can i put a b20z throttle body on a d16?

 

yes you can there alost all 60mm except type R and some very old models are 59 i beleive i have a b18b 60mm

 

so would it make any difference to but a b series tb on?

 

Not unless you also machine out the material between the throttlebody and the intake. If you look inside the intake manifold when you have the bigger throttlebody attached you will see that there is a significant amount of material "sticking out" around the sides of the throttlebody inlet. So, if you pay to have the machining done it can make some difference.
But just putting a bigger throttlebody on without correcting the flow of the intake will make little to no difference.

I learned this the hard way. I bought a Skunk2 throttlebody thinking it would let more air in to my intake manifold. Turned out that I had to spend another $150 to have a machine shop shape the old manifold to allow the air to flow freely from the throttlebody through the intake and in to the engine.

 

ok, thanks

 

Or spend the $150 on a nice Die Grinder/bits and do it yourself.

 

definately true and it'll get you some good porting experience. Maybe even step it up to do your own cylinder head. I've also head your whp gains aren't gonna be much unless you are forced induction. Maybe someone can clarify this.

 

yes you can but as they said your not really going to see any gain inless you bore the manifold

 

this is true i did it myself for free with a porting bit i had, on a stock engine this mod probaly wouldn't serve much purpose, with mods or boost you will see results 4mm still helps