Drop In Filter Dyno Results - FT-86 SpeedFactory

[MiguelAE86]

WE DO BIG THINGS

[Sportsguy83]

Originally Posted by Hanzo

Sometimes it's better to have some restriction to increase the speed of flow. It's like if you pinch the tip of a water hose the water flows faster.

Exactly. Hope everyone drops the myth no filter should be the best.

[xjohnx]

Originally Posted by Hanzo

Does these filter make the car run any smoother in the higher rpms?

You're welcome to snag the K&N from my BRZ and take your car for a spin if you'd like. It's a 30 second swap out.

[FT-86 SpeedFactory]

Originally Posted by sportsguy83

Exactly. Hope everyone drops the myth no filter should be the best.

The best at sucking small rocks and bugs into your engine.

[MarkMash]

not sure if this has been asked yet - what's the sound difference like to stock? much different? better? louder? cheers

[xjohnx]

Originally Posted by MarkMash

not sure if this has been asked yet - what's the sound difference like to stock? much different? better? louder? cheers

K&N is slightly louder than stock.

[YoKeutla]

Originally Posted by MarkMash

not sure if this has been asked yet - what's the sound difference like to stock? much different? better? louder? cheers

There is a noticeable difference in sound. In my opinion, I think the motor sounds much better with the drop-in filter now. Before, you couldn't really hear anything with the exhaust being so quiet. Now you can really tell you are getting up in the rpm range and I think the engine doesn't sound as raspy in those high rpms.

[xjohnx]

I used photoshop to overlay the stock vs K&N run:

[E92M3Guy]

All three runs added to the FT86 Dyno Database:
http://www.ft86dynos.com

Stock:
http://www.ft86dynos.com/showDyno.php?recID=517

HKS Filter:
http://www.ft86dynos.com/showDyno.php?recID=518

K&N Filter:
http://www.ft86dynos.com/showDyno.php?recID=519

AFE Filter:
http://www.ft86dynos.com/showDyno.php?recID=520

[YoKeutla]

Originally Posted by E92M3Guy

All three runs added to the FT86 Dyno Database:
http://www.ft86dynos.com

Stock:
http://www.ft86dynos.com/showDyno.php?recID=517

HKS Filter:
http://www.ft86dynos.com/showDyno.php?recID=518

K&N Filter:
http://www.ft86dynos.com/showDyno.php?recID=519

AFE Filter:
http://www.ft86dynos.com/showDyno.php?recID=520

Might want to note that we were running on 91octane. 93 is not easily accessible where we are from

[E92M3Guy]

Originally Posted by YoKeutla

Might want to note that we were running on 91octane. 93 is not easily accessible where we are from

Fixed. Thanks.

[Tainen]

Did you run each configuration 3 times on the dyno?(including baseline)

The reason I ask is, I've dyno'd my car like... 6 times now, and each time, the power fluctuates the first two runs and the 3rd run is the stable HP figure that is repeatable, and always the highest number as well.

[d1ck]

Originally Posted by Hanzo

Sometimes it's better to have some restriction to increase the speed of flow. It's like if you pinch the tip of a water hose the water flows faster.

When you pinch off the end of a hose you're creating what's called a nozzle which reduces the cross sectional area which the water has to flow through. This is why the velocity increases. You can determine the velocity through a known opening by doing the following:

Velocity (ft/s)= Flow Rate(ft^3/s) / Area (ft^2)

However, you're not getting more flow by doing this, that literally makes no sense. Try breathing through a straw and you will know what I mean. It's much easier to breathe through your open mouth or nose which has a larger cross sectional area than a straw.

You're also creating a restriction which reduces the flow rate through the entire system system (Hose). Therefore by pinching the hose off you're increasing the velocity of the water, but also reducing the flow rate. The amount the flow rate is affected depends on the efficiency of the orifice as well as the area.

Now that you've (hopefully) learned some basic fluid dynamics you will understand why what you said has nothing to do with the increase from installing a filter.

That said, I can't explain why that happened, but I'm thinking it could be due to intake resonance which would have been designed with the filter in mind. Unfortunately I don't know anything about this field.

Alternatively it could be a simple artifact in the dyno testing and within the margin of error of the dyno. In this case it would have no significance.

[Hanzo]

Originally Posted by d1ck

When you pinch off the end of a hose you're creating what's called a nozzle which reduces the cross sectional area which the water has to flow through. This is why the velocity increases. You can determine the velocity through a known opening by doing the following:

Velocity (ft/s)= Flow Rate(ft^3/s) / Area (ft^2)

However, you're not getting more flow by doing this, that literally makes no sense. Try breathing through a straw and you will know what I mean. It's much easier to breathe through your open mouth or nose which has a larger cross sectional area than a straw.

You're also creating a restriction which reduces the flow rate through the entire system system (Hose). Therefore by pinching the hose off you're increasing the velocity of the water, but also reducing the flow rate. The amount the flow rate is affected depends on the efficiency of the orifice as well as the area.

Now that you've (hopefully) learned some basic fluid dynamics you will understand why what you said has nothing to do with the increase from installing a filter.

That said, I can't explain why that happened, but I'm thinking it could be due to intake resonance which would have been designed with the filter in mind. Unfortunately I don't know anything about this field.

Alternatively it could be a simple artifact in the dyno testing and within the margin of error of the dyno. In this case it would have no significance.

Interesting, I was thinking if you pinch down on a hose (not all the way down) your cross sectional area will still be the same since the hose would squash and widen (I may be wrong). Good info though, thanks!