It is my understanding that the overboost protection decreases fuel delivery to non-turbo levels if an overboost condition exists? If this is the case then as long as the injection pump is sensing boost all the way up to this point it will be delivering maximum fuel. The MB system is fairly sophisticated for a mechanical system. If they designed it this way then there should be no problem. Granted I wouldn't run on the ragged edge, maybe a max boost of 13psi. MB's have fairly high compression ratios, I believe about 21:1. Add about 15psi and a good heavy sustained load and you will quickly approach peak cylinder pressures that will likely blow a headgasket and possibly damage rod bearings. There simply isn't enough room in the combustion chamber for all that fuel/air and the heat it creates. Intercooling would go a long way to improve durability if you insist on running higher boost levels with high compression. I doubt you will do any real damage unless you use your MB to tow or drive WOT up very steep mountain passes every day. If you do intend on running max boost get an EGT gauge. That will tell you what is really going on in your engine. Modulating the "gas" pedal to control boost is a bad idea. Often EGT's will skyrocket as the boost decreases. The reason is there is now less air to burn the fuel and cool the engine. RT

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