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Engine Specific Info and Questions => IDI Engine => Topic started by: jaed_43725 on January 30, 2013, 05:20:50 pm

Title: Whats the best alternator?
Post by: jaed_43725 on January 30, 2013, 05:20:50 pm
Mine died on me so I am gonna replace it. But I would like to know what one is best and if there are any over 90A. Thanks for the input.
Title: Re: Whats the best alternator?
Post by: nwcali6 on January 30, 2013, 05:44:47 pm
Mine died on me so I am gonna replace it. But I would like to know what one is best and if there are any over 90A. Thanks for the input.

  I have a 120 on my 96 TDI from the factory, have a spare 120 sitting on the shelf.  My 1.6 had a big truck 120 modded to it when I bought it.  I'd say stock, or if you want to add it, 120's are fairly common and the route I'd go.
Title: Re: Whats the best alternator?
Post by: 8v-of-fury on January 30, 2013, 06:33:49 pm
Be careful, stressing that crank pulley with too much load could cause the crank gear to crap out.. and the belt will come off......
Title: Re: Whats the best alternator?
Post by: R.O.R-2.0 on January 31, 2013, 12:08:03 pm
Mine died on me so I am gonna replace it. But I would like to know what one is best and if there are any over 90A. Thanks for the input.

run the smallest alt you can, that will still meet your charging demands..

do you NEED a bigger alt than stock? got a big stereo, or lots of lights?

i run a HUGE stereo off a 120a TDI alternator, and 2 batteries..

what alternator do you have now? assuming a 90a? or does your car not have a/c? (65a alt w/o a/c)
Title: Re: Whats the best alternator?
Post by: scrounger on January 31, 2013, 01:09:42 pm
I have followed this thread,

Can appreciate the loads on the belt. 120 amps takes 4.5 horsepower to use it at it's rated power if it is 50% efficient. No wonder many have belt problems. It isn't free. The Mercedes 300D uses a 65a unit and it is driven by two v belts in parallel.

A pretty amazing amount of power is being used up, if you have it humming. Of course if you are just charging the battery back up from a start that output won't be that high for long still that is a lot of load on a cold belt. I figure that most who need it have much more going on than just transportation.
Title: Re: Whats the best alternator?
Post by: jaed_43725 on January 31, 2013, 02:09:58 pm
I went with a Ultima 90A. As I have A/C. There was one wire different the D+. But otherwise everything is good.
Title: Re: Whats the best alternator?
Post by: scrounger on January 31, 2013, 02:20:58 pm
At what point are your alternator wires going to be overheating.
Title: Re: Whats the best alternator?
Post by: 8v-of-fury on January 31, 2013, 05:05:19 pm
I run the same size charging wire as I do positive battery cable ;) as well as a ground from the case of the alt to my neg batt terminal.

I never have a dimming light, or any issues. For further clarification, I have 90/100W lows, 100w highs, 100w fogs, fairly big stereo (im 22, of course i do), fan on high, rear defroster.. doesn't even think about working for it ;) lmao. My lights alone pull 44a..
Title: Re: Whats the best alternator?
Post by: scrounger on January 31, 2013, 05:20:14 pm
Sounds like a plan having thick wiring. You can't go wrong with running battery cable to the alternator.

My car has a big fat expensive wire in it that was hooked to the battery and went into the trunk  where it terminated on a jumbo fuse block. The wire is the size of battery cable maybe 4/0, has a translucent red cover and has very fine stranded wires in it. Have no idea what it was for.

I disconnected it from the battery for safety. Thought that if I wanted to move the battery into the trunk it would make a nice cable. I would probably do that except that many times the car is loaded to the gills and it would mean leaving something behind. Back when I was 22 I had a new 73 toyota. I had the suspension cut down and the battery in the trunk. The car has been gone since 78 but I still have the cable, am pretty sure I paid about 34 dollars for it, the price of 100 gallons of gas at the time.

I listen to the AM radio on occasion but prefer silence, well not silence but not more additional noise.
Title: Re: Whats the best alternator?
Post by: shorttimer on January 31, 2013, 07:09:53 pm
I agree that beefy wiring is the way to go. Checking grounds is really key, too. Not to jack the thread. Another thing I do (I started doing it on winterizing my motorcycles first) is using a product called DeoxIT, by a specialty chemical company called Caig. It's used in applications for de-oxidizing electrical connections on high end audiophile gear. I stumbled across it many years ago & have found it to work fantastic. Works on any electronic connection. Just a very small spray is needed & then I pack the connector with dielectric grease, with my finger, for an impermeable connection. The connection can be submerged in water with no problems. If there is obvious corrosion sanding/wire brushing will help first.
Title: Re: Whats the best alternator?
Post by: 8v-of-fury on January 31, 2013, 07:22:43 pm
Scrounger, me tinks your car was owned by a young guy with a stereo.haha

shottimer, good info. I love die-electric.
Title: Re: Whats the best alternator?
Post by: R.O.R-2.0 on February 01, 2013, 01:43:40 pm
Will a 120amp tdi alternator drop right on to a 1.6td? Or is the bracket setup different?



you need an ABF alternator bracket, a TDI 120a alt, a VR6 water pump pulley or a TDI power steering pulley, a 1.8T harmonic balancer..

thats just to get you working without a/c or power steering..

and its a bad idea to run a serp setup on a diesel without doing the TDI crank sprocket mod.. you run the risk of twisting the end of the crank off, when running a serp setup on a stock 1.6 crank and sprocket..