Cummins ISX Non-VGT Cam | Lumpy Larry Camshaft

If you’ve converted your ISX from VGT to a single geometry turbo, you already know the tradeoff:

You gain simplicity and top end power…
But you lose the 3rd stage of the engine brake.

This Non-VGT ISX camshaft is the solution serious drivers run to bring braking performance back where it belongs.

The Problem with VGT → NON-VGT Swaps

Factory VGT-equipped ISX engines rely on exhaust housing restriction to help create the 3rd stage of engine braking. When you eliminate the VGT:

• No exhaust housing closure
• Reduced backpressure during braking
• Noticeably weaker engine brake performance

And while no camshaft can physically close a turbine housing like a VGT, this one addresses the problem where it matters most — in the valve events.

⚙️ The Solution

This camshaft — commonly used in factory non-VGT ISX applications in Australia — is designed specifically for fixed-geometry turbo setups.

It:

• Strengthens Stage 1 & Stage 2 engine braking
• Improves braking authority in single turbo conversions
• Helps offset the loss of 3rd stage braking
• Delivers a noticeably more aggressive exhaust note (sick, right?)

The result? A truck that actually feels controlled on the downgrade again.

 Why It Works

The cam profile is optimized for non-VGT operation, improving the engine’s internal braking characteristics rather than relying on turbo restriction.

You won’t magically recreate VGT housing closure — but you will dramatically improve usable braking force in the first two stages.

And yes… it sounds mean.

⚠️ Important Notes

• Designed for fixed-geometry (non-VGT) turbo applications
• Not intended to restore factory VGT-style 3rd stage braking
• Professional tuning and setup strongly recommended