embelo

I'm putting in a big amp and I've been told by my installer that I'm gonna have to upgrade the alternator to produce enough power to let the amp run at full power.

Does anybody know of a company that produces alternators that fit a '93 ES (or any ES for that matter)? I've found a whole bunch of "GM Model" alternators, but knowing Lexus there will only be one specific brand that will fit. Does anybody know the scoop on this?

Thanks a lot -

Matt

Tom_ES300

Contact your local Lexus service dept and ask them what alternators are available for your year. They will be rated by amps. 50 to75 amps is a typical range for cars, trucks will go up to about 100. See if you can figure out what rating yours is; check for a model number on the case of the alt. or check the paper work that came with the car. You'd hate to unknowingly rip out a 80 amp alt and upgrade it to a 65 amp alt!


A quick look here appears to say there is only one size:
http://autoexpress.safeshopper.com/491/2095.htm?75

But this place syas two kinds of 80 amps:
http://catalog.auto-parts-wholesale....=1993&x=90&y=9


Vehicle: 1993 Lexus ES 300 V6
Part: Alternator
Rebuilt
80 Amp
Fits
Year: 7/1992-7/1993


To view shopping cart contents, click the View Cart link above. Product Brand List Price Core Qty
Alternator Reman
F4000-101147 Denso $299.79 234.36 $40.00
Alternator
F4000-51662 Bosch $299.79 146.78 $75.00


Tom

Luc

You may want to try and find a local store that can rewound the alternator for you to get a higher amperage rating, say 130A. This way, you still use the stock electronics, since it has a voltage regulator. Most of the remanufactured ones only account for OEM vehicles without any extra electrical loads. Contact www.mralternator.com as well, though they don't have a listing for any Toyota/Lexus, they might be able to do something.

Luc

1loudlex

I tried to look all this up before and came out with nothing. I emailed a lot of places that rebiuld them and they said no. I wanted like a 200 amp alt, but i guess that I am not going to get it. 80 amps is not going to do anything. Save your money. Let us know if you find anything.

Adam " lexist "

Sooner

put a pulley on from a rx 300 that will increase the output

j2tha0e

cheepest way....just get your alternator rewound and get a cap. should be no problem.

embelo

Adam -

Tom from Mr. Alternator says there exists a 130 amp alternator that runs $210 from him. He says "if you can change the OEM one, you can change ours," so it must be pretty identical to the stock.

Sooner -

Whats this you mean about a pulley to increase the output? I don't follow...

Luc -

Do you know roughly how much that would run me? What kind of shop could do that (audio install or like mehanic)?

Thanks for the info Tom.

What's concerning me is that as the car exists, the lights dim when I hit the brakes (I suppose from the electronically controlled brakes drawing a lot of current), if I'm driving and the music hits a deep bass note, the lights (including interior lights) dim. Every 3 to 4 months I have to drop a new battery in the car (I assume because the car's electronics draw so much current that the alternator cannot produce enough and the car drains the battery to make up the lost ground between the draw and the alternator). Does this sound like an alternator problem? Logically I'm assuming because cars are made to handle only what's stock, the extra amp draws too much power. By my rough calculations (as outlined by Crutchfield) my amp should only add an additional 45 amps to the car's draw, but I suppose on a car that's already stressed (given that stock cars still see the light's dim with the brakes). I'm getting tired of trying to get a warantee replacement on my battery, I'm gonna shoot for the alternator.

You guys recommend it?

Thanks -
matt

Sooner

it is a smaller pulley and will spin faster.trust me it works.good luck

1loudlex

I am not going to get a new one now. I wont have my car for that much longer, so not going to spend 210 on that. thanks for the info though.

Adam " Lexist "

Luc

That will probably depend on how much amperage you want, but I'm only assuming at least $100. Audio stores will not do that, unfortunately, you may have to check the yellow pages for that. Sorry to be so vague. As far as the smaller pulley, it may not work properly with the harmonic balancer in the car. But if someone has tried it and it works, that's the other option. I don't know if having the alternator spin faster will give you more amperage or faster charging time. To me, the amperage is still limited by the coils, not by the size of the pulley.

Luc

Tom_ES300

Technically, assuming that you don't run into any other limits such as having too small a wire gauge, the current out of an alternator increases with the speed of rotation. A fast spinning alternator produces more electricity than a slowly spinning one. You never see the lights dim-out while travelling at 65 MPH, do you? If you swap the pully size on the alternator, you can make it spin faster at slower car speeds. The big warning sign that should be flashing in your mind right now is, ?"If it was that easy, why didn't Lexus do it? ".

Making the ALT spin faster at low speed means making it spin really fast at high speed - will it break?

A new pulley size will change the dynamic balance - will it vibrate and wreck the bearings?

A new pulley size will change the belt tension - will the tensioner pick up the slack? or break the belt?

So you see, there are a lot of potential complications. You don't just slap on a new pulley and drive away.

Tom

Luc

Tom, those are good valid points you mentioned. I can see that there would be more current generated by the alternator at higher rpms. My original thought was that having a smaller pulley will not exceed the factory ratings of, say, 85A. It would just reach that max value faster, and then the battery rectifies it to DC, so the battery would be charged faster, having current readily available.

Luc

embelo

I kinda agree with Tom, my Physics 112 class has taught me that the slightest variation in a rotating object can inflict massive changes on the dynamics of the system, especially at this high an RPM. The thought about the belt tension occured to me too, i'm just not sure, it's a little bit sketchy. I'm borrowing an multimeter from my physics department to try and gauge how much amperage the amp produces. By my calculations, I should exceed the amperage rating of the alternator slightly, by at most 5 or 6 amps (if it's producing its full 80 amps). It doesn't seem logical to me that the battery would drain every few months like it does now. Theorhetically, it should eventually drain, but 3 months? That's really fast for a battery with a 72-month warantee. I'm willing to debate if the alternator is even producing close to its rated amps.

I'm gonna look into the re-winding, it seems like the overall most effecient option. Either that or i plunge for a new alternator. I'm still wondering if a GM alternator will fit in our engine compartment. Alternators don't vary much in size, i could only imagine a necessary adapter bracket or something, does anyone know? It's just that there are at most 3 options I've found for the Lex, but dozens and dozens for GM cars.

Lemme throw another possibility out there. I took out the system and then took my car back to the dealer to complain. I just bought the car and I'm carried under their warantee, so I was aiming for a new battery or something. They said that the mechanic thought that maybe the alternator belt was slipping on the alternator pulley and not spinning with the engine, just spinning at a really low RPM and not generating current so the entire car was primarily running from the battery. He said he couldn't replicate the problem in the bay but that my description of the problem (the battery light coming on when the car's in idle) sounded like that could be it. Does this sound possible? I didn't really believe it, if it's slipping it should slip, it shouldn't be sporadic. Any thoughts?

Thanks everyone for your help.

-matt

Sooner

we have at times for the people who dont drive ther car but 10miles a week and then its with full system load it works i havent seen one come back but who knows maybe i was just lucky i do agree some of the points are valid but this was recomended by an engineer

Tom_ES300

Why thank you; hey wait. Was that an insult??

The #1 cause of PBD (premature battery death) is overcharging it. How do you do that in a car? If you've blown or damaged your voltage regulator, the voltage at high speeds will be greater than the max allowed 15.5 volts. This fries batteries. Have you checked your voltage while reving the engine? Whith sound system both on, then off?

Tom