Sorry swim is a newbee, but he have utfse whit no results on this ratio. 1:2.1 E/I2. Please can somone tell?

You obviously cannot search on the ratio itself (as people aren't writing it in a standardized way), you need to search for the word "ratio" together with other keywords, such as "I2" and/or "RP". You have a lot to learn when it comes to using a search engine. Also read the relevant posts on this topic linked from

Post 408293

(Rhodium: "The Stimulants Forum FAQ", Stimulants) before asking any more questions.

https://www.thevespiary.org/rhodium/Rhodium/worlock/toc.html

Although not up to date with current trends this still remains  one of the better all around references ever made on the subject. The ratio info given there is still completely valid and it should appropriately be considered a benchmark guide when ratios are concerned.

https://www.thevespiary.org/rhodium/Rhodium/worlock/rxn1.html#rati

Both the site as a whole and the ratio info within have provided advice that has worked 100% of the time for swim's buddy and many others. keeping in mind of course that not all of this info is always  applicable to many of the huge problems that plague today's newbee chem/stim students.

What's really meant by stating that is for newbees to make sure to still read liberally from all of the stuff on that FAQ reference page that Rhodium gave. That FAQ page is in fact the best reference available to get all the new and current info.

Worlocks is actually more of a History page now. But still an excellent general reference. In sorta the same sense as  owning a vintage era edition of Vogels might be.