View single post by Judson Manning
 Posted: 07-16-2006 08:29 pm
PM Quote Reply Full Topic
Judson Manning

Joined: 03-14-2005
Location: Atlanta, Georgia USA
Posts: 406
You can actually get down to 28mm chokes in a DHLA45 and up to 36mm in a DHLA40.

Choke size determines maximum amount of flow (assuming the head is breathing to its maximum capability).  For a 2.0L engine you need the following choke sizes to produce maximum flow at the designated RPM:

5000rpm = 32mm

6000rpm = 35mm

7000rpm = 41mm

8000rpm = 46mm

SCCA E-prod rules mandate the 34mm chokes, and I can confirm even with a ported head, free-flow exhaust and high-lift cams, the 907 doesn't produce any power over 5500rpm.

Stock JH chokes are 35mm and 37mm for the 2.2 variant.  For street use, I was happy with 34mm in the 2.0 and currently like the 36mm in my 2.2.  Top end suffers a little, but low-end throttle response is fantastic.