TB overbore

Are you replacing the throttle plate to go with a bigger bore? From what I remember, the location of the shaft bearings for the throttle plate make it pretty much impossible to enlarge the bore without a lot of work, even with a bigger throttle plate to match.

I know from experience the EGR spacer can't be bored much past 65-67mm, you'll break through the wall.
 
im lookin at the EGR plate right now, and the OD is 75, so youre probably right, now the egr plate the I installed had a bigger OD, I dont quite know what it came from, ill bet its from an explorer, but I just installed a 65 tb and plate that I bought together
 
In that case, i might go with a 70mm and port match the intake to it.

You running an explorer intake?


Reason there is no point to porting a stock throttle body larger is because you are still left with a 60mm or 65mm blade.

70mm TB, and perhaps 75mm or larger MAF
 
Modifying throttle bodies is much more trouble than it's worth.

QFT!!! :stupid:

Speaking from experience. I ruined a couple of perfectly good stock throttle bodies trying to machine them out to 65mm. There just isn't enough wall thickness to work with. By 63mm you've compromised its structural integrity. Meaning a hard bump with the inlet hose installed and you'll snap the neck right off of it.

At 64mm, you can start to actually see the inner wall starting to discolour because you're getting paper thin in spots that you could essentially push through with the tip of a screw driver.

...and by 64 1/2mm, you've broken through and made yourself an expensive paper weight.

The spacer on the other hand will bore out to 65-67mm as stated...but again that's of little use unless you've got a matching throttle body to couple with it.
 
QFT!!! :stupid:

Speaking from experience. I ruined a couple of perfectly good stock throttle bodies trying to machine them out to 65mm. There just isn't enough wall thickness to work with. By 63mm you've compromised its structural integrity. Meaning a hard bump with the inlet hose installed and you'll snap the neck right off of it.


Mine was a SVT throttle body. I also modified two Mustang throttle bodies to fit on Contour SVTs (there are no aftermarket TBs available). With that being said it is extremely tedious and you have to be uber careful.