If your goal is to make more than 725 horsepower, reliably, with an LSA supercharger, Harrop has a reality check for you. A factory LSA supercharger is small by today's standards. With the right mods, an LSA is good for around 725HP. People squeeze more power form the platform by spinning the units well beyond their rpm limit. There are some useful upgrades such as porting and cooling to help an LSA supercharger exceed that 725HP ceiling, but consider the alternatives. Harrop's inverted 2650 is better solution -- about 40% better. Their 2650i LSA "inverted" supercharger is bigger than an original LSA blower and can accept factory LSA parts, including the lid, fuel rails, and sensors. The Harrop LSA 2650 readily supports 800HP, 900HP or even 1000HP with the race port version supporting 1200 HP-plus. Best of all adapting a Harrop LSA supercharger to your hot rod is easy. 

Bigger is Better

At the heart of Harrop's LSA 2650 inverted supercharger is Eaton's high-twist, 4-lobe TVS 2650 rotor package. While the factory LSA also is based on a TVS 4-lobe design, the R2650 rotor package benefits from 10-plus years of development. The supercharger can make more power on the same engine without working as hard.  In addition to more displacement, the 2650 rotor package is more efficient and more reliable with improved rotor twist, more bearing strength, and redesigned timing gear teeth.

Factory LSA - Bargain or Bust

We see brand new PN 12670278 LSA superchargers for sale everywhere. Average pricing is around $2300-$2500 plus a $300 core charge.  You'll also want to add in the cost for converting to a solid isolator. That is just the cost for the supercharger.  You will still need a $1600 lid, $500 fuel rails and more.  Still $4,000 is a great bargain for around 725 HP-plus on a 6.2-liter LS with the right engine mods. This certainly explains why our drive kit for OEM LSA superchargers is a best-seller. Opinions vary, but 16,000 rpm is a safe, reasonable rev limit for a factory LSA supercharger. Some folks say 21,000 rpm. A few say 23,000 rpm-25,000 rpm. Keeping air temps down at those elevated speeds requires numerous expensive mods, but really -- over-speeding an LSA supercharger creates a ticking time bomb. There is a point at which superheated air causes power to fall off a cliff, and extreme heat can even trigger a meltdown.

For that reason, it is best to avoid used "marketplace" LSA superchargers with unknown mileage. There is a very real possibility that the unit has been over-revved, overheated, and generally abused.  It may also have a faulty isolator. If you are looking for an LSA bargain, try to score a lid, fuel rails and sensors, then upgrade to a Harrop 2650 supercharger.

Harrop LSA - More than just a three letter name

If you're already running a factory 1.9L LSA supercharger, we have good news. Harrop engineered their supercharger housing to accept a factory LSA lid and intercooler. The Harrop LSA2650 also accepts factory fuel rails and all sensors. If you're starting from scratch, check out Harrop's LSA2650 lid. We think the cast ribs and billet water manifold adapter intercooler fittings look sharp, but more importantly the slightly taller Harrop lid works better than the stock lid. The left-hand bias inlet is positioned similarly to the LSA, and Concept One can confirm clearance for LS3 and Nick Williams 103 throttle bodies at the time of this article.  A 120mm throttle body looks like it will clear, as well but call to confirm. 

Check clearances before you buy

Installing a supercharged LS engine in an old hot rod or muscle car comes with its own challenges. You need hood clearance above, header and frame rail clearance on the sides, and cooling system clearance in front. Throttle body clearance is another serious consideration. We can confirm that Harrop did an excellent job designing their inlet (aka snout) for effective hood and accessory drive component clearance. We can even confirm that 4" intake tube will clear the alternator of our MAX10R accessory drive system. As there is no single recipe for fitment, be sure to consider and measure for every component before purchasing a supercharger. Apply common sense. For example, if you can only fit a 3" air intake tube, choose an appropriately sized throttle body. That 120mm throttle body that your friend's are "peer-pressuring" you to buy? It requires a 4.5" air intake tube diameter.   

Regarding supercharger lid to hood clearance, Harrop Performance offers two appropriately named lid designs. The "high lid" (shown) is 0.9 inches taller than a factory LSA lid. If you can fit the high lid, benefits include superior air flow and a larger intercooler core with high density fin, closed pitch tubes and billet end tanks.  Conversely, Harrop's "Billet Low Lid" is shorter than a factory lid. As Harrop's 2650 supercharger is the same height as the OEM unit, the overall height with the Billet Low Lid is shorter than a stock LSA. Last but not least, with a factory LSA lid, the Harrop 2650 is slightly taller than a stock LSA.    All measurements are from the top of the block (not from the valley cover). Smooth, uniform airflow into the throttle body from the air intake is as important as overall diameter.

As throttle bodies keep getting bigger, available clearance between the throttle body and the alternator can become an issue. Concept One has confirmed that its MAX10R accessory drive can clear a Nick Williams 103mm throttle body.  Harrop also makes a 120mm Race Port inlet option. It has a very large oval inlet that can accept up to a 120mm throttle body with an 126mm x 70mm throttle body. The Race Port option may present additional hood and or accessory drive clearance issues.

LSA Accessory Drive - MAX10R

Whether you have a factory LSA supercharger or one of these Harrop LSA 2650 units, you will need a stout drive system. The late-model Camaro and Caddy crowd typically piece together factory and aftermarket drive solutions, but an LS-swapping hot rodder  needs to upgrade all accessories while choosing a supercharger drive system. All of the drive components need to work together with perfect pulley alignment and no belt slip.  

For a high horsepower supercharged LS, a 10-rib serpentine belt with multiple idlers is highly recommended to prevent belt slippage. Accessories on that same engine can be driven by an 8-rib belt with fewer idlers. A dual-drive belt system is the solution. Concept One's MAX10R drive system is an engineering masterpiece. It is exceptionally compact for great all-around clearance. The complete kit includes everything that you might need for proper installation including a high-clearance billet thermostat housing and a billet remote-mount power steering reservoir. If you are considering an LSA supercharger for your hot rod and you want to make 1000+ horsepower, consider a Harrop LSA 2650 supercharger with MAX10R drive system.

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LINKS:

Harrop USA Website

GM Authority LSA Factory Specs

MAX10R Drive System for Harrop LSA 2650

MAX10R Drive System for factory LSA