Looking to put a mini alternator on. Will 35 amp be enough or do I have to spend a extra $200 bucks to get another 10 amps.

With todays cars I would want all I could get.

What application is the car used in?

As this is the race section it would be a race car . Drag race only, 2 batteries , the usual MSD electronics. electric water pump and cooling fan. I see the auto parts stores have 35 amp alternators for under $70 bucks, Jegs / Summit have have 45 amp for $250 up. So is the 10 amps worth it? Of coarse the price goes up with more amps 55 +

It might work since you have 2 batteries. Even if 35 amps doesn't keep up with the electric pumps and fans it is still adding a charge back to the battery. If you have a voltmeter on the car you'll be able to see if you're losing charge during a race or staying even. If you want to be more scientific about it buy an inexpensive amp clamp gauge and check to see what is happening when the car is running and everything is on. Or install an ammeter into the system (can be tricky to do on a race car) and then you'll know if you are charging or discharging.

This is the one I bought for my blue duster but haven't put it on yet. I paid extra for a 90 amp but when I took it to have tested put out around 55 amps. I gave him a bad review on it but its LONG GONE. He said he never had them tested and offered my money back but I kept it and will use it.


https://www.ebay.com/itm/BLACK-90-A...t-1-Wire-Street-Race-Chevy/192461495401?

That's timely, I was just looking on E-Bay at the what was out there. Just so happens I was looking at the same alternator and wondering how they could sell a 90 amp for $120. bucks. Even as yours tested at 55 amps if it last it would be a good deal. It does have a 3 year warranty and the seller has a 100 % feed back now. I'll keep looking to see whats best.

I think my generic GM 1-wire on the drag car is about 50 amps.
Runs the MSD, water, fuel, electric fan, headlamps, brake lamps, gauge lamps & tach fine with 2 normal Group 24 batteries.
I run a digital voltmeter and it's never under 12.7 no matter what.
Normally that increases after every pass.
Quick Google search shows the Denso 90 amp units as cheap as $73, mostly around $100.
As far as being the Race section, lots of guys post here for street/strip stuff, so an application/usage isn't necessarily obvious.

Lots of alternator/charging system discussion lately. Every situaion is unique. Remember alternator speed is directly related to its amperage output.Advertised amperage rating is almost always max output under idea temperature conditions. Most auto parts stores with test benchs usually have single speed units that cant test thru-out the full operating range,merely identifies its ability to determine if it is able to produce some kind of charging rate. And the bench is only as good as it's operator.Alternators that are producing low amperage, during testing, could be driven too slowly,have a bad diode, or mislabled/rated. With a bad doide,you would see an amp ripple when monitoring with an induction type probing clamp.With a failed diode,AC current would be migrating back into your 12v electrical system. Thats a BIG problem for any ECUof any component-think high dollar ignition units and others.What I'm saying is to use the services of a reputable alternator shop that has the ability to check charging rates at multiple speeds. Very important for accuracy. A typical 90amp full funtioning alternator will only put out 55amps at low speed.It would be worth the time to do a second check, it could have been misdiagnosed. Bill

Just going to pass on what the guy that owns the alternator shop that tested mine said. He told me the small framed ones like the one I had tested are not capable of the amperage mine was advertised at putting out.

60 amps and it doesn't get much cheaper than this !!

http://store.440source.com/Lightweight-Alternator-Retrofit-Kit/productinfo/122-1004/

Look at a NAPA rebuilt for a 1976-1980 dodge truck with air conditioning that puts out 65 amps

It's not a mini

Sorry to be a pedant here but if the current demand is more than the alternator can output, you will be drawing from the batteries. Sure the alternator will help as will the extra battery. For info on our car with a 105 amp powermaster alternator, we run electric w/p, dual fans, electric fuel pump, a small data logging system, gauges and a good ign system we are pulling close to 60 amps. I can't remember what the ampage breakdown was for each item though. It pulled another 35amps with all the lights on IIRC. It was one of the reasons why we re-wired it and changed most of the lamps to LED's. Haven't tried measuring total amps since but the logger says we maintain a constant 14.1 Volts making a pass. We also run a -ve wire ring in the car too.The Powermaster alt came with a "dyno" sheet, at 900rpm idle it put out 70A and by 1500 it was at max, 107A.

You are absolutely correct, do you want a mini? If so the stock alternators on the Cummins diesel motors look a lot smaller than the early ones on the gas motors in the trucks and motorhomes

I have a Denso that I bought from a local starter alt shop for $125. It was sold to me as a 120, but another shop later told me it was a 90. Works great on the street with many acc. Both shops told me to stay away from the mini's as they are not capable. He had a brand new one there a customer brought in, it was a powermaster, Lasted 3 days on the guys car. He said their garbage the way their built. I have a powermaster mini starter on the bench. Lasted about 2 months. Took a sh!t leaving me stranded. Garbage as well. I would look for a small Denso if it were me. Money well spent.

That looks like the one I use, but i'm told its a 90A. What ever mine is, it works great. Have had it on the car for 10 or so years now.

I have to run a mini as the engine is not able to mount a alternator in the stock location. The alternator will be mounted down below between the tube chassis and the oil pan.

Ok. Well, my Denso is mounted low beside the frame rail on passenger side using the DLI brackets.

I got a call this morning from a older tech from Powermaster catching up on calls on Saturday morning, I left a message on this past Thursday morning wondering what size wire to use on my race car with one of their 100 amp single wire alternators. He said to use a #4 cable instead of the #10 wire I have been using, I ask about using two #10, one to each battery and he said no, don't do that He also said you really need to use the threaded built in ground hole to ground the alternator to the engine with a # 4 cable also, he said do not to rely on the anadised motor plate as a ground
IHTH others about the alternators and application
I'm going to follow his advice Maybe I can get rid of a random Mr. Murphy issue on my ignition system