What is the diameter of the H23A1 throttle body and ensuing intake?

I have heard different accounts on the compression ratio. I have always assumed it is 9.3:1. But lately, I've seen places that list it as 9.8:1. Which is correct?

My old F22A6 Accord had dual stage intake runners which opened at around 3500-4000 rpm. At about what RPM do the secondary intake runners open on the H23A1?

 

Dont know the exact mesurment, but the H22 and the H23 have the exact same throttle body, and connecting intake chamber.

 

H23 CR is 9.8:1

TB is same as h22a...62mm stock I believe

 

the compression for usdm is 9.8:1 for si's, i believe. i'm thinking the throttle body is in the 60's somewhere, like 64-68 somethinglike that i think, and the secondary intake runners open up at 4500rpms

 

That would make it 2.440945 Inches. Sounds a bit on the small side to.

 

So I guess my question is what diameter would my intake piping need to be?