Hot Rod magazine brings us a no nonsense buildup of a street supercharged LS7 engine. The engine features the following modifications:
- Custom Eaton TVS supercharger Setup
- Cogged 4” wide belt drive system
- 13psi boost pressure setting
- 90mm custom fabricated intake system and throttle body
- Integrated intake manifold with custom air to water intercooler core
- Rebuild engine with billet connecting rods
- Forged pistons with a lower 9:1 compression ratio
- Under piston oil squirters custom tapped into the main oil feed
- Custom split pattern camshaft
- Lift: 0.620”
- Duration 220* / 235* with 118* LSA
- Wet sump oiling system conversion using OEM oil pump and oil pan
- Return style fuel system conversion with 65lb/hr injectors
- Custom ECU reflash peaking out at 19* total timing
- Untouched factory CNC’d cylinder heads!
The results of these straight forward modifications are an impressive 811 crank horsepower @ 6300 rpms with a respectible 824ft.lbs of torque @ 3900 rpms.. what’s even more impressive is that these figures were achieved with the engine breathing through the factory exhaust manifolds…
What’s also noteworthy here is that if you’ve been reading up with the blog then you will see that the piston design chose by Harrop is very similar to the design I described in a recent article :
Introduction to Piston Design for forced induction engines
The piston used by Harrop features:
- Thicker piston crown for increased strength and a lowered primary ring for reduced ring operating temperature
- Thermal barrier top coating for better combustion efficiency with lower timing numbers as well as less localized heat transfer on the piston crown
- Dished piston (for lower compression) but with a raised outer ring for better squish
- Low friction skirt coating
- A forced side relief design with a longer skirt in the direction of rotation for stability and a shorter skirt in the perpendicular direction for reduced weight and friction
- Lastly: reinforced pin bosses for better load carrying potential
Read the full article on Hot Rod here
