ho alt in a civic
Printed From: the12volt.comForum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=116953
Printed Date: May 21, 2024 at 3:27 AM
Topic: ho alt in a civic
Posted By: blackcivichatch
Subject: ho alt in a civic
Date Posted: October 14, 2009 at 9:52 AM
Replies:
Posted By: haemphyst
Date Posted: October 14, 2009 at 10:58 AM
1: The 96 Civic DX made 106HP @ 6200RPM with 103 ft-lbs @ 4600RPM. The LX, (the most powerful model that year) made 127HP @ 6600RPM with 107 ft-lbs @ 5500RPM. These are "pretty stock" numbers, so if you are getting 130HP, you have "pretty extensive" mods, or are simply mistaken about your engine's specifications. (Dave's also a Civic guy! 
)
2: Little. ...from the alternator load itself... Now, all the additional weight and accessory electrical load WILL affect your bottom line. How much? NOONE can tell you, but see the next point.
3: 1HP = 770W. 770W/14.4V = 53A Using this information, for every 53A you are pulling from your alternator, (you must also add losses, so probably somewhere more like 40A @ 75% efficiency, a reasonable number) that is one HP less that will never get to the ground.
4: I got mine from HOAlternators.com. If I remember correctly, it wasn't cheap, but it is an AWESOMELY built alternator. Obviously beefier parts than the OEM, all sealed ball bearings (no bushings), lifetime rebuild warranty. I think it was about $550.00. I could be wrong on that, though. Call them and find out for sure. Failing that, your car might have room for a large case GM/Delco, for somewhere in the 300A range.
:::::EDIT:::::
HOAlternator claims 87% efficiency across the board as "typical" efficiency for their alternators. 53A * 87% = 46.1A draw for a 1HP loss JUST from the alternator. The amps also have losses in them, so be sure to include those numbers when adding all this up!
46.1 * 50% (for Class A/B amps - a worst case scenario) will be 23A. 23A * 14.4 = 330 watts. So again, using this information, and including as many ASSUMED losses as I can, every 330 watts of accessory load you add, that is one less horsepower you will have to propel your car down the road. (Class D amps will allow somewhere in the 560 watt range, i.e. 2000W equals approximately 4HP.)
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
)
2: Little. ...from the alternator load itself... Now, all the additional weight and accessory electrical load WILL affect your bottom line. How much? NOONE can tell you, but see the next point.
3: 1HP = 770W. 770W/14.4V = 53A Using this information, for every 53A you are pulling from your alternator, (you must also add losses, so probably somewhere more like 40A @ 75% efficiency, a reasonable number) that is one HP less that will never get to the ground.
4: I got mine from HOAlternators.com. If I remember correctly, it wasn't cheap, but it is an AWESOMELY built alternator. Obviously beefier parts than the OEM, all sealed ball bearings (no bushings), lifetime rebuild warranty. I think it was about $550.00. I could be wrong on that, though. Call them and find out for sure. Failing that, your car might have room for a large case GM/Delco, for somewhere in the 300A range.
:::::EDIT:::::
HOAlternator claims 87% efficiency across the board as "typical" efficiency for their alternators. 53A * 87% = 46.1A draw for a 1HP loss JUST from the alternator. The amps also have losses in them, so be sure to include those numbers when adding all this up!
46.1 * 50% (for Class A/B amps - a worst case scenario) will be 23A. 23A * 14.4 = 330 watts. So again, using this information, and including as many ASSUMED losses as I can, every 330 watts of accessory load you add, that is one less horsepower you will have to propel your car down the road. (Class D amps will allow somewhere in the 560 watt range, i.e. 2000W equals approximately 4HP.)
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: blackcivichatch
Date Posted: October 14, 2009 at 11:19 AM
Posted By: KarTuneMan
Date Posted: October 14, 2009 at 9:12 PM
You mean my system is only 1.2 horse power....
I am no longer impressed. 
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Posted By: blackcivichatch
Date Posted: October 14, 2009 at 10:07 PM
Or you can think of it as "Your system produces 924,000 micro joules per second" 
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UNLABELED Custom Car Club President
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UNLABELED Custom Car Club President
Posted By: incognyto
Date Posted: December 26, 2009 at 1:41 AM