ST200 box + bellmouth

[grey fist]

Anybody else have this idea? Used Blox composite bellmouth and 2 1/2 coupler. Immediate impressions: BOV now very audible, low end torque seems better.

Coupler might be a bit short, sucking hot air from behind radiator. Couple options to make it longer, longer silicone tube supported with a P-clamp off of frame rail or bracket at bottom of radiator with flex hose.

 

[M-Sport fan]

^^^I thought that velocity stacks don't do anything, if they are not facing directly INTO the forward air stream?

 

[the duke]

^^^I thought that velocity stacks don't do anything, if they are not facing directly INTO the forward air stream?

Incorrect. Airflow is a fluid and is erratic and dynamic. A bellmouth (Velocity stack) smooths in fluid flow by providing gradual are reduction to keep laminar flow.

The location of the source is sort of irrelevant. You're primarily concerned with mass air speed. You want to keep the mass flow the same (or as close) to a larger cross-section by speeding things up. You do this by reducing obstructions and providing smooth transitions. The turbocharger is feet away through ducting but it's pressure drop (Vacuum/pull) is providing a driving force. Combined with the tubing size this is the airspeed/flow. While everything is a system, the location does not matter. The requirements for the turbo are the same (essentially) 1 inch from the compressor inlet all the way to the air filter.

You're thinking more of Pressurization in an intake manifold at the back of the valves. That's primarily driven via resonance frequencies.

 

[M-Sport fan]

OK, thanks.

But wouldn't the system as a whole, power wise, benefit (much?) more with that bellmouth at the end of the standard ST200 hose, in an opening in the front bumper/fascia?

(Or is there such a thing as 'over-pressurizing' the air before it reaches the compressor?)

 

[Fordman]

OK, thanks.

But wouldn't the system as a whole, power wise, benefit (much?) more with that bellmouth at the end of the standard ST200 hose, in an opening in the front bumper/fascia?

(Or is there such a thing as 'over-pressurizing' the air before it reaches the compressor?)

Yes, the bellmouth reduces entrance (pressure) loss - wherever it's located. Plumbing to the front bumper helps to reduce Temp increase. Plumbing to a bell mouth at fog light delete optimizes the secondary circuit. Some may not want to give up the fog light, in that case a duct with a smooth ID with a bell mouth in the bumper cavity would be optimized.

 

[Intuit]

Neat idea. It will definitely suck up a lot of road debris that the tires ahead naturally flip-up.

 

[Fordman]

Neat idea. It will definitely suck up a lot of road debris that the tires ahead naturally flip-up.

Understand the comment.

The vacuum pressure in the secondary duct is pretty low. I've done well over 100 runs logging on the interstate for my tuner and doing intake config optimization. Have about 1000 miles with the final configuration. Nothing in the air box or air filter yet. Biggest factor is probably the vacuum pressure and the initial vertical section of the duct just after the fog light bell mouth.

 

[grey fist]

Revision B. Swapped out the coupler for a longer tube. Sourced a 12" length, ended up cutting it to about 9" to position the bellmouth just above the left side intercooler hose. With 4 ply silicone no additional securing needed, not even using clamps. Not completely below the radiator, but I think a safe compromise between temps and potential water ingestion. Don't currently have ability to monitor temps but took it for a canyon run over the weekend with no apparent heatsoak.

I'm liking this mod. Looks stock, will pass Cali smog or roadside audit. Not really any louder than stock other than BOV noise. Butt dyno says it's pulling harder in 1st and 2nd.

 

[M-Sport fan]

^^I'm going to do this as well once I get an ST200 air box and hose.

 

[Fordman]

Revision B. Swapped out the coupler for a longer tube. Sourced a 12" length, ended up cutting it to about 9" to position the bellmouth just above the left side intercooler hose. With 4 ply silicone no additional securing needed, not even using clamps. Not completely below the radiator, but I think a safe compromise between temps and potential water ingestion. Don't currently have ability to monitor temps but took it for a canyon run over the weekend with no apparent heatsoak.

I'm liking this mod. Looks stock, will pass Cali smog or roadside audit. Not really any louder than stock other than BOV noise. Butt dyno says it's pulling harder in 1st and 2nd.

Seems you've found a good compromise. If you ever get an AP3, you can compare temps from your original, compromise, and maybe bumper cavity (Ford ST200) if interested.