njedwardz

Hey everyone,

Down here in south LA, we're getting daily temps over 100* - which means that proper cooling requires pushing the fan system as far as it will go without melting the connectors. What that also means is that generally the factory electrical system simply cannot meet the demand of running the fans, fuel system, A/C, ECM, ignition, and a 2000 W stereo system simultaneously without putting a heavy load on the battery.

In these conditions, I was seeing the voltage drop down to around 11.5 V, which is far from what you'd want to see considering that you're looking for at least 14.2 or so..

In order to combat this, I installed a Mechman Billet-Tech 170 A alternator, which I sourced from Bret at RKT performance (BLOWNBLUEZ06@RKTPerformance). According to the test sheet provided with the part, it puts out 145 A at idle and 176 A at cruise - both substantially more than could be expected from the factory piece.

Since my car has around 60,000 miles on it, I figured it wouldn't hurt to go ahead and swap out both belts, so I did so with Continental Poly-V belts. For those interested, the main belt is 4060798, and the AC belt is 4040410. These are built much better than the factory ones, and they make much better contact with the pulleys.

Here's a few photos:

New alt and belts - MADE IN USA!:


Old vs. new - quite a difference:


New alt/belts installed:


Note that there is not a ton of clearance between the top mounting bolt and the output stud on the new alternator - I added some electrical tape for peace of mind, although I have no reason to expect any contact between the two.

During my several-hour test drive today, at no point did the voltage drop below 14.5 V - a marked improvement! Typical idle voltage is 14.8 V now, where on the best of days before I was seeing 13.6 V or so.

All in all, I would highly recommend putting in one of these if your alternator is going out, or if you're just looking to upgrade to something more up to the job.

BLOWNBLUEZ06@RKT Performance

Thanks for your feedback! I'm proud to be the vendor for these as they've been a great product for me to offer.

Larry Myers

I'm a proponent of the Billet-Tech alternator. Vastly superior to the oem piece.

Have had one on my Vette for almost three years. Without regard to rpm it never reads less than 14.6. And it looks good too.

victorf

To further the distance from the top mounting bolt, I chose the option of removing the rear section to re-clock, along with an extension for plug in supplied by Mechman in the new alternator and rotate to remount in a different position.

njedwardz

I considered doing that, but after some thought I decided that it wouldn't be necessary as long as I made sure to keep the battery disconnected if the alt ever needs any service (which should be a no-brainer anyway). I figured there was a higher chance of me messing something up pulling the alternator apart than there was from me keeping the stud close to the bracket.

I may be studying electrical engineering, but that doesn't mean I want to learn alternator disassembly on the one that's going in my only car.

The black finish on the alt really does look great...

realcanuk

It's very simple to clock it to where you want the plug. I'm turned it so it faces down. Just looks cleaner to me.

Monte4ever

I was looking into getting a 240amp alternator. With all your accessories running, including the 2000 watt stereo, does the 170 amp alternator keep up? If it does good cause I would rather get the lower amp version.

BLOWNBLUEZ06@RKT Performance

With a 2KW stereo, a 170 might be able to keep up. It depends on how often the stereo is on full tilt and for how long. To some degree it even matters what kind of music is being played. Bass is the most demanding of power so if it's music with a constant bass and you're playing it wide open all the time, the 240 is going to be the ticket as well as a bypass cable to carry the additional current across the car.

EnginerdVT

How does the clocking work and what additional parts are needed? I saw something about a plug extension? Does anyone have aftermarket valve covers with one of these? I am hoping that it would clear my proform valve covers that I had to clearance my stock alternator for.

timd38

I got one about 3 years ago, love it!

BLOWNBLUEZ06@RKT Performance

I can't imagine the Proforms being taller than the Katech and my alternator fits them just fine, without any clearancing. The billet alternator provides about 3/8" more clearance on the bottom compared to OEM units.

Clocking can be done carefully and at the risk of the buyer. I do it with the alternator face down on the bench, using a soft towel to prevent any scratches on the pulley. Remove the 3/8" nuts and then the plastic rear cover to expose the 4 inverted Torx bolts, also called EI. If I recall correctly, it's an E6 socket that's needed. Remove the bolts and carefully turn the back and front cases in opposite directions and in 90 degree increments until you've got in the desired position. Insert the bolts back and tighten them to 62in lbs. Re-install the rear cover and the nuts. Tighten them wrist tight (about 30 inch lbs).
I can get you an extension. They cost around 35.00

Thanks,
Bret

BlindSpot

Bret - Thanks for your reply to my pm re: the alternator bracket, much appreciated!

CMY SIX

gee lived in Cali it gets hot there too and moved to Alabama it gets hot here too, installed a DeWitts radiator which is cheaper then the mechman and going down the road on a 100 degree day can't get it over 180, sitting traffic same day can't get it over 200 and when the fans come on they pull it right down to 180, treat the disease not the symptom's

Curt D

I see where you're going with this....if he gets a radiator it will help his 2000w audio system

njedwardz

Well, the alternator was $489, and the cheapest DeWitts is $629, so..yeah. Maths. The DeWitts with the trans cooler is $710. That assumes you want to keep the factory fan setup instead of moving to the D3 PWM setup, which is another $900. So that's $1600 instead of $500. I'll probably have that setup before the summer anyway, because the car is a good bit more aggressive than it was last year, but that's beside the point.

Injector and spark behavior is also far more consistent at 14.5 V+ than 13 and below, which is really important for a good idle with h/c, especially if you want to keep your idle RPM near stock.

My methodology behind my modifications are to make the vehicle perform the way I want it to. Until 2 months ago, this car was my only vehicle, and saw 20,000 miles of abuse every year. That means, no matter the electrical load from fans, injectors, plugs, AC blower, stereo, fuel system, etc., the voltage shouldn't ever drop below 14 V. With the stock alternator, that just wasn't possible. Sure, a better radiator would keep the car cooler at lower fan speeds, but I want it to be able to run at maximum fan speed without any issues.

You also need higher electrical system capacity in the winter, since batteries are inherently weaker when temperatures are low. Having a larger alternator prevents the electrical load from dipping into the battery's already low reserves.

TL;DR: I wanted a bigger alternator for a variety of reasons, so I bought one and it's performed great.

EnginerdVT

Did you need a (harness or power wire) extension to do this?

realcanuk

No. Wires reach no problem.

EnginerdVT

Awesome, I'll use the writeup that's in here or try and find a video that shows how to clock it.

BlindSpot

There is no real need to clock the stock Mechman factory position, unless I am missing something. My install put both connections in place with plenty of clearance. The plugin harness is not stretched or out of place. The primary voltage cable fits with a positive mechanical bolt in place connection and a rubber boot. This connection is almost as good as being welded in place and it might as well be a mile away from the alt bracket. There is no need to tape it or anticipate it is going cause a short.

EnginerdVT

Understood but if you clock it 180 degrees, it leaves you with a cleaner look and the attachment point for the cables under the alternator.