Well considering we have no camber, taking speed at any corner isn't going to help. Our cars are boats, relatively speaking.
Anyways, the best trick I've discovered is give the car up early in a turn. What I mean by that is, brake hard and early....earlier than what you think you need and set the car up for the corner. Give up some speed on the inlet, and gain it on the outlet. You should be getting on the gas at or before apex at every corner this way. You'll carry alot more speed into the next section.
Our car can't drive like a FRS, BRZ, S2000, Miata...you need to drive it like a Corvette.
With that being said, this might help explain my point. It is my latest autocross. Listen when I get on the throttle, how my turn inputs are...etc. I don't like to shuffle steer, some people will tell you to do it but IMO it is difficult to recover quickly from slides or when the tail starts to escape. You can see how quick I can recover from a small slide or oversteer when my hands are still at 9 and 3...about.
Lastly, and this is the hardest 2 things to do:
1. Always on the brake or gas. Do not coast no matter what
2. Make your steering input, and hold it. Use the gas to modulate through the turn. Don't see-saw the wheel...you'll end up chewing away time.
Hope this helps: