I just put a powermaster 140 amp brand new alt on my 350 TPI setup and I notice that during acceleration I can hear some noise from the new alt while driving, from inside the cabin. It is not like a bad bearing noise, it is a medium frequency noise more like a fan noise. I can make a video if anyone wants to hear it. I contacted powermaster and they were good about getting back to me very quickly but they just said return it if I don't trust it. They didn't give me a straight answer as to whether a small but noticeable amount of noise during accel. is normal w/ this unit.

Question: For anyone who has a high amp aftermarket alt like this, especially if you have a powermaster 140 amp or higher unit, does yours make a little noise under acceleration that you can hear inside the cabin?

I am guessing the aggressive cooling fans in this thing might be to blame, I have no hood blanket, and my exhaust is pretty mild, but at the same time if this is not normal to hear the alt at all, I should probably exchange it (pain though since it was bought online, having to ship and re ship stuff).

Thanks!

Steve

 

I am running a duralast gold 140 with a fiberglass cowl hood and didnt notice any more noise than the factory 140 that came with my car. Do you have a picture of the pitch of the cooling blades

 

There is no factory 140 and there is no Duralast Gold 140. The factory alt is a CS130 105 amp and the Duralast Gold (I replaced it with the powermaster, I have that exact alt) is also a CS130 105 amp. I know those are quiet but I wanted a bigger alt, hence the 140, and its slightly noisy-ness.

 

I have the powermaster 140 amp. Bought it from summit racing. I have no loud noise at all. I would swap it out if I were you.

 

Ok will do, thank you for sharing your experience!! -Steve

 

my Power master 140amp... sounded like a super charger... loud enough to hear on a 400+ HP combo

 

Ahh here we go, I'm not crazy. I am very picky when it comes to noise, I am bothered by things most people chalk up to "road noise" and don't care about. And my exhaust (3") is pretty quiet compared to most aftermarket stuff so I can hear things that someone with a loud exhaust would not even be able to hear anyway. 88gta did you ever do anything about the alt and did it keep performing okay, albeit a little noisily?

 

my exhaust was pretty loud.. pretty rad cam.. I only had it in for a few months... it was louder when first installed... the alt worked flawless.. if someone had a stock setup.. I would complain... the whine would get very annoying... mine was more from idle to like 30ish... I also had underdrive pulley's... that Alt requires a 17000 - 18000??? if i remember correct... max rotation

 

I don't run UD pullies and I have an extremely mild cam (LT1 roller in an L98) so the exhaust is pretty smooth and not loud inside the car. I can't hear the alt at idle or cruise speeds, only when accelerating, then it sounds like I am supercharged a little bit.

 

I have the powermaster 140 amp setup and I dont notice any noise, but my turbos are very loud so if any whining is happening, its the turbos I hear not the alternator...even the exhaust is loud enough to drown out engine noise in general....but just revving in the driveway and not getting the turbos spooling, my alternator seems quiet. I have sat under the hood holding the throttle open to 2500 rpms or so and never heard anything odd, more injector noise and valvetrain noise than anything.

If it makes noise only under load, then I wouldnt be able to tell on my setup.

 

So what you're telling me is, make everything else louder, then don't worry about it. Haha. That would certainly be one answer.

 

yes, you are correct when accelerating... in your case.. I would call Powermaster make them send you a tested alt.. that does not whine.... tell them you will return after approval.... once i was over 1/4 throttle there was no way to hear the whine ;-)

 

If mine is whining, its still doing its job keeping voltage up with all the electronics i have on this car. But i dont think it is, I havent heard anything like a supercharger whine from under hood.

 

PS do the math on your pulley's... if i remember correct... the stock setup will rotate like 20000 - 21000 this will void that alt's warranty.... ouch

 

Thats a good question on pulleys... my alternator is NOT using the stock pulley from Powermaster. Its using the march electric water pump kit pulleys and i dont think its spinning the alternator as fast as the stock TPI based accessories pulleys are, or as fast as a underdrive kit would for serp belt TPI setups would.

The march electric water pump kit alternator pulley is abit larger than any of the stock stuff. I notice with all the fans on and water pump, idle voltage drops alittle still with 800 rpm idle, but if i go to 950-1000 it stays ok til I turn head lights on...then it drops out alot. So i am likely not spinning it fast enough

 

I used to be into fancy chrome and that long ago and put a powermaster chrome 140 amp alternator on my 305 TPI. Looked awesome but that thing was the biggest POS I ever wasted my money on. Lasted all of about 4 months and then left me stranded away from my house. Had to AAA the car back home. After that I got an autozone lifetime warrantied alternator and never had a problem with it for the rest of the time I had the 305 in the car. If I can use stock parts, I will always take them before aftermarket stuff (minus performance parts obviously).

 

were not talking fancy CHROME.. chrome alt & starters get way to HOT.. your begging for trouble..... it can happen... LOL now boasting of the chain "KMART like" auto Parts stores.. that now day's it's a standard... to replace your parts in months... not years....
well you will get a lot of practice changing your parts.... but hey you do have a lifetime warranty... I think that means lifetime turning wrenches...

 

An alternator takes me 15 minutes to change. Coming up with the money to buy another BETTER alternator when my non-lifetime warrantied one goes...and it will since I drive my car hard since thats what I built it for, is expensive after a while. The cheap autozone alternator I put on my car lasted 2 or so years and I took the motor out with it still working fine. I agree that sometimes you get a bad one, but they rebuild them with cheaper parts to cut costs and autozone is less than 10 minutes from my house. I don't mind swapping one out for free if it goes. Every car I've used an autozone part in has been fine. I have never had to use one of my lifetime warranties yet. It's so much more convienent than shipping parts and dealing with manufacturers over the phone to get something fixed.

As far as the fact that it was chrome, if powermaster offers it in chrome, then it better work and be designed with the heat factor in mind. It wasn't cheap and if a big company such as powermaster is willing to sell it, they better design it to last...which mine didn't.

 

Here is a video of how loud my Powermaster alt is. I showed this video to powermaster and they agreed this noise is not normal. The alt is on its way back for a warranty repair/exchange. I will keep you posted on my progress



The thing is LOUD

 

Ive got a 140 amp and I dint get any additional noise from it ???

oh btw I am using bbk underdrive pulley's and again...no problem

 

Yeah they think mine was dropped during shipping, causing internal damage. Hopefully #2 arrives here okay.

 

I just wanted to update this thread (I hate unfinished stories).

I sent the very loud Powermaster 140A alternator back to powermaster directly. They put new brushes and bearings in it and sent it back to me. The alternator no longer charged at all when I got it back (hey it was quiet though!!! haha). I contacted the same tech at Powermaster who had overseen the return and repair of my alternator and he promised he'd get right back to me about this ongoing disaster-saga. I never heard from him again. I brought the alternator back to an Advance store, told them how much of a problem it has been, and they gave me a full refund.

I will definitely not use a Powermaster again...I put the Duralast Gold 105 amp alt back on for now and it works fine. I wanted a 140 amp alt because the 105 can't hold 14.x volts at idle with AC and all accessories on (it holds 13.5 though, its fine, I just wanted a little more reserve on hand).

I don't know what's going on in the aftermarket the past few years, it seems that even some of the big name brands are selling crap now.

 

Problem is that everyone is trying to be competitive on there performance parts pricing, but that leads to parts being assembled in china. Unfortunately thats where things are going these days. I used to love MSD stuff but found out most of it is assembled in china now.....I won't buy thier ignition stuff anymore because of that.

Glad you at least got a working alternator in there though!

 

Yeah guess where the working alternator is made...Mexico. Mexico seems to be the "premium" country of origin lately if you have to compare it to China. Powermaster won't tell you where their alternators are made...the packaging has no country of origin on the assembly or even the parts. Wherever it was made, I got the worst dud ever and then the major problem was that their in-house guys in Illinois completely ruined it when they "fixed" it.

 

I have a 230 amp alternator but the shop that built it for me is out of business so it will be a sad day when it dies.