In BMW circles both noelle motors and the 750i are legendary names. Company founder Karl-Otto Noelle was the former head of engine development at Alpina in the 1980s where he extracted impressive power from engines, sometimes using turbocharging.
Another legend among BMW enthusiasts is the 750i, a badge that first appeared on the bootlid of the V12 powered (E32) 750i. The current car that wears this label only has eight-cylinders, but thanks to a pair of turbochargers, direct injection and Valvetronic it generates a much more potent 450 hp and 650 Nm.
Exploring the significant headroom in the bi-turbo V8 (N63B44) motor, the engineers at noelle motors mapped out a three stage upgrade programme.
With just software optimisation the noelle motors S1 conversion takes output to 570 hp with 740 Nm, which shaves the benchmark 0-100 km/h sprint from the standard cars 4.7 to 4.0 sec.
The S2 conversion combines a free-flow exhaust downpipe with the appropriate ECU remap for 600 hp, 770 Nm and a 0-100 km/h time of 3.8 seconds.
The peak of the noelle motors 750i engine upgrade programme is the S3 version, which adds modifications to the turbochargers to the larger downpipe and tailored ECU remapping for 629 hp and 820 Nm of torque. This delivers a 0-100 km/h time of just 3.6 seconds, placing the noelle motors 750i firmly in the super sports car league.
Virtually no other factor influences driving pleasure and the sensation of engine power more directly than the ideal axle ratio. However, the ECE test cycle used to determine the respective CO2 emissions is driving the trend among vehicle manufacturers for longer rear-axle ratios as a means of complying with increasingly stringent CO2 limits. In many cases, a vehicle's dynamic performance suffers as a result.
Parameters that deliver theoretical fuel consumption benefits on the test bench generally have little to do with real-life driving conditions. On specific vehicles, a shorter rear axle ratio can even achieve better fuel consumption figures because the need for drivers to downshift – several times in the case of the eight-speed automatic transmission – when accelerating is eliminated.
<p">With this in mind, noelle motors has developed a shorter rear axle ratio with an electronic locking differential for the current BMW M5/M6 with the V8 bi-turbo engine and 7-speed DCT transmission. The ratio is reduced from the standard 3.15 to 3.64, thus turning seventh gear into a "driving gear" and enabling a theoretical maximum speed of 370 km/h at an engine speed of 7200 rpm.
A sports rear-axle differential is also available for the current BMW 550i, 650i and 750i models (without xDrive) equipped with the V8 bi-turbo valvetronic engine (N63TUE) and eight-speed automatic transmission. In this case, the ratio is reduced from the standard 2.81 to 3.46. As a result, Vmax is now reached in eighth gear rather than seventh, offering a theoretical maximum speed of 361 km/h at 6,500 rpm.