SteveVB
Elite Explorer
- Joined
- July 8, 1999
- Messages
- 2,518
- Reaction score
- 9
- City, State
- Gaithersburg, Maryland
- Year, Model & Trim Level
- 04 Rubicon w/stuff
My take:
On the Tb and MAF I would agree with everyone who says that the TB adds some response, and that the MAF does little. The factory MAF is 55mm, and the Factory TB is 58mm FYI.
The restriction in the 4.0 IMO seems to be the heads themselves. The valve and port sizes are restrictive for the volume of cylinder they feed. Unless you add a SC, larger valves, HD work, or a cam to increase the amount of F/A mix past the valves the upstream work isnt worth much. I dont have any data to support this, but just a few back of the napkin calcs about the cylinder volume, compared to valve sizes, and relating it to a stock 5.0-which has similar, if not smaller cylinder volume. I realize its much more complicated than that but it seems to me to have some merit.
Now if you have a SC, or have increased lift and/or duration for the valves then I think the TB and MAF become important.
I would spend the MAF and TB money on headers, chip, air fiter.
On the Tb and MAF I would agree with everyone who says that the TB adds some response, and that the MAF does little. The factory MAF is 55mm, and the Factory TB is 58mm FYI.
The restriction in the 4.0 IMO seems to be the heads themselves. The valve and port sizes are restrictive for the volume of cylinder they feed. Unless you add a SC, larger valves, HD work, or a cam to increase the amount of F/A mix past the valves the upstream work isnt worth much. I dont have any data to support this, but just a few back of the napkin calcs about the cylinder volume, compared to valve sizes, and relating it to a stock 5.0-which has similar, if not smaller cylinder volume. I realize its much more complicated than that but it seems to me to have some merit.
Now if you have a SC, or have increased lift and/or duration for the valves then I think the TB and MAF become important.
I would spend the MAF and TB money on headers, chip, air fiter.
