Hi ,

I have changed the Intake system and exhaust system on my Firebird 3.1 (1990) and i think the stock throttle body whit the small plate is now many to small to let enoug air flow to the engine , is this correct and does somebody know where to get a larger one for this engine?

Thank you for helping.

Schneemann
Germany
www.knightrider.de

 

What did you change on the intake and exhaust? Was it the filter hoses and the muffler? If so, you'd need to do many more changes besides intake & exhaust to be able to see any benefit from a larger throttle body. (Heads, camshaft, rocker arms, etc)

 

One major problem with adding a larger TB is the neck port of the upper intake. When I changed to a 62mm size, the neck fist had to be reinforced with more aluminum then honed out to acccept the larger TB bore. You will notice a difference in the responsiveness of the larger TB but to recieve the full benefit, poting the middle and lower intakes, polishing the heads, will also be a good idea.

The fiero store - www.fierostore.com ofers one that is larger. You may want to gve them a call and ask some questions about it.

BTW, what intake system do you replace it with?

 

I took an Holley filter 8*6 inch and made an rounded tube 78 cm diameter on myself which I took insted of the stock intake , looks now link the intake you can buy at K&N for Trans AM and works realy good. (costed just $30 all together)

Greetings
Schneemann

 

*points at Tom's reply* Your throttle body isn't a restriction at this time. A larger throttle body won't do anything until the existing throttle body is limiting your airflow. Until you've done some serious internal work, if you want better throttle response, press the pedal further.