Why do some cars have a clutch booster?

Question

The 3000gt vr4 has one for that reason they use very stiff pressure plates even the non turbo version could have used one but it doesnt.

Answer 1

The only ones Im aware of were on old Fords, like mid 60's to early 70's. They were on the heavy clutches that people complained were too stiff. They were made by Bendix. I think they got their power from the power steering pumps if I remember right. But anyways, they were to make depressing the clutch easier.