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SR Performance Underdrive Pulleys - Polished (86-93 5.0L)

Item 525568
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    Features, Video & Details

    • Free Up Horsepower
    • Complete 3 Piece Kit
    • Durable, Lightweight Aluminum
    • Polished Finish
    • Premium Quality Construction
    • Fits 1986-1993 5.0L V8 Mustangs

    Review & Installation Video

    Review & Install Video

    Hey guys, Adam here with americanmuscle.com. Today I'm bringing you a detailed overview and installation of the SR Performance Polished Underdrive Pulleys, fitting all '86 to '93 5 liter Mustangs. In this video I'll be going over exactly how underdrive pulleys work and what they are in regards to the benefits to your engine. I'll talk about the materials and construction, and I'll top the video off with the installation, which I'll let you know upfront here, underdrive pulleys are a very simple bolt-on mod, something that will get a one outta three wrenches on our difficulty meter. The SR Performance Underdrive Pulleys in the polished finish we have here today will be for any '86 to '93 5 liter Mustang owner who might be looking to free up some of the energy that the engine is using to power the factory pulleys in order to free up horsepower that can be used in other performance mods. Now on top of that, the installation is extremely simple, it's a very simple bolt-on mod here that we'll talk about a little later in the video, but upfront this is something that just allows you to pick up some horsepower in other areas instead of using that power for the factory pulleys. So the first thing I wanna touch on exactly is what are underdrive pulleys, what do they do, and what benefits do thy have for your engine. Now in a nutshell, underdrive pulleys basically cut down on parasitic drive train lost by reducing the amount of power it takes to run your accessories like the alternator, the AC compressor, and the water pump. So to explain that a little bit further, the engine basically uses it's own power to run all the pulleys together starting at the crankshaft pulley or the drive pulley. Now this particular pulley can actually be reduced in size to use less power which can eventually use less power on the engine and free up around 10 to 15 horsepower. So right here I wanna mention that freeing up 10 to 15 horsepower does not mean that you're gonna gain 10 to 15 horsepower from adding underdrive pulleys. What that basically means is now instead of using that extra power on the factory pulleys, you have underdrive pulleys in their place and that power can be redirected to other performance mods, such as the bolt-ons like a cold air intake, intake manifold, cylinder heads, cam, exhaust, things of that nature. Now you have the ability to add 10 to 15 horsepower with other mods such as those.Now another valid question you might be asking is, if you're reducing the size of the crankshaft pulley, wouldn't that mean that you're alternator isn't running at full capacity, which of course affects a lot of different things in the engine and the car alone? Now that's a valid question for sure, but of course when you're reducing the crankshaft pulley size, you're also gonna compensate by adding other pulley sizes as well. The changing in these sizes of the pulleys can actually reduce the amount of stress going on the engine and it'll run absolutely at maximum potential, of course. Now if you're running a smaller pulley for the alternator which we have here with the underdrive pulleys and you're running, like, a massive amplifier in your trunk, you might see a little less power, but of course it's nothing to really ruin any driveability, you just wanna make sure you're checking with your amperage and things of that nature with your alternator as well as your amp.So everything you can expect as far as pulleys are concerned, you can see right here on the table with me today. Everything you see here, you would get a crank pulley, an alternator pulley, and of course a water pump pulley. Now all these come in with SR Performance being one of the most budget-friendly options on the market. Now reducing the parasitic drive train loss is very simple with just shy of a hundred bucks. Now my personal opinion, it's not too bad of a price for this considering you'll be freeing up 10 to 15 horsepower. Now redirecting that power could definitely mean the w

    Free Up Horsepower. A set of SR Performance Underdrive Pulleys reduce parasitic drivetrain loss by cutting down the amount of power your accessories take up, these underdrive pulleys will free up 10+ horsepower, without sacrificing cooling and charging functionality of your Pony.

    Premium Quality Construction. CNC-machined from lightweight aircraft grade quality aluminum alloy for strength and durability, these SR Performance pulleys feature a bright polished finish that will give your engine bay an eye-catching high performance appearance.

    Easy Installation. These SR Performance Mustang Underdrive Pulleys installs quickly and easily in under 2 hours with no modifications required.

    Application. This SR Performance 3-Piece Aluminum Underdrive Pulley Kit is designed for use on 1986 to 1993 Ford Mustangs equipped with the iconic push rod 5.0L V8 engine, including the LX 5.0, GT and SVT Cobra models. Reuses stock belt.

    SR Performance

    Fitment: 1986 1987 1988 1989 1990 1991 1992 1993 Details

    MPN# 525568

    CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov

    What's in the Box
    • (1) water pump pulley
    • (1) alternator pulley
    • (1) crank pulley
    • (4) bolts
    Installation Info
    Tech Specs
    UnderDrive Pulley Specifications
    Year/Model:1986-1993 5.0L V8 Manufacture:SR Performance
    Material:Aluminum Finish:Polished
    Crank Pulley: Piggyback SFI Certified:No
    Will it fit my Mustang?

      Customer Photos (11) Submit Your Photo

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        Questions & Answers (9)

        5 Top Rated Questions

        Will this work on my 351W

        • The SR Performance Underdrive Pulleys are designed for the 5.0L 302 blocks. They are not designed to work with the 5.8L 351W.

        Helpful (1)

        Hi so the pulleys will get you 10/15 more horse only if you do other mods?? Is this correct I want to get me a set . My mods are shorty headers h- pipe a set of flow masters right now I want to put on the pulleys and a different mass air unit. I have a speed density system I am going to keep the SD system. Then possibly different upper and lower intake. Is it worth it to to buy and install the pulleys with these few mods? Will I get the 10/15 horse? Even if I don't go with the upper and lower intakes? Thanks much Mike

        With the SR pulleys will the car full charge at idle?

        • These SR Performance Underdrive Pulleys will free up 10+ horsepower, without sacrificing cooling and charging functionality of your Pony.

        Helpful (0)

        you usually need a different belt with under drive pulleys, what is difference with the SR pulleys since it reuses the stock belt? Thanks -Will

        • The SR Performance Underdrive Pulleys are sized to be able to reuse the OEM belt. This is true of both the BBK and SR underdrive pulleys we offer.

        Helpful (0)

        will these pullies work with a car thea has an a/c delete?

        • Yes, these Pulleys would work even if you have deleted the A/C.

        Helpful (0)
        Post Your Question
        4 More Questions
        i have an a/c delete on my 92 gt are these ok to install with that mod in place? 1 answer
        Has the issue with the crank bolts been resolved yet? I want to order this kit, but with the complaints about the crank bolts being the wrong size has put me off. The last thing I want to do after I get everything apart is to have to stop what I'm doing and go buy the correct ones. 1 answer
        Can you use the stock size serpentine belt? A different review said the belt needs to be an inch bigger, is this true? 1 answer
        What are the dimensions of the pulleys? Diameter specifically 1 answer

          Customer Reviews (62) Write a Review

          Overall Rating 4.7

          out of 5 stars

          Installation Time:Less than 1 Hour

          Installation Cost:0-$100

          • Performance Gain 4.232143 4.2
          • Fit 4.767857 4.8



          • 5/5

            Installation Time: Afternoon

            October 20, 2019

            A little bling

            This is a great set of underdrive pulleys with excellent manufacturing quality. The stock water pump pulley took a bit of persuasion to remove but once that was off the installation went quite easily. It is hard to be sure but the car did feel a bit more responsive to throttle input and peppy after the installation.

            RickTamiS

            Year: 1988 Submodel: GT

            Helpful (0)

          • 5/5

            Installation Time: Less than 1 Hour

            August 10, 2019

            Review from SR Performance Underdrive Pulleys - Black Aluminum (86-93 5.0L)

            Their black and lightweight

            I wanted a set of black aluminum pulleys and American muscle had exactly what I was looking for...AWESOME

            Turbofox92

            Year: 1991 Submodel: LX

            Helpful (0)

          • 5/5

            Installation Time: Less than 1 Hour

            June 13, 2019

            Great Product

            Everything bolt as it should. the parts feels and looks quality made.

            Jerrick

            Year: 1993 Submodel: GT

            Helpful (0)

          • 4/5

            Installation Time: Less than 1 Hour

            May 31, 2019

            Review from SR Performance Underdrive Pulleys - Black Aluminum (86-93 5.0L)

            Good

            Had some scuffs on the alternator pulley, but all in all good quality and fast shipping.

            Slow5Oh

            Year: 1993 Submodel: GT

            Helpful (0)

          • 5/5

            Installation Time: Less than 1 Hour

            May 08, 2019

            Review from SR Performance Underdrive Pulleys - Black Aluminum (86-93 5.0L)

            Nice product!

            Went on with no issues and reused the factory belt

            Trigr9

            Year: 1993 Submodel: GT

            Helpful (1)

          • 5/5

            Installation Time: Afternoon

            May 08, 2019

            Sweet and strong

            These pulleys are really nice and polished very well.

            Widgeonwing

            Year: 1989 Submodel: GT

            Helpful (0)

          • 5/5

            Installation Time: Afternoon

            February 14, 2019

            Look great

            Nice set came quick easy install really look great

            JoeG

            Year: 1989 Submodel: GT

            Helpful (0)

          • 5/5

            October 24, 2018

            Works beautifully on my 331 stroke motor

            Iam very please with the product!!!!! These Pullies work and fits exactly its attended to!!!!

            LorenzoW

            Year: 1984 Submodel: Other

            Helpful (5)

          • 4/5

            Installation Time: Less than 1 Hour

            October 22, 2018

            Great Pulleys

            Wish it came with all the bolts and the ones I did get were not correct for my application but that was no big deal. The pulleys themselves are exceptional. I wish they had a power steering pull with this kit.

            NicholasH

            Year: 1985 Submodel: Other

            Helpful (4)

          • 5/5

            Installation Time: Less than 1 Hour

            October 15, 2018

            looks sweeeeeet!!

            looks and fit were excellent. my only complaint is there no PS pulley to match!!

            erikh

            Year: 1991 Submodel: GT

            Helpful (4)

          • 5/5

            Installation Time: Less than 1 Hour

            September 10, 2018

            Review from SR Performance Underdrive Pulleys - Black Aluminum (86-93 5.0L)

            SR Underdrives

            Quality product, durable finish on the pulleys, all hardware included for mounting, much lighter than the stock pulleys. Overall, there's nothing bad to say about these. I haven't put a ton of miles on them but I did notice a slight throttle response increase and a quicker RPM gain out of the hole. Well worth the money.

            BrandonF

            Year: 1989 Submodel: LX

            Helpful (3)

          • 5/5

            Installation Time: Less than 1 Hour

            September 10, 2018

            massive improvement

            Glad I added these to my stang, they look good and went on super easy. With a few other minor mods that I have done you can tell a difference in performance.

            DavidR

            Year: 1991 Submodel: GT

            Helpful (5)

          • 3/5

            Installation Time: Less than 1 Hour

            September 07, 2018

            Looks nice, wrong hardware

            Looks nice but wrong hardware with kit, they supply unnecessary water pump hardware (which they incorrectly label as crank pulley hardware), and dont supply the necessary crank pulley hardware since the oem bolts dont clear the shallower pulley. Disappointed.

            Brandon

            Year: 1989 Submodel: LX

            Helpful (4)

          • 5/5

            September 03, 2018

            Hope to be soon!

            Have,not installed yet Mustang is in body shop for paint

            RobertT

            Year: 1993 Submodel: LX

            Helpful (4)

          • 5/5

            Installation Time: Afternoon

            June 26, 2018

            Review from SR Performance Underdrive Pulleys - Black Aluminum (86-93 5.0L)

            Happy with the upgrade

            Everything fit the way it was supposed to. Easy to install and noticed a small uptick in power. That’s pretty much what I was hoping for.

            SaulW

            Year: 1988 Submodel: GT

            Helpful (6)

          • 5/5

            March 06, 2018

            Review from SR Performance Underdrive Pulleys - Black Aluminum (86-93 5.0L)

            pulleys

            Product looks to be of very good quality and workmanship.

            DarmonJ

            Year: 1991 Submodel: GT

            Helpful (6)

          • 4/5

            Installation Time: Afternoon

            January 10, 2018

            Review from SR Performance Underdrive Pulleys - Black Aluminum (86-93 5.0L)

            Very nice

            Was exactly what I expected The only issue was that the bolts were packed in with the crank pulley and the threads marred up the ribs for the serpentine belt other than that beautiful product will buy again for my wife’s mustang and I will recommend to my friends for sure

            DustinH

            Year: 1989 Submodel: GT

            Helpful (8)

          • 5/5

            Installation Time: Afternoon

            December 28, 2017

            Great buy

            I bought these pulleys for my 95 lightning. It took me a afternoon because i dont have an impact gun. I had to take my alternator off and take it to a friend's house to swap the pulleys. Other than that, they fit right on. The supplied bolts worked nice on the crank pulley. They look really nice and it feels like it freed up a couple horses. I did have to get a smaller belt though. 985 worked fine.

            SvtB

            Year: 1993 Submodel: Other

            Helpful (8)

          • 5/5

            Installation Time: Shop Install

            Installation Cost: 0-$100

            December 18, 2017

            89

            Looks great on the car, will be able to add HP with the new chip!

            ChadC

            Year: 1989 Submodel: LX

            Helpful (8)

          • 5/5

            Installation Time: Afternoon

            September 06, 2017

            Review from SR Performance Underdrive Pulleys - Black Aluminum (86-93 5.0L)

            Five thumbs up

            Beautiful pieces and fit as they should! Lightweight and strong

            Rogerb2

            Year: 1987 Submodel: GT

            Helpful (7)

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