Background:
The ARM Motorsports Turbo Inlet Pipe/Elbow (TIP) for the Mk7 is the subject of a flow test.
The turbocharger inlet elbow is an important component of the intake system as it significantly contributes to the pre-compressor pressure loss. The ARM Motorsports TIP is sized for best use with stock-size turbochargers, IHI IS20 and IS38, and aftermarket turbos using a similar-sized (~49 mm) compressor inlet.
Test Process:
The elbow is attached to a stock accordion hose and then the top half of the stock airbox. The outlet of the ARM TIP is connected to an adapter that simulates the inlet to a stock-size turbocharger, and this adapter connects the intake parts to the flow bench.
The flow bench is operated at a depression of 28″ of H2O, and the airflow rate through the intake parts is measured.
A second test is performed, replacing the stock accordion hose with a Racingline inlet hose. (Shown above.)
Another variation of the test involves replacing the top half of the stock airbox with an APR PEX intake, retaining the Racingline inlet hose, and replacing the stock-size adapter with a hybrid-turbo size adapter. (Shown below.)
Test Results:
The ARM TIP flows 398 CFM @ 28″ of H2O.
This result, along with other inlet elbows that have been tested similarly, are shown on the following chart:
Replacing the stock accordion hose with the Racingline hose led to an airflow increase to 402 CFM @ 28″ of H2O.
Swapping to the APR PEX intake and hybrid-size adapter produced an airflow increase to 485 CFM @ 28″ of H2O.
Note: The configuration with the APR PEX intake is a significant departure from the format I use for testing elbows, where the stock airbox top is used to smooth airflow into the inlet hose. This configuration is more like what is used for intake testing.
Conclusions:
The ARM Motorsports turbo inlet elbow underwent a flow test. When tested in a standard configuration, the TIP flowed 398 CFM @ 28″ of H2O, which is the second-highest flow rate that has been measured.
Two intake component variations were tested. Interestingly, when joined with an APR PEX open intake, Racingline inlet hose, and joined to the flow bench using a hybrid-size adapter, the ARM TIP supported a flow rate of 485 CFM @ 28″ of H2O.
This is less than has been measured with elbows designed for a hybrid-size turbo but better than average compared to a handful of other stock-size elbows that have been tested with the hybrid adapter.
One possible explanation for the higher flow rate might be that the main body of the elbow has a smooth transition to the outlet.
Some other elbows that have been tested have a more substantial change in diameter at the outlet than the ARM TIP has.
Although the ARM Motorsports TIP performed well in the hybrid-turbo intake test, the product is designed for use with a stock-size turbocharger and excels in that application.