01-01-2012, 04:18 PM
Dum-Dum Wrote:- Diesels should run ever so slightly rich to make peak power so a very very light hazing of smoke on full blow is ideal
I agree with you on lots of things.
This isn't one of those things.
If you're hazing at full power, your EGTs are going to be absolutely insane - my car completely clean with the vanes wide open is hitting close to 900*c - I've seen 1000*c before, that's what killed my last VNT, I melted the vanes and turbine wheel.
On tiny little turbos like K14s, any hazing on boost and you're going to absolutely annihilate the turbine wheel, bearings and cook the oil. It may produce good power, but it's going to destroy the poor turbo.
HDis don't really get this issue, if they're hazing it's usually from too much fuel, rather than too much duration with regards to smaller turbochargers (Past about 180HP, yeah, you will get nuts EGT problems from too smaller injectors), therefore the EGTs won't be nuts, because IDIs have long injection lengths due to the heat able to be held in the PCC, they end up with blistering EGTs VERY quickly. That typical grey haze is from it still partially burning when the exhaust valve opens - that is the type that cracks heads, burns valves and destroys turbos.
