The LS7 is by far the most powerful production motor ever made by GM, not to mention being one of the most powerful naturally aspirated V-8s made by any manufacturer. Its 427 ci of fury is darn near the most fun you can have with your clothes on. Actually this motor is so sexy it makes you want to take your clothes off, which is exactly why GM enthusiasts have been foaming at the mouth since its introduction. GM Performance Parts hoped to prey on these very desires by placing one of its fully assembled, handbuilt LS7s into a 1999 Camaro Z28 for the purpose of showing just how easy it could be.
The 1999 Z28 was the perfect vessel given that F-body owners represent a large chunk of the market for GMPP, and also because its light, aerodynamic chassis and solid rear axle would best demonstrate the LS7s potential on the track. As you'd expect from the vast similarities between Gen III and IV motors, the retrofit was relatively easy (by hot rod standards). The greatest challenge was accommodating the dry sump lubrication system, which required relocating the battery to the trunk and installing a BMR tubular K-member. The stock oil tank (minus two inches of height) now resides in the battery's place with custom-made oil lines and fittings. For clearance and to adapt the F-body accessory drive scheme, the GM engineers used a Z06 A/C compressor and ATI Super Damper balancer. On this project the intention was to stay with a cable throttle, as most F-body and hot rod owners would prefer, which meant ditching the LS7 electronic throttle in favor of a UMI 90mm unit. A custom wiring harness was also put together by the GMPP engineers, and connected to a prototype MEFI-4b computer. Plans are to release this Marine-based speed density computer with fine-tuned spark and fuel tables for others looking to retrofit LS7s into their sinister rides without using MAF and electronic throttles.
With the custom tune developed by the engineers (with the help of UMI Performance), and a few other goodies this stock LS7 puts out a good bit more than the 505hp version in the Z06. For starters a set of Kooks 1 7/8-inch stainless steel headers, Y-pipe and a 3-inch MagnaFlow cat-back provide significant improvement over stock exhaust. A BMR torque arm and subframe connectors were used in conjunction with a Strange S60 rear end to bulletproof the driveline, enabling solid launches on slicks at the track. The beefy 35-spline axles and enormous 3.73 ring gear were sure not shatter, unlike the questionable stock pieces, even with the mighty LS7's potential. A set of 4.56 gears have replaced the 3.73s, as the Camaro is no longer likely to see highway duty as it did on the Hot Rod Power Tour, which along with a SPEC aluminum flywheel helps spin the motor up to its 7,200 rpm red line. Similarly the stock LS7 clutch and pressure plate have been traded for a track-friendly unit from Centerforce to engage a stock Tremec T56. For the purpose of keeping things as realistic as possible and using as few mods as necessary, the rest of the Camaro is kept pretty much stock. However, the results speak for themselves-and you can only imagine the seemingly endless potential of this monstrous motor. Suddenly owning an 11-second car that runs and drives like a stocker became a whole lot easier.