So my 91 turbo drops a little voltage when rpms increase, in idle it shows 13v-13.3v and when I floor it or increase rpms it drops to about 12.9-12.5v is this normal? New battery 2 different alternators and still the same thing... Battery is in the drivers storage bin... Any ideas?

 

When you relocated the battery to the storage bin, did you upgrade battery cable sizing? Have you checked/cleaned/replaced your grounds?

 

What is your belt situation? If accessories such as power steering, air pump, and AC are removed it's not uncommon to have belt slippage (though normally with the water pump).

Do you run a dual sheave pulley and Banzai Racing alternator tensioner? Is it possible you're over/under tensioning the belt and causing slippage?

 

I agree with DC5Daniel. Check your belts. Had a similar situation with my stock belt setup. I recently replaced all my belts and now car is charging as expected. May not be your problem but it's a good place to start the trouble shooting process