Originally Posted by CDW6212R
Ditto, the stock 4.6 TB bolts on, I have one that came from eBay and is ported/polished. The stock SOHC is almost the same, one is 65mm or so and the other is 68mm. Most people have gone to the 70mm, either FMS or another aftermarket TB.
The opening in the intake is about 70mm, that's why most people haven't even thougth of the 75mm size. But there is a huge following of the belief in smaller is better, so 99% of all posts are going to wrongly tell you that 75mm is too big.
I mentioned the 75mm size because it is a common 4.6 TB to find, and I'm sure that it will bolt on. It wouldn't hurt to clean up the opening of the plastic intake just a bit to make it match the TB. There is an aftermarket TB on eBay now that's about $90.
FYI, the TB we have, like the 4.6, is very simple with no EGR or IAC holes. Just take care of the old gasket of yours and swap the TPS to the new TB. Adjust out any slack in the cable with a zip tie on the foot pedal cable end. It's a bolt on, I would go with the 75mm if I did it again. Regards,
Thanks Rick and Don for the info! I'll start searching the internet for a "bargain" throttle body. When I get one I'll do before and after dyno testing. If there is a definite improvement then I'll try my hand at tapering the intake plenum opening to match the throttle body output opening. I seem to recall that the intake plenum has an opening of 65mm. My plan is for the intake airflow velocity to increase as it makes it's way to the plenum. That would be achieved with a 4 inch dia air filter output, a 90mm MAF sensor and a 75 or 70mm throttle body.
By the way, since I have my own throttle cable mod (http://www.explorerforum.com/forums/...d.php?t=248731
) under the hood, I won't need to crawl under the dash to zip tie the foot pedal cable.