Hello,
I`ll try and be a bit more helpful!!
The pitlane speed limit can be changed to whatever you want by using GP3 Master by Sven Mitlehner - just search for it using any search engine eg Google etc
Then on the bar line at top click on the red car symbol (Miscellaneous) which brings up another screen
Click on the Miscellaneous tap on that and at the bottom is the Pitlane Speed Limit - just set it to any speed you want using the up/down arrows.
Hope this helps
Regards,Colin