Is switching the stock throttle body to a 70mm and new plenum a big difference?? Anyone done this?? And what about the spacer??

 

Its not going to be huge. Blue Notch did the plenum swap and liked it as far as I know.

 

I have the Trickflow plenum and TB. There is a small difference, but nothing huge. I would just skip the spacer.

 

Ok thanks for the info :-)

 

Put a 78 ml BBK on mine. Instant sound difference from the exhaust and love the sound of the air sucking in when you accelerate. Throttle response was improved but nothing dramatic but a good mod none the less.

 

Did you add a tune? Cuz I hear anything over 70mm can hurt the engine if it's not heavily modded?? Did you just do the throttle body or plenum too?

 

Should be fine: http://www.allfordmustangs.com/forum...no-charts.html

Wish I would have known before I bought my 70mm.

 

Hmm then I guess I will go with the 75mm... Thanks for that link

 

yeah even the 7mm tb did better than the 70mm!

 

Timing adjusters set at 12 degrees ? ? Referring to article in link

 

A bigger throttle body will help out if you have already replaced the exhast system with hi flow cat and mufflers, but if nothing have been done you will not see any improvement in performance. The stock TB flows about 900 cfm which is good for about 450hp

 

Check out Muscle Mustang and Fast Fords website, they did a whole article on intakes and TB's showing what worked and what didn't. They dynoed the stock setup for a base line and every setup change. some lose power, some made power.
Check it out, it's just what you need to help you find the right combo.

 

A bigger plenum and TB would decrease the MPG? In theory more air require more fuel. isn't?