Buy the two cheapest S4 in the country and track them!

So the goal for this year is to get back on track in a low cost way… and have a hoot doing it! After I sold my truck and trailer a few years ago, towing a car to the track is no longer an option (and to be fair I don’t want to deal with all of that right now). I want to go back to more simple times when I could just pack up and go!

I have become a huge fan of Audi after I picked up my first one a couple of years ago (enter the RS5 when I sold the truck). Peter Krause commented on one of my pics of the RS5 last year that my car was the best car he had ever driven on track (same model, not my car – mine is a Sunday driver). That got me really curious. That curiosity won’t go away so I neeed to satisfy it 🙂

Modern Audi’s are a little on the heavy side so the cars will be a little bit of an underdog. That’s OK as I love making things better and at the same time improving myself 🙂 These things have so much potential.

The cars:

  • 2010 Audi S4 – 7 speed sequential (DSG), No sports diff. One owner, 116K on the clock and serviced by a Porsche garage all its life (from NJ)
  • 2015 Audi S4 –  7 speed sequential (DSG) , Sports diff and dynamic suspension. 38K on the clock with fairly good service history (from MD)

Both the 2010 and the 2015 Audi S4 horsepower is claimed to be 333HP from the factory. This has been found to be more in practice but it doesn’t take much to get them to over 500HP! It is surprising that the 2015 Audi S4 horsepower wasn’t increased as part of the B8.5 facelift, but if it isn’t broken… 

I’ve gone through both cars and have ordered all of the necessary parts. As part of the preparation for the first event both cars are getting brake upgrades, and the 2015 is having the straight through pipes replaced with a proper exhaust system! I also have to replace all of the front control arms on the 2010. Other than that, both are in great shape!

Why Two?

Well, one of the primary reasons is to ensure that I can carry out the season without any issues. The other is to compare the stock vs modified versions and illustrate any improvement. Lastly, it’s to tell a funny story if one of them breaks down.. just like the infamous Top Gear cars that used to lurk in the background during the specials (in case one of the presenters’ cars needed help). 

Also plan to have others joining me through the season (including Ross Bentley) and the two cars will vastly help. 

The Story

The plan is to hopefully demonstrate how accessible and enjoyable track driving can be. Starting with the cars in stock form (except for the brakes which are essential), I will document the progression of the cars throughout the season. They will be driven to the track so at some point they may even get small trailers 🙂 With Audi joining Formula 1, it is an excellent time to engage the Audi community.

The Audi A4 platform was chosen as it is one of Audi’s most popular models (and there are plenty of interchange parts from the S4 to A4). The sequential box is being used as there are more of them available. I would have preferred a manual and I might take a bit of flack from the “save the manual” community. The truth is the manual cars are getting more expensive and there are some benefits to the DSG on track. 

The goal is to demonstrate that you can have fun at the track with high mileage cars, and to answer questions like: “how much of a difference does a sports differential make to performance”.

Development through the year

  1. Upgrade driver first – Of course the most important thing and where much of the discussion will happen 🙂
  2. Weight savings – the Audi’s are heavy. I have materials on the way to make carbon fiber fenders, doors etc etc. Some weight savings will be seen in the brake area (as the setup will be lighter than stock – calipers and rotors) – think Colin Chapman, “simplify, then add lightness!”
  3. Suspension upgrade/tuning – starting with the roll bars! I also have a set of springs to do a direct comparison of the stock setup to an easily accessible/common setup. Apparently the stock suspension performs very well but we’ll see (roll bars might have to come earlier).
  4. Tune/mild modifications – This platform is very stout. Out of the box it’s 333 HP. With a few minor modifications and cooling you can easily get to 450 HP; 550 HP with a few more tweaks. Really want to analyze how and if adding tons of power can change your performance on track with pros and cons. Note,  the 2015 Audi S4 horsepower will be increased whilst leaving the 2010 stock. 
  5. Rear wheel drive modification! Sacrilege for the Audi Quattro fans, but many are interested in it. Will it help or hurt the platform? This mod will be left for at least half way through the season and is completely reversible. Depending on how the power to weight works out I may have to do this prior to doing the stage 1 tune… we will see. All very easy to do though. 

Rough outline (all of the road racing events are with NASA and schedule can be found on their site:

Updated 🙂


  • Intro both cars, general maintenance (engine, ignition, gearbox and diff) – Talk about the plan for the year. Replace the straight through exhaust on the B8.5!
  • Dyno video of both cars in starting state (after maintenance) – B8.5 might borrow the stock exhaust from the B8 to show the difference between exhausts (Any guesses on the 2015 Audi S4 horsepower?)
  • Event: (Ozarks) – Tire upgrade – Change in performance comparison between sports diff and open


  • Diet Stage 1 – Interior removal – 0-60 runs and comparisons
  • Event: One Lap of America – Fingers crossed!
  • Event: (Heartland Park Topeka) – Suspension upgrade (starting with roll bars, springs on the dynamic dampeners)


  • Diet Stage 2 –  Carbon fenders/hood/sunroof – 0-60 runs and comparisons  
  • Event: (Hallett)
  • Event: (Potential new track TBD)


  • Diet Stage  3 – Carbon doors and trunk
  • Event: (Ozarks)


  • Stage 1 tune and dyno
  • Event: (High Plains) -September
  • Event: (Autobahn) – Stg 2 tune – realizing the max of 2015 Audi S4 horsepower


  • RWD modification
  • Event: (Heartland Park Topeka)
  • Event: (Ozarks) – completes the story – after all the mods etc is the car better or worse?

Data Driven

At each step there will be a data driven approach. Many aspects will be measured (brake temperatures, brake fluid moisture content, ambient temperatures, track temperatures, tire temperatures and tread depths etc). Time will of course be paramount, but I intend to break down the performance to corners vs just focusing on entire laps.


One thing I haven’t mentioned yet is that all of the modifications etc will all be fully reversible. That allows me to get to the end of the year and either put the cars back to stock and sell them… or…. commit to turning them into full track cars! Who wants to see how far we can take the 2015 Audi S4 horsepower!

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