82 mm throttle body - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

WILD6 · 12-30-2004, 22:22

i have a series 3 au xr8 and i was wondering if theres any advantage to be had from putting the 82 mm throttle body that is fitted to the series 3 t series motor.
thanx in advance
from adam

eb2flyz · 12-30-2004, 22:26

unless you have a wild stroker, it will be a real guttless, lack s**t loads of torque and be an absolute pig to drive, what is the combo that you have now?

EDXR8 · 12-30-2004, 22:34

Quote:

Originally Posted by eb2flyz

unless you have a wild stroker, it will be a real guttless, lack s**t loads of torque and be an absolute pig to drive, what is the combo that you have now?

Yeah exactly, you would need a wild engine to need anything more than a 70mm TB. 70mm TBs flow around 720cfm which equates to 450hp or 340kw before restriction.

ebxr8240 · 12-31-2004, 03:38

I must ask ? How does a big t/b make em un torque ??
It's not like its carb where it needs some vacuum to draw fuel through etc???
What I can see happening is idle and low speed crusing may be an issue ...
Asuming inlet, heads and especially maf are up to same airflow...

WILD6 · 12-31-2004, 17:08

its still sotck at the moment just exhaust extractors cold air intake but sometime later this year i hope to go the head, cam and manifold route and then in the future either stroker or supercharge. what about once i did the head and cam would it be a benefit?

EDXR8 · 12-31-2004, 17:53

Quote:

Originally Posted by WILD6

its still sotck at the moment just exhaust extractors cold air intake but sometime later this year i hope to go the head, cam and manifold route and then in the future either stroker or supercharge. what about once i did the head and cam would it be a benefit?

Still there is no reason to go that large, plus most aftermarket manifolds only have a 70-75mm throttle opening so any larger will be useless without a lot of port work. A 65mm TB flows around 610cfm which is around 280kw so will be fine for any NA 5L and maybe some mild 347 strokers. For forced induction or decent 347 setups would benefit from a 70mm, with only wild engines would need to go any larger.

MrLandau · 12-31-2004, 22:25

Before you go spending big dollars on a throttle body, spend a small fraction of the cost and get SADesign book "5.0lt Ford Dyno Tests" (SA61) and turn to page 28. They do some real world testing on throttle bodies and what happens when you under or over throttle body a motor. You can go as big as you want but once you get much over the maximum theoretical flow of the motor - it all becomes wank factor.
Tested flow figures
58mm Ford TB - 526 cfm
65mm Accufab - 616 cfm
70mm BBK - 726 cfm
75mm Accufab - 845 cfm
90mm Accufab - 1225 cfm
You wouldn't put a 850cfm Holley on a 6000rpm limited 302 - so other than spending more money on something you don't really need - why perform a modification that will lose HP and TQ?
The Ford Explorer/Cobra/AU manifold only has a 70mm opening on it to start with - TrickFlow make a version of their "R" series manifolds with a 90mm opening (and their box upper which is much like the T3's) and bring the lower RPM up 700rpm but their other manifolds are all 75mm openings.

Shane

PigDog · 01-01-2005, 06:20

Yep and even on the T3 it came on the 82mm was nothing more than wank factor.

Gambit · 01-01-2005, 15:31

Would a T3 be more responsive with a 70mm t/b like the one on the au3? Would it lose any power or torque?

EDXR8 · 01-01-2005, 17:26

Quote:

Originally Posted by Gambit

Would a T3 be more responsive with a 70mm t/b like the one on the au3? Would it lose any power or torque?

Shouldn't loose anything because as you have seen they flow 726cfm which is good for 340kw, but it would probably pick up some throttle response with the smallerTB.