Supercharger gurus

[utah_ee]

Greetings!

I am interested in adding a supercharger to my M but need some guidance from the smart people in the room. Thanks in advance!

I live at ~4300ft above sea level and am curious how this should affect my decision regarding the super charging system/kit to purchase with most performance of the money.

Done some research on superchargers and how they work. A quick look at an altitude and air pressure chart indicated I am about 2.3psi less atmospheric pressure than someone at sea level. Wouldn't this mean I would need a supercharger (non-inter cooled) creating 2.3psi of boost in order to get the same volumetric air pressure that would be obtained at sea level without a supercharger (i.e. air/fuel mixture)?

Can I then apply this logic when shopping supercharger kits?

For example, looking at the ESS VT2-595 kit. It produces 6psi of boost, though at my elevation would be lacking the affect of this boost by about 2.3psi. Could I counter act this phenomenon by increasing boost by reducing the pulley size to the VT-650 kit pulley that produces 8psi?

Would it then be appropriate to purchase a ESS VT2-595 full kit and VT2-650 kit pulley and belt? Would there be a performance difference between this and a full VT2-650 kit? Why?

Your help in understanding these details as I shop for a supercharger is very appreciated.

Jason

[Patrón]

i'm not an expert but from what i've read on posts here, the high altitude guys are using smaller pulleys to compensate for the altitude. 17 years ago i had a supercharged acura at 4-5K ft above sea level and had less boost than advertised due to the elevation. i never changed the pulley and always ran very rich. i'm hoping someone at high altitude with a pulley swap chimes in. the guys at sealevel are lucky.

[Longboarder]

Jason you are spot on. You should get the ESS 625 with the blue injector and swap the standard 6.5-7 psi pulley system for a 10psi pulley system and you will end up right around 7.5psi. Just make sure you have access to 93 octane AND remember that you could blow your motor at WOT if you drop elevation or you have an unusually high pressure 30.40 millibars and above on a cold day where your density altitude drops below 2,000 feet.

[617E90M3]

Originally Posted by Longboarder

Jason you are spot on. You should get the ESS 625 with the blue injector and swap the standard 6.5-7 psi pulley system for a 10psi pulley system and you will end up right around 7.5psi. Just make sure you have access to 93 octane AND remember that you could blow your motor at WOT if you drop elevation or you have an unusually high pressure 30.40 millibars and above on a cold day where your density altitude drops below 2,000 feet.

Good insight. Watched you videos.. Your car cooks!