NextGen Performance Gives Factory-Recall LSA Blowers New Life on 4.8, 5.3, and 6.0 Gen IIIs.

Here’s How.

Written by Steve Magnante on

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Brothers Josh and Eric Buzzell of NextGen Performance have found a way to bring low-buck, supercharged performance to junkyard-sourced 5.3-, 5.7-, and 6.0L LS2 and LS3 truck engines, which they then swap into cars of every description. It all started with the 2014 GM factory service bulletin affecting more than 10,000 2009–2013 CTS-V Cadillacs and 9,900-plus 2012–2013 ZL1 Camaros. It seems their Eaton-sourced superchargers started making odd noises at idle after a few seasons of use. Owners of these potent 6.2L, 556hp (580 in Camaro), LSA-equipped factory hot rods complained of “loose marble” rattling sounds at engine speeds below 1,200 rpm. Function and performance were not affected, but GM had to react under the increasing public scrutiny. After all, these cars weren’t cheap to buy, and rattling sounds at idle were unwelcomed by owners of these sinister brawlers.

The result was a nationwide warranty-repair campaign (as described in GM Service Bulletin No. 13313) launched in May 2014. Because GM didn’t want to risk having service technicians disassemble the faulty blowers and affect spot repairs, they simply yanked the entire supercharger unit and replaced it with a fresh (and upgraded) assembly. As for the take-off units, some got smashed by sledgehammers and others wound up on eBay.

With more than 20,000 LSA engines affected by the repair campaign, a large chunk of loud-but-functional, take-off superchargers suddenly showed up online for less than a grand. This is where the Buzzell brothers and NextGen Performance entered the picture. They figured, why not find a way to adapt these surplus blowers for use on dime-a-dozen pickup truck and SUV LS2 and LS3 junkyard engines? Thanks to the heavy use of corrosive road salt in the Northeast, their local boneyards were crawling with Gen III V8-powered Chevy and GMC pickups and SUVs. Though their rusted frames and bodies forced scrapping, their potent LS engines were still going strong.

Typical GM warranty-repair, take-off LSA blowers (“rattlers”) bought from online sellers look like this when you open the box. They lack the intercooler, lid, injectors, and fuel rails since the GM warranty program calls for the reuse of those unaffected items on the host vehicle. We’ll show you where to get the missing goods.
Typical GM warranty-repair, take-off LSA blowers (“rattlers”) bought from online sellers look like this when you open the box. They lack the intercooler, lid, injectors, and fuel rails since the GM warranty program calls for the reuse of those unaffected items on the host vehicle. We’ll show you where to get the missing goods.
The blurred line on the worn LSA supercharger drive pulley is the result of torsional isolator failure. When failed, toggling the pulley back and forth delivers an 1/8 inch of lash, which is the source of the “marble” sound at idle. On a new or repaired blower, lash is negligible.
The blurred line on the worn LSA supercharger drive pulley is the result of torsional isolator failure. When failed, toggling the pulley back and forth delivers an 1/8 inch of lash, which is the source of the “marble” sound at idle. On a new or repaired blower, lash is negligible.
Repairing the damaged isolator begins with removing the throttle-body inlet snout and blower drive pulley housing. The trio of steel drive pins engages the torsional isolator.
Repairing the damaged isolator begins with removing the throttle-body inlet snout and blower drive pulley housing. The trio of steel drive pins engages the torsional isolator.
Inside the supercharger case, the torsional isolator is visible. Notice the absence of traditional paper gaskets. All mating surfaces rely on RTV.
Inside the supercharger case, the torsional isolator is visible. Notice the absence of traditional paper gaskets. All mating surfaces rely on RTV.
It’s not necessary to extract the rotors from the rear of the case, but we’ve done it here for clarity. The offending torsional isolator is held in Eric Buzzell’s hand. When new, the rotors exhibit a dark-gray, anti-scuff texture. The consistent-width bands of wear seen here are normal and no cause for concern. Buzzell warns, “Never use anything more abrasive than your fingers when cleaning the rotors and don’t use anything else than AC Delco Supercharger Oil, PN 10-4041” (5.1 ounces does the job).
It’s not necessary to extract the rotors from the rear of the case, but we’ve done it here for clarity. The offending torsional isolator is held in Eric Buzzell’s hand. When new, the rotors exhibit a dark-gray, anti-scuff texture. The consistent-width bands of wear seen here are normal and no cause for concern. Buzzell warns, “Never use anything more abrasive than your fingers when cleaning the rotors and don’t use anything else than AC Delco Supercharger Oil, PN 10-4041” (5.1 ounces does the job).
The coiled spring inside the plastic body of the torsional wear isolator is harder than the driveshaft its wrapped around. After failure, the spring misaligns and begins to wear into the shaft (notice the low spots). Does it run OK? Sure. Does it make clunking sounds at idle? Yes.
The coiled spring inside the plastic body of the torsional wear isolator is harder than the driveshaft its wrapped around. After failure, the spring misaligns and begins to wear into the shaft (notice the low spots). Does it run OK? Sure. Does it make clunking sounds at idle? Yes.
The pointer highlights where the end of the spring wears through a wall within the plastic isolator. Once this happens, the spring is no longer preloaded or concentric with the shaft. The results are the rattling sound and odd driveshaft wear patterns (seen earlier).
The pointer highlights where the end of the spring wears through a wall within the plastic isolator. Once this happens, the spring is no longer preloaded or concentric with the shaft. The results are the rattling sound and odd driveshaft wear patterns (seen earlier).
GM and the aftermarket have come up with numerous remedies for the problem. At the top is the stock parts layout, below (left to right) are the stock isolator (failed, note misaligned spring), solid aftermarket replacement and Eaton replacement. Each is effective at taming the offensive noise. Pick your favorite. Once installed, the noise is eliminated and reassembly can begin.
GM and the aftermarket have come up with numerous remedies for the problem. At the top is the stock parts layout, below (left to right) are the stock isolator (failed, note misaligned spring), solid aftermarket replacement and Eaton replacement. Each is effective at taming the offensive noise. Pick your favorite. Once installed, the noise is eliminated and reassembly can begin.
There are two (stock) intercooler solutions. The black powdercoated, ribbed Chevrolet Performance Camaro ZL1 unit (right, PN 12622236) and Cadillac CTS-V units interchange, but the Camaro item is 3/4 inch taller. The Camaro intercooler plumbing feeds at the front of the engine and requires specific OE click-fit couplers. The Caddy plumbing faces the firewall and accepts traditional rubber hoses and clamps for easier installation. Both run about $550 new, but can often be found for less as take-off items from LSA hot rodders.
There are two (stock) intercooler solutions. The black powdercoated, ribbed Chevrolet Performance Camaro ZL1 unit (right, PN 12622236) and Cadillac CTS-V units interchange, but the Camaro item is 3/4 inch taller. The Camaro intercooler plumbing feeds at the front of the engine and requires specific OE click-fit couplers. The Caddy plumbing faces the firewall and accepts traditional rubber hoses and clamps for easier installation. Both run about $550 new, but can often be found for less as take-off items from LSA hot rodders.
Both intercooler units are interchangeable, but the taller Camaro intercooler (foreground) has more plenum volume and uses a slightly larger core. This may account for the 24hp higher claim (580 versus 556). Note the Cadillac’s firewall-facing, fluid-entry/exit location, and conventional hose barbs. The internet is packed with Caddy CTS-V take-off units from folks who swapped up to ZL1 Camaro equipment. Note to horsepower heroes: Both of these OE intercoolers are known to crush under extreme boost levels. But at the stock 9-psi setting, they’re fine.
Both intercooler units are interchangeable, but the taller Camaro intercooler (foreground) has more plenum volume and uses a slightly larger core. This may account for the 24hp higher claim (580 versus 556). Note the Cadillac’s firewall-facing, fluid-entry/exit location, and conventional hose barbs. The internet is packed with Caddy CTS-V take-off units from folks who swapped up to ZL1 Camaro equipment. Note to horsepower heroes: Both of these OE intercoolers are known to crush under extreme boost levels. But at the stock 9-psi setting, they’re fine.
Eric points out the cathedral-type, intake-port window used on LS1, LS2, and many LS3 engines. The LSA intake manifold uses the rectangular port common to most Gen IV engines. What to do?
Eric points out the cathedral-type, intake-port window used on LS1, LS2, and many LS3 engines. The LSA intake manifold uses the rectangular port common to most Gen IV engines. What to do?
Fortunately, I.C.T. Billet offers the perfect solution in its machined-billet adapter plates. Complete with integral silicone sealing rings, these 1/2-inch-thick plates require longer intake-manifold fasteners. Here, one has already been bolted to the cylinder head.
Fortunately, I.C.T. Billet offers the perfect solution in its machined-billet adapter plates. Complete with integral silicone sealing rings, these 1/2-inch-thick plates require longer intake-manifold fasteners. Here, one has already been bolted to the cylinder head.
With a replacement torsional isolator fitted and the LSA blower/intercooler reassembled, installation on most LS2 and LS3 engines is stymied by the alternator. Clunk! Here, the throttle-body mount and alternator are fighting for the same space. This non-powdercoated, smooth-top LSA blower is from a Cadillac donor vehicle.
With a replacement torsional isolator fitted and the LSA blower/intercooler reassembled, installation on most LS2 and LS3 engines is stymied by the alternator. Clunk! Here, the throttle-body mount and alternator are fighting for the same space. This non-powdercoated, smooth-top LSA blower is from a Cadillac donor vehicle.
To allow progress, the offending alternator mount is sliced away as shown. The idler pulley unscrews and will be reused. NextGen Performance offers modified alternator adapters on an exchange basis. Truck-sourced LS engines come with the deepest crank pulleys. The NextGen’s LSA blower adapter kit is designed to work on these donor engines.
To allow progress, the offending alternator mount is sliced away as shown. The idler pulley unscrews and will be reused. NextGen Performance offers modified alternator adapters on an exchange basis. Truck-sourced LS engines come with the deepest crank pulleys. The NextGen’s LSA blower adapter kit is designed to work on these donor engines.
NextGen designed this 1/4-inch-thick steel adapter plate that’s pre-drilled and tapped. Manufactured by NextGen machinist Jeremy Farrow, production items will be powdercoated.
NextGen designed this 1/4-inch-thick steel adapter plate that’s pre-drilled and tapped. Manufactured by NextGen machinist Jeremy Farrow, production items will be powdercoated.
The idler pulley is transferred to a pre-tapped hole on the NextGen adapter plate.
The idler pulley is transferred to a pre-tapped hole on the NextGen adapter plate.
On the passenger side, the stock belt tensioner is retained (left) but with a NextGen dual idler pulley plate placed beneath it. NextGen uses OE-type, 54mm, high-speed pulleys with fully welded spacers to eliminate flex.
On the passenger side, the stock belt tensioner is retained (left) but with a NextGen dual idler pulley plate placed beneath it. NextGen uses OE-type, 54mm, high-speed pulleys with fully welded spacers to eliminate flex.
With all of the reworked pulleys in place (thanks to the two adapter plates), this LS1 is ready to accept the refurbished LSA supercharger.
With all of the reworked pulleys in place (thanks to the two adapter plates), this LS1 is ready to accept the refurbished LSA supercharger.
The Buzzell brothers set the huffer in place. Note how the NextGen alternator relocation plate provides needed room for the throttle-body.
The Buzzell brothers set the huffer in place. Note how the NextGen alternator relocation plate provides needed room for the throttle-body.
All snugged down, the NAPA drivebelt (PN 060956) turns all of the factory-issued accessories, plus the LSA blower. On an otherwise stock 5.3L LM7 (the most common boneyard Gen III), an easy 400 hp results.
All snugged down, the NAPA drivebelt (PN 060956) turns all of the factory-issued accessories, plus the LSA blower. On an otherwise stock 5.3L LM7 (the most common boneyard Gen III), an easy 400 hp results.
Viewed from the passenger side, the NextGen adapters look factory. Be sure to tell Josh or Eric exactly which member of the LS engine family you’re working with for best results.
Viewed from the passenger side, the NextGen adapters look factory. Be sure to tell Josh or Eric exactly which member of the LS engine family you’re working with for best results.
The fuel rail can be obtained from several sources: this one’s a Caddy CTS-V unit (PN 12605222). The existing ECM on the host vehicle must be reprogrammed to work with the added supercharger. NextGen offers this service, as do hot rod shops across the nation. For best results, select a shop with a chassis dyno.
The fuel rail can be obtained from several sources: this one’s a Caddy CTS-V unit (PN 12605222). The existing ECM on the host vehicle must be reprogrammed to work with the added supercharger. NextGen offers this service, as do hot rod shops across the nation. For best results, select a shop with a chassis dyno.