The Subaru SVX World Network   SVX Network Forums
Live Chat!
SVX or Subaru Links
Old Lockers
Photo Post
How-To Documents
Message Archive
SVX Shop Search
IRC users:

Go Back   The Subaru SVX World Network > SVX Main Forums > General SVX Babble

Reply
 
Thread Tools Display Modes
  #16  
Old 12-21-2001, 10:21 AM
249SVX 249SVX is offline
still in love with Hannah
 
Join Date: Mar 2001
Location: Lebanon, PA
Posts: 295
Re: i am interested.

Quote:
Originally posted by 1994SubaruSVX
get that info for me if you can chris.

thanks beav. obviously i didnt know that.

so what the smaller pulleys are doing is not allowing the alternator to recharge the battery fast enough. correct me again, if i am wrong. learning is fun.
Yes, let me know as well. The rubber stuff on my OEM is starting to crack.
__________________
silver 92 SVX-"Hannah" -R.I.P. NOV. 1991-jAN. 17, 2003
red white and blue 2000 Suzuki TL1000-r-"Bethany" This grips me more than a muddy old river or reclining Buddha.(now running Metzlers!
black 1987 Toyota MR2-"Helga" -Turbo conversion will now commence.
1996 Legacy Outback-"Gilda" white with brown trim
Reply With Quote
  #17  
Old 12-21-2001, 03:40 PM
Beav's Avatar
Beav Beav is offline
Not as old as Randy
 
Join Date: Nov 2001
Location: Louisville, KY
Posts: 3,883
Significant Technical Input
Consider that everything in your car runs on 12 volts (don't get picky about the electronic circuits, their power supplies still use 12 volts .) What adds up is the amps (actually watts are the real ticket, but we'll get to them in a minute.) Eight or nine to run the 'puter, ignition and fuel pump. Twenty five or so for the hi speed blower. Add some more for the a/c field and rad fans. Where are we now, around 74? Turn on the lights, add 15 or so. Now you know why you need a big alternator. But to save precious weight (can you say CAFE?) they make the alternators smaller. More output + smaller alt = higher heat. Higher heat = shorter life.

Also consider this: ten gauge wire is rated for thirty amps, period. Why do OEMs force 100 amps through ten gauge wire? Duh! Burnt connectors, hardened wire and reduced output are results, not to mention underhood fires (ask Ford.) If you're re-wiring your alt, 3 x 10 ga. wires to the battery would be best. Or 2 x 8, etc. (more difficult to bend and route.)

The reason for going to forty two volts? Here we go back to amps. Volts are pressure, amps are flow and watts are one times the other (IxE=W.) A twenty five amp blower motor at twelve volts equals three hundred watts. Three hundred watts divided by forty two volts equals seven amps. Get the picture now? Just don't lick your finger and stick it in the lighter socket.

The main reason smaller pulleys were used by racers was to slow down the speed of the driven devices. Let's say an OE alternator was designed to be driven at a 3:1 rate. Average continuous engine speed about 3,500 rpm. 3 x 3,500 = 11,500 rpm. Now think about a racing engine, continuous rpm 6,000. 6,000 x 3 = 18,000 r's. Doesn't take long at that speed to grenade an alternator. Water pumps would spin so fast and pump water so quickly that the water didn't stay in the radiator long enough to pass off enough heat. The decreased parasitic loss was a bonus.

Beav
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 07:47 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
© 2001-2015 SVX World Network
(208)-906-1122