I was coming off an on ramp onto a stretch of road before a highway. No one behind me so I was starting in 2nd and shift at around 4k to forth at probably 3/4throttle and when I get into 4th and get past 4k, my slip light comes on (TCS on) and the Z jerks till I let go the throttle. What happend because I'm stunned?
Clear day, dry road...

 

Were you still in a turn when it happened? What size tires do you have? Are the fronts and rears the same type and age? Have you replace fronts OR rears lately?

 

Yup, fronts or rears need to be replaced. The diameter offset between the fronts and rears being worn has started to trigger the SLIP light. That is exactly how my SLIP light started coming on, exiting a freeway via a sweeping ramp. In my case, I replaced the rears and the issue went away until the front were too worn then the SLIP light came back on about a 1000 miles later.

A new set of tires will fix this issue.

 

I have 235/18/40F on 8.5 rim and 285/18/40R on 9.5 rim.

Can't be the tires, they are only 3 months old.

And no, I was on a straightaway.

 

i don't think those tires are a good combo. the rears are too tall. you probably need to go 255 in the front to go with the 285 rear.

or go 275 in the rear to go with the 235 front. even that size is cutting it close.

use a tire calculator. the difference should be close to the differences of the stock set-up.

 

While the front to rear stagger is rather large (1.6" vs 0.7" stock) I can't say I've ever heard anybody have problems with too large of a stagger, it usually shows up when the stagger is too small or negative.

Unless you hit a bump in the road and that caused the rear to break traction, I'd just attribute it to a one-time glitch in the system.

 

285/35 would have been your ideal size when comparing your fronts. As Dave said, probably a glitch or a loss of traction somewhere that you didn't notice. Those size tires should work well together. If the problems persist or becomes more frequent, then start to worry.

 

The tires are good, size wise they are.
From the eye, the sizes look different, as if the fronts were 35 and the rears were 40 or 45. It's because of the tire.
The rears actually read, "285/40ZR18" and the fronts read, "235/40/18F"

I think that "Z" makes them a bit taller.

You can see in this picture how the rears look taller;


I don't remember anything being in the road, or I would of avoided it.
Must of been that damn glitch.

"So we just went ahead and fixed the glitch."
"Great."
"So, uh, Milton has been let go?"
"Well, just a second there, professor. We, uh, we fixed the *glitch*. So he won't be receiving a paycheck anymore, so it'll just work itself out naturally."

Had to throw in that office space quote lol.

 

I have this problem with my Z all the time. I have 265/30/19 in the front and 275/30/19 in the rear. I think it started when I put this setup on. I calculated it is pretty similar to stock. They are trying to figure it out at the dealer now.

 

It's similar to stock in that the front is shorter than the rear, but not even close in the actual stagger. The stock stagger is about 0.7", yours is only 0.2". The "recommended" stagger is between 0.25 and 0.75". Your car is apparently oversensitive to the small difference and causes VDC/TCS to kick in. With 275 rears, you would have had to use 245 fronts.