We tested a 401 CID LS2 engine and gained 6 lb-ft and 5 HP at 4,000 RPM, with gains throughout the entire RPM range using the Volcano inserts over the baseline!

The engine had 11:1 compression, mildly ported stock LS2 heads(ported by Volcano Manifolds), a Lunati hydraulic roller cam, comp cams roller rocker arms, and an Edelbrock Victor Jr intake manifold.

EFI was controlled by a Holley Terminator X ECU, sequential injection with 48 lb/hr injectors, and a Holley 4150 style 1000 CFM Throttle Body.

The exhaust was Kooks long tube stainless headers with 1 7/8″ Primaries and 3″ collectors.  

The entire fuel and induction system can be purchased through Volcano Manifolds including the Intake Manifold w/Volcano System , and the entire EFI system, fuel system, and plumbing.  

To Purchase Intake Manifold

To Purchase Holley Terminator X EFI Systems

The graph below shows the two curves the performed the best and the lowest…in this case the baseline test being the lowest performance, and one of the Volcano Inserts being the best for this application.  The Volcano Inserts also smoothed out the curve and maintained full peak torque for a longer sweep in the midrange….


Sometimes the Dormant Volcano comes alive and surprises you!  In this chart showing all 3 currently available Volcano Inserts and the baseline*, the Dormant Volcano outperformed the baseline and the two taller Volcano inserts, which is not what we expected and shows you how important it is to be able to change the Volcano insert in only ~5 minutes at the track or on the dyno to see what works best for your particular application.  The Dormant Volcano and the baseline are the only two visible in the chart above.  

More Results

*The baseline is an extremely thin nearly flush plug with no locking or aligning features, machined solely to mimic the factory manifold without any modifications to the plenum floor.