PLease help me . 
I´m doing a project were i just have km/h and Rpm/s . But I don´t have knowledge to do it .
I just have a Peugot 106 tachmeter but i don´t know what more I need to make it work.
You use a REV Burner i think so and a arduino ring? That all i need?
has you can see i´m little poor on this .
(Sorry for my rwriting , any douth please say it) 
Basically what you have to do is to connect the +, - and S1 terminals of the rev burner to the dashboard.
Terminal + and - are 12V and ground. the S1 terminal sends the signal for the rev counter.
The hard part is to find where on the dashboard you have to connect the wires. Unless somebody has already worked with the same dashboard and has shared the information, you will have to investigate yourself where the 12V and rev counter signal have to be connected on the dashboard.
I found very useful to download the PDF with the maintenance manual of the car. often there is information on the wiring of the dashboard and connector description.
It's quite a bit of work, I know.Another option you have is to use a standalone aftermarket rev counter. that's very easy to connect because it has only 3 wires and comes with instructions