January 30, 2008Ok, so Im lookin at throttle bodies, and apparently you cant put a 4.6 75mm on a 5.4, and vice versa. Whats the difference between the 4.6 and 5.4? is the bolt spacing different on the plenums? I dont see why it wouldnt work. Theres a lot more 75mm tbs for the 4.6 than for the 5.4.
Forums : Performance General : Aftermarket Throttle Bodies (958 Views)
January 31, 2008HI!... Are you looking at MUSTANG 4.6 TB's instead of TRUCK 4.6/5.4 TB's? The 4.6/5.4 truck TB's are identical. I've swapped them plenty of times. If you want to go with a larger TB, get yourself a BBK 75MM TB. Remember though that you will see little or no gain at all unless you port the TB ELBOW to match the larger TB.
January 31, 2008I was actually looking at having a sheet metal plenum made cuz my fiance's dad owns a fab shop and will build me one for free. And yeah, most of the 75mm 4.6tb's i see say for mustang AND 4.6 f150, but then they say they dont work with the 5.4. HOWEVER, I was 99% positive the 4.6 and 5.4 plenums were the same, and that the difference was between the car and truck versions. What specifically IS the difference between the mustang and truck tb's? If its just the bolt spacing for mounting, that wont matter since like i said, im having a plenum fabbed.
February 1, 2008CRAP! so... I cant delete my egr cuz I need it for emissions, so i guess a sheet metal plenum is outta the question. havin bungs welded on for everything else wouldnt have been a problem, but its gonna look like **** with that much extra crap welded on. o well.
know where I can pick up a used plenum? Ive tried ebay, craigslist, and all my local junk yards. itd be nice if I could find an extra one to port and bolt up, cuz i cant have my truck down for too long.
April 22, 2008Neil,
Can you purchase the ported TB elbow anywhere. What sites have the best deals and which one is the best.
April 22, 2008check your local craigslist, as well as ebay. i picked up 2 of em within the past month, gave em the full p&p treatment, and sold em (as well as doing my own in the process). If I happen to come across another I'll let you know, and could port and ship to you for a reasonable price.
April 23, 2008My next question is will I see anything other than a loss in gas mileage with this and my upgrades. I have a 5.4 and have installed electric fans, intake, underdrive pulleys, and computer. Next will be exhaust. I just don't know if this will just hurt me with my upgrades or will I see an increase in power and or gas mileage.
April 23, 2008surprisingly enough, my mileage has gone up to 13.2mpg city since I went with a 75mm w/p&p plenum, and a larger maf. i was getting 10.9mpg before.
August 7, 2008Going blown again if anybody wants a p&p n/a plenum...
January 11, 2017
Recently came across this forum hoping to find an idea why my fuel mileage went so bad... In a shop they told me that the problem is most probably about a throttle position sensor, as it gets that error code. Thought that this discussion had something about it. Anyways, will have to buy one for my F150 and replace (https://www.carid.com/throttle-position-sensors/). Luckily, it`s cheap enough, hopefully helps....