Turbo 2.5L fueling question...

[TheRob]

If I am using extra injectors mounted in the cold side IC pipe to supply fuel in boost, then a BOV (not a BPV) would be the correct method of equalizing pressure during a throttle close, right? I used to turbo cars with MAP systems, but with the MAF systems used on the 2.5L Ranger, it would seem that a BPV is the right answer if you're using something like a Megasquirt or a chip or something like that. However, if you're using a completely separate set of injectors that are run off its own MAP sensor, then a BOV would work correctly I think. If a BPV were used with an extra injector setup, then closing the throttle under boost would potentially lead to a rich condition as the MAF would be seeing seeing the extra air from the BPV firing, but that air wouldn't be going into the engine. Am I thinking about this right, or does someone have any experience with such a setup?

Thanks,
-Rob

 

[martin]

Would the computer not see the tps in the throttle closed position and reduce the fuel?

 

[TheRob]

...

It would, for sure, but it would also get the input from the MAF, which I'd think has a HEAVY influence on the fueling decisions for that cycle.

-Rob

 

[TireIron]

when you run a BPV you circulate it into the system after the MAF, so it is already metered air. The MAF does not read that air a second time. If you use a BOV on a MAF system you lose the air that has already been metered so you have extra fuel and you run rich every time you close the throttle.

So with a BPV the air passes the MAF once and then stays in the system until it enters the engine so it knows how much air it has and uses the correct amount of fuel for that.

 

[TheRob]

...

Ahhh, of course. Now it makes sense. Thanks for the heads up.

-Rob