Hard to start
 

When engine warm hard to start when engine cold no problem to start

I had the same problem and finally was not able to start at all. Turns out it was gas pump relay.
The mechanic told me that this is very rare problem, but was not expensive to fix.
Maybe it is the same with you. Good luck.

You are not providing any information to help you here. What does the engine do, do you hear the start click, does it turn over, is it normal engine cranking or slow. No mechanic is going to be able to help unless you provide details about the issue. Hard to start doesn't provide any information to help you out.

I still recommend taking it to a mechanic and having them look at it.

When you try to start it, does the tach needle bounce at all? What sounds do you get?

hard to start
 

The engine turn very very slow but finaly start

Go to youtube and study up on "load testing" starting systems.
or google load testing starting systems.
All you need it a digital volt meter.
Then load test the starting system when hot.
you will then know where in the starting system the problem is.

It does sound like a starter problem.
But load testing will tell you if it is the starter or some other problem like:
The battery
Wiring
or wiring connections.

Known issue. Wiring gets heat soaked. Best course of action is to replace the battery to junction box and junction box to starter with higher grade cable & ends or get new cables from Porsche.

hard to start
 

Thank you all the information was well appreciated I will have the car check by a Mechanic and let you know what he found
My feeling is a bar wiring condition I encontered this problm in the past with another type of car ( Mustang high performance ) and I had to replace the wiring from the battery to the starter

A proper load test of the starting system will tell you if it is the:
Battery
The wiring
A wiring connection
A relay
Or the starter