70 or 75 mm throttlebody?
- Thread starter loco556
- Start date
gruvee87vertgt
20+ Year Stangneter 
For a non supercharged stang you need a 70mm......btw I have a 70mm bbk tb and spacer for $150 shipped.
STANGateURlilSS
Founding Member
well it all depends on what engine.. and how built it is.. i mean if your running a stock 5.0l.. its useless to run 75mm tb.. but if it is a 306 with alum heads, cam, intake.. and a blower then yeah i can see putting a 75mm on it.. but you also got to realize what manifold your running.. if it is stock.. you might a 75mm is bigger then the tb opening on the manifold.. so..
TB size thoughts...
65 MM TB for a 302-306 N/A street strip.
70 MM TB for forced induction on a 302-306 or a N/A 327-347 street/strip
75 MM TB for a forced induction 327 or any 347 full race application.
The logic is that small TB works to keep intake velocity up which helps street performance & quick throttle response.
65 MM TB for a 302-306 N/A street strip.
70 MM TB for forced induction on a 302-306 or a N/A 327-347 street/strip
75 MM TB for a forced induction 327 or any 347 full race application.
The logic is that small TB works to keep intake velocity up which helps street performance & quick throttle response.
Just remember that a 75mm TB flows nearly 2 times the amount of air a 302 can even think of using. I would say that big of a TB is a waste on a 302 block (stroker)...whether it be a h/c/i 302 or stroked 302.
www.accufabracing.com has the charts of how much air flow the engines at a certain cubic inch can breathe in.
That is at 100% volumetric effiency which very few engines have....so they more than likely won't even flow that much.
The "bigger" the blade...the more goosier the throttle will feel.
www.accufabracing.com has the charts of how much air flow the engines at a certain cubic inch can breathe in.
That is at 100% volumetric effiency which very few engines have....so they more than likely won't even flow that much.
The "bigger" the blade...the more goosier the throttle will feel.
Thanks for the info.. Would a 70mm have any negative effects over a 65mm for a non-induction or stroked motor? I don't mind spending the cash, I just hate having to take a step backwackwards and downsizing if I don't have to. O'yeah, whats the difference in horsepower that each t.b. can support? I have read through alot of the other threads regarding this general topic so I hope I have'nt stirred up to much Sh^%$&.
A 70mm TB, preferably from Accufab would flow plenty for a N/A 302 based engine, even stroked.
I don't have horsepower charts, but I have heard the 65mm TB flows around the 400hp range...but I believe it is higher than that from what I have seen.
A 75mm TB is a waste of room in my opinion.
Most get it to go with the crowd, when they can't even get close to using it all.
I don't have horsepower charts, but I have heard the 65mm TB flows around the 400hp range...but I believe it is higher than that from what I have seen.
A 75mm TB is a waste of room in my opinion.
Most get it to go with the crowd, when they can't even get close to using it all.
cobra2798
New Member
Im running a Professional Products 65mm TB, I think anything more for a N/A setup is just overkill5spd GT said:
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