I will shortly be installing a FFIM on my car that is currently flanged for a Q45 throttle body. From what I have read online the Q45 TB is like an on/off switch due how much larger then stock it is 83mm vs 60mm. So I guess my question is what TB would be best for street use. Should I just buy the Q45 to stock TB flange and run stock, switch to the Q45 TB or find something in between such as a 65, 70, or 75? I have read up on the mustang TB and I know that they say to use 70 if staying N/A and 75 if boosting but that is on 4.6L engines. Also, I read Figgie's post about using an LS2 DBW set up but not sure if that is something I would even attempt. Lastly, what ports would I need on a new TB besides throttle cable and a TPS sensor? I like the look of this TB http://www.jegs.com/i/BBK+Performance+Products/129/1700/10002/-1 would there be any issues going this route? I know that the stock TB has vacuum ports and a provision for the PCV system. If I used a catch can and supplied vacuum to the hoses from those ports from a distribution block would that enable the system to operate as intended? Some info to help I am currently at BPU upgrade level and am trying to overbuild things now to handle 600 HP so I don't have to keep redoing the same stuff. Thanks for any and all help. Sorry if these are noobish questions. I just don't want to buy and install the Q45 if it will diminish the cars streetability.
What size throttle body
- Thread starter Jay C
- Start date
If your FFIM has a Q45 flange... Then use the Q45 TB. If you're using the stock intake manifold, use the stock TB.
NOOOOOOO!!
Just like everything else, size matters but not in the way you guys are thinking!
Too big a TB and it literally becomes an on/off switch in the lower TP%. Bucking and bronco-ing.
Too small and the top end suffers.
Personally I would not go above 90mm on a cable driven TB.
On DBW.. go as big as the new ones are (110mm on the LS-A engines).
Just like everything else, size matters but not in the way you guys are thinking!
Too big a TB and it literally becomes an on/off switch in the lower TP%. Bucking and bronco-ing.
Too small and the top end suffers.
Personally I would not go above 90mm on a cable driven TB.
On DBW.. go as big as the new ones are (110mm on the LS-A engines).