My friend told me that change a bigger size throttle body diameter can increase the power in Honda Vtec. Can our Z also do the same, any company selling a bigger throttle body?

 

Crawford was working on it, but I don't think they came up with anything retail-able.

IMO if you widen the throttle body, the MAF sensor will be a bottleneck. And if you widen the MAF sensor body, it will be a serious b1tch to tune.

 

I read a Japanese magazine, a tuning company change the throttle body to 90mm ( I don't remember correctly size) that why I am seraching does any after market parts can be use

 

It's not that bad.
The sensor in/out function for the SAFCII works wonders.

 

No, of course not THAT bad, but beyond the capability of some people.

I believe Audible Mayhem has done this. You could try PMming him.

 

Ya, I saw the thread and am awaiting said dyno results.

Currently I'm using a Land Rover MAF housing on mine. Our MAFS are different though.

If you get bored, http://forums.maxima.org/showthread.php?t=517758