4age 20v Blacktop Velocity Stacks

Greetings Everyone,
In my Ae100 corolla, I've swapped in a 4age 20v B/T with 6fwd Gearbox (Came off an Ae111 Levin). I have presently the stock intake in the car. I had a set of Generic 75mm Velocity Stacks which I ran in the car for a short period. It sound amazing, however when I was competing at my local Autocross, the car gave me a very lazy take off in the lower RPMs. It was a Very hot day however, but I have the bonnet tilted a bit at the back to allow cool air in the engine bay. I dont like the Hood Scoops.
My question is....Has anyone who's running Velocity stacks notice any Whp Gains and come across a way to prevent the car from bogging on the lower RPMs with the Velocity stacks? And what sizes do you recommend?
Awaiting you guys feedback!