whats the difference between tuned port injection and regular fuel injection???

 

Fuel injection covers any system where fuel is delivered through an injector, as opposed to a carburetor. Tuned Port Injection is GM's name for a particular Multi-Port Fuel Injection system that uses tuned-length runners.

 

Regular injection is quite open to interpretation. For most IrocZ owners, TPI would be the regular injection. But here's some specific injection methods and how they operate . . .
TPI Tuned Port Injection
- First appeared in '85.
- "Tuned" refers to the eight long tube runner design of the intake.
- Known for providing good torque but running about of breath at RPM's over 4500.
- Uses a 8 injectors (a single injector for each cylinder).



TBI Throttle Body Injection
- Also introduced in the mid 80's.
- A relatively reliable and simple design.
- Uses only two injectors positioned over the intake's throttle body (similar location as a carburetor. This is a less accurate air/fuel mixture than the TPI's multiple injector system.
- Looks very similar to a carburated system and can use many of the same parts (intake manifold, air cleaner, etc). This can reduce it's cost compared to the a TPI system. Some call it a smart carburetor.



Those are the two most popular FI systems for the 3rd gen V-8's. There's also a CFI (Cross Fire Fuel Injection) which used twin TBI's ('82-'83).

 

cool thankx for the info