Upgrade Work

AN line collection

What started out as an oil line upgrade has expanded to include fuel lines and shortly wastegate signal and actuator lines.

an-lines

I purchased the oil lines when I decided to swap out turbochargers and replace the stock oil lines.

oil_lines2
(L) Induktion Lines (R) AU Tuning Lines

I had on hand a set of Induktion oil lines that had been purchased for a previous setup, but the more robust lines being sold by AU Tuning were an appealing alternative, which became an easy decision when the Induktion lines were sold off.

I started to DIY a set of fuel lines for use with an SRM intake manifold that was modified to fit an RS4 throttle body.  Not too long into that project the aggravation of trying to cut and fit the fuel lines, coupled with my concern about having fuel spraying inside the hot engine compartment due my own ineptness at building this type fuel line led me to contact Marc aka ‘cinesnow’, a forum member on the Audizine website who had developed the oil lines I now had a pair of.  I inquired about having a set of fuel lines built up and he agreed to help me out.

srm_im_fuel_linesA couple of weeks later I had a set of very solid fuel lines for use with my modified intake manifold.

When I removed my K03 turbochargers for a rebuild I began to think about how I could better hook up the sensors on my car.  One in particular is set up to monitor the compressor housing pressure via the signal line.  Normally I have a sensor tee’d into the silicone hose but it occurred to me that an AN fitting might work well in that role.  I knew that  Marc had designed a set of wastegate and signal lines with AN fittings and stainless hose and so I contacted him to see about having a line slightly modified to accept an AN fitting with a port for a pressure sensor.  He thought this would not be difficult and had a set worked up with the modification I had requested.  That pair of lines should be arriving soon, especially good timing since my K03’s are due back from being rebuilt shortly.

 

 

Testing

AWE S-Flo Testing

Going through some old files I came across this picture:

AWE S-Flo Tested
AWE S-Flo Tested

The first vendor claim that I tested, AWE’s S-Flo intake.

The product is a cone style air filter that was purported by AWE to have increased air flow rates through the MAF sensor by 25 grams-per-second.  That is an astonishing increase in airflow rate simply by changing from the stock airbox and flat panel filter to an open element cone type filter.  At the time of the AWE S-Flo’s introduction in the 2000 time period I hadn’t yet grasped that with the stock MAF sensor a grams/second change resulted in nearly a 1 for 1 wheel horsepower change.  That would have meant the S-Flo should have resulted in close to 25 additional wheel horsepower if it in fact did increase airflow rates by 25 g/s.

I had been reluctant to try the AWE S-Flo, a prior test performed by another Audiworld forum member on a K&N panel filter had shown no improvement over the stock air intake system.  Still, I was hopeful AWE was accurate in their claims for the product and when a Group Buy was started to give a discount price on the S-Flo I decided to give one a try.

As the buy group members began to receive their products I was slow to get around to installing mine.  Another forum member with a car setup just like mine had recorded some measurements of airflow.  An important point to remember is that back in the mid-2001 time frame all of the B5 S4’s were relatively uniform in terms of modifications, there simply was not all that much that could be done to the motor outside of a Stage 1 tune, exhaust muffler system, and intake filter.

The other forum member, “Black BiTurbo”, had his car setup just like mine, and he provided me with the VAG-COM readings from his car with the AWE S-Flo installed.  I recorded my car and compared our data.

The results shown above were a small surprise and a big disappointment with AWE Tuning.  There was no difference, using the S-Flo was no better than the stock air intake system.

I began to bring this point up with AWE representatives on the forum.  They said they would be dyno-ing an S4 with their S-Flo intake to prove the performance gains.  Months passed with no dyno test being conducted, then years went by, still nothing.  Eventually after making the same claims for over a decade AWE stopped selling the product, never having backed up their claims as they had stated they would.

If you look around you can still find other vendors peddling the AWE S-Flo with the same unsubstantiated claims, 

Our scan tool measurements recorded increases of 25 grams-per-second of air through the mass air flow sensor (MAF) at various points of the rpm range, with a dramatically smoother flow curve. Dyno tests repeatedly show a 8-9hp power gain to the wheels!
What a load of crap…

I ended up sending my unused AWE S-Flo intake back to the vendor for a refund.

Audi B5 S4 Information and Testing