Oh, really? My bad, I thought it did up hp IRL. It's been in the game since day one and it doesn't bother me. Have you player one make races or am I not recalling correctly right now...? Every one make race that I've been part of, others than once...I didn't own the car and it was given to me for the race by default. I couldn't tune it, etc. It put everyone a level playing field. I don't think you can use your own car for one make races and I'm fairly certain there is a select, set list of cars to choose from.
The advantage when you put the same car side by side is negligable. If you win against someone with the same setup and an oil change, you were going to win anyways and the same goes for losing.
You can't adjust the power limiter or anything in one make races as far as I know. If you can use your own car, that is news to me and I am wrong. Either way, the game limits horsepower, not torque and torque contributes to your PP. It's still not free torque, so don't get too upset.
It's not a simulator, it's evolving into one and it is a single old school tradition left in the game.
To boot, if you could tune cars in one make races...anyone running an oil change would be racing with less horsepower to match the same PP (because of the extra torque), if the host thought for a second and figured setting a PP limit in that case was wise. But, that should not matter.