This is an example of why I have tried to keep the added openings on my stock airbox on the forward facing side and have retrofitted a baffle on the lower opening I created.
After driving in some rainy conditions the dirty water from the road has coated the bottom of the airbox. If this area was more open it would be possible for the water to coat the air filter instead.
In addition to the White Dog Racing Bipipes that I flow tested a couple of days ago the box contained a set of the intercooler inlet pipes that replace the stock components for use with the Silly Rabbit Motorsport RS4 side mount intercoolers.
These inlets in addition to being made of metal are larger in diameter than the stock components they replace.
For the flow testing I attached the inlet to the SRM intercoolers and mounted them onto the flowbench. I began with the stock hardpipes and couplers supplied with the SRM intercoolers.
Both the driver and passenger side flow performance was measured.
Then I swapped to the White Dog Racing inlet pipes and checked the airflow again.
Finally, for comparison with a completely stock setup I used the stock S4 intercoolers with the stock inlets.
Airflow through each of the setups was measured at a depression of 28″ of H2O.
The chart above illustrates a number of pieces of data:
The airflow through the intercooler and inlet is increased measurably, but only slightly, by using the larger White Dog Racing hard pipes, when evaluated on the flow bench.
For a typical user the larger inlet pipes may not provide much performance benefit, but for the all-out build where optimizing every part matters, the White Dog Racing hard pipes do provide measurable gains.
Things progressed this weekend with the TTE550 turbochargers, but it’s been a bittersweet continuation of the project with the sudden unexpected passing of “Daz Dillinger”. Daz is a person with whom I have partnered on several projects since we were first introduced several years ago. It has been his knowledge and generosity that have provided the foundation upon which this project, as well as others, have been built. I will have more to say about Daz’s work with me in a separate posting.
The first drive with the TTE550’s has been successful, although with two issues to address. First was a high pitched siren sound when boost hit about 20 psi, something I immediately thought was a boost leak. After hooking up the boost checker I confirmed my hunch, that yes there was a hose clamp on the upper passenger side intercooler that was not tight enough. It was a relief to have the problem be located in such an easily accessible location.
The second issue, which is a known obstacle to overcome with the changing out of turbochargers, is that the TTE550’s use an 8 psi-preload on the wastegates, and the FT21’s used about 14 psi. Thus the tune now will under-boost on account of the wastegate differences.
