Does this makes sense - is it gramatically correct?

Yazmam daha iyi konuşmamdan.

You wanted to say "my writing is better than speaking" , I can understand that but it´ s not corect how you wrote it.

Thankyou for telling me, yes that´s what I wanted to say. Why is it wrong? 

It´s not wrong...

yeahhhh!

In Turkish, we often place the predicate (verb) in the end of the sentence.

For example, you can say;

Brütüs Sezar´ı öldürdü (Brutus killed Caesar) 

(This is the answer for "who did Brutus kill?")

you can also say;

Sezar´ı Brütüs öldürdü

(This is the answer for " who did kill Caesar?")

The first sentence is the formal one (subj + obj + verb) but when you anwer the question "who did kill Caesar?"  the object should come before the subject (obj+ subj + verb)  

Also saying "Brütüs öldürdü Sezar´ı" or "Öldürdü Sezar´ı Brütüs" or "Öldürdü Brütüs Sezar´ı" is possible?

Yes..

You don´t always have to use the predicate in the end of the sentence. (especially when the sentence is not an answer for a question)

This type of sentence is called "devrik cümle" (inverted sentence) in Turkish and often used in poetry.

Now coming to your sentence, it doesn´t follow the formal word order but still correct.

Thanks, I understand, this would be normal order:

Yazmam konuşmamdan daha iyi .