when a new ku31 calls it quits

mx5002 · Postby **mx5002** » Thu Feb 06, 2014 8:34 pm

the tyre was around 1500kms old

1st fast lap in my second session in between turns three and four the car basically went sideways and kinda torque steered off the track.

we thought i may have broken an axle or something in my cusco lsd.

i drove the car home along the freeway with no real issue except for when i would accelerate or change gear the car would pull hard to the right

got home to pull it all apart.
Checked the diff oil.... fine
Checked the axles.... fine

started to pull the exhaust down after inspecting all the subframe so i could remove the diff to open it up when i noticed the rear left tyre looking a bit "overinflated"
all the pressures were set at 34psi when i got to wakefield.

i put it next to the other rear tyre

it seems as though the belts have broken through or something causing the sidewalls to lose they're strength
going to talk with the tyre shop tomorrow

davekmoore · Postby **davekmoore** » Thu Feb 06, 2014 9:50 pm

Is this called delamination?

For sure it's an opportunity for the retailer to separate themselves from others by simply swapping it for a new one.

Apu · Postby **Apu** » Thu Feb 06, 2014 10:47 pm

Mmmm...the KU31 wasn't meant to be a track tyre, so that does technically void whatever warranty that may exist

hks_kansei · Postby **hks_kansei** » Thu Feb 06, 2014 11:18 pm

davekmoore wrote:Is this called delamination?.

Delaminating is usually a bit more dramatic.

It's odd to see the tyre have suddenly increase diamter though, I have seen sidewalls fail and distort, but I've only ever seen it in small sections and show up as a tumor like below:

Never, ever seen what has happened to you though, never even heard of it happening!

davekmoore · Postby **davekmoore** » Thu Feb 06, 2014 11:43 pm

Gotcha. But how else can a tyre increase in diameter so much without a heap of internal delamination in one or more layers?

deviant · Postby **deviant** » Fri Feb 07, 2014 1:17 am

Apu wrote:Mmmm...the KU31 wasn't meant to be a track tyre, so that does technically void whatever warranty that may exist

I doubt they would warranty replace a tyre that has been on track.

It is certainly an odd failure, it would be interesting to cut it open.

Is this likely to have hurt the diff having tyres of radically different sizes?

mx5002 · Postby **mx5002** » Fri Feb 07, 2014 6:09 am

Apu, my car is far from a track car.. It was my first time and wasnt going out to break any records. That said it would have been the 9th lap and 8 of those were in the previous session.

As for my diff, the clutch plates in it wouldn't have appreciated it on the drive home. However my Centre is not a cone lsd. It's like a locker when a certain amount of torque is applied so it should have been open/disengaged on the highway...
Time will tell I guess

mx5002 · Postby **mx5002** » Fri Feb 07, 2014 6:13 am

But yes I understand they aren't race tyres...
Half the field had road tyres on aswell

I think it may be the sidewall or radials that have failed causing the tyre to lose its structure

Magpie · Postby **Magpie** » Fri Feb 07, 2014 6:31 am

Don't mention track use, call it spirited driving through the hills. Also it looks like the first signs of the tyre about to shred itself. You are somewhat lucky that it held together.

hks_kansei · Postby **hks_kansei** » Fri Feb 07, 2014 7:24 am

Magpie wrote:Don't mention track use, call it spirited driving through the hills. Also it looks like the first signs of the tyre about to shred itself. You are somewhat lucky that it held together.

I wouldn't even bother with "spirited driving"

Just don't volunteer the information, just mention that you cornered fairly hard a few times if they ask.

A lot of people would just associate the term "spirited driving" with going too hard on the road, skids, drifting, and all that.

mx5002 · Postby **mx5002** » Fri Feb 07, 2014 9:30 am

Yeah I will call them later today.

I won't be using the words "track" or "spirited driving" lol

More so spewing that my gv lip was destroyed when I ran off track

Regie · Postby **Regie** » Fri Feb 07, 2014 11:47 am

mx5002 wrote:Yeah I will call them later today.

I won't be using the words "track" or "spirited driving" lol

More so spewing that my gv lip was destroyed when I ran off track

welcome to the Broken GV club. there are more and more members joining by the week

mx5002 · Postby **mx5002** » Fri Feb 07, 2014 11:57 am

Yeah it survived my father in law ripping it off in his driveway but wasn't so lucky this time round.. Might have to see about a group buy lol

manga_blue · Postby **manga_blue** » Fri Feb 07, 2014 12:01 pm

There's a series of cords that run around the circumference of a Tyre to stop it from doing that. It looks like all yours failed. Probably thousands of drivers have punished KU31s without that happening. I reckon it's a manufacturing fault.