Dyno Results Vishnu Tuning Step-by-Step DYNO results (Procede+PWM Meth+Cat Deletes)
Vital Statistics
  • Vehicle / Motor
  • Dyno Type
  • Dyno Correction
BMW E9x M3 (S65 Motor)
Configuration (from Baseline)
  • Vanguard TI CAT-Back Exhaust
  • 91 Octane (US), 95 Octane (RON)
  • 6-Speed Manual Transmission
Modification (since Baseline)
  • Both CAT Delete
Measured Results:
  • Torque
  • Horsepower
275 FT/LBS
359 HP
@ 3850 RPM
@ 8200 RPM
(372.9 NM)
(364.0 PS)
(38.02 KGM)
(267.7 KW)
Baseline Measurements:
  • Torque
  • Horsepower
246 FT/LBS
346 HP
@ 4000 RPM
@ 8000 RPM
(333.5 NM)
(350.8 PS)
(34.01 KGM)
(258.0 KW)
Performance Gains:
  • Torque
  • Horsepower
13 HP
(39.3 NM)
(13.2 PS)
(4.01 KGM)
( 9.7 KW)
Dyno Graphs:

Excerpts from Article

Continued from this Dyno Database entry.

Today, we had two updates to the car and tune. First, we eliminated both primary and secondary cats. Stock X-pipe and resonators were retained. We used 2.5" crush bent aluminized steel piping that we fabricated at a local muffler shop. Nothing fancy. Cost us less than $100. I suspect using proper mandrel bends may be worth an extra hp or two.

We also got control of AFR targeting, giving the Procede to change factory AFR setpoints by +/- 3 points. This is a very wide adjustment range. AFR target changes are mapped via 3D table. RPM vs. Airflow (in kg/hour):

The first thing we did was quantify the gains we got from deleting both sets of cats while running the stock tune. Compared to yesterday's "no tune" baseline, todays "no-tune" baseline (with cat deletes) were good: