here is my set-up

b16a1
noredline B1 camshafts (a tiny bit more agressive than CTR)
crome

I have done a lot of research which confused me even more, here is what I have come up with so far.

50 mm ITBs are more for people who want to drag race since it offers more top end power
low-mid 40 mm diameter are for people who want more mid range power (good for road race, which is what I want to do) and god knows a b16 needs mid range.

Now on the other hand I have been told and I have read that 42 mm itbs will choke engines that rev higher than 7800 rpms but my cams can make power up to about 8800 rpms. I know the diameter also depends on the head design but it will stay stock.

so what is true about this and what isn`t, and for my setup, will 42mm itbs make power up to about 8500 rpms or will it choke before that. Would I be better off with hayabusa 46 mm itbs?

Keep in mind I dont want to drag race, this car is a daily driver and a week-end road racer.

thanks all for your help and sorry for another itb questions thread.

 

i dont have much experience in the smaller home made itb's but id say the 42's would choke off earlier than the 46's. but it might make a buttload more tq in the mid range also. and since your road racing you dont need to spin the motor the extra rpms. if you have the means get both and just test them. thats the only way you'lll truely know what has a better curve on your motor.

 

https://honda-tech.com/zerothread?id=1419258

i wouldnt go with anything smaller...hayabusa itbs

 

what road race series do you plan to run in with itb's?

 

I plan on just going to lapping club events, roadraceteam.com events. Here in montreal theres the track lapping club where there is a 2 hour lapping session every monday evening

thanks for the replies, I guess for now i`ll stay with the 42s and if I start building my engine for higher comp and higher rev then I`ll go for a bigger diameter ITB setup