My 440's were at 85% duty cycle with 325whp. This goes back to tuning and other variables. I maxed out my 1,000's with about 550whp. I have been told people get over 600whp on them but that was not the case with my car. Considering i have a huge aeromotive fuel pump with all new larger hard lines running to a fuel cell i dont think it was a lack of fuel volume or pressure. I told him to get 550's for his set up of 300whp.