i did this but not on a 4efte i did this way back late 90s on my r5gtt and used 2 stock turbos and its well worth it for sure it depends how u do your pipe work i used 1 turbo for 2 cylinders if your going to just plump them back to back then i cant see it make much difference u will only get more heat from 1 turbo entering the other and get loads of isseus