The bike frame is far down the list of things you should be addressing to gain speed.
A few items that will help:
- Optimize your position on your existing bike. Get as low as possible.
- Get decent tires and tubes.
- Use tight fitting clothes. Nothing flapping in the wind
Each of the above items can be worth 10-20W. Once you've addressed the above work on staying out of the wind when riding in group. Plenty of free speed when drafting others.