Alternator - Any reason not to go bigger?

[MinuteMan]

Looking at HO alternators. Spoke with a couple brands and they reccomended a 250a alt for my set up, and quoted me 250a up to 425a alts

My question is:

Is there any reason to not go bigger? If I'm spending around $500 on a 250a, it's not that much more of a jump up in price to get the 370a or 425a.

Ease of installation is the only selling point I see for the 250a, (uses same belt).
But, If I'm going to replace the Alt, I'm going to replace the belt at the same time either way, so doesn't seem like that much more money or trouble to jump up to "the biggest I can get".

Am I wrong? Any other advantages to going with a lower amperage alt?

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[Bobbytwonames 5,000+ posts]

Looking at HO alternators. Spoke with a couple brands and they reccomended a 250a alt for my set up, and quoted me 250a up to 425a alts

My question is:

Is there any reason to not go bigger? If I'm spending around $500 on a 250a, it's not that much more of a jump up in price to get the 370a or 425a.

Ease of installation is the only selling point I see for the 250a, (uses same belt).
But, If I'm going to replace the Alt, I'm going to replace the belt at the same time either way, so doesn't seem like that much more money or trouble to jump up to "the biggest I can get".

Am I wrong? Any other advantages to going with a lower amperage alt?

How many watts are you looking to run? Have you done the big 3/4? Do you want to upgrade in the future? Everything plays a part.

 

[MinuteMan]

How many watts are you looking to run? Have you done the big 3/4? Do you want to upgrade in the future? Everything plays a part.

Right now I'm looking to run:
Taramps Smart3 Bass ( rated 190a musical 278a Sinusoidal )
Taramps DS800X2 (38a 77a)
Taramps DS800X4 (51a 102a)

So, ~ 4600 watts (279a M 475a SS)

I akready have three Energie SC1600's going in a bank in a back.

Big 3 is planned, nothing is installed yet.

I don't think I've ever built anything, and not then upgraded again later. So that's exactly why I was thinking, just go as big as possible and leave headroom for future upgrades.

 

[Popwarhomie 5,000+ posts]

Most companies don't recommend going over 240-270 on a daily driver. If it's not a daily go big.

Large case vs small case makes a difference. My DC power 270 did 200 at idle. My AT 320 does 170 at idle.

 

[MinuteMan]

Most companies don't recommend going over 240-270 on a daily driver. If it's not a daily go big.

Large case vs small case makes a difference. My DC power 270 did 200 at idle. My AT 320 does 170 at idle.

It is a daily.

What's the downfall of going larger? That's what I don't know. Just too much stress on the electrical system?
I've got no problem getting the 250a, but if it makes sense to bigger, I'll do that.

250a thru 390a Im looking at are small case and
270 and 390 idle around 200a. I don't know idle on the 250a.

 

[HondaCRV03]

I have a 320a for my daily. Got mine from Singer. Only thing I have is a check engine light for high amperage charge. But everything else is fine. Lights, AC, radio, etc works as it should. Do what your budget allows

 

[MinuteMan]

I have a 320a for my daily. Got mine from Singer. Only thing I have is a check engine light for high amperage charge. But everything else is fine. Lights, AC, radio, etc works as it should. Do what your budget allows

There's an issue. In my state a check engine light is an automatic failure at yearly inspections...

Thanks, that's something I didn't think about.

 

[HondaCRV03]

There could be way around it. Talk to whoever you plan on buying from. I'm in Florida. Emissions aren't a thing anymore. So I don't mind the check engine light

 

[metalheadjoe 10+ year member]

Most companies don't recommend going over 240-270 on a daily driver. If it's not a daily go big.

Large case vs small case makes a difference. My DC power 270 did 200 at idle. My AT 320 does 170 at idle.

What's the reason behind that recommendation?

 

[Popwarhomie 5,000+ posts]

Honestly I don't know. Just what I was told years ago from DC Power and I never even questioned it. Could be completely wrong.

 

[hispls 5,000+ posts]

it's not that much more of a jump up in price to get the 370a or 425a.

I do not believe anything you'd fit under the hood of any street legal non CDL type vehicle will make anything like 425A real world. I'd say avoid anybody trying to blow that sort of smoke up your arse.
Apart from that, there's probably half a dozen reputable shops that should do fine. Nathan at Excessive Amperage has always done me right and I stick with him. I see a lot of locals run Ohio Generator with good results and I've dealt with Mike Singer before in trade and I'd vouch that he is at least a genuine enthusiast and an honest seller.

 

[MinuteMan]

I do not believe anything you'd fit under the hood of any street legal non CDL type vehicle will make anything like 425A real world. I'd say avoid anybody trying to blow that sort of smoke up your arse.
Apart from that, there's probably half a dozen reputable shops that should do fine. Nathan at Excessive Amperage has always done me right and I stick with him. I see a lot of locals run Ohio Generator with good results and I've dealt with Mike Singer before in trade and I'd vouch that he is at least a genuine enthusiast and an honest seller.

Quotes I got were from Brand X and Singer. Singer only quoted me up to a 250A.

I appreciate all the help

 

[dsw1204]

You can't have too many amps coming from your alternator. It will not hurt your car electrically. It will not burn up anything. I am assuming that was your concern when you made this thread.

 

[MinuteMan]

You can't have too many amps coming from your alternator. It will not hurt your car electrically. It will not burn up anything. I am assuming that was your concern when you made this thread.

That was indeed some of my concern.

Also things like popping a check engine light as mentioned above. Are other upgrades required? Like does a 390a alternator require 2/0 or 4/0 wire instead of the 1/0 I have...

Just trying to see if there was something I wasn't thinking of before tossing a chunk of change at "the wrong" alternator

My mind tells me to get the biggest I can afford, but I'm no expert. This is my first build.

 

[dsw1204]

That was indeed some of my concern.

Also things like popping a check engine light as mentioned above. Are other upgrades required? Like does a 390a alternator require 2/0 or 4/0 wire instead of the 1/0 I have...

Just trying to see if there was something I wasn't thinking of before tossing a chunk of change at "the wrong" alternator

My mind tells me to get the biggest I can afford, but I'm no expert. This is my first build.

As with the alternator, you can't go too big. The bigger, the better off you wold be. However, I would think 1/0 would be plenty big.