I've seen many times people saying that the 75mm tb is overkill and looses power for a n/a 4.6. I was looking on C&L's website and they say that the 75mm tb is the way to go even with a N/A 4.6. They have dyno graphs showing the increase (on mildly modified 4.6 gt's and supercharged...the graph showes 3k to redline...maybe the 75mm looses power below 3k???). I'm trying to decide which one to get...according to C&L'
s website I should get the 75mm...help me out guys...

 

If you get a C&L plenum then get a 75mm throttle body, otherwise get a 70mm ... I personally don't care for the C&L plenum on a NA car.

 

MD, yeah I would get the plenum to go along with the tb...so you don't think it is a wothwhile mod on a n/a 4.6 (plenum and TB)? or are you saying the C&L plenum isn't as good as the Accufab plenum?

 

Im not a big fan of tb/plenum changes until its the last mod available. I even went cams before I did tb/plenum work. Even with an accufab your lucky to get 7 hp to the wheels for the $400+ your gonna spend on a plenum/tb combo. I just got a 70mm tb and ported my stock plenem... just as good.

 

Where did you get your stock plenum ported and how much? Will local shops do this?
How much are the TB's alone?

 

I ported the plenum and I scored a FRPP 70mm tb for $90 from someone off these boards and bluprinted that too.

 

Bastard. It's so hard to find deals with my Cobra. It seems that everything is either hard to find, deal wise, or it's just so damn expensive new. I should have just waited till next summer and get an 04 Cobra.

 

blueprint a T/B?..odd..I need to finish my garage so I can open up stock parts for more hps at a low cost.....[sm=icon_rock.gif]

 

Work the butterfly & butterfly screws and smooth the ridge into the butterfly area... if you want lessons gramps I can arrange it [sm=icon_rofl.gif][8D] You can't "port" a throttle body around the butterfly area or you'll get too much air past it and a high idle - so you do what you can.

 

*L* ole young one...lesson I much teach...I know all that you explain but calling filing down 2 screws blueprinted*L*..as for porting I was talking about some else as for the t/b a good polished of the throat and a tad bigger hole drill in the blades will help greatly as in also thinning the plate out from the middle to the ends helps flow..feel free to write this in your book