Hmmm, you should watch what you are talking about. As for his suggestion of putting a proper non turbo motor in there is the smartest decision you will ever make.
As for why your car is running shit? Its because the turbo is missing doofus. And want to know another thing? Your non turbo'd car is still illegal for you to drive on your p's because it was registered as a turbo.
So instead of spitting in people's faces like a spoilt brat, just take what he says and reply in a manner as follows, no thank you, I would rather try something else