The Parts:
A Revo turbo inlet hose was made available for testing by another GTI owner who loaned it for this flow test.
The Revo inlet hose differs from the turbo inlet parts that have been previously tested by virtue of it being a hose that connects from the airbox to the turbocharger without the use of a turbo inlet elbow. Instead of an elbow the Revo inlet uses a small transition that is part bell mouth and part locking mechanism.
The Test:
Test setup is the same as with other inlet elbows, with the top half of the GTI stock airbox attached to the inlet of the hose and the outlet to an adapter that connects the part to the flowbench.
The flow test is first performed using an adapter that is sized the same as the inlet to the IS20/IS38 turbocharger compressor.
With this adapter the Revo inlet hose flows 405 CFM. This ranks among the group of highest flowing stock adapter setups that I’ve tested.
Note: The Revo inlet hose is comparable to other inlet elbows that require the use of a larger than stock hose. A number of inlet elbows that have been tested previously were tested using a stock accordion hose only.
Next a silicone adapter is used to attach the Revo inlet to the flow bench. This adapter simulates what a larger than stock turbocharger might have for a compressor inlet. There is no specific turbocharger model that the adapter simulates.
With the larger adapter the Revo flowed 452 CFM. This is at the bottom end of the setups that I’ve tested with aftermarket hoses.
Results:
The charts below show the Revo results along with other products that have been tested:
Conclusion:
Flow testing of the Revo inlet produced airflow measurements of 405 CFM with an adapter replicating the IS20/IS38 turbocharger housing, and 452 CFM with a large adapter.
The Revo inlet is among the best performing inlets when paired with a stock turbo housing. With a larger than stock turbocharger inlet the Revo does not flow as well as other products that have been tested.
Looking the part over and comparing dimensions with other elbows that have been tested the inlet to the metal adapter is the largest of the inlets that I have measured. It doesn’t appear that the Revo inlet takes advantage of that size due to the construction of the inside of the silicone hose. There’s a decrease of the inside diameter about an inch into the hose, which helps position the metal adapter, but at the same time it reduces the hose cross section down to about 69mm whereas the adapter inlet is 74mm. On the outlet side the ID is 48.1mm which is on the smaller side of the parts I’ve tested.
Would you be able to test the Turbotechnics inlet pipe? It’s similar to the Revo one as it’s a single silicone hose which replaces both the accordian and TIP, however the diameter appears to be more consistent and the bend leading into the turbo inlet isn’t as sharp.
If I can get a sample to test yes I can.
I would bet the Turbotechnics inlet pipe outperforms this by a wide marging
With an IS20/IS38 turbo housing inlet it would be unlikely to perform much better.
i bet $5 and a ham sandwich that it would, but it doesn’t matter because the turbo technics setup only fits RHD right hand drive cars because the brake master cylinder for USA/Left hand drive cars is in the way 🙁
actually…. you might be right, since through the 48mm is20/is38 opening it looks like maxes out at ~400cfm anyway
love all your research by the way! data really cuts through the noise….
have you tested the larger MST turbo inlet with the 53mm opening on the normal is20/is38 sized housing?
I’m curious how the larger MST “hybrid” inlet would flow on a is38 turbo, since I have is38 now but want to upgrade later onto larger hybrid and curious which one to buy
and i owe you $5 and a ham samich it appears 🙂
Thanks! I did test both versions of the MST inlet elbow, here’s where it’s at:
http://mygolfmk7.com/2019/07/mst-performance-intake-analysis/
THANKS!!!
that is super interesting, and honestly surprising, that both sized MST inlets flow identically through an is20/38 inlet size.
I would have assumed the larger 53mm inlet creates a “lip” or edge where it goes into the turbo given the inlet pipe opening is larger than the turbo inlet hole, but apparently that doesn’t matter one iota in actual flow data. super interesting!
Revo omong highest flow, but it didn’t reach 410 CFM. 5 CFM less than what the turbo can take. My takeaway from all this testing is that the max airflow into an is20/is38 inlet is 410 CFM. So the goal for best intake for least $ is to have your air filter + box, hoses, turbo inlet pipe etc flow just above or at that 410 rate to the turbo. In that respect.. Revo doesn’t make it and I’d choose a setup that flows 410.
The maximum airflow into the IS20/IS38 compressor is not 410 CFM. The test on the flowbench involves increasing airflow through the parts and observing the pressure differential across the parts. When continued increases to the airflow results in a pressure differential of ~1 psi (28″ of H2O) the airflow is no longer increased and the airflow is recorded. This is driven by a limitation of the measurement equipment, the digital manometer that I use maxes out at about 32″ of H2O. At 32″ there would be more than 410 CFM, I chose to stop at 28″ because it is a common measurement point for flow benches.
When I measured the vacuum at the turbo inlet (link to test below) I recorded ~ 3 psi at max, so three times what I’m testing at. Relative performance between the products will remain the same.
http://mygolfmk7.com/2019/10/air-scoop-airflow-test/
hey Jeff, If I sent you one of these with an air filter would you be willing to flow test how an intake flows with/without it and with/without an air filter? I have yet to see a single car in my history that did not gain at least some power from putting one of these BPI velocity stacks on the end of the intake instead of the normal air filter, everything from 200whp all motor hondas, to big power toyota supras, to Evos to 1k+ whp procharged LS cars.
https://www.bpi-us.com/dyno-tests
If you’ll take care of the shipping I’ll run flow tests with it. What air intake would the filter connect to?
cool. I run mine on a MAperformance intake setup but any of the “filter on a stick” intakes would work, like CTS, or maybe the MST or VWR one without the heatbox/shield.
if you don’t have an MST intake laying around I could maybe ship you my whole intake but that would make it more expensive
I still have the MST setup if you think it will work.
http://mygolfmk7.com/2019/11/mst-performance-intake-system-flow-test/
Is there a difference in flow using a cotton drop in filter vs a foam filter drop in from revo?
I don’t know, I have not tested those products to make a comparison.