ENGINEERING UNBOXED: Precision 8085 Turbo!

Gale Banks explains how moving from a Precision 7675 turbo to a Precision 8085 should push the otherwise stock Killing A Duramax L5P over 1,000 horsepower. The RPM needs to go from 2800 to 3800 while holding the cylinder pressure down to avoid pushing the crankshaft down to the oil pan. Gale already got rid of the stock camshaft, now it’s time to change the turbocharger.

Precision Turbo sent over an 8075 and an 8085 and we get into the difference after opening them up. Effectively, when the turbo housing gets larger, you get more mass flow through the wheel per rev. Smaller responds quicker, but it becomes more restrictive at higher mass flow.

With a minor cam change, Gale can add the 1,000 horsepower he’s looking to squeeze out of the stock L5P. Gale explains how he’s going to do this without pulling the pin out of the grenade. If Precision Turbo sounds familiar, it’s because Gale talked about them on Killing a Duramax before. Be sure to follow us on YouTube to see what kinds of gains we get with the comp cam.

On the next episode of Engineering Unboxed, Gale gets a box of precision HD clamps, V-band clamps, stainless steel flex couplings, AN fittings, hoses, flanges, tubing, and accessories that will transform both engine dyno cells.