Category Archives: Avant

Audi RS3 Predictions

The new Audi RS3 is a car I’ve followed due to the similar size with the Audi B5 S4.  Showing up with 400 HP is something that makes the RS3 even more appealing.  Of course there are many other changes that the RS3 will bring with it, but on the flip side the B5 S4 has a lot going for it, beginning with being a better looking car.

2018 Audi RS3
Photo copyright manufacturer

Not that the RS3 is ugly, it simply lacks the classic look that the B5 S4 has.

Brilliant Black Audi B5 S4 Avant

Since I’ve been thinking about the RS3 I naturally started to ponder what the power potential of the car would be.  With the Audi TT-RS having a similar 5 cylinder 2.5L engine I figured that would be a good substitute for the new RS3 engine.  To get an idea of what the aftermarket might do to up the ante on this engine I checked out the APR 2.5 TFSI Stage III GTX Turbocharger System.

APR’s figures seem to be determined with their Dynapack dyno.  My experience having my car dyno’d on a Dynapack, (APR’s no-less), showed that the readings were slightly greater than a Mustang dyno, making them a little more than what I’ve recorded on the street.  This is a reasonable outcome as the Dynapack eliminates the wheel to roller losses of a drum type dyno.

APR’s dyno reported CHP values are lower than the RS3’s advertised 400 HP, thus I’m now wondering how good of a substitute this engine will be, but until the RS3 is released the TT-RS will have to do.

Taking the APR Stage 3 kit wheel torque values and plotting them versus some B5 S4 dyno results obtained with BorgWarner RS6 turbo’s, and a single pull from an S4 with TTE780 turbo’s, the results are remarkably similar, with some minor, but potentially significant differences.

BW RS6 vs TTE780 vs APR TT-RS Stage 3
BW RS6 vs TTE780 vs APR TT-RS Stage 3

The TT-RS produces torque slightly faster than the BW RS6’s on an 2.7T engine, but about the same as the S4 equipped with TTE780’s.  I would have expected the BW RS6 to generate torque faster than the TTE780 and I attribute this unexpected outcome to the RS6 curve being the composite average of 6 different car dyno’s.  There is likely individual B5 S4’s with BW RS6 turbo’s that do generate torque faster than the TTE780 equipped S4, and therefore also the TT-RS.

At the top end the TT-RS has slightly more TQ/HP than the BW RS6 equipped S4.  Again, the TTE780 is shown outperforming the aggregated RS6 data, and this time the TT-RS as well.  Given the larger size of the TTE780 compared to the BW RS6 turbo this result is not surprising.

Overall, while this is merely an academic exercise in predicting how the B5 S4 with RS6 turbo’s would compare to the not yet available RS3, I’m pleasantly surprised to see how well the old B5 S4 2.7T may compare to the latest release from Audi.

Avant Finishing Touches

Today was directed at some loose ends on the Avant.  I completed the installation and bleeding of the Stoptech BBK on the front end of the Avant.

Avant with Stoptech 332 Big Brake Kit
Avant with Stoptech 332 Big Brake Kit

Then, because the alignment was horribly out of whack, on account of all the components being moved over from the Sedan, I brought the Avant in to the Alignment Specialists (in St. Charles MO) to have an alignment performed.

Avant alignment

A few hours later it was back on the road and driving well.  I then stopped off at a local Cat Scale to have the Avant weighed.

Avant weight

I’m impressed that it is only 20 lbs. heavier than my Sedan S4 (shown below).

Audi B5 S4 Vehicle Weight Sheet
Audi B5 S4 Vehicle Weight Sheet

Finally it is time to start giving some thought to how I have the suspension dampers set.  With the information provided by Performance Shock from when they rebuilt my Stasis Öhlin Motorsport coilovers I’ll be conducting some experiments to see what settings I like.

Stasis Öhlins Motorsport (Front) Shock Absorber Dyno
Stasis Öhlins Motorsport (Front) Shock Absorber Dyno
Stasis Stasis Öhlins Motorsport (Rear) Shock Absorber Dyno
Stasis Stasis Öhlins Motorsport (Rear) Shock Absorber Dyno

Brake Swap In Progress

Given the better resistance to brake fade that the Stoptech brakes exhibited as compared to the stock S4 brakes during my braking test I’ve decided to install my Stoptech brakes on the Avant.

I began with removing the Stoptech’s from the driver’s side of my Silver Sedan and then removing the corresponding stock S4 brake from the Black Avant.  I was equipped this time with appropriate plugs for the ends of the brake hard lines, so that I did not have a brake fluid mess to deal with.

The install of the parts on the new vehicles went without fanfare.

Stoptech 332 BBK Installed on Audi B5 S4 Avant
Stoptech 332 BBK Installed on Audi B5 S4 Avant

With the driver’s side complete, aside from bleeding the brakes, I’ve stopped for the day and will try to get the passenger side completed tomorrow.

Also noticeable in the background is the blue shielding that covers the line to the Stasis/Ohlin Motorsport Oil Reservoir, the Motorsports are now completely in place on the Avant.