MST Performance sent information about a revision they have made to their MQB turbo inlet kit. The inside diameter of the outlet of the latest version of this inlet elbow has been increased to 53 mm versus 48 mm of the original model.
A sample of this revised inlet elbow is being sent to have flow test measurements made.
Does « The bigger the better » applies ?
Is there a risk of having a too big OD on TIP? (Turbulence, loose of vacuum effect, etc???)
If the turbo is not big enough (is12) maybe too big TIP diameter could reverse the efficiency of air flow?
I’ve looked at the diameter measurements of the various inlet elbows and compared that with the airflow each produced and there is a clear point where continuing to increase the size of the elbow doesn’t provide any additional airflow. There’s a chance this latest revision to the MST pipe will not perform any better than the version that was already tested.
I’m trying to find a way to accurately measure the airflow exiting the elbow with a velocity probe, but I still have some work to do on that.
The less airflow through the elbow the less the benefit there is from a larger elbow.
If you are installing a hybrid turbo with 52-53mm compressor inducer it will most likely make a diffirence.
Another aspect to consider is if the car is being retuned with the parts swap. Simply swapping one intake part for another is unlikely to make much of a difference with an advanced torque based engine management system like the SIMOS. The ECU is going to be tuned to deliver a certain level of TQ based on driver request and it will modify boost, afr, and timing to deliver. A less restrictive part isn’t going to cause the ECU to deliver a higher TQ value, it will just be able to deliver what is programmed with less work input to the turbo. WGDC might be a better measure of the affect that the aftermarket inlet elbows have on engine/turbo performance. The slight gains seen without re-tuning would likely derive from a more efficient system operation.
53mm for hybrid turbo, 48mm for stock turbo.
This is something noteworthy as well. If an aftermarket turbo goes away from the compressor inlet diameter that the IS20/IS38 use and go larger, a larger inlet elbow outlet would be a good idea.
I’ve been meaning to re-measure some of these elbows using a larger adapter to simulate an aftermarket turbo. The few tests made with a silicone adapter instead of the stock diameter printed adapter showed a good bit more airflow.
Hi would great if you could do a test up against the Turbo Technics Large Bore and Intake hose as everyone is telling me this is number 1 out there. Thanks
So all inlets you have there are 48mm except MST which is 53? Some of them “look” at least 50.. Could you measure a few?
Cant use this with is38 then?
Roberto, yes it can be used with an IS38. The IS20 and IS38 have the same size inlet of the compressor housing.
I’m so confused! MST’s website says v2 (53mm) is for hybrid turbos and the original (48mm) is for stock is20/is38. Will both versions physically fit a stock is20?? Just the inner diameter of the outlet is the difference between the two?
Hey Rob, your understanding is correct. Both versions will fit with the IS20/IS38 turbos, the larger one is not likely to provide any performance benefit with an IS20/IS38 turbo due to the size of the inlet to the turbo.
Great! Thanks for the fast response and thanks for taking your time to do all of this!!