Supercharger Belt Length Chart

Please note that the belt length suggestions shown below are offered as a guide. While every effort has been made to ensure accuracy in this data, there are variations in effective belt lengths between belt manufacturers.  The belt recommendations below should be within 0.5" or less of the ideal length. The original belt tensioner on the supercharger drive will accommodate slight discrepancies in belt length, but belts that are too loose for the application may result in slippage at higher engine speeds, and belts that are too tight will cause premature failures in the components on the supercharger drive. If you have questions about how to read the tension indicator on your car's belt tensioner assembly, please contact us.

1999-2004 Lightning 

Supercharger Pulley Size Crank Pulley Size 2.93 (stock) 2.80 2.70 Stock (7.40") 65" 65" 64.5" + 2 lb (8.10") 66.5" 66.5" 66" + 4 lb (8.60") 67.5" 67.5" 67" + 6 lb (9.10") 68.5" 68.5" 68" + 8 lb (9.55") 69.5" 69.5" 69" +10 lb (10.0") 70.5" 70.5" 70"     Notes:

Add 0.5" to the calculated belt length when adding our auxiliary idler bracket with a 90mm pulley.  Add 1.0" if the bracket is fitted with a 100mm idler pulley Add 0.5" to the calculated belt length any time a 100mm pulley is used in place of a 90mm idler pulley on the blower drive.   Crank pulley diameters shown are measured from the top-of-tooth across to top-of-tooth, which is the effective diameter.  Overall ring diameters as measured with a tape measure are generally about 0.25" greater, as flanges can vary slightly. The supercharged Harley-Davidson F150 uses a 3.40” supercharger pulley, as originally equipped.  The original belt is 66.3” in length.  The belt data shown for the Lightning is applicable to the HD F150, if adjusted for the larger supercharger pulley as necessary. Belt data is not available for the 6.55" underdrive ring, or for crank pulley rings sized 10.5" and 11.0"  These pulley rings are intended for custom installations.

 

2003-2004 Mustang Cobra

	Supercharger Pulley Size
Crank Pulley Size	3.65 (stock)	3.00	2.90	2.80	2.70
stock (7.40")	75.1"	74.50"	74"	73.50"	73.50"
+ 2 lb (8.10")	77"	76.50"	76"	75.50"	75.50"
+ 4 lb (8.60")	78"	77.50"	77"	76.50"	76.50"
+ 6 lb (9.10")	79"	78.50"	78"	77.50"	77.50"
+ 8 lb (9.55")	80"	79.50"	79"	78.50"	78.50"
+10 lb (10.0")	81.50"	81"	80"	79.50"	78.50"

 

Notes:
Add 1.0" when adding the Metco auxiliary (snub) idler, fitted with a 90mm pulley.  Add 1.5" if the bracket is fitted with a 100mm idler pulley.   Add 0.5" to the calculated belt length any time a 100mm pulley is used in place of a 90mm pulley on the blower drive. Add 0.5" to the calculated belt length with the 3.0" alternator pulley, 1.0" to the belt length with the 3.20" alternator pulley, 1.5” for the 3.50” alternator pulley, and 2.0” for the 3.70” alternator pulley Crank pulley diameters shown are measured from the top-of-tooth across to top-of-tooth, which is the effective diameter.  Overall diameters as measured with a tape measure are generally about 0.25" greater, as flanges can vary slightly. Belt data is not available for the 6.55" underdrive ring, or for crank pulley rings sized 10.5" and 11.0"  These pulley rings are intended for custom installations. Provided belt lengths for crank pulley kits assume the crank idler pulley is positioned in the idler plate hole according to the installation instructions.  Using the upper hole in the plate with +4 lb and smaller rings will add at least 1.0" to the calculated belt length.  The exact amount of added length varies as a result of the crank pulley ring size, crank idler pulley size, and alternator pulley size.   Our crank pulley kit with the stock-diameter pulley ring adds between 1.0 and 1.5" to the required belt length, as a result of the added distance to the crank idler pulley.

2009-2015 CTS-V & Camaro ZL1 LSA Applications

OEM Belt Length: 66.0"

With Innovator's West balancer and 8.60" pulley ring: 67.5"

With IW balancer, 9.10" pulley ring: 68.0"

With IW balancer, 9.55" pulley ring, and MRB1000 Idler Pulley Relocation Bracket :  K080685

With IW balancer, 10.0" ring, and MRB1000 Idler Pulley Relocation Bracket:  K080700

With IW balancer, 10.5" ring, and MRB1000 Idler Pulley Relocation Bracket: 72.0" 

The addition of our 2.40" or 2.50" supercharger pulley to any of the above combinations will require a belt approximately 0.7" shorter than the lengths shown above.

With 2.40" or 2.50" supercharger pulley, with or without our 100mm supercharger idler: 65.3" belt: K080653.

 

2016 & Newer ZL1 & CTS-V LT4 Applications

An original-length belt can be retained with the installation of our 2.30" supercharger pulley.

With the 8.60" crank pulley kit:  Gates K080834HD

With the 9.10" crank pulley kit:  Gates K080842HD

With the 9.55" crank pulley kit:  Gates K080850HD

With the 10.0" crank pulley kit:  Gates K080865HD

With the 10.5" crank pulley kit:

 

2015 & Newer Hellcat Challenger, Charger, Demon, Redeye, Trackhawk, TRX, and Durango

Most users retain the original 58.5” length belt (or suitable equivalent) with the 3.20” and 3.10” supercharger pulley sizes. 

With 2.95” supercharger pulley:  K100575HD

With 2.85”, 2.75”, and 2.65” supercharger pulleys:  K100572HD

With 2.50” and 2.40” supercharger pulleys:  57.0”

With Innovators West or ATI overdrive balancer, no other changes:  60.0”

With 2.85/2.75/2.65 supercharger pulley, and Innovators West or ATI overdrive balancer:  K100594HD