GT4 RS - spin on track
#16
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Not sure about an RS, but upon a spin, a regular GT4 PDK will go automatically into neutral, or at least clutches disengaged, and the car will refuse to move under its own power before some cycling of the shifter. Additional trivia: a small jump/unload near redline and WOT is the only time I've seen the PDK make an uncommanded upshift while in manual mode. My track has a little dip that'll trigger this anytime I hit it.
Looks like he turned in some while pretty loaded on the brakes and with cold tires, and maybe the outside was also on the paint.
Looks like he turned in some while pretty loaded on the brakes and with cold tires, and maybe the outside was also on the paint.
Last edited by enduro; 09-11-2023 at 08:39 PM.
#17
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Pretty hard on those mag wheels. Can't be great on the brakes either. Glad no serious damage or injuries
#18
Instructor
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Without the data, a lot is speculation. A few observations:
1. street tires come up to temp fairly quickly, but we don’t really know how long he had been on track
2. Painted curbs seemed dry, and wet/slickness of them likely not a factor
3. The mid engine box/cayman is far less prone to oversteer than rear engine 911. In fact a little trail brake is normal, as they can push entering corners. However any car will oversteer with the right(wrong) inputs.
4. My speculation is the car was positioned over the left side curb, or a portion of the track that was undulating. Observe the bouncing/porpoise in the camera and at the wheel. Braking initiated while still bouncing, in combination with the initial turn in, unsettled the loaded left side rear. Possibly complicated by too high a speed for the given corner. I think I woulda worked up to a corner entry that high, and not tried it on an initial, or early lap.
opinion only, ymmv
1. street tires come up to temp fairly quickly, but we don’t really know how long he had been on track
2. Painted curbs seemed dry, and wet/slickness of them likely not a factor
3. The mid engine box/cayman is far less prone to oversteer than rear engine 911. In fact a little trail brake is normal, as they can push entering corners. However any car will oversteer with the right(wrong) inputs.
4. My speculation is the car was positioned over the left side curb, or a portion of the track that was undulating. Observe the bouncing/porpoise in the camera and at the wheel. Braking initiated while still bouncing, in combination with the initial turn in, unsettled the loaded left side rear. Possibly complicated by too high a speed for the given corner. I think I woulda worked up to a corner entry that high, and not tried it on an initial, or early lap.
opinion only, ymmv
#19
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
With that said it has bitten me a couple of times, e.g. here where I had a bit too much throttle and steering angle.
The following users liked this post:
UncleDude (09-12-2023)
#20
#21
Three Wheelin'
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I would be very interested to know what his rear toe was set at. If not at least 12-15 minutes, then that is part of the problem. The clubsports run 17 minutes or almost 3mm. If he was rebounding off a bump while braking and turning in, then that rebound toe out on the left rear would have helped send him into the gravel. Something similar happened to someone else that we all know a few years.
The following users liked this post:
dnimi123 (09-12-2023)
#22
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
It sounded like you lifted at 1:30 causing the left front to bite, but in any case, it was a good save. As someone mentioned above, when a mid engine platform starts to go, it's hard to catch it.
The following 2 users liked this post by DFW01TT:
cafe_racer (09-12-2023),
GT4RSFAB (09-12-2023)
#23
Advanced
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Does the light on the tach mean the PSM is off on a GT4RS? On my Boxster if I put it into PSM Sport mode the light also comes on the tach. I know the GT4/Spyders have a different button set up so was wondering if its different to my car.
#24
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Hard to tell without data, as others said, looks like he turned in really early and lifted instead of braking in a straight line. Not familiar with the track but that looks like a 2nd or 3rd gear corner.
Also, if his steering wheel was on the correct side he might have been able to save it
--Aaron
Also, if his steering wheel was on the correct side he might have been able to save it
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
--Aaron
__________________
The following users liked this post:
abarthguy (09-12-2023)
#25
Advanced
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Hard to tell without data, as others said, looks like he turned in really early and lifted instead of braking in a straight line. Not familiar with the track but that looks like a 2nd or 3rd gear corner.
Also, if his steering wheel was on the correct side he might have been able to save it![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
--Aaron
Also, if his steering wheel was on the correct side he might have been able to save it
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
--Aaron
The following users liked this post:
josephr25 (09-13-2023)
#26
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Watching it again this morning, I realized that he makes an early downshift under braking right as he starts that slight turn. I'd guess a confluence of factors: cold tires, lift/hard-braking, compounded by a high RPM early downshift unloaded then slipped the back tires just too much to accept any turn-in, possibly coupled with that well-known rear toe-in waggle issue (assuming factory suspension settings).
The following users liked this post:
josephr25 (09-13-2023)
#27
Rennlist Member
Join Date: Sep 2007
Location: Ontario & California
Posts: 438
Likes: 0
Received 57 Likes
on
32 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Glad he's okay, & the car will be fine as well.
Sounded like he downshifted (subtle L hand movement) & he had already began the turn in.
If tires weren't up to temp yet, it wouldn't take much imbalance in the car to spin.
Sounded like he downshifted (subtle L hand movement) & he had already began the turn in.
If tires weren't up to temp yet, it wouldn't take much imbalance in the car to spin.
#28
Three Wheelin'
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I would be very interested to know what his rear toe was set at. If not at least 12-15 minutes, then that is part of the problem. The clubsports run 17 minutes or almost 3mm. If he was rebounding off a bump while braking and turning in, then that rebound toe out on the left rear would have helped send him into the gravel. Something similar happened to someone else that we all know a few years.
Last edited by vantage; 09-14-2023 at 01:47 PM.
#29
Addict
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Same question. If I recall he has a Manthey alignment? I just don't recall if he has a non-stock rear toe link (OEM clubsport or 3rd party) to dial in more rear toe than allowable stock. Really hard to tell whether any lack of rear toe as the weight shifted to the front played any role.