My B9.5 S4 Build

[Midlifemods]

I bought a used (1,500 miles) S4 Premium in Quantum Gray back in late 2022.


I knew I was going to modify it so I didn't care that it was Premium trim. I didn't even care to lose the sports dif. I had a plan to modify it with 034 Motorsport parts starting with the cheapest and going to the most expensive. My goal was to maintain it's comfortable street quality, but make it more track and canyon capable. I launched a YouTube channel to document my journey. This was my first attempt at YouTube. My brand was going to be midlife crisis dad jokes and car mods. This was the first video I released.

https://youtu.be/sag01T2qXC4

The first mods I did were the 034 Motorsport Rear Sway Bar https://store.034motorsport.com/034m...5-allroad.html

and 034 Motorsport End links https://store.034motorsport.com/dyna...5-allroad.html

I also did H&R sport lowering springs.

Right after installation, I took the car to Buttonwillow Raceway to test the car out. Here is my installation and track day video:
https://youtu.be/BUQ1q2bUvyw

The next mod I did was the 034 Motorsport transmission mount and insert.
https://store.034motorsport.com/dens...s5-q5-sq5.html
https://store.034motorsport.com/034m...-aluminum.html

These mods were super simple and made a big difference in shifting feel.

Here is the installation video:

https://youtu.be/jRzSRvTKv9U

The next mod I did was the 034 Motorsport front strut brace. https://store.034motorsport.com/034m...-aluminum.html

This was another simple installation that added some nice rigidity to the chassis.

I tested it at auto cross and saw a slight improvement in my times. Here is the video of installation and testing:
https://youtu.be/0WdRk3_Daks

The next mod I did was the 034 Motorsport rear subframe mount inserts. https://store.034motorsport.com/bill...9-audi-a4.html

This mod was more about increasing the life of the subframe and less about immediate driving improvements.

Here is the installation video:

https://youtu.be/UvwiZt8CMpU

The next mod I did was the stage 1 ECU tune on 91 octane. https://store.034motorsport.com/b9-b...-software.html

What an amazing difference this made. The pops and bangs and increased HP are a lot of fun.

Here is the video on the tuning process:
https://youtu.be/E2SSDUCXmCU

The next mod I did was the JXB Performance Driveshaft Carrier https://www.jxbperformance.com/produ...arrier-upgrade

This Reduces drivetrain slop, restores and maintains driveshaft alignment and installs without having to remove or disassemble the driveshaft.

Here is the installation video:
https://youtu.be/3dVRkqaY4Nc

The next mod I did was the 034 Motorsport Cold Air intake https://store.034motorsport.com/x34-...-3-0-tfsi.html

and the 034 Motorsport SuperDuper Turbo Inlet https://www.034motorsport.com/superd...-sq5-3-0t.html

Here is the video of the installation:

https://youtu.be/xVQANI_RP2Y

The next mod I did was an E85 tune with 034 Motorsport and a Wagner Competition intercooler. https://store.034motorsport.com/wagn...-s4-b9-s5.html

Here is the video of the installation:
https://youtu.be/AIsHJsjoR04

I signed up for a track day at Laguna Seca with 034 Motorsport so I knew I would need a brake upgrade so the next mod I did was the 034 rotors, carbotech pads, and 034 stainless steel brake lines. https://store.034motorsport.com/2-pi...9-5-s4-s5.html
https://store.034motorsport.com/2-pi...9-5-s4-s5.html
https://www.034motorsport.com/stainl...s5-q5-sq5.html

Here is the installation video:
https://youtu.be/R5lv3_A8DYE

Now I had to test the car on the track. The car did great considering how heavy it is. I did cook that pads by being a bit too aggressive at first without properly bedding the brakes. Here are my laps:
https://youtu.be/RR2ojMRewIQ


After all the mods, I was curious, after all the mods, what my HP was, so I took the car to a dyno shop:

https://youtu.be/-T-y6c6jjiA

The next mod I did was new 034 Motorsport flow formed wheels https://www.034motorsport.com/ztf-lp...1mm-bore.html#

Here is the video:

https://youtu.be/RFEzGc3GGzM

This isn't a performance mod, but a cosmetic one. No performance gains, but looks much better.

https://youtu.be/7wC2QKlJRrw

I discovered I had a moderate boost leak so I took my S4 to the shop to investigate. We conducted some basic diagnostics, including a smoke test, and then finally replaced the PCV unit. Will this fix the boost leak issue? Watch to find out. Watch until the end to see some new under the hood bling.

https://youtu.be/ho42T3cGE30

[Goonz]

Your video on the 034 tune is what inspired me to get mine a few years back. Thanks for your insightful videos.

[Sean@TAG]

Wow!! Very cool build!! Excellent and informative writeup too!! Let us know if there is anything at all we can help with on the next round, and congrats!!

[Midlifemods]

Thanks! how do you like the tune?

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Wow!! Very cool build!! Excellent and informative writeup too!! Let us know if there is anything at all we can help with on the next round, and congrats!!

Thank you! I appreciate the support. You've got a great shop!