Scared... Hard shudder / hard acceleration

[HeRoze]

Help.

2001 986-S 50K miles (does NOT list the M222 - traction control)

I was stoplight racing some bling-covered pickup, just because the mood struck us both. First time I had really hammered the car. Hard off the line in 1st - red line - 2nd, quickly flooring it... I felt a bad mojo shudder/vibration that kept up for a few seconds. very reminiscent of ABS shudder (but I was definitely not braking). It was time to back off anyhow, so I did and it drove fine. I'm nervous to try and repeat. A little more info... the car may have drifted a bit, but not sure if I just veered a little on the steering.

I could use some advice. I'm a bit fearful of dropping the transmission or something equally disastrous until I know what this is, but want to drive it hard when I feel like it.

[JFP in PA]

Help.

2001 986-S 50K miles (does NOT list the M222 - traction control)

I was stoplight racing some bling-covered pickup, just because the mood struck us both. First time I had really hammered the car. Hard off the line in 1st - red line - 2nd, quickly flooring it... I felt a bad mojo shudder/vibration that kept up for a few seconds. very reminiscent of ABS shudder (but I was definitely not braking). It was time to back off anyhow, so I did and it drove fine. I'm nervous to try and repeat. A little more info... the car may have drifted a bit, but not sure if I just veered a little on the steering.

I could use some advice. I'm a bit fearful of dropping the transmission or something equally disastrous until I know what this is, but want to drive it hard when I feel like it.

Check both your engine (particularly the front) mounts and your trans mounts; one or more may be torn..............

[Highlander]

Sounds like you experienced "axle tramp". When the rear tires break loose, rather than just leaving black streaks on the pavement, the suspension geometry causes the wheels to kinda bounce up and down *very* violently. This is affectionately know as "axle tramp" even though it's the wheels actually bouncing up and down.

Nothing to worry about - except maybe your launch technique :D

[HeRoze]

Check both your engine (particularly the front) mounts and your trans mounts; one or more may be torn..........

Good idea... from what I've read it can be a hereditary issue anyhow.

Sounds like you experienced "axle tramp". When the rear tires break loose, rather than just leaving black streaks on the pavement, the suspension geometry causes the wheels to kinda bounce up and down *very* violently. This is affectionately know as "axle tramp" even though it's the wheels actually bouncing up and down.

Nothing to worry about - except maybe your launch technique :D

Sounds like a possibility... does the 986 S have enough guts to pull that off slamming 2nd gear on a redline shift? It did feel like things were breaking loose back there. it sounds like a strong possibility. I'm hopeful that is what it was (it certainly makes sense in retrospect) the descriptions I read make it sound like it happens at launch, not at 35+MPH...

Launch technique? comes from a Magnum R/T Auto (floor it) and Honda VTECs (always shift at red-line).

Edited January 25, 2014 by HeRoze

[san rensho]

Boxsters are not drag racers. They skip and shudder when you launch hard. Stop abusing your clutch.

[HeRoze]

Boxsters are not drag racers. They skip and shudder when you launch hard. Stop abusing your clutch.

Ohhhhkay. the input regarding the cause is appreciated... The rest? Meh.

[secretagent214]

You described it as sounding like the ABS system in action. Since the ABS system makes a very rapid, almost buzzing vibration, the first thing that comes to mind is a torn engine mount (as JFP said). The second is a problem with the flywheel. The Boxster uses a dual mass flywheel which helps to absorb engine vibration. If that dual mass flywheel is going bad, you might notice unusual vibrations.

[Highlander]

Check both your engine (particularly the front) mounts and your trans mounts; one or more may be torn..........

Good idea... from what I've read it can be a hereditary issue anyhow.

Sounds like you experienced "axle tramp". When the rear tires break loose, rather than just leaving black streaks on the pavement, the suspension geometry causes the wheels to kinda bounce up and down *very* violently. This is affectionately know as "axle tramp" even though it's the wheels actually bouncing up and down.

Nothing to worry about - except maybe your launch technique :D

Sounds like a possibility... does the 986 S have enough guts to pull that off slamming 2nd gear on a redline shift? It did feel like things were breaking loose back there. it sounds like a strong possibility. I'm hopeful that is what it was (it certainly makes sense in retrospect) the descriptions I read make it sound like it happens at launch, not at 35+MPH...

Launch technique? comes from a Magnum R/T Auto (floor it) and Honda VTECs (always shift at red-line).

"does the 986 S have enough guts to pull that off slamming 2nd gear on a redline shift?"

Yes it does, even on sticky Hoosier A6's - been there done that!

I was just pulling your leg with the launch technique jibe :thumbup:

Is the car driving OK? Any residual problems?

[HeRoze]

Hey, it drives fine. no issues at all. i haven't looked at the engine mounts... i'm redoing a kitchen afternoons and weekends, so time is limited. I will though.