Generally interested to hear what others think and how they feel regarding blanking.
For some who may not know what the EGR valve does, then it is simply a valve which sits between the inlet and exhaust manifolds. It lets exhaust gases pass from the exhaust manifold to the inlet manifold. There a few benefits (believe it or not - not enough to sway me.):
- Exhaust temperature at low revs/part load is reduced. This is because the valve allows 'inert' gases into the combustion temperature, increasing heat capacity (heat absorption).
- Due to the lower temperature; NOx (Nitrogen Oxide) emissions are reduced
- Pumping losses are reduced especially at throttle body. Due to engine not having to work hard in moving air.
- Due to reduction in pumping losses it is supposed to increase MPG. I'm not sure personally.
There are the downsides to the valve however:
- In deisels however, particulate matter is produced which is returned to the inlet manifold and mixes with oil to form the 'gunk' which most members have complained about having to remove.
- EGR valve is inclined to jam. If jammed open power output across the rev range is affected especially 1,500rpm-2,000rpm.
- Production of particulate matter is produced. This is due to the fact that the amount of fuel which can be burned is lowered. To compensate for this, means of particulate emission reduction has been intruduced - the DPF.
- Energy is wasted as particulates are produced (this is where I am not convinced the MPG saved in pumping losses is large enough).
- With the mixture of oil vapour, exhaust gases and particulate matter from this valve, acidity levels in the inlet manifold are supposedly raised.
For more info have a look here: http://fordwiki.co.uk/index.php/EGR_..._-_Explanation
Blanking off the valve has the potential benefits:
- Increased engine response
- Elimination of particulate and exhaust matter from the inlet manifold
- As the combustion temperature is increased, higher exhaust temperature put the turbocharger at risk.
- DON'T DO IT IF YOU HAVE A DIESEL PARTICULATE FILTER (DPF)!!!