MHDesigns

I hate to ask this question again. I'm running:
B18A with b16A head.
ITR pistons 11.6:1 compression ratio.
Knockoff header and exhaust
Blox IM
Warlboro 255

I'm looking to go for a bigger TB because I think my high compression will benefit a little from a larger TB than 60mm. I know it won't be much so if you don't like the idea at all get out of my thread. I only want advise from people with aftermarket TB's and similar setups/experience.

My question is "is a 68 too big"
I know it would be too big on other motors but will it still lag due to my high compression? The reason I ask is the 68 I'm looking at is cheaper than the 65 I was looking at because there's no tps. and I don't need new tps.

So I guess what I'm asking is will I get a better throttle response out of a 68 than a 65 on my motor, or will a 65 be as big as I should go. Thanks for any help.

*EDIT*I know I will have to port match either way. The blox IM is 64mm inlet I think.

Ruben19

are you running aftermarket cams

MHDesigns

head is stock so no

Ruben19

65 or bore your stock throttle body to 64mm
that's what i did with mine.
and yea blox im are 64mm inlet

MHDesigns

actually I would rather hold on to the stock one to put in the "bone stock parts" pile if I can find a cheap enough aftermarket unit. I will look into it though. So you think 68 is too big... any others with experience? all input would be greatly appreciated.

Ruben19

if you had bigger cams i'll run 68

MHDesigns

well I plan to build the head(cam suggestions?) when its not so hot out here(113 outside 124 in my garage....ugh) Maybe I'll run a 68 for now till I build the head up. I guess if it kills low end too much I can just put it aside till september or so.... Ill think about it.
Anyone else?

MHDesigns

bump for anyone who can shed light

ddd4114

How does compression affect airflow through the throttle body?