Heavy Cotton T-Shirt
This is really not what the time machine was created for. Doc Brown would be so disappointed that you to would use it just for personal gain and pleasure. Who care though? You don't! And you only want chick to gun it to 88 and flux your capacitor. That is all you need to send her back in time. Show her that you have the 1.21 gigawatts needed to send her back in time with this T-shirt; just as long as she fluxes your capacitor then you will be at 88 in no time. Just make sure you wear this T-shirt and all will be fine not matter where you go.