It is quite true that a properly shimmed mechbox can run perfectly fine with 7.2V. We upgraded a MP5 (we put in a spring which is almost one inch shorter but a little harder than the TM stock one) and have it driven by an EG1000 + a non-name branded 1800mah 7.2V battery and managed to achieve a consistent ROF of 24~26 at FPS of 298~302. However, there is one exception – if you are using EG-560, the “7.2V test” may not give valid results. EG560 needs at least 8.4V to pull a stiffer spring. With proper power input, EG560 can produce ROF as great as that offered by EG1000. EG1000 can give relatively high ROF even with low power input. However, it is also fairly easy to get over-heated. On stock gun using high mah (those with 2500mah or above) NIMH battery, stay at 7.2V in summer time – you don’t want to cook your motor within an hour.
The ICS Turbo 2000 motor is kinda on par with the EG700 in terms of performance. They are less likely to get over-heated and are therefore more 8.4V friendly on stock guns. However, because of the slightly different shape of the pinion gear, the Turbo 2000 may produce some strange metallic noise on non-ICS guns. The NEW Turbo 3000 offers almost doubled power – you will see a visible difference when pulling a real stiff spring.
The Cybergun GPX 5000 motor (which comes with the A15 Evolution, available in long form only) has two ball bearings and based on our test results it gives a 8~10% ROF improvement over a EG1000 on a M100 equipped TM MP5K PDW. Torque-wise, it works fine up to M130 but at this level the ROF advantage seems to have diminished.
* FYI, these motors are considered “weak” given today’s standard.
