Customer Reviews (25) Write a Review

Overall Rating 4.5

out of 5 stars

Installation Time:Afternoon

Installation Cost:$100-$250

• Performance Gain 4.0625 4.1
• Fit 4.125 4.1

• 4/5

  Installation Time: Afternoon

  May 02, 2019

  Awesome!

  Definitely noticed an increase in power, install was a little tedious but in the end it was worth it!

  Dan

  Year: 2009 Submodel: GT

  Helpful (0) Thanks for your input!

  • Performance Gain 4

    4

  • Fit 3

    3
• 5/5

  Installation Time: Afternoon

  December 09, 2018

  nice upgrade

  easy to install if you follow the instruction submitted by a customer.look much better than the factory ones.would purchase again and recommend to anyone

  DannyK

  Year: 2006 Submodel: GT

  Helpful (3) Thanks for your input!

  • Performance Gain 4

    4

  • Fit 5

    5
• 5/5

  Installation Time: Less than 1 Hour

  September 17, 2018

  BBK underdrive pulleys

  Easy to install, damper bolt could make or break the deal. Be prepared to get a tightly torqued bolt loose. I put car in 3rd gear with parking brakes on, still wasn't easy

  PatrickM

  Year: 2005 Submodel: GT

  Helpful (4) Thanks for your input!

  • Performance Gain 5

    5

  • Fit 5

    5
• 5/5

  Installation Time: Afternoon

  July 23, 2018

  Great!

  Had VT Performance in Oceanside install while installing BBK throttle body and CAI. Everything looks great. It’s a completely different car. Would recommend these bolt ones to anyone looking to go faster yet still remain smog legal.

  TravisR

  Year: 2005 Submodel: GT

  Helpful (6) Thanks for your input!

  • Performance Gain 4

    4

  • Fit 5

    5
• 5/5

  Installation Time: Less than 1 Hour

  March 04, 2018

  Easy install

  Worth the money. Quicer rev. Easy install and good add on

  AlexR

  Year: 2005 Submodel: GT

  Helpful (6) Thanks for your input!

  • Performance Gain 3

    3

  • Fit 5

    5
• 5/5

  Installation Time: Shop Install

  Installation Cost: $100-$250

  September 30, 2017

  BBK Underdrive pulley

  I felt good about my purchase,there were a little complication with the new bolt but with that resolved.I notice there is some difference in performance.

  EdisonC

  Year: 2008 Submodel: GT

  Helpful (8) Thanks for your input!

  • Performance Gain 4

    4

  • Fit 5

    5
• 5/5

  Installation Time: Shop Install

  Installation Cost: 0-$100

  September 07, 2017

  BBK pulleys are great!

  I have just completed having BBK Underdrive Pulleys installed on a 2010 Mustang GT that I recently acquired. The 2010 GT has an automatic transmission, so I will soon be testing out the performance. I expect good results because I already have the same BBK pulleys installed on my older 2007 GT with a 5-speed manual tranny. I have been pleased with performance on my 2007. The BBK pulleys fit well and look Great!

  ROBERTR

  Year: 2010 Submodel: GT

  Helpful (6) Thanks for your input!

  • Performance Gain 4

    4

  • Fit 5

    5
• 5/5

  Installation Time: Afternoon

  December 01, 2013

  Looks Nice

  This is the second one I have installed and went on as expected. I bought a puller at Harbor Freight and so far it has installed two set without issues. Just buy a new crank bolt to replace the original and the install should go without any hitches.

  Alpha9500

  Year: 2008 Submodel: GT Paducah, KY

  Helpful (7) Thanks for your input!

  • Performance Gain 5

    5

  • Fit 5

    5

  • Bang for your Buck 5

    5
• 4/5

  Installation Time: Afternoon

  May 24, 2013

  Great Product, just a couple catches

  These pulleys look great and they provide a noticeable gain to power and throttle response and *maybe* a 1mpg gain. Just know that a couple of 'gotchas' come with installing these. First off, I had to cut down one of the bolts on the pump because the water pump pulley was making contact, which is obviously not good. The second problem is that it is very hard on alternators. Since installing these in mid 2011 I've gone through 2 alternators because the pulley is running at a different speed and chewing them up. My next alternator is going to be more solid so hopefully it will hold up, but if you aren't willing to buy anything better than autostore brand refurbished alternators then this product is not for you.

  CK42

  Year: 2006 Submodel: GT

  Helpful (9) Thanks for your input!

  • Performance Gain 4

    4

  • Fit 3

    3

  • Bang for your Buck 3

    3
• 5/5

  Installation Time: Afternoon

  January 27, 2013

  Great product

  Easier to install then I expected. Looks great, more power and better gas mileage. Really a great product.

  Rick99

  Year: 2010 Submodel: GT Orlando, Florida

  Helpful (8) Thanks for your input!

  • Performance Gain 5

    5

  • Fit 5

    5

  • Bang for your Buck 5

    5
• 1/5

  Installation Time: Afternoon

  June 18, 2012

  More Power, Less Handling

  I had this pulley installed by a shop. They said the bolt it came with was not the right thread type for my car and that the bolt was a low grade. So they had to use the factory bolt. When I got it back the first thing I noticed was the HP gains at the top end. Though after a couple of long drives I noticed the negative effects, on long hills there’s definitely a noticeable loss in low end torque but the big one is the steering on bumpy roads the front end becomes unstable and on smooth roads the car seems to understeer more. The reason is the pulley kit is designed to slow down the rotation of engine accessories one of which is the power steering pump. The low rotation causes a lower pressure in the system which is very noticeable at higher speeds. And to let you now the suspension on my car is not stock. I have steeda adjustable anti-roll bars, a strut bar, and rear adjustable control arms. So the steering effects are more noticeable than stock.

  Ohatarcale

  Year: 2008 Submodel: GT Flagstaff, AZ

  Helpful (8) Thanks for your input!

  • Response from AmericanMuscle

    We've forwarded your feedback on the included bolt to BBK. Our purchasing team will work with them to make sure they're including the right bolts (and high quality bolts) with these kits. As you said, underdrive pulleys are designed to cut power to all of your engine accessories, leaving more power to your engine itself. We don't often hear of customers noticing any negative handling effects from any underdrive pulley kit.

    Rob Hunt, Customer Care
    

  • Performance Gain 4

    4

  • Fit 1

    1

  • Bang for your Buck 1

    1
• 5/5

  Installation Time: Afternoon

  June 01, 2012

  good product

  good product, it would have been nice to get the alternator bolt that comes with other products from other sites but i'm loyal to AM. if you can't break the bolt loose just use the "crank method". make sure you take the fan and air box out, position a breaker bar up against the passenger wall of you engine bay and make sure it is connected to the crank bolt, and crank over your engine..don't start it..just break the nut loose. after that it was just like the instructions as far as install. i had to grind the alternator bolt down for the water pump pulley to have clearance.

  stangster7777777

  Year: 2007 Submodel: GT California, USA

  Helpful (8) Thanks for your input!

  • Performance Gain 4

    4

  • Fit 3

    3

  • Bang for your Buck 4

    4
• 1/5

  Installation Time: Shop Install

  Installation Cost: $250-$500

  May 20, 2012

  Poor quality/ dont waste your money!

  I bought these underdrive pulleys based on these "ease" of installation, the BBK name and for performance. The instructions were clear but as we did everything the way instructed, the longer bolt given for installation stripped. I took it to a Ford dealer where the Mustang tech had to finish the install. He said the instructions with the longer bolt is the wrong way to do it and finished the install for me. He said the crank pulley was flush against the seat. They have squealed ever since. I have tried numerous things to resolve the problem with no success. There was no noticable power increase. They look good but I am going to have to pay to put the factory pulleys back on. I dont recommend this mod. Spend your money elsewhere on a better mod. Oh by the way, BBK wont return emails or phone calls to help either! American Muscle is great and I will continute to buy from them. These pulleys just suck.

  JMoore23

  Year: 2007 Submodel: GT Huntington, WV, USA

  Helpful (9) Thanks for your input!

  • Performance Gain 1

    1

  • Fit 1

    1

  • Bang for your Buck 1

    1
• 5/5

  Installation Time: Less than 1 Hour

  April 03, 2012

  Awesome Product

  I really don't feel a difference in my accessories; however, decent gain in hp. I installed with FR500 Axlebacks & Magnaflow True-x w/ High Flow Cats.

  BCINBLK

  Year: 2007 Submodel: GT Danville, VA

  Helpful (7) Thanks for your input!

  • Performance Gain 5

    5

  • Fit 5

    5

  • Bang for your Buck 5

    5
• 5/5

  Installation Time: Afternoon

  March 19, 2012

  2010 GT Convertable

  This was an easy install. Didn't even have to remove the fan, there was enough room to use a 4 inch puller.

  epeer

  Year: 2010 Submodel: GT Fort Irwin, CA

  Helpful (9) Thanks for your input!

  • Performance Gain 5

    5

  • Fit 5

    5

  • Bang for your Buck 5

    5
• 5/5

  Installation Time: Less than 1 Hour

  December 27, 2011

  Nice gain / lillte costs

  Not a bad gain for little costs. Free up some HP !!

  lawrencecar1

  Year: 2007 Submodel: GT

  Helpful (7) Thanks for your input!

  • Performance Gain 4

    4

  • Fit 5

    5

  • Bang for your Buck 4

    4
• 5/5

  May 24, 2011

  Great Product

  Great product looks fantastic in my engine bay. When you go to a parts store to rent the pulley puller, make sure you get the chrysler one with the three prongs, just like the instructions say. My crank pulley was badly rusted so it took about 30 tries to get that thig off, but it was worth it (my mechanical skill is low, so I blame that) I also had a clearance issue with a bolt on the alternator rubbing on the water pump pulley, so I ended up trimming the bolt. Engine revs faster, and I have been getting 30 miles/tank better, which will pay for the part eventually (which is what I told my wife). Great part from AM, I don't buy my parts anywhere else

  Connor

  Year: 2006 Submodel: GT

  Helpful (11) Thanks for your input!
• 5/5

  April 27, 2011

  Gret product

  Great product adds good response to your car. Install instructions are thorough and helpful. Great bolt on for your car.

  Michael S

  Year: 2006 Submodel: GT

  Helpful (7) Thanks for your input!
• 5/5

  November 20, 2010

  good so far

  looks great, pull the fan (super easy) and have impact wrench. get a new crank bolt from ford for they are torque turn. 1 time use application. have an impact wrench and a torque wrench. the final install torque (36 ft lbs +90 degree turn) seemed to be a 1/2 inch impact as tight as it goes. make sure you silicone the key way. a 3in 3 jaw puller worked great, i put the socket on the bolt and used that to keep the puller shaft centered. havent thrashed on it yet cuz i had a trunk full of tool box and didnt want it smashing up my trunk and i wanted to let the silicone dry

  donald

  Helpful (17) Thanks for your input!
• 5/5

  October 21, 2010

  BBK UNDERDRIVE PULLEY SET

  I LIKE THE PRODUCT VERY WELL IT MAKES MY GT A LITTLE QUICKER THROUGH THE GEARS AND A LITTLE BETTER GAS MILLAGE. IT ALSO SLOWS DOWN ALL THE ACCESORIES TO MAKE THEM LAST LONGER DID NOT NOTICE ANY PROBLEMS WITH AC PERFORMANCE STILL WORKS THE SAME AND THE POWER STEERING IS OK ALSO CHARGING IS GOOD TOO DID NOT GET HOT OR ANYTHING A VERY GOOD PRODUCT.BUT IT WAS HARD TO INSTALL WITHOUT TAKING THE FAN OFF. HAD TO RIG UP A SHORT PULLER TO GET THE BALANCER OFF AFTER THAT A PIECE OF CAKE I WOULD RECCAMEND THIS PRODUCT

  MEL PERKINS

  Helpful (12) Thanks for your input!