The issue is not how much the turbo can supply. It is how much it can supply efficiently.
The map has air mass on the x axis and pressure ratio on the vertical. The more pressure you run, the less air mass you can pump. There are islands of pressure/mass flow where the compressor provides air compression more efficiently than elsewhere. If you turn up the wastegate pressure beyond design pressure, you move out of the efficient part of the compressor map. So the compressor heats the air more for the same pressure. Which means less mass is delivered than would otherwise be the case. This is important on all turbodiesel engines but particularly the non-intercooled 617. I believe stock boost is 9psi by the way. The motor itself can be boosted much higher, e.g. 3 atmospheres, but there is no reason to do this without increasing the fuel and providing an intercooler. Overall with a non-crossflow, cast iron head I think the 617 is not a great motor for high power. It can be done; dieselmeken will modify the MW pump now. But you would need a new turbo, the pump, and a good intercooler to get any real power out of it. On Fri, Aug 17, 2018 at 1:37 PM Mitch Haley via Mercedes < mercedes@okiebenz.com> wrote: > I think the waste gate is supposed to be right around 14psi for my > 617.950, I doubt any 617 is over 20psi stock. > > _______________________________________ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
