Here are the specs for both vehicles, the Gintani supercharged M3 is the camera car:
Mod List - ESS M3
SGM 08 BMW M3
ESS VT2- 650 - 8 PSI
Challenge Race X- Pipe
Eisenmann Rear Section
KW V3 Coilovers
Volk TE37 9.5/10.5 + Yokohama AD08 265/295
Mod List - Gintani M3 - CAMERA CAR
MR 08 BMW M3
Gintani Stage 2 - 7.5 PSI
OEM Rear Section
Toyo R888 275 only rears
Style 219 OEM Wheels
Now there are no honks in the video so it appears the Gintani car gets a jump. Regardless, there is no denying it pulls away definitively as which point the ESS supercharged car just gives up and gets off the gas. What explains this results considering the Gintani car has a 7.5 psi boost pulley versus 8.0 for the ESS VT2-650?
First of all, tuning is an important difference. Gintani Stage 2 kits are usually custom tuned to the application. ESS VT2-650 kits come with a canned tune. One can of course get a custom tune but the actual kit is one size fits all. These are simply different approaches and have their merits but for maximum performance a custom tune tailored to the vehicle and fuel is always preferable.
Secondly, the Gintani Stage 2 kit features a revised manifold with improved flow. When trying to make the system as efficient as possible the manifold design of course is important. A freer flowing manifold should show less boost.
Gintani also has a Vortech T-Trim option which is a slightly larger blower capable of more CFM than the V3si ESS uses. Again, pros and cons here as the self-lubricated V3si is very nice from a maintenance perspective and the T-Trim requires tapping the oil pan for lubrication. A pro of tapping the oil pan is the oil can be changed and cooled more easily. A con is if something were to go mechanically wrong with the blower a small piece of metal has a chance (however slim) of entering the cars oil system. Again, pros and cons and there are blower choices available for the Gintani kit although one is locked in with the ESS kit.
Keep in mind these cars not running meth and the Gintani Stage 2+ setup can run higher boost and more aggressive timing with a custom meth tune which ESS does not offer with their kit.
Hopefully we see more videos like this as there has been far too much dyno racing by fanboys.