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APR INTAKE DIY SOUND DOOR

Twist1

Autocross Newbie
1. You're going to compare the WGDC of two different vehicles and attribute similarity or difference to the airbox? How are you controlling other variables that could affect WGDC?

2. APR has the lowest flow of the 7 aftermarket products tested. Since I have to purchase the majority of products that I test I have incentive to acquire products that have a high likelihood of performing well, because I could be using one for a while. APR was being put up against some of the "best" intakes that I could source.

3. Removing the housing from the APR intake increases airflow through it substantially. I believe the constraint in their design is the channel from the inlet to the filter section, it narrows a bit. The Eventuri that I am presently using has a similar opening but as the width of the intake narrows the height increases. I suspect the cross sectional area of the Eventuri increases along the flow path and the APR intake decreases, before opening into the filter housing.

4. Both the APR and Eventuri intakes were flow tested in the same manner, with the inlet open without any restriction. The scoop is something I've looked into as well and the difference it causes is miniscule, less than one hundredth of a psi during the measurements I made at 50 mph.

5. The flow bench exists in the real world. It's a real device purposefully designed to measure airflow through parts like the intake. The measurement device was calibrated prior to each intake test. The "real world" comparison you are planning is a poorly suited means of evaluating airflow through the APR airbox.



See above, the scoop does next to nothing.
Also, can you post your data on how the APR intake did with the housing off?
 

Twist1

Autocross Newbie
I think it's a nice intake and I wouldn't lose any sleep using it. Judging it based on relative performance of a small sample of intakes is of limited value.
Im going to be dyno soon. Ill do one with it fully on and another with just the inlet pipe attached.

I bet they are within the margin of error of the DJ xD
 

MyGolfMk7

Go Kart Newbie
Location
FL
Car(s)
B5 S4, Mk7 GTI
I think real world tests are more relevant than a flow bench when it comes to some of the designs like APR or eventuri. They were designed to have moving air on a moving car. Yes the area around the filter is smaller than others which your tests point out. However, one piece that I do agree is comparable to real world results is the TIP testing. Due to how air is moving through that a flow bench is going to show the ones that flow the best. I sold my APR TIP but I just am not sure how an APR intake with my grill sliced open, an air scoop shooting air into it, and the backside cut out is gonna flow like a stock intake lol. I just don't see it.

And no my test is simple: put CTS intake on and log. put APR intake on and log. Same car. Same conditions.

I have no sway one way or the other. I've sold some APR parts just want to see which is best for my TBB dbv2 which just hit 31psi last night with my "stock" flowing intake fine.

Do you know that for a fact? Or are you telling me what their marketing says?

Whether air is being forced through the intake, or pulled through, is irrelevant to measuring the pressure drop caused by the intake, which is the goal of flow testing.

The ram air test I just did was intended to determine what the airflow at the inlet to the APR/Eventuri style intake is, to see what a car moving through the air would do to pressure in that region, the results were telling.

Maybe somebody thought there was moving air in that area caused by the vehicle movement, but I've found no evidence that there is any. At least nothing of a magnitude that has any meaning relative to what the turbo is doing to pull air in. I doubt any company that markets an intake as taking advantage of under hood airflow made the effort to find out if there is any. I suspect they guessed/hoped and marketed the product as taking advantage of something that they did not know exists or not.
 

Twist1

Autocross Newbie
Do you know that for a fact? Or are you telling me what their marketing says?

Whether air is being forced through the intake, or pulled through, is irrelevant to measuring the pressure drop caused by the intake, which is the goal of flow testing.

The ram air test I just did was intended to determine what the airflow at the inlet to the APR/Eventuri style intake is, to see what a car moving through the air would do to pressure in that region, the results were telling.

Maybe somebody thought there was moving air in that area caused by the vehicle movement, but I've found no evidence that there is any. At least nothing of a magnitude that has any meaning relative to what the turbo is doing to pull air in. I doubt any company that markets an intake as taking advantage of under hood airflow made the effort to find out if there is any. I suspect they guessed/hoped and marketed the product as taking advantage of something that they did not know exists or not.

If you're asking if I have hooked up pressure sensors to an inch within the apr system to measure the pressure then put the same sensors in the stock intake to compare.. no I have not.

I am going to compare it to the cts 3.5" however and see if theres any noticeable anything in the logs. If it flows as bad as your tests imply, making 3 bar of boost on my system should put quite a strain on WGDC. As someone else had that issue and pointed to the APR intake as the cause (referencing your test). I'll post my results here.

Without the grill cut out the APR intake is literally awful.
 

MyGolfMk7

Go Kart Newbie
Location
FL
Car(s)
B5 S4, Mk7 GTI
If you're asking if I have hooked up pressure sensors to an inch within the apr system to measure the pressure then put the same sensors in the stock intake to compare.. no I have not.

I am going to compare it to the cts 3.5" however and see if theres any noticeable anything in the logs. If it flows as bad as your tests imply, making 3 bar of boost on my system should put quite a strain on WGDC. As someone else had that issue and pointed to the APR intake as the cause (referencing your test). I'll post my results here.

Without the grill cut out the APR intake is literally awful.

My point about the intake being designed to work with air flowing over the car, what's the basis for you saying that "They were designed to have moving air on a moving car."? How do you know that was part of the design of the product? When I say design I mean the person/people who designed it, the engineers if that is who did it, were thinking about capitalizing on that when they came up with the design. Not the people who are marketing it.

If APR had actually taken pressure readings don't you think they'd point that out with some specifics, not put up a simple picture with zero details about the pressure differences measured versus speed? I was able to take pressure readings versus vehicle speed with a simple probe and gauge and I'm not making $460 a pop selling the things.

Your test involves comparing a product that has been measured with a product that has not. If you cannot find a difference between the two on the dyno you are going to conclude the measurement was invalid? Why not conclude that the level of performance of the unmeasured (CTS) product is the same as APR? It's an equally likely conclusion.

What's the approximate pressure drop across the APR intake for the test conditions you're planning? Based on what you believe the flow test shows, how much change in WGDC is predicted?
 
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