ported throttle body
04-14-2010, 11:15 AM
#5
Ported TB is definitely worth a few HP and as mentioned better throttle response plus it's cheap. However if you're going to go to a 90 or 92mm FAST in the future I probably wouldn't waste the time on a ported stocker - put the money towards the 90/92mm fund.
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04-14-2010, 04:25 PM
#8
No?
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.
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.
04-14-2010, 11:12 PM
#10
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i personaly wouldnt spend the money,if any thing i would do it my self again. its not relly hard you just need to take your time and pay attention.i did mine in about a hour.do a google search there is a good link for a how to.or pm me and i can send you the link.
04-14-2010, 11:59 PM
#11
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No?
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.
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
04-15-2010, 09:43 PM
#12
When porting the stock throttle body, you do NOT change the diameter where the blade/butterfly is. This area is left 100% UN-TOUCHED. What you are doing is removing the ridge in front of the blade, and opening and smoothing the path from in front of the blade to the outside edge.
