4D34 For Excavator Diesel Engine Turbocharger 49179 - 00260 ME073623 Diesel Engine

Specification

Description

How does a turbocharger help a small engine?

This kind of power can be easily provided by a downsized engine with a turbocharger. Hanging a turbo on a small engine allows a little engine to breathe big. With only 6 to 8 pounds of boost pressure, a turbo can increase power output 15 to 25% or more over a naturally aspirated engine.

Turbo Tweaks

Dialing up the boost pressure is a quick and easy way to increase power in any turbo engine – up to a point. The stock fuel injectors in many diesel engines can safely handle higher boost pressures but that’s usually not the case with gasoline engines.

The flow capacity of the stock injectors in a gas engine can quickly max out if turbo boost is increased more than a few pounds beyond stock levels. This may cause the fuel mixture to go dangerously lean, resulting in detonation, melted pistons or a blown head gasket. To prevent such a disaster from happening, the flow rate of the injectors have to be matched to the boost pressure and airflow delivered by the turbo. Consequently, if you want to dial up the boost pressure for more power, you’re going to need a set of higher flow injectors.

In gasoline engines, more octane is also needed as boost pressures go up. The engine’s knock sensor can back off timing and boost pressure if detonation is detected, but that also kills performance. Most turbo engines recommend premium fuel because the higher octane helps the air/fuel mixture resist detonation. Premium pump gas is usually only available with octane ratings of 91 or 93, so higher octane racing gas or alcohol (methanol or ethanol) may be needed if turbo boost pressures are increased beyond stock.

The bottom end of most turbo engines is strong enough to handle a moderate increase in boost pressure over stock. But for a real killer street or race engine that’s running lots of boost, stronger pistons, connecting rods and crankshaft are probably going to be a must.