I see this question asked a lot and I will probably be doing this to my car soon. So...
What is it?
77mm bore replacement throttle body for the LSJ. The Stock LSJ throttle body is 68mm bore.
LS4
Stock
How to find one.
GM Part Number: 12568580
or buy one from a junk yard.
COLORADO 04-07 Throttle Valve Assm; (3.5L)
BRAVADA 03-04 Throttle Valve Assm; (4.2L)
CANYON 04-07 Throttle Valve Assm; (3.5L)
ENVOY 03-07 Throttle Valve Assm; (4.2L)
GRAND PRIX 05-06 Throttle Valve Assm; (5.3L)
HUMMER H3 06-08 Throttle Valve Assm; (3.7L)
IMPALA 06-07 Throttle Valve Assm; (5.3L)
ISUZU ASCENDER 03-07 Throttle Valve Assm; (4.2L)
MONTE CARLO 06-07 Throttle Valve Assm; (5.3L)
RAINIER 04-07 Throttle Valve Assm; (4.2L)
SAAB 9-7X 05-07 Throttle Valve Assm; (4.2L)
TRAILBLAZER 03-07 Throttle Valve Assm; (4.2L)
How to Install it.
The throttle blade on the LS4 throttle is wider then the stock throttle body and will not open all the way if installed on the M62. There are two options on how to install it.
1. Buy a Throttle body spacer designed for the LS4 Throttle body.
2. Port the inlet of the blower to widen the opening.
For that, you will need a dremel tool an aluminum cutter and sanding/polishing wheel to smooth things out.
First, dremel off the small lip on the LS4 throttle body on the side that touches the SC.
Disassemble the M62 to separate the housing from the rotors.
http://www.redlineforums.com/forums/ion-redline-discussion/44878-m62-blower-work.html
or stuff a rag into the inlet so no shavings get on the rotors.
Loosely install the TB on to the SC and trace the inside diameter of the throttle body on to the SC inlet to indicate how much material to remove.
Dremel away!
I prefer to separate the M62 housing from the rotors because it allows you to smooth out the entire inlet of the M62.
Then polish everything smooth with a polishing bit. Clean and reassemble the SC. Install the throttle body back onto the SC and the SC back onto the engine.
You will also need a 3.5" to 3" coupler to attach the throttle body to the intake.
Tuning for the LS4.
Change the ETC Area Scaler value from 2950 to 4500. ZZP recommends changing the value to 3688 but there are many values that work.
Lastly, recalibrate your MAF.
If anyone else has anything to add please do so.
:bigthumb:
What is it?
77mm bore replacement throttle body for the LSJ. The Stock LSJ throttle body is 68mm bore.
LS4
Stock
How to find one.
GM Part Number: 12568580
or buy one from a junk yard.
COLORADO 04-07 Throttle Valve Assm; (3.5L)
BRAVADA 03-04 Throttle Valve Assm; (4.2L)
CANYON 04-07 Throttle Valve Assm; (3.5L)
ENVOY 03-07 Throttle Valve Assm; (4.2L)
GRAND PRIX 05-06 Throttle Valve Assm; (5.3L)
HUMMER H3 06-08 Throttle Valve Assm; (3.7L)
IMPALA 06-07 Throttle Valve Assm; (5.3L)
ISUZU ASCENDER 03-07 Throttle Valve Assm; (4.2L)
MONTE CARLO 06-07 Throttle Valve Assm; (5.3L)
RAINIER 04-07 Throttle Valve Assm; (4.2L)
SAAB 9-7X 05-07 Throttle Valve Assm; (4.2L)
TRAILBLAZER 03-07 Throttle Valve Assm; (4.2L)
How to Install it.
The throttle blade on the LS4 throttle is wider then the stock throttle body and will not open all the way if installed on the M62. There are two options on how to install it.
1. Buy a Throttle body spacer designed for the LS4 Throttle body.
2. Port the inlet of the blower to widen the opening.
For that, you will need a dremel tool an aluminum cutter and sanding/polishing wheel to smooth things out.
First, dremel off the small lip on the LS4 throttle body on the side that touches the SC.
Disassemble the M62 to separate the housing from the rotors.
http://www.redlineforums.com/forums/ion-redline-discussion/44878-m62-blower-work.html
or stuff a rag into the inlet so no shavings get on the rotors.
Loosely install the TB on to the SC and trace the inside diameter of the throttle body on to the SC inlet to indicate how much material to remove.
Dremel away!
I prefer to separate the M62 housing from the rotors because it allows you to smooth out the entire inlet of the M62.
Then polish everything smooth with a polishing bit. Clean and reassemble the SC. Install the throttle body back onto the SC and the SC back onto the engine.
You will also need a 3.5" to 3" coupler to attach the throttle body to the intake.
Tuning for the LS4.
Change the ETC Area Scaler value from 2950 to 4500. ZZP recommends changing the value to 3688 but there are many values that work.
Lastly, recalibrate your MAF.
If anyone else has anything to add please do so.
:bigthumb: