Stock turbo and the highest boxed settings you can peg egts pretty quickly. At least way back in the s-06 with tnt-r days I was able to peg egts pretty quickly with stock turbo and injectors. I wouldn’t go more than 50hp injectors and be mindful of your egts. Anything more than then it probably won’t be as enjoyable after awhile as hard run bursts you wanna do will be shorter before exceeding the stock turbos efficiency to provide the air needed and keep things cool. After a year of really hard playing with the s-06 tnt-r on the highest settings the stock turbo gave out and an engine rebuild was in order.