Ive been searching and every where i get different answers im wonder since i cant get one of each and measure them myself what are the bore size for a B16b(ctr), b16a2(si), b18c(gsr) and the b18c5(itr)

 

http://www.maxbore.com/

they have a bit of info on sizes.

 

B16b(ctr) 62mm
b16a2(si) 60mm
b18c(gsr) 60mm
b18c5(itr) 62mm

For the money it costs to buy a larger TB, you can get an aftermarket one in 65, 68 and 70mm sizes for like $130

 

68mm Blox TBs are only $100 shipped in the marketplace. I have one and have no complaints.

 

having a oversized tb wont help much with having oem manifold, to make the most power from your intake you need to match the inlet on the mani and the tb

 

this is gospel. Many people (somehow) overlook this. Even aftermarket(S2, Blox, Edlebrock, etc) manifolds all need to be portmatched at the TB.

 

yup ^ to get the most you gotta keep going, no stoping for "thats good enough"

 

^^werd.
you could have the biggest throttle body ever. without being portmatched, its fkn useless lol. kinda like having a full exhaust setup with bigger piping and then at the end, it goes to like a 1 inch muffler hahaha.

 

im wondering if these sizes you say are where it connect to actual intake or the outlet where it connects to the intake manifold???

 

These sizes you guys post are they on the manifold side of the throttle body or on the intake side of it...
I was told from a guy selling me a Integra type R one that 64 is the intake side and
62mm is the side that mates to the manifold.. is this correct????

 

i have an ek9, b16b, stock type r TB and IM... can i upgrade from the stock 62mm TB to say a 65mm without having to change the IM? the type r IM's are suppose to be a bit bigger that the Gsr or Si IMs.

 

Yes the ITR/CTR are bigger than the regular b16/gsr but yet to get the most out of a bigger throttle body you would have to port match it with the IM, but i do suppose you could just bolt it up

 

some one answer my question plzz

 

its supposed to be the size right through. i checked my ctr TB and its the same size right through, doesnt get bigger or smaller at either end.

 

I just put a thread up in this. I was going to do a matching BBk TB/IM install but was told it will really do me jackshit.

 

IIRC that is because you are putting it on an otherwise stock D-series

 

Ah, indeed.

 

Will I have problems with my 70MM Throttle Bodys fitting my Skunk2 intake manifold without any mods or do i need to mod it so the intake manifold will be the same size as the throttle body?

Mando

 

You knew the answer to this question before you even asked. Port match.

 

yes they will fit. will it work well? no. you could have gathered that info IN this post.

as grumble said and like 5 others port match first.

 

Yo can you actually confirm if a 62mm throttle body will fit on a b16a 60mm intake manifold? And even if not noticable, would it make minimal difference? I have both on shelf and would wonder which to install on my b16a2 with b18c5 itr head & b16a intake manifold

 

Try posting your own thread mate!, this thread is older than Clint Eastwood

For the record putting a 62mm TB on a 60mm manifold will actually make you loose performance/HP. The 2mm step will cause issues if not port matched!