Does any one know the diameter of the throttle body on a 98 4.6. And does anyone have an after market throttle body. HOw well did it help with power?

Also what is having one ported and polished and does it help?

Im looking at doing somthing behind my intake to help more air.

 

HI!... All the 4.6/5.4's run a 70MM stock TB. BBK makes a aftermarket 75mm TB. If you run the larger 75MM TB you will need to port match the TB ELBOW to the same size or you are gaining nothing.

 

agree^

 

so how would i acomplish this with the elbow
can you buy it

 

die grinder and some sanding discs.. and very good amount of patience

 

so pretty much what your doing is just boring it out more than it already is. No switching of the elbw or anyhting? Can i do the smae for the throttle body. Im a machinest by trade to i have all the tools to make a new throttle plate at work. If i could bore the throttle body and elbo then make a new plate that would give me more flow. What about sensors?

 

yah u can do that by yourself good luck with the throttle body mod. you would have to make your own throttle plate bar.

 

I can do that. I already manufacture the ones for the jets the navy flys i think i can do the one for my truck. What im worried about is sensors. Will that change how my MAF reads?

 

Sure, if your efforts are not in vain, the maf will be reading more air, add more fuel, and you will gain a few hp.

 

haha damn if its successful ! lol make me an 80mm throttle body

 

I will investigate this weekend. I dont think it will be to hard to machine a new throttle plat for it. It will be making the shaft that the rod rotates on...LOL I will followup with more this weekend.

 

make a thread post some pics! if u are suecessful. patent it and people on here will likely buy em from ya i know i would

 

I bored out my spacer to the new size today. Helped a lot with flow i could feal a bit of a differance and there was no noise. Got ride of the damn helix and that helped a lot. I will be boring out the throttle body and elbow. I will keep you guys posted.

 

HI!... If your talking about boring out a TB spacer don't bother. Been there done that, dynoed that, lost H.P. TB spacer don't work. It's a concept for carbs that works very well but on F.I engines it is useless where the after market company's put it. It doesn't do anything for you between the TB and TB ELBOW.

Also if your going to bore your factory TB out to a larger bore make sure you make a new butterfly as well. Also the butterfly is not round. It is slightly EGG shaped and has opposite cut backs at both ends.

 

thanks for the info about the butterfly. I didn't know that. have you done this?