EVAP vacuum source

Got a slight dilemma -

A lot of people delete the EVAP system on race cars but on my rally car I would like to have it functioning.

On a stock setup there are two vacuum lines going to the throttle body. I am running a 960 throttle body on a modified b21f intake and there are no ports to connect the vacuum lines from the canister on the throttle body. I know on a stock throttle body, when you remove the fittings for the evap lines, the hole where it is actually drawing air from the manifold is tiny.

I was thinking of hooking the lines up to the intake pipe pre turbo to be the vacuum source for the evap system. I know some modern cars do this.

Any better ideas?

Usually the EVAP valve activating signal is whats called "ported" vacuum- that's the tiny hole that has vacuum depending on the throttle plate position. Plus there may be an electrical or temperature valve to have better control of when the canister is commanded to purge.
The larger purge line may be connected into manifold vacuum or just any intake air stream. When connected to manifold the purge should be distributed evenly between all cylinders so the closer to throttle body the better.
Since you don't have the throttle port you can try using engine vacuum to activate purge- just get that from past the vacuum check valve - same as climate control vacuum source so you will not feed boost into the purge valve.

My 1989 740 GLE 16v had a a purge solenoid. I was surprised to see that. Maybe run a computer that can activate a purge...