Throttle body VS. Spacers!?!?!?

What is the difference between getting your TB machined or putting a spacer on?
Besides spacer making your TB touch the hood, what are the pros and cons and performance gains between the 2?
:confused1

i have had both and ended up taking off the spacer because i didn't notice that much of a difference and bored out my tb at home to 62 straight through. with a bored out tb i noticed a difference in acceleration on the freeway and just a little more torque fuel economy went up about 1.5 to 2 mpg but it might have been because i cleaned out the tb. i would shoot for a 62 mm tb before a spacer or save your $$$ and do both at 62mm.

DurbElites said:

i have had both and ended up taking off the spacer because i didn't notice that much of a difference and bored out my tb at home to 62 straight through. with a bored out tb i noticed a difference in acceleration on the freeway and just a little more torque fuel economy went up about 1.5 to 2 mpg but it might have been because i cleaned out the tb. i would shoot for a 62 mm tb before a spacer or save your $$$ and do both at 62mm.

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boring out the taper on the bottom of the TB will make it 60mm straight through, its a very good side TB for the 4.0

if you have an exhaust (2.25 or bigger), header, high flow cat, the 62mm TB will really help the engine breathe, but then you'll need to run a MAP adjuster otherwise youll be running to lean.

Oh, and spacers don't do anything noticible, they go along with the fact that longer intake runners provide more low end torque (and do make top end suffer). one inch doesnt do anything.

Boring the tb, or at least removing the taper, will acually let in more air, while the spacer just moves the powerband. I removed the taper for the price of a few dremel grinding discs, a couple rubber polishing wheels, and about an hour of careful work. I doubt the spacer is worth what they sell for, but why not if you have access to a mill or a drillpress. I plan to make one in my next CNC class.

Slip Kid said:

Boring the tb, or at least removing the taper, will acually let in more air, while the spacer just moves the powerband. I removed the taper for the price of a few dremel grinding discs, a couple rubber polishing wheels, and about an hour of careful work. I doubt the spacer is worth what they sell for, but why not if you have access to a mill or a drillpress. I plan to make one in my next CNC class.

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yeah, thats a good way of putting it, moving the power band....but again, not a noticible amount