Hey guys,
I've recently upgraded my sub setup to 4 12's and a Fosgate Punch 800.2. Even after installing a 1 Farad cap, I'm still seeing voltage drops down to 11-11.5 V with the car running when the system is cranked.
The birth sheet states the amp is good for 950 W, but at 14.36 V. Even before I put any stereo equipment in, I never saw 14 V. How do I get the higher voltage that the amp wants? My alternator is stock. Is this my weak link? I don't think I'm into the power range where I need to add an extra battery, but would this help? Any input would be greatly appreciated. Thanks!

Kevin
'87 IROC
Clarion Pro Audio 6550 CD deck
Autotek 4x100 Street Monster amp for mids/highs
Rockford Fosgate Punch 800.2 for subs
Rockford Fosgate Punch 1.0 Farad capacitor
2 Pioneer 3-way 6x9s in rear sails
2 Eclipse 6 1/2s in doors
2 Polk tweets on A-pillars
4 HyperPro 12s
Rockford Fosgate power & speaker wire
Monster Cable interconnects

 

It sounds like your alternator is seriously overtaxed. A cap will help if wired properly (less than 12" of cable between it and the sub amp) but a bigger alternator definately is in order.

------------------
The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
"I didn't know a bored out Ford could go so slow" -Shenandoah

 

Yes, the cap helped tremendously, and yes it's only got about 8" of wire between it and the amp. Before the I put in the cap, the voltage would occasionally drop as low as 8 or 9 V, and my headlights and dashlights were acting like strobes!
As for the alternator, anyone have any suggestions as to where to look for an stronger, or which ones will fit in an 87 IROC with the least modifications? Sorry to be so vague, but I've never had to look for one before. Thanks for bearing with me!
If it matters, it's a TPI 5.0 with MAF.

Kevin

 

http://cgi6.ebay.com/ebaymotors/aw-c...&userid=csking

This guy has been sellin alternators online for a long time... i remember there being a website on some of the auctions i dont have it right now... but its a good place to start



------------------
White 91 3.1 RS.
T-Tops
12" tube in the "trunk" (That hole they call a trunk anyways)
16" ROH Rims
Firestone Firehawks
BOSCH plugs and wires.
Energy Suspension Tranny mount and bushings

 

www.mramp.com i think...

 

Thanks guys! Csking didn't have anything listed in his auctions for 87-up, but I've contacted him to see what he can offer. As always, I appreciate the advice. Thanks!
Kevin

 

I know your post is "old" (all of six days), but you may want to look at https://www.thirdgen.org/messgboard/...ML/009974.html for a couple sites/ideas of upgrading your alternator, as well as an interesting discussion (at least to me).

Also, while I've never done it, I would think that if you want a little more voltage, you could relocated the alternator voltage sense wire to your amplifier buss (on my '91 Camaro this wire is on the starter solenoid stud). While that will increase the voltage to the rest of the car, I would think that it shouldn't be too much. Perhaps switching this sense wire between these two points (starter and amplifier) with a relay and the amplifier "turn-on" wire would be a good idea - then you'd get a slightly higher voltage only when the amplifiers are "on". See the following paragraph though, because if your voltage drop between the amplifier(s) and alternator is too great, then the battery could be damaged by too high a charge voltage. The solution is to use the proper size wire.

What size wire are you using between the amplifier(s) and the battery? Determine the voltage drop and see if it's too much. You can easily do this by connecting a DMM on the low volts scale (2 volts) and measure the voltage between the battery positive and the amplifier positive. Ensure that the amplifiers are at the maximum level you intend to listen to so you'll get the proper current draw. (Zero current = zero volts when measuring a single conductor.)

Also, with the car running measure the voltage drop from the alternator output stud and the amplifier positive power input.

[This message has been edited by Stuart Moss (edited June 21, 2001).]

 

sorry did not double check link. here it is... http://www.performancedistributors.com/new.htm