Hello, me again

Last weekend we had the last race on our club, my car was not good at all, I tried many settings on the speedo but they didn't seem to work well.
I was using a SP MMM 10.5T brand new but the top speed was similar to a 17.5T.
The case is that on monday, I pluged the PRO LCD (I am using my existing SP one) on the car and them pluged on the PC and turned it on, so them I discovered how to change properly the program and saw that the whole weekend I was using a MOD software on it.
Change to 119 software and today went to the track again, the plans was to spend the whole day trying new speedo and car setup for the next year, but the car behaved like a 17.5T, I am really disapointed and don't know what to do really.
Any clues?