I have had my car on the road for a couple of years, but finally have gotten tired of the various oil leaks on the donor cars (2002 wrx) high mileage engine. I am putting in a new 2.5L hybrid set up and am debating which turbo to go with. The standard answer I get from local Subaru tuners is a 20g, but it seems a bit large for what I want. Possibly am learning towards an 18g, but this is based off reading about WRX's. I want to keep the 5 speed, so will not be running over 300hp(at the very most) . This is mostly street use and while anything over stock is probably over kill, it seems like a good time to upgrade.
What are others running and at what point does the hp simply become too much for these light weight cars?