Since I've added more electronics to the car, power consumption is a bit more than the poor old 90A alternator can take so I'm looking at a 140A beast instead. Is there anything that's off the shelf with little wiring modification required?

 

i know what you mean in power comsuption but as far as i know not any out juz take ur alternater to a shop and have them try rebuilding it with more amperage also i recommend you get a spare battery in the trunk along with a power cap either upgrade to a red or yellow top and also put a spare battery in the trunk to keep up with the damnd of power your system is demanding

 

Just exploring my options other than a rewind. As for batteries, I've already got one yellow top in the back (since I had to relocate it). A second battery will not do anything for the insufficient charging current from the alternator - problem not solved.

 

Look into the quest alternators. I believe they should bolt right on or just need one hold drilled out. I think they are 120-125-130A. Go to a parts store and pull 2 new alternators and check it that way.

~Alex

 

http://cgi.ebay.com/ebaymotors/200am...temZ7958309001

This maybe in my future.

 

What type of electronics you got. The maxima's charging system is great in comparison to others. I was running my two kicker solobarics L5 with a 2400watt amp at ~1300watts RMS daily my speakers were being run from a 400watt amp at about 300watts RMS and I usually blasted my system so I was pushing the wattage hard. Not to mention fulltime 55watt fog lights, headlights, and A/C or heater. I never had an alternator problem nor did I have to worry about my battery. I had my system for almost two years then my tranny died. Unless you're pushing way over 2500watts you are good. I was running on the cars original alternator also.

BTW putting a second battery in the trunk IS gonna add stress to the system as well as a cap because the alternator has to charge them as you're pulling power with your electronics. All you need to do is make sure your battery has good and clean grounds as well as your accessories. You can order a grounding kit from Matt93SE and that will pretty eliminate almost all of that dimming at idle. A few have ran much more wattage in their stock 3rd gen maximas and didn't have to worry about the alternator not once. They used single battery setups and no caps. Not needed IMO.

I am running my current system in a 89 Camry that uses a 70amp alternator and she doesn't hesitate to crank every morning regardless of temp. I had horrible dimming in her and she would take like 3-5 seconds to crank. SO I took a few hours replaced, cleaned and sealed all the factory grounds, cleaned the battery terminals, and cleaned the terminals to the alternator. All in all this job costed me about 5 bucks for some stock guage wires and everything else was basically in the garage. I barely even notice dimming when blasting my music to all hell now. A few hours could have been saved by buying a HO alternator but I will be out by at minimal 200 dollars not including shipping and labor hours (which may be more time because bolts tend to rust very tight).

 

I'm only running half the audio power (RMS) you are, albeit from high current amps, but I am running a MoTeC M800 ECU in a piggyback set up (in order to keep the auto's TCU happy since it needs a comms line to the Nissan ECU). In addition to that, a Jacobs Pro-Street ignition system and that's about it. The thermo fans run a little more regularly now because of the additional heat brought on by the turbo and exhaust, despite their thermal insulation. Reality is, a 90A alternator just isn't enough for even the audio set up alone as it used to be bad enough back then and even blew out the diode pack and regulator the last time ... similar to the dying alternator before that too. That's proof enough that a bigger alternator is necessary.

Exactly my point.

Heheheh. Matt and I are pretty good friends and coincidentally, we're both electrical engineers too.

I overengineered my stuff using what spare 0GA welders cable I had left over from the +ve lead I ran for the battery. After taking several measurements, I found the lowest resistance ground point was where that big weight sits in the middle behind the back seat, measuring in at only 0.03 ohms. Taking into consideration the battery would draw around 10A if run reasonably low, that means a 0.3V drop. This is proven by the 2 voltmeters I run ... one from the alternator feed (monitoring the ignition line but calibrated to mirror that of the alternator) and one in the cap sitting in the back seat behind the arm rest, which gives me a good reading of the battery. Between the two, I see exactly what I predicted - 0.3V difference.

I agree, a 2nd battery is not a solution and only adds to the problem and the cap isn't that big a strain given its capacity and consequently, its demand from the alternator. As for those who haven't had to worry about their alternators, I'm not that lucky. Keep in mind as well now that I have a little more heat in my engine bay with the modified exhaust system and turbo, despite their HPC coatings and whatnot. It's not a lot of heat added, but you can easily see the difference in the alternator's performance between a cold start and a warm run. Somewhere in all this, I think I've failed to mention that it is being underdriven but that point is moot when even at 3000RPM on the open road, I'm still seeing a crummy 12.3V from the alternator and that means only 12.0V at the battery!

All in all, I've already figured I need a higher output alternator. Now I just need to find the right one, particularly if there's an off-the-shelf alternative to a rebuild which needs little or no modification.

 

do a google search for Irragi HO alternators... I bought an Irragi 180 amp (peak), 110 amp (idle) for around $400 shipped. This alternator is absolutely awesome...

 

Thanks for the tip. I'm waiting to hear from Excessive Amperage as well, just to explore all the options, but the Iraggi Dominator that you and Jbr8k have pointed me to looks like the ticket! What are they like with the Unorthodox Racing underdrive crank pulley?

 

Never had been a fan of the underdrive pulleys, in part for this very reason. Nissan had to swap out their pulleys on the alternators several years ago (some may or may not recall this) for the very fact they were underdriven and causing problems on the stock setup. I'm not convinced this is a "moot" point. It does appear that the upgraded alternator will resolve this though. Curious: Do you have measurements from your alt. output before the underdrive pulley? Would full output of a stock alternator be sufficient to charge and maintain your system?

You mentioned added heat with the turbo setup. Have you tried Redline: Water Wetter?

 

Not whilst driving with the turbo and MoTeC. My upgrade path was the same as most here ... first the bolt-on's followed by the nutty stuff

It's only an assumption and I don't see a need for any improvements there. On the open road, my temps read as low as 76 and as high as 98 ... Nissan would be happy with that.