Why in the world would you drop the clutch at 4000 RPM's? No Flame here, BUT, these cars will fry Viper Tires from 2500RPM's like nothing in bone stock form.
It is "HOW" you do it, NOT "IF" you do it. You can smoke your tires to your hearts content as long as no matter what you do the clutch is engaged immediatley when you do it.
The only time to slip a clutch is at the drag strip due to our IRS. Even there you can do it in a manner that will be effective and NOT prematurely wear out your clutch, however, it always adds to the wear and tear. It just depends on how much you slip and from what RPM's you start.
I'm sure your clutch is fine, but you should bring that car over to my house for some tire shredding lessons and I'll take you for a ride in my car and then you can learn how it's done. 4000 RPM's is for the Drag Strip with Drag radials and a nice sticky track. My car will give you a sore neck after about 5 of those on any given day, but it is hard on a clutch, not deadly, just hard.
I swear it's all in how ya do it. I can't tell you how many times a babied car get's trashed by inexperienced users on the first time they finnaly decide to GO FOR IT! To bad you didn't have a couple of Mustangs before this one, ( I'm guessing here ). Then you would be well versed on how easy it is to spin tires.
Let me know if you want some lessons....I just happen to have some street tires that are worthless and need to be FRIED!