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Customer Customer States Mechanic Fails Engine Transmission Gas Diesel off road race 4x4 street car daily driver scam dealership dealer technician how to

Wow, All these alternator upgrades around here have turned into a kind of a uh well, what do you want to call it? It's a contagious situation. That's right, we've got a 2004 Chevrolet Silverado for a 5.3 Silverado it's a Suburban that's twice I've done that to this truck I Keep calling it a Silverado probably cuz when you get inside it looks like a Silverado but then out back we don't have a bed. we have more people containment area. So anyway 2004 Chevrolet Bourbon 5.3 customer States Need more electrons? So we are going to modify this vehicle ever so slightly.

What I have here in my hand is an underdrive I Think it's a 41 mm diameter alternator Drive pulley. So what we're going to do is swap out the current alternator pulley which is going to be a larger diameter than this one and we're going to put this smaller diameter pulley on this engine. And what that's going to do is at idle and low engine speeds, that alternator is actually going to turn faster so it'll be capable of its peak output at lower engine speeds. For example, if you've got the AC or the heat on full blast and you're stuck in traffic, your alternator will be alternating faster and you will not deplete electrical loads.

So it's going to be a real quick, easy job. We're going to go under the hood here. We're going to pop the belt off. We're going to unbolt the existing Nator pulley.

We're going to pop that pulley off. We're going to put this pulley on and then reverse procedure. Now one thing: I am going to do is take some testing measurements of engine output or alterator output rather at idle, and we're going to see if there's any difference in uh, current output from this current AL from this existing alternator. We're going to compare the old pulley with this new pulley right here.

So stay tuned because this is going to be a very good video uping the hood. Look who that guy is. Okie Dokie! First things first: you guys may have noticed that I kicked on the high beams and I kicked on the blower motor fan. That's full speed.

Uh, actually I think this thing has rear. uh, a rear blower motor as well. So let's go turn that one on. What I'm going to do is we're going to leave it at idle, the engine at idle, and we're going to turn on the maximum number of loads.

Then I'm going to take an amp meter. We're going to measure the amp output of this alternator at idle. We're going to record our measurements, and then we're going to swap the pulley out with the smaller diameter pulley and then re-record measurements for a second time. Now, before we get started, let's let's go ahead and take note that this vehicle is equipped with dual batteries.

Uh, this entire Gmt800 platform had the capability of a secondary battery, but most Vehicles only gotten a single battery. Well, our guy with our Suburban Here he went and found the Uh, the battery tray that goes in the passenger side and then equipped this vehicle with a secondary unit and we're going to make sure that those units stay charged now. Taking a quick peek at our alternator pulley that's the factory unit and we can see here I'm blocking some of the light, but we can totally see that this other pulley is much much smaller in diameter, so that should definitely affect that alternator's capability at idle. Sure, let's go ahead and fire up the digital meter here.
We have an external amp clamp. Let's let this thing stabilize and we can adjust it out to zero. It has to be calibrated with this little knob right here and I'm adjusting the wrong way going that way. close enough.

There we go. That'll do it all right. So we've got our single wire for our output side on the alternator. All we do is flip this clamp on and it's going to tell us the amp, current or the amp draw that this alternator is producing and look at.

Here, we're at 60 amps, 60 amps. That's actually quite a bit of power, so it makes 60 amps at idle. All right. Let's go ahead: shut off all of our loads, high beams off fans off powering down engine shut down.

Let's proceed to swap this pulley and then we can take another measurement so you can see here. we're not making any current, see if the batteries are drawing any current. Nope. Check this one here.

Nope. Cool beans. All right. let's goe and shut this thing down.

Park that and we can get to work on our Nater pulley. So I'm going to make this easy on myself. I Will remove this intake ducting real quick. like then we can get to our tensioner.

so we've got one hose clamp right back there. Let's get that guy dug out. I should probably take this engine cover off, but I think I can sneak it out. We'll see one clamp down another over here at the mass Airf flow sensor.

Unscrew that one. let grab this whole unit, wiggle it back, disconnect it from the mass airc up and out going in with a 15 mm Flex head spline. Drive ratcheting wrench. So we pull this guy back.

It relieves tension on the Belt see that right there and then all we need to do is reach on over with tension untensioned. Slide that off The Idler pulley and now the alternator is free from the belt so we may just relax our wrench. Let that hang out right there. Good You go all right.

So we can see our nating unit. it's held on to the alternator shaft with this single B single nut not bolt. I think that's a 24? Let me let me grab one here off the cart. Yeah, 24 mil.

What I'm going to do is stick this on the walk. a 90 impact gun. I'm going to hold the pulley. hit it.

That came right off. Right Tool did it. Probably couldn't do this with a ratchet. she slides off and that is our original pulley.

Again, let's compare the original with the uh. undersized pulley. You can see a huge difference in the size. So what that will translate into is a F faster shaft speed on this alternator, and since it has a faster shaft speed, it will come up to its peak output at lower engine.
RPM So I'm basically simulating a higher engine RPM when the vehicle is at idle. now. yes, these will run super fast if this engine is sitting here. turned up to like 6,000 RPM.

But the reality is is most Street engines if not all, do not ever see those high RPM ranges. and if they do, it's rare and in short burst. For example, you're on a uh, an on-ramp or something. uh-oh I don't have enough socket.

The socket won't fit inside of this pulley, will it? Yeah, it fits. If it's I'm going to need to put a like a swivel on this or something. Hey check this thing out. This one of my first tools that I bought when I was a tire guy back in my late teens.

Got got it from a Sears it's a Craftsman halfin Drive Universal swivel. I've had this thing for uh oh about 20 years I Think weird huh? It's weird to have inanimate objects longer than I've had children click all right. pulley is installed. You see our nater is rotating freely.

The fan inside is Fanning. Let's go ahead and get that belt back in position. so again, reach over grabbing the tensioner or the the wrench rather that's on the tensioner. We're pulling tension out of the belt or slack out of the belt rather and I need to slip this over the power steering pulley.

Now the astute amongst you will notice this is a seven rib pulley whereas the one I removed was a six rib pulley that is of no mat. As long as we get it lined up properly on the inside and using my Iometer. If we follow the belt down from the bottom at the power steering and come on up with it, we can see that we are in line correctly. If we had this thing over here on that outer pulley, the belt would be walking a little bit sideways and it may actually want to pull the belt off of this idler right here.

so by my eye that's in good shape. Let's go ahead and get the Uh Airb box back together and then we'll restart this engine and check some measurements and see what we get ducting coming in. Slide it down, connect the mass, air flow and airbox, and then connect the throttle body just like so. two more screws for our worm gear, hose, clamps, cage and then Uno Moss r right there.

Please become tight. There we go. Good to go. That guy is secure.

This is mine now. All righty. let's fire up the amp clamp one more time. Turn that guy on and I think that's our setting.

Need to recalibrate it? I think one point five, let's turn it down some. No, not 9 amps too many. Uh, there we go. 2 amps.

Whatever. That's fine. All right back inside, let's go ahead and restock the engine and we'll see what this alternator is now making at idle. It may not be making any extra because we may not have depleted all the loads, but we'll see so we'll start it.

High beams all the way on Blow lower fan all the way on and output. Look there. 82 amps. Now we're making more power.
alternator's choing along, the belts running good 87 amps and it's holding steady at 87 86 85 Okay, so that's proof in the pudding. We got 20 more amps out of just a little bit of a pulley. Now again, that's not really beneficial if you're wound up to like 7,000 RPM And you're driving around on a racetrack, but on a street vehicle that has a lot of electrical systems. Two blower motors, two batteries, bunch of Lights fog lights, radio, electric windows, power seated Heats all that cool stuff, then you may or may not find it beneficial to have a little bit extra electrical power.

Potentially what that can do is prevent you from shutting down with a discharge battery and that can also help extend battery life. That's my estimation on the situation, but proofs in the pudding: We can see more power here. I Like it? Uh, yes, that alternator will probably require more Force to turn it and it's going to take down fuel economy ever So very much slightly. Uh, probably not enough to be consequential for most consumers in in my opinion.

Of course that's not reality. I'm not an engineer, but that's just kind of how I see it. So all right guys, hope you enjoyed this. uh, short little video about Overdrive Aln I Enjoyed making this video for you guys.

Let me know what you think about the situation down in the comment section below. Again, thank you guys for watching and most importantly, have yourselves a fantastic day! See you guys later in the video into Vortex Suburban into 53 dual battery overdrive alternator in a transmission.

96 thoughts on “Overdriven alternator setup! more power for cheap”
  1. Avataaar/Circle Created with python_avatars @danielcruz9446 says:

    Daaamn! that AC sounds terrible. 🤮🤮

  2. Avataaar/Circle Created with python_avatars @alanvotta3847 says:

    You always "AMP" Me Up
    Good video,short and sweet

  3. Avataaar/Circle Created with python_avatars @robertwright5487 says:

    That's one noisy blower motor.

  4. Avataaar/Circle Created with python_avatars @tomtke7351 says:

    you speak electricity well when you use term "load." That's the term us 'sparkies" love most. Circuits 101 is tons of series, parallel, series-parallel LOADS with resistive and reactive elements….

  5. Avataaar/Circle Created with python_avatars @jimburgess9205 says:


  6. Avataaar/Circle Created with python_avatars @Darkvirgo88xx says:

    I love those vs the old squeak with a firm shift solid pulleys. My favorite just for sound is the other variation the one way clutch sound on the old Mitsubishi alternators used in the Crown Victoria Police Interceptor starting the production year 2004.

  7. Avataaar/Circle Created with python_avatars @dodgymalaka says:

    I would have liked to see the voltage. A stock alternator rarely produce full voltage at idle. Guess this mod will help.

  8. Avataaar/Circle Created with python_avatars @williamlett6207 says:

    Where did you get the smaller pulley and the part number please???

  9. Avataaar/Circle Created with python_avatars @julianstewart1301 says:

    Hey Ray, I have a 2011 Ford Expedition. I had to put a little money into it this year, but I wanted to hold on to it. I really enjoy that vehicle. I see, a lot of your customers and you are doing the same, so I'm feeling a little bit better about the money I have been spending. Thanks so much.

  10. Avataaar/Circle Created with python_avatars @michaelwinslow5975 says:

    What are the cons of any are there to reducing the pulley size?

  11. Avataaar/Circle Created with python_avatars @franklinstevens9249 says:

    Scotty we need more power I'm giving it all she's got captain

  12. Avataaar/Circle Created with python_avatars @charlessmarr7107 says:

    Engineered for the tests not for the actual real world usage.

  13. Avataaar/Circle Created with python_avatars @pma7675 says:

    Is this recommended for sustained high speed use

  14. Avataaar/Circle Created with python_avatars @eddieMurphy11111 says:

    that's a great idea so the nator runs a bit faster i might have that done as being a radio am we often need a bit more amps, thanks for the video

  15. Avataaar/Circle Created with python_avatars @j.t.cooper2963 says:

    My 2006 Crown Vic Police Interceptor has a huge 200 amp alternator and has a slightly higher idle speed than a regular Crown Vic to avoid such problems at idle speeds.

  16. Avataaar/Circle Created with python_avatars @johnellis9147 says:

    I have a couple questions. One: do you think this would be beneficial on my Detroit DD-15 to help power up my inverter? And Two: Where can I find a smaller overdrive pulley?

  17. Avataaar/Circle Created with python_avatars @brandogeberbin7563 says:

    i would have just bought the bigger alternator. 275amp or a rebuilt 380 amp

  18. Avataaar/Circle Created with python_avatars @sparksalot4950 says:

    Morning Ray, electric subjects always provide the best commentary!

  19. Avataaar/Circle Created with python_avatars @steveo7767 says:

    Does the tensioner make up for the pulley size difference on the belt?

  20. Avataaar/Circle Created with python_avatars @michaelabbott511 says:


  21. Avataaar/Circle Created with python_avatars Hola! @The_DuMont_Network says:

    You are measuring the CURRENT output, expressed in AMPERES, or AMPS for short. Not "Amperage".

  22. Avataaar/Circle Created with python_avatars @dcinsc7237 says:

    Hey now! Slow moving jeeps on a trail at night with all those lights…this is good! Thanks Ray.

  23. Avataaar/Circle Created with python_avatars @briansandlin2039 says:

    They need to make a CVT alternator or a CVA

  24. Avataaar/Circle Created with python_avatars @randybeard6040 says:

    From Original Metal Pulley to a Low Life Plastic Pulley–not Good…

  25. Avataaar/Circle Created with python_avatars @leonhart2452 says:

    When I had my Ram 1500 with a 318, I was going to get the battery tray for an extra battery like used on the diesel engine. I would wire it so the truck would charge it but not draw from it. That way I can jump start things with out risking damage to my truck.

  26. Avataaar/Circle Created with python_avatars @air-vacsystemsinc.7770 says:

    Not sure what a power seated heat is.

  27. Avataaar/Circle Created with python_avatars @reallybadaim118 says:

    Ribbed for her pleasure.

  28. Avataaar/Circle Created with python_avatars @moneysaversilver says:

    See your ideas are contagious

  29. Avataaar/Circle Created with python_avatars @Budsnow_Legacy says:

    Where do you source your pulleys from? I want to do this to my old plow truck as it has an electric over hydraulic pump and I don't usually run it much over idle

  30. Avataaar/Circle Created with python_avatars @garyholt369 says:

    Why does the truck has two batteries

  31. Avataaar/Circle Created with python_avatars @papaw5405 says:

    I would have at least inspected the belt. Older belts tend to reach the end of their lives when asked to drive a different sized pulley, either larger or smaller, than they are used too. At least that has been my experience. Maybe you did inspect it off camera.

  32. Avataaar/Circle Created with python_avatars @Hotaru_T0m0e says:

    Measuring the current drawn only shows the load requirements. Nothing else.

  33. Avataaar/Circle Created with python_avatars @garyholt369 says:

    Don't you need a smaller belt

  34. Avataaar/Circle Created with python_avatars @dalejones3862 says:

    Simple upgrade ray

  35. Avataaar/Circle Created with python_avatars @lactosis--undefined says:

    My pro opinion is, since its on top and easy to get to cool. On the other hand unless you worked for the Circus as a contortionist I would not put that pulley on a buried alternator. I'm sure he knows, he just forgot to mention that. Love the channel though,Rainman is Topnotch.

  36. Avataaar/Circle Created with python_avatars @kenore4003 says:

    Good tools will stay with you for a lifetime. I still have tools from the first Craftsman tool set that I bought when I was 16. Just turned 72. Those have been joined by many more over the years.

  37. Avataaar/Circle Created with python_avatars @Dannysoutherner says:

    My how times have changed. I remember people, including me, going to larger pulley for better horsepower. It isn't much but you slow the alt and water pump it is a notable increase in performance. Now with all these power hogging electronics people went the other way. On tools, yeah I have many still that I bought as a young wrench 40 years ago. Sadly I've lost some. Losing anything Snap On sucks. Just feels bad.

  38. Avataaar/Circle Created with python_avatars @Flies2FLL says:

    The obvious question is that the alternator is still going to be good for the RPM's when the engine is at redline?

  39. Avataaar/Circle Created with python_avatars @paulocarvalho6480 says:

    For all I've seen so far, this has to be your easiest job. Quick and simple part exchange. Having a clean engine ( no oil spillage that I can see) also helps.

  40. Avataaar/Circle Created with python_avatars @drgregoryhouse says:

    More current = more heat = less alt life, but alts are cheap and easy to install, i guess.

  41. Avataaar/Circle Created with python_avatars @GarryFishermusic says:

    Thanks Mr RainmanRay repairs and alternator up grades
    great video greater master mechanic

  42. Avataaar/Circle Created with python_avatars @OldMadScientist says:

    Swapping to a smaller pulley pushes the alternator to work at it's upper limit continuously, thus shortenly the alternator's lifespan. The winding coil, bearings, and brushes were not designed to work at these upper limits on a continuous basis. Anyone thinking of doing this would be further ahead by swapping the alternator for a larger amp model designed and built for the higher amp production.

  43. Avataaar/Circle Created with python_avatars @ldenorio says:

    surprised you didnt need to put a smaller belt on

  44. Avataaar/Circle Created with python_avatars @stasnider4296 says:

    Good morning Ray