ST-185 Alternator Scoop, WTF is this thing for [besides the obvious] Options

[DEATH]

First off - if the mods think this belongs in chassis electrical, please feel free to move it. I figured I'd put it here because it really only pertains to those of us running the forced inducted ST-185 engine.

Anyway, the Alternator scoop shown above - I'd like to have a real discussion about it, it's usefulness, whether or not it's really a requirement for those of us running the ST-205 hood with the big upper vents and any and all development info anyone has ever read or heard about it.
I'll start by saying I've been through an inordinate amount of alternators and I've had fires and melting of the alternator wiring on a few occasions and I'd like this BS to stop before I burn my car down eventually. Stephen_lee and I have been all over this area. Re-wiring the area a few times and still I have problems as recently as a week ago.
SupraKid was awesome enough to go waaaay out of his way to locate, purchase and ship me a replacement alternator [the one you see above] in record time and I want to do this correctly so that I don't burn this one up. Thanks again Andrew

All that being said - do you guys think I should install the scoop? I've never had it installed before but I have collected all the peices and tubes that are included in the system so I could def hook it up if I wanted to.
What are the pro/cons here?

This post has been edited by DEATH: Sep 30, 2010 - 9:07 AM

[stephen_lee]

there are a few reasons Toyota could have added this duct

1. Alt efficiency (amps out) relies heavily on temperature.
2. The voltage regulator has 6 diodes that convert the ac output to DC, these tend to get HOT, and hot diodes = less power transfer and less life
3. To help keep the turbo heat away from the alt.
4. Cooler windings transfer current better.
5. Magnetism works better with lower temperatures.

basically a hot alt is less efficient. a cooler alt will ALWAYS output more amps, last longer, and be generally 'happier' than a hotter one.


DEATHs burn ups were on the signal wires this time, which could either have been exhaust heat melting them directly, OR the heat made the wiring brittle, which then cracked it and shorted the wires.

[DEATH]

the heat made the wiring brittle, which then cracked it and shorted the wires

From what I could see this is exactly what it looked like.
I stripped the wire all the way back to main harness and replaced it all with that high temp [600*] high voltage [3000v] wire I keep in stock and am so fond of. Then I insulated the new main power wire by running it through an uncut peice of extra thick heater hose. Hopefully this will keep the heat off the wires themselves and with the new alternator maybe it'll be trouble free for a while