Does "был крутой" means the same as "был крутым"?

Question

I'm reading Незнайка в солнечном городе and just encountered something I cannot properly make sense of:

Подъем был такой крутой, что ...

Obviously, подъем (= climb, rise, ascent, etc.) is a male noun, but why is the adjective not in instrumental case? At least I learned that it should be instrumental with был and будет in such a sentence.

I tested it with Google translate. I know it's not reliable for translation, but it usually offers interesting alternatives. Google translate gives me:

подъем был такой крутой = climb was so steep

and in the version, I though was the proper one with instrumental case:

подъем был таким крутым = rise was so cool

Now I have two questions:

1. Why is the adjective not in instrumental? Or in other words, which grammatical construct is it that I didn't learn about?

2. Is Google translate right, does the adjective really mean something different if I put it in instrumental case? Why is that?

I would be happy if someone could enlighten me.

Answer 1

These two versions actually mean the same thing (without differences in emphasis or anything else). Google Translate is often not a suitable source to rely on because it translates phrases and sentences by patterns.

Nominative instead of instrumental case here is kind of colloquial transformation.

Answer 2

The major difference is about 'durative predicate' vs 'temporal predicate'. This difference in predicates is not so obvious in English, although it can be rendered by its means as well, cf:

подъем был такой крутой = climb was so steep

подъем был таким крутым = climb had been/used to be so steep

Answer 3

This might be obscure, but the fact is that in Russian 'такой' is sort of special word. It has extra meaning, I would translate as "soooo". And 'таким' has no such association. Saying 'такой крутой' is like 'soooo steep', and 'таким крутым' just 'so steep', or maybe just 'steep'. Because the listener ear could just omit 'таким' as a service word, which is not possible for 'такой' which is a very-very special word, as said.

Ok this might need some proof. Consider this:

такой-сякой! 
ты кто такой? 
да, - я такой! 
какой-такой (павлин-мавлин)? 
ух ты какой!

Those idioms are complete sentences, are quite powerful, and can be only explained and understood if you comprehend the strange special meaning of the word 'такой'.