Car
Car: BMW M3 E46 (200x) – Arthur
Engine: 3.2 24V (L6) (S54B32)
Manufacturer data: 343 ch (338 hp) @ 7900 rpm – 365 Nm (269 lb.ft) @ 4900 rpm
ECU: Siemens MSS 54
Mapping (David & Vincent): Performance optimization
Configuration: Carbon-M airbox – Decatalyzed line – Supersprint manifold
Fuel: UL 98
PerfectPower Weighing
Date: Monday, July 7, 2025
Place: France (91)
Result: 1575 kg (3472 lb) with full tank (63 L)
PerfectPower Car Sheet
Note: The car weight is given with a full tank (PerfectPower and manufacturer standard) and the additional weight with a 80 kg (176 lb) person on board (arbitrary standard), but these two fields must of course be systematically adapted to the real measurement conditions during each session!
PerfectPower Results
Single session – Adjustment
Date: Monday, July 7, 2025
Place: France (91)
Session Objective: Optimal adjustment VANOS – Injection – Ignition (power measurements)
Software: PerfectPower Androïd 7.1.3
Hardware: David’s Xiaomi MI 8 + RaceBox Mini 25 Hz driven by PerfectPower
Measurement conditions:
- Mode 2 “GPS only”
- DIN 70020 standard (engine results corrected for 1013 hPa and 20°C (29.92 in Hg and 68 °F))
- Calculation of losses on parameters (standard mode in PerfectPower)
- With 3 people on board (Arthur & Vincent & David) and with full tank
- In 2nd gear from 2000 to 8200 rpm (rev limiter)
- With the WIXGEAR universal magnetic windshield mount even if it doesn’t matter in mode 2
- Official Result of each map tested = Average of 2 measurements performed in both directions of the road according to the strict recommendation of PerfectPower in order to eliminate the effects of road slope and wind
I) Final map (map 11)
Official Result = Average of the 2 measurements
Comparison of results with manufacturer data for this engine (S54B32):
- Max Power: + 1.2 ch / hp & + 0.3 %
- Max Torque: – 5.7 Nm & – 1.6 %
Reminder: The S54B32 is one of those few engines that have been homologated with the so-called “maximum” engine policy, which consists of retaining for the homologation the most powerful engine among all those measured! This policy was very popular in the 80s-90s for many sports cars, but we can note with amusement that the BMW M3 E46 being from the early 2000s, it has somewhat extended the tradition!
Typically, a standard S54B32 delivers around 325 ch / 320 hp (a 5% “loss” compared to the BMW reference S54B32…), and on this basis, we observe a gain of 19 ch (344 – 325) / hp & 6 %.
Note: You can’t fully appreciate it if you’re not a BMW M3 E46 specialist, but the power and torque curves of this M3 E46 are MAGNIFICENT, superbly filled from the beginning (2000 rpm) to the end (8200 rpm)! Indeed:
- The torque is already relatively high from 2000 rpm (> 250 Nm), but above all the maximum is already almost reached from 4000 rpm and it remains for 2500 rpm, up to 6500 rpm!
- Likewise, the power is remarkably rounded and close to its maximum (reached at 7600 rpm) between 7000 and 8000 rpm!
I believe that this is the ONLY M3 E46 where Vincent and I have achieved such perfection of curves, and we are very happy with the development carried out, especially since as you will discover it in chapter II below, this M3 came yet from far away…
II) BEFORE (map 8) / AFTER (map 11 final) Comparison
Official Results BEFORE (white) / AFTER (red)
Calculation of BEFORE / AFTER gains (excluding injection – see note 1 below):
- Max Power: + 9.4 ch / hp & + 2.8 %
- Max Torque: + 10.4 Nm & + 3.0 %
Note 1: Map 8 is not a starting map (it is true that we could guess it given its number!), it is a map already optimized on the injection settings! Vincent and I who have years of experience on these engines (we have tuned dozens of them) do not need to carry out PerfectPower measurements to optimize injection, so we only start them afterwards.
Note 2: Actually, this was the second tuning session with this M3, since during the first tuning session, we had not managed to exceed 330 ch (325 hp) despite all our efforts (with however a big torque from 2000 rpm), and we knew that such a low score was not normal in this mechanical configuration from which we typically get around 345 ch (340 hp), so we entrusted it to one of our M3 specialists at the PerfectPower Lab, Stephane, who found the causes (incorrect valve clearance and tired catalysts) and of course carried out the necessary repairs. The rest, you know! A big thank you to Stephane for this excellent work!