Will a B18 throttle body fit a D16Y8? If so, is the bore any bigger? Would the HP be worth the switch?

 

the TB goes right on. it is 4mm biger. any B series TB except for a type R is 4mm bigger and goes right on. you want to get the LS, b20, or b16 TB gasket though for whichever one you get. you will also want to port match the TB to the IM. the car would be a little more responsive, might gain one or two HP.

 

yes it is worth it. i actually have a 98 h22 throttle body on my d16.
the stock one is 56mm, b18,b16,b20 is a 60mm, h22 is a 62mm. the h23 actually has an 62mm throttle body as well

i did port match my intake to the size of the throttle body. the engine was definately more responsive. seems to work very well on my tiny little engine!

 

hmmm, i thought the stock D16Y8 was 62mm

 

no, stock d16y8 TB is 60mm. i measured one the other day. i need to measure my b20 one and see how large it is, as well as my d16z6 Tb...to see if there is really any diff......