying different combinations for gearing. Smmmurf keeps it in 4th through that turn, but I'm not going through it as fast as him so I find the car lugging in 4th down the straight. I guess I need to learn how to go through turn 6 faster and keep it in 4th....

I'll have a talk with that tree about pissing on the course too...

Originally Posted by rice_classic

Nice editing... but um, I think we're gonna need to see that spin from at least another half dozen angles!

LOL. I was lucky the driver of the M3 behind me came up to me afterwards and offered a copy of his video.

[Doborder]

My question is has anyone else experienced the vacuum hose blowing off as well?

[rmagic]

great video when you going down weight will transfer more to the front and it's lot easier to get the the car upset .

[BlaineWasHere]

The track does flatten out a tiny amount right as you sorta dip into the apex. That's easy to do on slippery tires.

[smbstyle]

Hope you were wearing dark colored underwear that day! Nothing wrong with a clean spin; just means you're finding the limits.

[BRZY]

Originally Posted by orthojoe

Here's a pic of the PCV line that blew off. Its behind the intake manifold near the firewall on the passenger side.

Thanks for the pic. Definitely adding a zip tie to that!

[Dezoris]

Originally Posted by BRZY

Thanks for the pic. Definitely adding a zip tie to that!

Use a hose clamp instead most zip ties are not capable of temps above 140 degrees and will either break or melt eventually. (Its a quick fix only)

[orthojoe]

Originally Posted by Dezoris

Use a hose clamp instead most zip ties are not capable of temps above 140 degrees and will either break or melt eventually. (Its a quick fix only)

Good point. I wonder why it didn't come with a clamp from the factory to begin with...?

[Dezoris]

Originally Posted by orthojoe

Good point. I wonder why it didn't come with a clamp from the factory to begin with...?

There is not much vacuum on that line to worry about however from higher revs you are getting a lot more blowby in that tube. Heat unburned fuel and oil going into the intake manifold would heat and expand the hose more than normal. With the high gforce spin and big throttle lift you would get more vacuum than normal from the intake manifold which could have sucked off the tube from the PCV valve.

Or it was just lose from the factory.

[track junkie]

orthojoe

It's great fun to watch that video and learn from your slide. Thank you for posting this.

This video is very helpful to me for correcting oversteer, it's one of my favorites. Watch in slow motion how he releases grip of the steering wheel at the beginning of the slide. (3:08) A faster/easier way to catch/correct for a big oversteer moment. You know the rest of it.

[ame="http://www.youtube.com/watch?v=wT2wkhg6LTQ"]2013 Porsche Cayman S Thrashed - CHRIS HARRIS ON CARS - YouTube[/ame]


For slow motion
http://www.youtubeslow.com/index.php?v=wT2wkhg6LTQ

I drove a 2007 Cayman S on track and currently drive a 2009 Z06 on track. My new BRZ picked up Thursday will get to the track for the first time next week on the oem street tires.
What track pads are you using for your car?

[Deep Six]

Seems like these cars are temperamental about being spun around? I took mine to Roebling two weeks ago just to establish a baseline with no mods other than Motul 600. I did a 180 entering turn 1 and slid off into the infield grass. Car did not want to restart at first and when it did it would stall at idle. Had a cel and the SL light on. Looked for a vacuum leak but could not find one. Car would run fine other than at idle and the lights went out temporarily. After trailering back to Central Florida it ran fine from trailer to my garage but all the symptoms including the lights returned the next day. My code reader read P071 system too lean bank 1 and P0108 manifold absolute pressure / barometric pressure circuit high. The dealer replaced the intake manifold gasket under warranty and there have been no issues since.

PS. In my observation the car is much more prone to severe over steer in 3rd gear. I don't have the technical background to back that up, it's just an opinion. Mine occured with traction disabled no dance. It was just after a 5-4-3 downshift from 120 to 70 and I may not have synced the engine and wheel speed very well, creating a harsh clutch disengagement.

[orthojoe]

Originally Posted by track junkie

orthojoe

It's great fun to watch that video and learn from your slide. Thank you for posting this.


I drove a 2007 Cayman S on track and currently drive a 2009 Z06 on track. My new BRZ picked up Thursday will get to the track for the first time next week on the oem street tires.
What track pads are you using for your car?

Thanks. Would love to hear your opinion on what happened what could have been done differently.

I'm using project mu club racer pads on the BRZ and PFC08 pads on the spyder. The Project mu pads are arguably overkill for stock tires, but they bite well and never fade.

Originally Posted by Deep Six

Seems like these cars are temperamental about being spun around? I took mine to Roebling two weeks ago just to establish a baseline with no mods other than Motul 600. I did a 180 entering turn 1 and slid off into the infield grass. Car did not want to restart at first and when it did it would stall at idle. Had a cel and the SL light on. Looked for a vacuum leak but could not find one. Car would run fine other than at idle and the lights went out temporarily. After trailering back to Central Florida it ran fine from trailer to my garage but all the symptoms including the lights returned the next day. My code reader read P071 system too lean bank 1 and P0108 manifold absolute pressure / barometric pressure circuit high. The dealer replaced the intake manifold gasket under warranty and there have been no issues since.

PS. In my observation the car is much more prone to severe over steer in 3rd gear. I don't have the technical background to back that up, it's just an opinion. Mine occured with traction disabled no dance. It was just after a 5-4-3 downshift from 120 to 70 and I may not have synced the engine and wheel speed very well, creating a harsh clutch disengagement.

Interesting. My car stalled at idle too, but plugging back in the vacuum line fixed the problem. You had a totally different issue.

I definitely over steered in 3rd gear. LOL