Will an L be effected much by temperature. Saturday the temp was around 20, but in the summer the temp will easily be in the 100's. Will there be a noticable difference. Would a air intake help any with the temp difference.

 

To answer your question as directly as I can. . .

YES.

Forced induction vehicles (especially turbo-charged) suffer from what I call 'heat sag'.
(they feel kinda slower when the temp is warmer)

Nitrous Oxide Systems, Inc. claims that 1 degree of temp is worth 1 hp I believe. I believe that figure becomes exaggerated with forced induction.
Normally aspirated cars feel the same effect, but to a much less noticeable degree. Only nitrous cars are immune, due to the nature of their power adder.

When it's cold out, and you are at a low altitude, Forced Induction (in any form) is just plain wicked. We also have the advantage in high altitudes over Normally Aspirated cars. When it's hot out. . .then nitrous has the upper hand, I believe.

There are always exceptions to this, though. But this is just what I have noticed.