Frequently asked questions

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Exhaust manifold - what is the benefits?
Is it dangerous for the engine to use sport exhaust manifold?
What is the optimal design for the manifold 4-1, 4-2-1?
How many hp improve the exhaust manifold?
Should we use a tubular exhaust manifold when tuning diesel engines?

When having an engine with forced induction, it is necessary to replace the turbocharger in order to achieve more power. The new turbocharger usually have different connecting flanges and different overall dimensions. Also, the location of the turbocharger presumably requires a better tuned exhaust manifold. To achieve a maximum effect, the exhaust gasses driving the turbo have to arrive for a shortest possible period of time with a minimal loss of energy. The stock cast-iron manifold is made after these guidelines but it also have drawbacks like: limited flow (due to the diameter of the runners) and uneven pulsation (in other words, the exhaust gasses are trying to get out in one pass and hence they are "pushing" each other). Tuned exhaust manifold should supply the gasses to the turbocharger with optimal flow and minimal windage. We recommend that you use a tuned exhaust manifold in all cases when the target power increase is greater than 40%.

Anti-reversion chambers

What is "reversion"? During valve overlap, when both the intake and the exhaust valves are open, part of the exhaust gasses travel back through the pipes and enters the combustion chamber. This happens when the piston moves downward in the cylinder thus creating vacuum. The exhaust gasses which return back contaminate the combustion chamber by displacing the fresh air/fuel mixture. This process effectively decrease the power and the efficiency of the engine.

The anti-reversion chambers help decreasing the contamination of the air/fuel mixture by exhaust gasses which returned during the overlap. The result is cleaner mixture, lower temperatures and of course, more power.