I've noticed some shuddering lately on the highway. When I floor it, the car shakes a little the rpms hit a flat spot then goes up. Is this clutch slip or a turbo problem? Are there any more tests I should do?
That sounds like clutch slip. What happens is that when you floor it, there's a little boost spike and a small spike in torque. This overcomes the clamping force of the clutch and it slips a little, but then it clamps again.
To test again, try 4th and 5th gear, flooring it to try to make a boost spike. Don't do this too much or else it will glaze the clutch. Try to gently roll onto the gas pedal to prevent this spike and it should help a lot. What mods do you have? The more mods, the more likely clutch slip.
You can drive on it for a while. Try to roll onto the throttle pedal instead of mashing it, that will help reduce the tendency for it to slip. Don't force power at low rpms, try to get the revs up a little and that will help too.
Of course, the more it slips, the more it have it's life shortened.
Try the stock Vr6 clutch, it will hold more than enough torque unless you are heavily modified. Since the stock vr6 clutch is a direct bolt on, you can also look at anyone who sells aftermarket vr6 clutches. Make sure you get a street disk, avoid the star shaped puck clutches for a street car.
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