no need to make stuff up here. turbulence does have some effect but the damn filter is a restriction. and also the blower spins at X rpm throught the curve, of course it will make more boost without the filter. a turbo works a little easier without the filter, but the boost is the same

 

Well with a turbo it will force it it to a higher (and most likely less efficient) spot on the compressor map. With a citrifugal blower it will do the same, but like mentioned since it spins at a given rpm to engine speed the result is less boost. With a turbo the result is hotter discharge air but the same boost. So different results, yes, but same concept.

The velocity stacks are made to keep the flow laminar for as long as possible, not turbulent. Most newer turbos (the BWs at least) have one built in as part of the cover design.

 

FYI..its called a "bell" volocity stack is a carb thing. additionally the temp coming out of the turbo is the same,

 

How will the temperature be the same if the turbo now opperates at a less efficient spot on the compressor map due to having an effective higher pressure ratio (additional pressure drop before the compressor)?

 

because the air is still compressed to a boost level which is around 11* per lb. its not moving much on the compressor map and its an air filter, restrictive yes but not that much.

when you lost 50hp was your boost exactly the same?

 

Right, but you must consider you are now starting at a lower pressure due to the restriction from the pipes. Small? Maybe, but still there. In terms of absolute pressure, going from 10-25psi is the same as going from 15-30psi. In terms of "boost seen after the compressor", the first case would be 10psi and the second case 15psi (assuming 15psi atmospheric pressure). But the turbo is raising the pressure by the same amount in both cases and doing the same amount of work.

Yes, boost exactly the same



Consider in my case above, a 76mm turbo on a 408 is clearly undersized and probably out of its efficiently range, so any small change in pressure ratio will be more pronounced.

 

first off im not "making stuff up" air flow is important and how the air funnels into the turbine makes a difference . most people call it a velocity stack not a bell even thou neither are incorrect , google velocity stack for turbo , and then google bell for turbo and see what one give you results... try it on ebay also and see if you get what your looking for.its the same reason that Mandrell bent tube flow better then the traditional bent tubing .

 

wish they would of done one with filter on cut out open , but cool graph .

 

What coolant tank do you have?

 

are you sure your boost was the same? maybe try another pull but sometimes the turbo will spool faster without the filter which on the dyno will make more power because the boost is there sooner. thats what it looks like on yours kinda, the graph is shifted left.