Throttle Body Questions

[2001Z71]

I have a 2001 z71 with the 5.3. what size is the factory throttle body, and is there a bigger one that i can buy and would it be noticable power gained from the mod? i have dual magnaflows, aftermarket intake (spectra), and a programmer on it now (not black bear yet). im looking to really wake it up without putting a new engine or super charger yet. what would yall do next?

 

[rich5368]

If I remember right the factory one is 85mm. Of course I could be wrong and it could be 82mm. I know I'm close though. A bigger TB may give you a few more ponies but with that alone on top of your mods you really aren't going to notice anything but maybe a little more throttle response. I fact all things being equal on your truck you may actually lose a little economy and power. If you want to really "wake up" performance I'd say look into maybe going with a bigger gear or a cam. There are articles out there by various magazines where they took a junkyard 5.3 and put crap edelbrock heads and a mild comp cam in it and twisted 450+ hp at the crank. HP costs money man and the more you want the more it costs, as I've learned building my hotrod.

 

[ATL]

unltil u do some heavier mods, a tb would prob make it run worse. it will lose bottom end power, itll run like crap until you get a tune, and you will have worse throttle response. i bet the power the stock throttle body can support would really surpise you.

to get a performance feel out of a 6000 pound vehicle, youre gonna have to make some significant changes; like heads, cam, blower, stall, etc