problem in the development of the car

I have in each component 17 designers working in the evolution of the car, 100% for next season. However the development takes about 1 month to enlarge a small percentage for next season.  why this happens?

How is your car for this season?

The better your ca is this season, the slower dev for next.

So for example if you cars this season is 1% you should see close to 20% per dev day if you only develope next season.
Where if your car for this season is 40/50/60% it will drop right down to 7%.
A 90% car this season would only see very low 2% dev for next.

Don't devide the designers equally if that causes producing of parts to take a long time. As you can have a new part every two days, increase the amount of designers on a couple of parts so that they will be ready within that time. Once those are done, move the designers to the other parts etc.

My car has on average 90, that's why I can't evolve my car, so I'm taking the hint of our friend. two components for day. thans a lot.

Cause your car is on 90% it'll take longer to get more dev. It's just a way of making the game a bit fairer