RXster

I've been following a post in tech support to try to find a replacement alt for the RX. According to one post an alt from a '98 Chevy pickup with a 454 engine will work with minor mods. It will produce 125A compared to the stock 80A and is exactly what I'm looking for. He said he paid $159 and had to modify the mounting ears. He bought a repair harness to get the mating connector. The connector apparrently has two wires just like the RX, one for signal from ignition switch and the other to charge light.

Has anyone else done this? I need part numbers because I'm having trouble finding the right one. I looked at the mechman ones and they are VERY expensive >$400.

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90 NA Vert w/ TII hood & Kaminari kit, K&N intake, RB header / presilencer, HKS 60mm catback, custom cold air box, custom FTP air inlet vents, modified TB, SS oil cooler hoses, OMP kit from PCV Tech, new paint, 140K miles, may add an SC whenever Mariah gets their act together.

RXster

Hmmm...no replies! I looked at another site and a guy claims that a 3rd gen (100A) bolts right in. Has anyone put in a higher current alt in a 2nd gen? Please post a reply with part number / year of alt you used, any mechanical mods and any wiring mods.
I need one fast!
Thanks

live4boost

iTrader: (2)

I was looking for the same thing. That would be great if the FD's fit. Some help please!!!!

David88vert

I am gettting a H.O. alt from Powermaxx Alternators. Should get it within about 2 months. I need to paint the car first. I have seen many of their alts. All are still running fine, years later. Of course, they are more expensive.

RXTASY1

I got a quote from Powermaxx for my 87 TII and it was over $400!!!

David88vert

So? That is way cheaper than continuing to replace alts. every few months at $100 a pop. but I do have a couple of amps in the car also. I'm also concerned with keeping my voltage up. I've already seen an engine blow due to an alt. going out.
He can build cheaper ones, but his best one is a 3 piece design. I've measured it at 258 amps at 15.5vDC, and it held it for over an hour with no drops in voltage. That one is still running and I measured it in 1994. It was one of my customers. It cost $800 installed.
Because it is so dependable and has such a good warranty, I decided it's worth it to buy it once and be done with it. Especially, with the money that I am putting into my new motor.

rx7_ragtop

I JUST finished putting an FD alternator in my 1988 convertible. It works great, easy to adapt. I have a full write-up on my website under "my car and mods" at:

http://www.geocities.com/rx7_ragtop

but here is a quick version:

FD alternator is "officially" 100 amps- but Chris at RP told me they have tested them as high as 130.

The saddle mount fits exactly, use the stock spacer and bolt. The adjustment side will require a bolt and nut.

You will need to have a bigger "ring connector" on the main positive- the lug is bigger. I also ran 2 additional 10 gauge wires to my battery positive terminal from the main positive on the alternator.

The 2 other wires (for the voltage regulator, etc.) have to be "adapted" on the 86-88. I used 2 wires approximately 6" long, with a male spade connector on one end, and a female on the other. Male goes to the factory harness, female to the alternator. Black wire goes to the top connector. I secured it all together with zip ties.

I'm pretty sure an 89+ is a straight bolt-in as far as wiring goes- the harness appears to be the same.

You have to either replace the pulley with one from a different alternator or drill out the old pulley/spacer to fit the larger FD shaft. You cannot use the FD pulley, it's for a serpentine belt.

(edited to make the wiring clearer...)

RXTASY1

Here is the info. on Powermaxx.

We offer a 155 amp set up for your RX-7.

The voltage is adjustable from 13.8 - 15.0 volts.

Cost is $425.00.

Shipping lead time is running 10-12 days after receipt of order.

Contact product specialist LorenzoMaxx @ 770-981-5940, or view our web site WWW.POWERMAXX.COM/MAIN.HTM.

RXster

RX7 Ragtop great post, thanks. I'm buying one from Bennett Auto tomorrow for $160 / lifetime warranty. I'll bring the pulley to a friend at a machine shop to drill out the old pulley. I doubt I have a drill that big.

RXster

Ok, I just put in the 3rd gen 100A alt this evening but ran into a few more fit issues. Since the alt housing is a casting, I suspect the tolerances got me. This housing turned out to be a little too large in some areas. Here's the stuff I had to do:

1. Open ID of both "V" belt pulley halves and the spacer that keeps the pulley from hitting the housing. Don't forget to do the spacer! I brought it to a machine shop and a friend did it in about 15 minutes. Discussed in previous post.

2. On the passenger side the alt fits snugly into a saddle flange. I had a fit issue here, but not the ID. It was the thickness of the back of the casting where the nut is pressed in. I had to take 0.100" off, otherwise it hit the top manifold of the engine. I wrapped up the alt real good in a garbage bag to keep the metal dust out and ground it down in about 5 minutes with a belt sander. It ended up just flush with the nut, so I didn't lose anything structurally.

3. The next issue was with a screw head that holds on the high current 12VDC black plastic connector. The upper bolt head hit the manifold of the car and prevented me from tightening the belt. I had to grind down the thickness of the head to about 0.060". Not much meat, but just enough left to grab it with a socket. It doesn't hold much anyway.

4. The protective sheetmetal cover that keeps debris out of the regulator section had to go. It interfered with the wiring harness behind the alt.

5. The lockwasher under the pulley bolt could not be used and the nut only grabbed a few threads even without it. To make sure it stays in place, I coated the threads with Loctite BLUE (removeable) and had the guy a the auto shop use a gun to drive it on.

6. The engine hook located on the top of the engine near the alt had to go in order to tighten the belt. It actually rubbed the casting.

Other:
The pulley lined up exactly with the belt.
It's nice that both connectors are rotated to the side to keep them away from the hood. I ran all my accessory wires directly to the high current stud so I didn't need to rewire anything else. If you put your electric fan, stereo amps, driving lights, etc. directly at the current source you get around changing out the 80A battery and starter wires.

Now I have enough reserve to install an amp and electric fan!!!!

vnova94

I have also been looking to upgrade my alternator..... I not too long ago, installed the 80-amp 89+ turbo alternator into my 86 GXL. It's putting out approx 70+ amps.

It fit exactly the same as the 86-88, except for slight modification for the two-wire connector.

My car seemed to run better with the new alternator, but went back to running lousy, with the voltage dropping with the accessories on....

I have two amps in my car..... headunit.... electronic crossover.... balanced inputs.... all drawing plenty of current...

I think the lack of current affected my engine accessories and is probably the reason my front rotor just blew....

Might be time to say the hell with it all, and go with the Powermaxx unit.

Matt