This morning the S4 went back onto the DynoJet dyno for a series of pulls with the BorgWarner K04’s and a moderate boost Daz tune.
The purpose of this session was to establish more baseline data for making comparisons to some aftermarket turbocharger options.
![Chart of BW K04 baseline dyno pulls](https://myaudis4.com/wp-content/uploads/k04_baseline.jpg)
The ‘final’ results peak dyno numbers are of less interest to me than the shape of the torque curve. I am expecting a K04-hybrid turbocharger to be capable of more peak torque and power than the RS4 K04.
Here is the boost profile that this tune uses:
![Chart of K04 Stg3 tune boost profile](https://myaudis4.com/wp-content/uploads/k04_dyno_boost_pull_1_and_2.png)
Boost and MAF
![Boost & MAF](https://myaudis4.com/wp-content/uploads/boost_maf_pull1_and_2.png)
Boost and N75 Duty Cycle
![Boost & N75DC](https://myaudis4.com/wp-content/uploads/pull1_and_2_wgdc.png)
Here’s a street pull:
Here is how the K04’s compare with K03 turbochargers on my car. K03’s are shown with two different tunes, one very aggressive and the other moderately aggressive.
![K03 (NVR & Nef tunes) vs K04 (Daz tune) Wheel Torque](https://myaudis4.com/wp-content/uploads/k03_vs_k04_torque.jpg)
What is notable about the chart above is how closely the torque curve of the K03 and K04 match one another.
![K03 (NVR & Nef tunes) vs K04 (Daz tune) Wheel Horsepower](https://myaudis4.com/wp-content/uploads/k03_vs_k04_power.jpg)
Below are the EGT readings for each turbocharger/tune on the dyno.
![Chart of K03 vs K04 EGT readings on dyno](https://myaudis4.com/wp-content/uploads/k03_vs_k04_egt.jpg)