Alternator Options And Opinions
 

Cross Post from Miata.net.

Hola! Although my car is mainly focused around the turbo and suspension, I do have a 1200W-RMS amp in there with 4 mildly upgraded speakers and a medium subwoofer. Add in the 50W HIDs and my desire to drive everywhere with the top down and the heater on max...

Well, you can probably guess that I find my battery too low to run from time to time. To further complicate things, I have a '00 (with a '03 alt) using a Mopar controler since I'm running MegaSquirt (see Alternator Control box from Mopar - AbeFM's Photos for details) which will seem to give me low 13V levels when everything is working.

The '03 alternator (Hitachi) has an "80A" stick on the side of it and I don't know if it's my controller, the alternator itself (I had this issue, but less often, with my original 2000 model alt), or I'm just plain using more power than 80A can supply. Its certainly borderline.

There are lots of big alternator enthusiasts who recommend these $500 and up alternators, which as best I can tell are optimized for putting out lots of amps at idle speeds for stereo contests and running big winches - but I DRIVE my car, so I'm really just looking for more steady state power at a low price.

I've seen mixed reviews about these: http://cgi.ebay.com/ws/eBayISAPI.dll...tchlink:top:en
Most say its fine but a lot seem to say they are bone stock. The seller (purportedly) says they are rewound with new diodes and an underdrive pulley.

I've heard you can get an alt off a millenia for like 90A, but I'm thinking I want to be in the triple digits. Does anyone know if there's something off a truck or whatever that I could make work?

Thanks!
-Abe.

Get your current one rewound? Or better yet, get a junk yard 94-97 one that doesnt need an external controller and get that rewound for moar powah?

Hmmmm, 100A, I wonder if I'd have to control it.

What does getting it rewound cost? Obviously rectifiers, etc, would need to be upgraded. The math says I need 100A to be even close, 80A makes sense it's falling short. There's a lot of TDI stuff in the 120-150 range, likely overkill but if it'd bolt up I'd be golden.

Spend time searching for higher amp alternators online or in catalogs at the local auto parts store. I did this for my Toyota truck and went from 60 to 100 amps with the same connection and a different length belt.

It was from a Camry or Sequoia or something.

The link below the alternator will tell you that its internally regulated
(Regulator Type: IR)
The problem with Subaru alternators is that the plug is on the wrong side and will be between alternator and block when you mount it.

there's plenty of mazda alts that are more or less identical (but the amperage) that should be PNP. If anything there might be the need for spacer/washers and/or a different lower bolt.

Old thread is old, but is the general conclusion here that the RX7 alternator posted above is the "go to" solution here?

correct.

Just remember you need the longer bottom bolt from the rx7 as well (or parts store)

Is this electrically plug and play, or did the RX7 alternators not send a signal back to the battery light on the cluster (not that it matters to Downmented's setup)


I thought the KL motor 626 90 Amp alternators where as close to PnP as it got. I'd be interested as my fuel pump dips when my FM big flow fans kicks on causing a momentary lean condition. Yes I need to tune voltage compensation but sometimes it kills my car entirely.

Was going to switch to a single 12" fan for the moment and try to work out ducting.

Wait, no the rx7 alternator is all heavy and has more capacity than you need. The Kia alternator is where its at.

Info?

Leafy isn't running A/C because race car.

A/C + Spal fan means needs moar amps for best results in my car. RX7.

Kia alternator is rated lower but seems to have higher real life output than the POS miata alternator. I was confused what alternator thread this was. I thought it was the one for men.

It's the one for cool men, apparently.

Sometimes, bigger is better.

Bigger is always better.

For 1.6 peeps the FC Turbo (RX-7 89-91ish) alternator is supposedly a direct bolt in. I'll find out this week when mine comes in.

And for 1.8?

@psyber_0ptix Confirmed that it bolts directly into the 1.8 as well without issue.

there are two different ones, like the miata, there's a slotted belt drive and a v-notch belt drive alternator for the FD and FC respectively.

both need different lower bolts.


1.8 miata:

https://images-na.ssl-images-amazon....M%2BqH1lyL.jpg

rx7 (100A)
https://images-na.ssl-images-amazon....L._SL1500_.jpg

kia (90A)
https://images-na.ssl-images-amazon....1QYJuYSflL.jpg




1.8 miata (65A)

https://images-na.ssl-images-amazon....1AZsgp4XAL.jpg


rx7 (100A)
https://images-na.ssl-images-amazon....L._SL1500_.jpg

kia (90A)

https://images-na.ssl-images-amazon....L._SL1134_.jpg'



the kia one looks pretty promising, and can be had for $100 brand new -- no core, and not remanufactured.


FWIW, on these three spec sheets, it says the miata alt is 12.1lbs, rx7 is 12.7lbs, and kia is 13.4lbs.

From thread: https://www.miataturbo.net/build-thr...2/#post1358144

The FC alternator does? Its a different pulley

FC for 1.6L. FD for 1.8L.

Does anyone know if the pulleys interchange?

elaborate.

i think the difference in the size of the pulleys is part of how you can achieve greater amperage.

I have a 3 month old FC alternator for my 1.6. Am in the process of installing a 1.8.

Don't want to buy new alternator, need new pulley.

im pretty sure you can. i remember reading someone doing that back in like 2006. but dont quote me on that.

I might measure pulleys.

Or i might get too lazy again and keep asking people on the internet if theyve done it.

Bob did it, good enough for me.

What are you doing that you need extra current for? Isn't this a track car? :)

--Ian

Its for my 12"s in the trunk on the way to the track.

(this car also gets daily'd quite often when not smoking like cheech and chong)

1.6L alternators are a fucking joke.

if I ran my headlights and a/c at the same time, I could watch my voltage drop over time at idle.

Poor engine couldn't keep up :'(

I've been running a Suzuki Samurai alternator. its rated for 70 amps which is more than a stock 1.6l alternator but its significantly lighter with less rotating mass than a Miata part however. bit of fiddling to get it to fit. pulley is a unorthodox aluminum one for a eclipse I think and I found the right electrical connectors to make an adapter to plug it in directly to the stock NA wiring and since its smaller it needs some customizing of the tensioner. It's been trouble free with a tiny LiFePO4 battery but I don't have AC or radio just a power hungry fuel pump, injectors, and voltage sensitive Hydra.

anybody ever use one of these? Got one from a guy who sold his car before he ever installed it.

1993-1992 1991 Mazda MX5 Miata 1.6L w/ MT NEW HD 130 HIGH AMP ALTERNATOR

lol,I take that to mean NOOOO! Anyone see anything wrong with it? If not I plan on running a bigger wire from battery to alternator with maybe a 100A fuse,to eliminate voltage drop when ac and fans come on. And yes I still have the V belt. Be nice to change that though.

Just pick up a used water pump pulley and crank pulley. Shouldn't be difficult at all. I suppose the only tricky bit is ensuring they didn't cheap out on the regulator

Yeah,I hear you.It would be a bad time to install an alternator, just to have it burn up an ecu or such. Time to look for the RX7 piece. I might still do the wires though. Thanks, Payam , for the input.

I'm also about to do the "big three" wire upgrade as I've swapped out the stock battery for a larger one.

why would an alternator burn up an ECU and such?

Improperly regulated?

--Ian

Westfield burnt up an ecu a few years back using the ms3 alternator control. I have not heard of any other instances

yeah but that's regulation issues, not additional amperage issues. That's always a concern regardless of the alternator used.

I was thinking about regulation . Maybe it is a long shot, but it is an ebay alternator. When I did a search on them, they had both good and some bad reviews

Sorry to bump an old thread, but I'm failing in my googles.

What year/model is the Kia alternator from? I can't figure it out. The 95-97 Sephia alternator seemed like a logical choice to search for since it's the same engine, but those seem to be 70 amp units.

Help? I need a manly alternator.

Google image search matched up the Kia alt image with one from here.
https://uedata.amazon.com/DB-Electri.../dp/B007Y85D0S
98-01 Sephia, 70 amp.

A bit of amazon search found this similar one.
99-01 Sephia, 110 amp.

Both are new and not reman. Rockauto has a bunch of new 99 Sephia alternators too. Now to find out if they fit.

http://revlimiter.net/blog/wp-conten...8/DSC_3006.jpg


For future info...The FD alternator is from a 1.3L 93-95 (in the US) Mazda RX-7. 100 amps, 5 groove pulley. 2 wire terminal that plugs into the NA socket and the same size hot post.
The Kia alternator is from a 99-01 1.8L Kia Sephia or a 00-04 Kia Spectra. It claims to be a 110 amp unit and has a 4 groove pulley same as the NA. 2 wire terminal and a tiny hot post.

http://revlimiter.net/blog/wp-conten...8/DSC_3037.jpg

http://revlimiter.net/blog/wp-conten...8/DSC_3040.jpg

The Kia alt needs some grinding in order for it to fit on the BP. The lower mounting tab needs some meat taken out of that support. It also needs the upper mounting tab drilled through to allow it to work on the stock tensioner.

http://revlimiter.net/blog/wp-conten...8/DSC_3058.jpg
The Kia unit I got was new, not reman. And it sucked. It couldn't hold voltage steady for anything when cold and when hot it could only manage 12.8 volts output. The engine would nearly die at idle when the fans turned on. My old stock alt did better than that. And I'd hacked it up, so I couldn't return it.

http://revlimiter.net/blog/wp-conten...8/DSC_3047.jpg
The FD alt needed a few bits sliced out in order for it to get more tensioner range. It wouldn't get too close to the block without these bits removed.

http://revlimiter.net/blog/wp-conten...8/DSC_3191.jpg
It works great though. Great voltage and good regulation. No bad behavior at idle when the fans kick on. Not bad for a remanufactured Mitsubishi alt.

I took a bunch more pix and wrote a blog post about this. Hope it helps some folks in the future.
Non-Stock Alternators That Fit Miatas ? revlimiter.net

Yep, I had to remove the same bits to get it to get the belt on, also swapped the pulley.
I started researching the Toyota Sienna 150 amp alternator. It looks like it could fit, but never actually got hands on it.

I never had to grind anything down for the FD alternator to fit. You're right it doesn't get as close to the block as stock, but it doesn't interfere when the belt is under tension so increasing the range in the wrong direction seems a bit moot. If it's a simple matter of getting the belt on, I think I just unbolted my waterpump pulley and set belts on the alternator first.

All I have seen is FD alt into NA cars, what is required to use FD alt in my NB with MS3 (Rev)?
I blew an alternator a while back and through in a old used on I have laying around, that one didn't last long and didn't put out enough power to fire the plugs at boost so I am thinking the extra amperage will help. Now I don't trust my car and want to get this issue sorted out. Thanks in advance for your help!

Same physical mods, and then follow the instructions posted somewhere around here to swap an NA alt into an NB, electrically. FM has a write up that's been posted here a few times. :)

FD has an internal regulator like a NA. What concealer said.

Hi everyone, sorry to bump this thread but I can't seem to find an answer...

I am installing the FD alt and unfortunately it appears that mine will require the physical modifications that some of you had to do (grind the casing).

I found a thread on M.net where someone used a larger belt instead of modifying the casing. The belt they used was a Dayco 5040350.

So I'm wondering if there's an advantage to using the stock Miata belt and modifying the alt vs. using the larger belt?

Thanks!

There would be an advantage to the belt solution. Buy the belt and report back . You will need to use a straight edge to make sure there is no offset in the alt pulley compared to the other pulleys the belt rotates upon.

Thanks for the recommendation! Thinking of buying the Bando version of the belt.

​I'm curious what your rationale is for using the larger belt compared to grinding the housing as most posts I've seen do. Personally I'm leaning towards the larger belt, but curious as to why it seems most people prefer to grind the housing and use the stock Miata belt.

A good reason to grind it would be that you already have a belt that will work.

A good reason not to grind it would be that if you ever have to replace it with minimal tools you won't be totally fucked. Also warranty.

Howdy all! Just reporting back.

I cross referenced the Dayco belt and bought the Bando equivalent (4PK890). It seems to fit well. We'll see how it works when I get the motor in.

I also used a M10-1.25 x 110 bolt to attach the lower mounting point. I found that a 100 bolt was short and didn't thread all the way through the mount.

I didn't grind anything down and everything appears to be lined up.

https://cimg7.ibsrv.net/gimg/www.mia...09abd96f3a.jpg