Throttle body is in!
Thread Starter
Staging Lane
Joined: May 2008
Posts: 91
Likes: 0
Throttle body is in! I purchased from a member on this board a stock throttle body that was ported to 52mm. Has very good rep for porting stock throttle body's. I did this b/c my car has been having some idle issues and for restoration. Anyways, got the throttle body and everything looks great. Its a nice piece considering it is a stock part.
This is my question, I took the throttle body and held it up to some bright light to see I could light inside and around the throttle blades inside the throttle body. I could see a very tiny amount of light around the outside of the throttle blades. IS this acceptable? meaning will it cause problems? I have not done this to my stock throttle body yet b/c it is my daily driver.
Any suggestion? I would really like to use this throttle body, just don't want any additional problems if I put it on.
Thanks
(Could post pics if needed just not now b/c at work)
This is my question, I took the throttle body and held it up to some bright light to see I could light inside and around the throttle blades inside the throttle body. I could see a very tiny amount of light around the outside of the throttle blades. IS this acceptable? meaning will it cause problems? I have not done this to my stock throttle body yet b/c it is my daily driver.
Any suggestion? I would really like to use this throttle body, just don't want any additional problems if I put it on.
Thanks
(Could post pics if needed just not now b/c at work)
TECH Veteran
Joined: Apr 2008
Posts: 4,985
Likes: 112
you really need to log what the IAC and TPS is with the new TB. IMHO a stock rebore to 52 is the best way to go if going larger TB.
TPS can be measured with volt meter (.67 vdc /-10%) and 4.5 vdc full open.
IAC counts want to be 25-35 with engine at operating temp. A scan tool is required to read IAC.
Bolt it on and see how it runs (idle). Typically on stock motors they are fine out of the box. Head/Cam cars "may" need some adjustment in the form of VERY SLIGHTLY opening the TB blades or enlargeing the hole for IAC by 1/64". DO NOT blindly drill or enlarge the hole without first reading wtf IAC counts are...if to high and moving the blades takes the TPS volts out of range (you can only barely crack the blades open without effectinging those counts much) than the drill mod is in order. Another option over drill is to slot the holes on TPS to bring TPS volts back in line if you open the blades to far.
TPS can be measured with volt meter (.67 vdc /-10%) and 4.5 vdc full open.
IAC counts want to be 25-35 with engine at operating temp. A scan tool is required to read IAC.
Bolt it on and see how it runs (idle). Typically on stock motors they are fine out of the box. Head/Cam cars "may" need some adjustment in the form of VERY SLIGHTLY opening the TB blades or enlargeing the hole for IAC by 1/64". DO NOT blindly drill or enlarge the hole without first reading wtf IAC counts are...if to high and moving the blades takes the TPS volts out of range (you can only barely crack the blades open without effectinging those counts much) than the drill mod is in order. Another option over drill is to slot the holes on TPS to bring TPS volts back in line if you open the blades to far.
Remember when changing to a larger TB you MUST change the tune on an A4. Ignore this and expect to be replacing the transmission. The reason is at a given throttle position the engine is flowing more air, and therefore, making more power which of course requires more transmission pressure.
Good luck
PS making more power at a throtle position does not mean you will necessarilly make more power at wot
Good luck
PS making more power at a throtle position does not mean you will necessarilly make more power at wot
I have had many people ask me this. The small amount of light you see is clearance needed to keep the throttle blades from binding up. If there was zero clearance between the blades and the bore they would stick when fully closed. I machine the throttle blade OD .003 / .004 of an inch smaller than the bore ID giving you .0015/.002 inches of clearance per side and is the light you are seeing.
Like mentioned anytime you change throttle bodies and want the idle to be best possible you need to check the IAC counts, also double check the TPS voltage as well.
Like mentioned anytime you change throttle bodies and want the idle to be best possible you need to check the IAC counts, also double check the TPS voltage as well.
