None. Make sure the transition between the diameters isn't a square corner. A taper or radii is best.
Are you sure that diameter spec isn't just for the OD of the spline section?
Hall effect sensors sense the presence of a magnetic field. They work great for crank and cam sensors, as yo can easily embed a small magnet in the flywheel, or elsewhere on the engine. I see that as being VERY difficult to do with an aluminum compressor wheel spinning at 150000+rpm.
I think traction in the winter is more important than the doors closing from the slope. My driveway is pretty steep, and even though the doors stay open for the most part, there's days in the winter i can't park on it, or slide down it while walking to the car.
1) Rent a flatbed tow truck on wednsday.
2) Put everyones car in the parking lot on it one at a time, and measure the angle at which the door closes as the truck bed is tilted up. Do it a few times for each car, using all the doors.
3) Show your boss your results on thursday.
The contrast of the light/dark reflections won't be very great, and you could have a hard time counting them at high speed, as some phototransistors can be pretty slow. Make sure you get a good fast one.
Another option would be to drill a small (1/8") hole right through the whole housing...
The turbonetics site is great for maps.
This site is an upgrade guide for the 3000GT twin turbo, and has compressor maps for a lot of Mitsubishi (MHI) turbos.
I know the way the turbines are defined with trim numbers, i was just hoping there were some quantitative numbers for flow and pressure like the compressors. It would make turbine selection easier. I can pick the right compressor, but turbine selection is more of a "this works in this car...
Is there even a map for the turbine wheels? I've found many maps for Garrett and MHI turbos, but never any information on the turbine wheels, besides diameters. Is there a simple way like a compressor map to describe the performance of the turbine? Is there any source for those that anyone is...
Applying 12V will make it switch. Applying a PWM of around 50-100Hz and varying the duty cycle from 0 to 100% will approximate 0 to 100% open or closed.
