ported throttle body
Trending Topics
This is from a rep at TPIS when asked about their 75mm TB's:
- the 75mm throttle body flows 910 cfm
- the IAC port on the intake remains intact and functions like stock
- the two tubes on the passenger's side (fresh air and EVAP) are deleted
- there is enough "meat" to bore it to 78mm and get 1,050 cfm
140 cfm to be gained from from a 3mm bore. I know the LS1 TB's are risky to take to 78mm, so staying safe would still get you close to 100cfm. Granted the stock TB is not designed like a TPIS TB.. but if you know what you are doing and as someone who was good at these said, "enlarge the "venturi" right before the throttle plate, and the rest of the bellmouth is reshaped/filled." then yeah, you should pull close to 100cfm more.
The Best V8 Stories One Small Block at Time
I tested the VERY first unit I ever ported several years back and it gained between 6-7rwhp and 5-6rwtq along with improved throttle response.
This is from a rep at TPIS when asked about their 75mm TB's:
- the 75mm throttle body flows 910 cfm
- the IAC port on the intake remains intact and functions like stock
- the two tubes on the passenger's side (fresh air and EVAP) are deleted
- there is enough "meat" to bore it to 78mm and get 1,050 cfm
140 cfm to be gained from from a 3mm bore. I know the LS1 TB's are risky to take to 78mm, so staying safe would still get you close to 100cfm. Granted the stock TB is not designed like a TPIS TB.. but if you know what you are doing and as someone who was good at these said, "enlarge the "venturi" right before the throttle plate, and the rest of the bellmouth is reshaped/filled." then yeah, you should pull close to 100cfm more.
IF you bore out the throttle body by 3mm and use the same 78mm butterfly, you'll have more problems than you want... low vacuum, ****-poor idle (unless you like to idle above 3500 rpm)...
You have fun w/that










