Rail Alternator

[Dunelover]

I have a CBM LS in my Tatum. 

On our last trip, my CBM 250 amp Alternator died (just the output voltage)  I had a spare Billet specialties 170 amp (one wire) so the trip was not a bust. 

Question... Why do I need  a 250 amp alternator? For the rebuild cost (at CBM) I can buy new Billet or other? 

So other than  4 radiator and oil cooler fans, Fuel pump, ECU & Engine, GPS and Radios,  I can't think of why I need that much current.  Question is:

CBM to repair 250 amp?

Alternator Shop repair 250 amp?

Buy New from Summit and what size?

Thanks

Rick 

 

[Realbadlarry]

I think there was just a thread about alternators on here....

 

[Realbadlarry]

Search Alternator ... there is a discussion

 

[J Alper]

factory is a 160 amp, 

So my alternator now is 15 years old,  

Factory alternators are 2.030,   this is bad if you are running a factory balancer size,   7.87 

I am also running a 10% underdrive,  balancer,  it is 7''  round,   

My alternator pulleys we make are 3.100 round 

What RPM are you running on the Alternator 

I am running max of 16,000 RPM,  

Some of the Billet Hi am alternator are Hi amp because they put on a 1.750, the more you spin them more amps they make, 

I would never spin a alternator over 20,000 RPMs  

The customers that use factory pulleys spin them over 27,000 rpms and they NEVER last,  

I dont care who makes them you get over or close to 20,000 they are going to burn up the electronics and them the alternator is toast, 

Look to see what RPM the alternator is turning and then start from there. 

 

[Sandkist]

So other than  4 radiator and oil cooler fans, Fuel pump, ECU & Engine, GPS and Radios,  I can't think of why I need that much current. 

2 Radiator fans 60 Amps

2 Oil cooler fans 20 Amps

Fuel pump 10 Amps

ECU, coils, injectors 5 Amps

GPS and Radios 6 Amps

Whip lights 5 Amps

Roof Light Bar 30 Amps

Bumper Light bar 15 Amps

Battery 10 Amps

Heated seats ?

Stereo ?

Transaxle pump ?

It adds up quickly.

 

[Jtmoney714]

I wouldn’t do anything less than 250amp. And put the larger pulley on it too. 

 

[J Alper]

I wouldn’t do anything less than 250amp. And put the larger pulley on it too. 

I hate to float our own boat,  but when it comes to offroad Alternator pulley by far we make the best,  we started for Pat Dean on the Race car 20 years ago,  

Will try to get them on our site, but it is the way to go, 

for Hi amp alternator, this has been a good one for us, 

Summit Racing

MechMan 8302240 MechMan G Series Alternators | Summit Racing

BNR,

Have had 2 go bad in 10 years 

250 AMP 8299N Chevy GMC New Alternator HIGH OUTPUT SILVERADO SIERRA HD | eBay

 

[Dunelover]

I'll confirm pulley sizes tomorrow.  CBM says their alternators are are specially designed for low RPM. 

I do call BS because today's cars operate at such low rpm even at freeway speeds. 

& yes I know amps do add up.  

 

[lincster]

Add up all the amps and see what size you need.

I disagree with the "NEVER last" comment.

My buddy has been running a 180 Amp alternator with stock pulley size for 9 seasons and it works just fine.

I pull 134 Amps with just fans (I have 6), fuel pump and heat exchanger pump, so I went with the CBM Billet alternator with a 3" pulley.

 

[r3meyer]

I disagree.  I run a standard 2 wire 160a alternator from Napa with a stock pulley.  Lifetime warranty.  I have had to replace it once so far.  I find its the sand that causes them to die.  The 2 wire is MUCH better than the 1 wire.  It senses load and adjusts up and down depending on needs.  The sense wire is run all the way to the front of my car so it will compensate for voltage drop and adjust as needed.

I took the original alternator off my car and kept it as a spare and just run the napa one.  If it dies, I swap it in camp with my original.  Once I get home I walk into napa with my original receipt, and they hand me another new one.  If you dont have Napa any of the auto parts store have lifetime warranty alternators so pick your place.

I have done an amp test on my car with everything on, fans, pumps, lights, radios, whips etc and because my car runs a lithium battery and the voltage is always around 14.6v my draw is usually only around 70-80 amps max but only at night.  Its lower then that during the day.

 

[wesinls]

Using this one for 2 years - no issues yet. LS3, dual radiator fans, small oil cooler fans, heated seats, electric power steering, light bars, etc.  (It's 160 amp). Volt gauge always above 14 volts even at idle with fans running.  I liked the fact that it was AC Delco...I'm using Odyssey PC950 battery...smallish, but was what I had room for from previous owners battery tray....so far so good.