fuel pressure problem

[69ptcamaro]

I've been chasing a bad hesitation in my car for 6 months. It only happens under a hard load, i.e. slicks on launch or WOT at a high mph on street tires. I don't get to work on the car much due to being away at school, so I haven't had much of a chance to fix the problem.



My setup is a 509 with a AZSM TPI setup. I would estimate the motor to make 600-650 hp. I have a Rick's tank with the Walbro 255lph intank pump. The calculations I did showed that it would support my engine; it is not however. Today we put a fuel pressure guage on the car while driving it. It drops down to under 30 under a hard load and even drops down to 32-35 under a mild load. The pressure also seems to bounce a lot (5-7 psi). I didn't know if this was due to vibration or what. I am using the regulator that came with the AZSM setup. I have it mounted on the outside of the subframe about 5 feet from the fuel rail.

Do I for sure need to go with an aeromotive or something similar? I have about $1500 in the Rick's setup, so I would really like for it to work. Is there anything else that could cause the pressure drop other than the pump being too small?

Thanks for any help. I have a build thread of the car in the projects section for anyone that is interested.