Fluidampr crankshaft pulley

Soon to be installed on my S4 is one of the Fluidampr engine dampers.

Fluidampr 2.7T engine dmapener

I’m not expecting to be able to detect any difference from the driver’s seat, but hopefully it will help with engine longevity, especially at higher than stock horsepower levels which I expect my car to be operating at.

Here’s it is on a bathroom scale, weighing in at 7.2 lbs.


And a couple more angles of the product.



Today I removed the stock crankshaft pulley and weighed it on the same scale to compare with the Fluidampr weight.


  • Stock: 4.6 lbs
  • Fluidampr: 7.2 lbs

Here’s the two parts side-by-side:


(L-R) Stock, Fluidampr

Installed on the S4.


F21 First Logs

After puzzling over the results I was getting yesterday (shown directly below) I began thinking about what I could have done during the turbocharger swapping that may have messed with the F21 wastegates.  The tune was ruled out after conferring with Daz, (who is helping with my tuning efforts), that this initial tune should have been similar to the K04 boost profile and had a low wastegate duty cycle.


Preload checks were good after installing the engine.

The one other change I had made was to solder a wire to the N75 to enable the boost cutoff safety that the TorqByte WMI controller uses.  The perplexing part was that I hadn’t completed the wiring, I’d simply spliced into the wire going to the N75 and left the rest of the wire coiled on it’s spool and tucked under the Y-pipe.  Without anything else changing I decided to look at this wire as a possible cause of the problem.  Sure enough, when checking the continuity on the N75 connector it was getting a good check with the ground terminal on the battery – that shouldn’t be happening.  Upon closer inspection I found that the end of the wire inside the spool was bare and had managed to come into contact with the top of the intake manifold.  I wrapped the end in electrical tape and the problem went away.  Out for a check with the N75 disconnected, proving that the wastegates were functioning correctly and limiting boost to 13-14 psi.

N75 electrically disconnected

N75 electrically disconnected

Then I reconnected the N75 valve and made a few abbreviated pulls starting at different engine speeds to assess how the boost onset looked.

Chart of FrankenTurbo Mixed Flow F21 Boost Onset

FrankenTurbo Mixed Flow F21 Boost Onset

In a follow up I’ll be comparing these results with similar data from the BorgWarner K04’s.

I have discovered that I have oil dripping from the driver side turbocharger – doh!  I was hoping that it may have been coming from the oil return line, but after checking I found those bolts to be tight so I am now left with trying to check the oil supply line, which will entail taking the engine back out.

FrankenTurbo F21 First Run

Got the S4 out on the road today with the first version of the tune to shake down the parts and make sure the car is running properly. Got on the throttle briefly to see how the boost comes on.


My intent is to operate around the same boost profile as I had with the K04’s in order to gather some comparison pressure and temperature data, so this will need to be toned down a little.  Then I’ll start to up the boost level and see what comes of it.

Running with FrankenTurbos

Finished reinstalling the engine today and started it up with the FrankenTurbo F21’s in the mix.  I’m still on the legacy tune from the K04’s and larger injectors so I just did a leak check and let it idle for a couple of minutes.

Engine installed with F21’s

This afternoon I swapped fuel injectors from the Bosch EV14 72 lb. to the same injector in a 60 lb. size.  I found that with the boost level I have been operating at that the 72 lb. injectors had a maximum duty cycle around 50%, I got the impression I had much more injector than needed for the pump fuel tune that I was operating with and anticipate using in the future.

Bosch EV14 60# fuel injector

Bosch EV14 60#

With the injectors swapped I then took care of a few checks.  First I checked the wastegate preload on the FrankenTurbo F21’s, this was the second time I checked them, once before installing the turbochargers on the car and now with them installed.  I had to make some slight clocking adjustments to the compressor housings after attaching the turbochargers to the exhaust manifold and I wanted to ensure that the preload was still equal for both turbochargers.

Next I attached the intake components so I could perform a boost leak check.  With that check good I set about installing the engine back into the engine compartment.  I have yet to find a quick way to get this done, mainly the issue is installing the axles as the engine is being lowered into place.  This is a painstakingly slow process.


Eventually things went back into their original places and the engine was back in the car.  Now I’ll begin the process of hooking everything back up.