stock '91 15 inch 6.5Jx15 ET55, the et35 rims have the inside rim 1mm different from the stock plane, so ALL the extra width is outboard so the outside rim 'face' will be 1.5 inches further out from what you have at the moment
the ET47 rims move the hub mounting face 14 mm further outboard on the wheel, so the rims both move inward 14mm, so the outer rim edge is just under an inch further out than stock...
8x17 et 35 will stick out 1.5 inches from what you already have,
8x17 et 47 will stick out about an inch further than stock
https://www.wheel-size.com/size/honda/nsx/1991/