My alternator crapped out on me over the weekend and I am seeking a new unit.

I found that the previous owner already installed an aftermarket unit otherwise I would have had the OEM unit rebuilt. I called a few of the dealers and the OEM part is discontinued now.

I do not have much faith in aftermarket rebuilt units from the auto parts store. Does anyone know where I can source an OEM mitsubishi unit from or know where to get a good rebuilt oem unit from?

 

Here's your best option:
IRP 140 Amp Alternator | IRPerformance


I believe you can buy outright or send in your to be upgraded / cover core charge.

-M

 

^ +1 on the IRP alternator, that's what I'm using and it works great.

 

Have you installed one of these yourself? I might not be able to use my core since it is already and aftermarket unit

I don't really need a higher output unit, I would really just like a Mitsubishi OEM unit new! Does anyone know a place we can buy brand new OEM Mitsubishi units?

 

Ok has anyone actually tested that above upgraded alternator with an amp meter? I was told by a local alternator rebuild shop that no one sells the parts to upgrade these Mitsubishi style alternators (I saw the numerious catalogs they used to source the parts). I bought a 140 amp unit off ebay a couple years ago and its crap. It's been the source of all my 20b electrical headaches (all because its wasn't putting out enough amps at idle). I did some research and apparently if someone trys to upgrade these alternators, they end actually putting out less amps at idle. If I let my car idle for long periods of time with the fans on, my battery would slowly discharge. My 20b with 6 coils and a single fuel pump draws 70amps at idle (no fans). Stock fd unit puts out 70 amps at idle and 100 amps above idle. Because I've been having such a hard time finding an upgraded alternator to fit my stock location (my custom intake limits space) I've since installed a 100% stock unit until I figure something out. My stock unit is doing much better than this fake *** upgrade but, it's still not enough.

 

You could just get a used stock alternator and have it rebuilt when it craps out.
There is nothing special about a stock FD alternator. It can be rebuilt easy and reliably. You could even do it yourself after watching a video or two on youtube

Maybe even buy two used ones, install one of them as is and have the other rebuilt good as new, ready to go for when needed.

IMO a rebuilt stock alternator should be as reliable as new. They are a very simple part.

Id go that route, unless you need the extra amps of an "upgraded" alternator.

 

Thanks. My alternators will only put out what is called for. This is achieved by a larger stator with more windings I fit in the stock case and matched voltage regulator. I do a full rebuild for the wear parts as well and bead blast the case so it looks new. No alternator should put out 140 amps or whatever the maximum capacity is unless that much load is placed on it. Stock max output is rated at 90 amps. If you need the full 140 amp capacity you must have some serious stereo equipment or major electrical issue.


I agree some of the ebay alternators and many others are junk. They have to be spun too fast to generate current so you get charging issues at idle and overcharging problems at high rpm. I found 140 amps is the best balance of charging ad output.


It is also important to check the rest of the charging system on the car. The alternator/battery harness gets beat up from heat and oil spilling on it from the power steering pump and ac compressor.


Poorly executed battery relocations with bad grounding is another common issue.


Undersized batteries cause issues as they don't have sufficient capacity, and the alternator is almost constantly charging them.


Deep cycle batteries are not really intended to run a car on. They take a long time to recharge and also put additional strain on the alternator.


Underdriving the alternator too far is yet another common problem.

 

I ended up picking one of the IR Performance units. I will report back with my findings. Everything else should be ok on the electrical circuit. I am using a full size odyssey battery in the rear bin wired to the starter with 1ga battery cable and a solid ground! The rest of the cables look ok.

If this unit doesn't work out I will just end up buying a used OEM unit and having my local guy rebuild if needed!

 

Well it looks like you may be the only company putting out something thats an actual upgrade. I did some more test recently with mine. 70amps at idle seemed really high so I removed my IGN-1A coils and put back the 6 LS1's. Since my Braile battery was also weak, I installed the brand new Miata battery I had in my Miata. Idle test showed 25 amps at idle. I was like WTF????? I know the IGN coils can't be that power hungry but that's what my meter showed. Today I reinstalled the IGN coils and the idle amps are the same as the Ls1's (25amps). So apparently my Braile battery was putting too much load on my alternator during the 1st test. Im gonna do a full idle load test this evening with fans, lights, and blower motor to see what my maximum idle load is. Do you know what your upgraded 140 amp unit puts out max at idle? I may need the Power Bastards import universal as it puts out 110 amps at idle and 220 amp max at 1,400rpms but, I think the power lead will ground out against my intake. I have a 2,500 watt 5 channel amp in the back thats not powered up yet plus a Bosch 044 to use with my swirl pot. I dont have enough amps out of the stock alternator to support these extras with everything else loading the alternator.

 

+1 - do you have any numbers on idle amperage?

Thanks!

Nick

 

That is going to change somewhat with idle speed, load, and the pulley you are running but I will post numbers shortly. I have the sheet just need to find it.

 

Thank you.

 

Exactly my same experience with the electrical shop I use.
They talk me out of the 140 amp upgrade for a 120 amp upgrade.
The extra wounds for higher output capacity doesn't happen at idle, only at higher RPM with the 140.
Your factory will do better at idle.
Also, the factory system is not designed to handle the extra amps, cables would get extra hot and could cause damage to the electrical system or even a fire.
With these old cars it's a risk I won't take.
I don't care or go by personal experiences like: "I have one and have had no problems with it".
That is an empty and corrupted statement.
It's like saying: "I smoke and never have had cancer or lung problems".
I went with the 120 amp upgrade, instead of the 140 and my headlights no longer dim at idle with the AC on.

 

IR,

If I send you my core will you paint the frame black after you media blast it?

 

Has anyone tried the 2011 GTR alternator ??
It looks very similar to ours

 

I second this question.

 

Yes $25 to paint the case.

 

Guys I'm working on some videos of my 140 amp alternator vs the stock one. I am absolutely slammed in the shop trying to wrap up some projects before the holidays so give me a bit. We did recently put one of them on a car with Sakebomb HID head lights, a multitude of gauges, dual fuel pumps, and 1000 watt stereo. It had no trouble keeping up at idle with everything on including AC and the stereo thumping. Beforehand the car had an Ebay "upgraded" alternator and it stood no chance.

 

I got a 200amp unit from Excessive Amperage works great

 

Would be nice if you could post the current draw at idle with all these things on. The stock unit maxes out at 70amps at idle.

 

I've since installed an alternator I had built from my local shop that comes from a Ford Escort. It's a 200amp unit. Need time to test it out some more as I'm still fixing some things with my set up. So far it appears to be doing much better than my stock unit. Only cost me $230.00.

 

I think alot of electrical related issues are the wiring to and from the fuse box along w/ condition of the battery

For example, I had a problem starting engines for years on the original wiring to the starter. Upgraded starter, replaced battery, upgraded grounds, upgraded wiring to the fuse box, etc.

It wasn't until I ran a direct 0 gauge wire, directly to the starter from the + on the battery that starter problems were resolved. The OEM wiring appeared fine, but must have been a big voltage/amp draw through the fuse box. Cranking RPM's must have doubled from simple wire replacement.

I would imagine that those with battery relocations, and those using stock alternator wiring are likely putting more draw on the alternator and/or the battery from the resistance of these old wires.

Looking forward to trying the IRP 140amp on next build

 

tvon, how much work was it fitting this unit! that sounds badass

 

I did this too and it made a world of difference!

 

I had a mind to take advantage of your Xmas sale, but for a couple things. One, (and I know you're busy) you haven't been able to post up the raw data. And two, some of the concerns raised earlier in this thread pertaining to the wiring not being up to snuff and this upgrade being potentially dangerous.

Can you comment as to the safety aspect and long term outlook of using your upgraded alternator?

Thanks

Nick