How much hp is recommend

[totalkey]

Hello, I start to work with file provider and most of his files for stage 1 is 25% -27% more power, I'm a little bit worried it's too much.
Somebody can say here it's safe to add more than 20% power for stage 1 without changing any mechanical parts?
Thanks

[Act Tuning]

First how do you know your provider is add 25%-27%, do you check then on dyno?? and you see this gain, or he telling you ? and for your question it realy depent on the car you work on and the hardware, there vehicle that you can add 18hp, and some you can 80%, like Pcr2.1 75hp can goes safe to 140ho, all serais go to 140hp 75,90,105. and surely you cant add 25-27% and tell for every car. so some 10% and some 80% all depent on the hardware and the car.