Alternator upgrade time on the cheap.

[curtis]

My alternator has been acting funny along with some electrical gremlins for some time. I've been putting it off because I wanted to use an alternator from a different car on here and build mounts where the air conditioner pump use to be. But can't wait any longer.

A friend of mine recently did a motor swap on a 2.5 legacy at the shop he works at and the stuff that came off the car has been in his way.

I know where the hell is Curtis going with this!!!!!!!!!!

The EJ25 Subaru's use alternators built by Mitsubishi motor corp. /ubbthreads/images/graemlins/devil.gif. Thing is that there 110 amps and looks like it will bolt right up the plug is different but still have the two wires and the main cable that runs to the battery. Also the plug in is in a different place but want interfer with the power steering pump.

I'll post install pictures tomorrow. If you can't wait to see pictures get on ebay and look up dsm alternator and subaru alternator and see what looks the same.

/ubbthreads/images/graemlins/applause.gif

 

[s_firestone]

I've been noticing that in looking at alternators on Ebay. Seems Mitsubishi makes a lot of alternators.

 

My '91 Ford Probe had a Mitsubishi alternator.

 

[DSMTurbo2]

well this may be useful or not... I believe you can get a HO alt for our cars just about anywhere. I THINK the low end is a 90A and the high is like 120A... just a thought.

 

[Terry Posten]

No, low is 75A and high is 90A.

 

[curtis]

If you look at some of the subaru forums the low is a 110 and the high is a 160. I read up on it this morning and someone was selling the 160s at double the price until an other member got word of it and did some searching. Looks like the 160 can be bought for $185. I paid nothing so I'm in the good except for time to do it.

 

[Terry Posten]

So, will a subie Alt work? That is an awesome upgrade then.

 

I imagine you will need to swap pulleys, no?

 

[thadirtybird]

.........first the tiller, then the car huh? /ubbthreads/images/graemlins/rofl.gif

 

[curtis]

^talk crap I'll put that Montgomery Ward/John Deere hybrid tiller on the hood of that kensington grey garage princess.

How's the radio install going....
....................................................................................
Well started the process

Removed the alternator...
Started comparing,
the plug on the subaru is the same just in a different spot...
the 12 volt feed hook up is on another also but no big deal it has an adapter to put it up on top but I removed it and used the phenolic isolator from the stock alternator.

The bottom mounts are the same distance apart... /ubbthreads/images/graemlins/grin.gif
The top mount has a little different offset than the mitsubishi one but haven't addressed it as of yet...only a few mm difference but don't want to shread belts.

It bolts up but haven't tightened everything up yet.


Pulley fiasco
The stock pulley on the mitsubishi has no means to keep the belt from jumping off the back of the pulley and is only about .030 or so off the housing of the alternator.
The subaru pulley has the anti jump off lip on their's and is spaced out more than the mitsubishi.

I was going to just swap pulleys but the subaru has a larger shaft, I started to drill it out larger but remembered I had some ford pulleys so I machined one of those to work because the shaft dia was the same and the ford dia was a little smaller than the mitsubishi and since I have an underdrive crank pulley though it might help.
I had to cut down the shaft that sits against the bearing in the alternator and machine off the lip that the fords have that keeps the belt from jumping off. Also I cut off a small lip on the subaru casting that comes out around the shaft. I took about .075 off of it but as long as the pulley doesn't hit your fine. The mitsubishi had a small lip just not as big.

For anyone doing this you can simply drill out the mitsubishi pulley and install it on the subaru alternator just remember you may have to run a spacer between the pulley and the bearing.

I'll finish tomorrow. The belt is a little long and will have to get a new 100 amp fuse. Dropped a tool and it had to hit the end of the cable and find ground at the same time. /ubbthreads/images/graemlins/banghead.gif /ubbthreads/images/graemlins/mad.gif /ubbthreads/images/graemlins/banghead.gif

 

[Hertz]

What are the Pros and Cons of doing this?

 

[Gvr4-330]

Cons == all the extra work and fabrication.

Pros == the higher amperage of the alternator. 160 amps vs. 90 amps stock.

Does that sound about right curtis?

Rob

 

[curtis]

Done except the fusible link I smoked last night.

All the extra work isn't a con but the pro...I hate fixing things without upgrading its feels like a waste of time. Total time involed was about 3 hours for removal fab and reinstall. I have a different radiator so removal is easy. It only took about 20 minutes to get it out.

I tested the alternator this morning at Adavnce auto and it tested good. I tried to test it at Auto Zone with the new machine but its broke already, It came up on the computer at 85 amps for the subaru one. Everything I read online said it was 110 amps. Maybe the years have something to do with it and auto zone haven't updated their database. /ubbthreads/images/graemlins/dunno.gif We looked up 12 different years and the all said the same. Anyway I know what it take to do it now and in the future if I want a 160 amp I can just buy one.

For the belt alignment I had to file the mounting surface down on the bottom pad next to the crank pulley. It had a rasied up spot that had to have about 1 mm shaved off. Then on the back side nothing had to be done because the sliding spacer will adjust everything tight. As for the top mounting point nothing had to be done, it bent over a little and bolted right up, the sloted mount that is. Since the pulley I used was smaller I had to get a 372 lenght instead of the 378 I had before.

If anyone has any questions in the future just yell. It wasn't that hard of fab job. I wish I had the time to rebuild the subaru one and upgrade it to 160 amps maybe the next time the tranny is out I'll pull it and drive it over to the local rebuilder.

 

[curtis]

The verdict

Drove it to Auto Zone to test on there tester.
At idle the car was putting out 38.7
Then while reving it at 2000rpm and having a load applied the alternator output was at 71.9 with the test lead connected about 3 inches from the alternator.

I wanted to hold it on the two step to test but the guy was afraid I would blow up his machine....nerd. Not sure what max would be.

I did notice one the first start up that the car idled smoother and also the voltage was holding steady at 14.00 to 14.20 at idle where before it would drop down to about 12.4 at idle. I'm happy it cost me a new belt and a new fusible link and a few hours time.

 

[spooling92vr4]

not sure if that would fit on the back of the motor where the ac compressor used to go... when i did my alternator relocation a while ago the stock pulley was really close to the framerail (this was my eclipse ) i think that stock subaru pulley would deffinatley hit

 

gvr4 alternators are 90/95amp?
I have a dsm 75amp alt on my car now and want to swap it with a 90/95amp ASAP!

thanks!
AR

 

[Terry Posten]

Wow, I don't even remeberthis thread.

I must be getting old.

 

High rating alternators will help you in resolving the issue. 200-250-300-350 Amp Alternators are highly compatible.

 

[Nabeel]

Good idea. I am using 90A GTS skyline alternator on my GVR4. It is almost bolt on. harness exactly the same. the reason I used it because my engine from 1g eclipse & has 75A alternator.
Your legacy alternator plug looks same as the 2g eclipse or 8g galant.

 

[Nabeel]

I would like to add that swaping pulleys at alternator may change the output to lower or higher Amp. correct me if I am wrong.