Focus Fanatics Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
175 Posts
Discussion Starter · #1 ·
I am thinking of buying a cfm throttle body, but my dad is under the impression that u have to reprogram the car or put a new chip in it. Is this true or do u pretty much just bolt it on readjust the throttle and let the system run its tests? Any help appreciated.
 

·
Jetsetter
Joined
·
6,659 Posts
bolt on, no need to reprogram or tune the car, but an ecu reset is a good idea and you can do that by disconnecting the negative side of your battery for 15-20 min to allow the ecu to reset then re connect and your good to go.
 

·
Shot me 3 deer!!!
Joined
·
9,247 Posts
you realy only need to reprogram the car when you start inducing more air. the tb wont give yo any more power but can in the long run. mods you can do w/o a tune are all boltons. but a tune is recommended after all of them. you will maximize performance w/ a tune, but a tune (in this case) is not needed for safety
 

·
C2H5OH
Joined
·
11,867 Posts
The 'chip' as you call it is flash EPROM. It is not replaceable and holds all the programming for the car.
When you modify the car near a point when the ECU can not compensate, that is when you need a 'tune'. The ECU can adjust fuel up to ~25%, but don't count on it always doing this. And, just because it can add more fuel does not mean the quantity of fuel it's adding is correct. Nor can you say the ignition timing is correct.
When you get a tune, things like the fueling requirements, timing adjustments and air flow corrections can be made. These are done to correct any error the ECU may be compensating for and ensures it is doing so correctly.

A throttle body swap does not allow more total air into the engine. But it does slightly change the rate at which air enters, which is throttle response.
Throttle response is how quickly throttle input translates into moving forward. A larger throttle plate allows more air into the engine when going from closed throttle to open throttle. The reason for this is surface area and differential pressure.
The atmospheric pressure is what forces air into the engine. The only reason this can happen is the pressure in the intake manifold is lower than that before the throttle body. It's the same thing that creates wind/weather. The larger the differential pressure the faster air can move. The larger the opening the greater the quantity of air.


I know that'll be confusing. Google the terms I've underlined and you should get a better handle on how it works.
 
1 - 6 of 6 Posts
Top