Are there any builds out there running w/o an egr and has there been any problems with knock?

 

No S5 engine came with EGR valves.


-Ted

 

How would EGR affect knock? As I understand it (which may very well be wrong), the EGR valve only is open under light throttle cruise, not wide open throttle.

-=Russ=-

 

EGR is often used on piston engines to keep the combustion temps under control.

 

Right... I know it's used under light cruise and such to help reduce temps to keep NOx emissions down - is it used under wide open throttle as well?

-=Russ=-

 

I run my non turbo with no EGR with no problems.

remember the US spec 86-88 were the only ones with EGR. The Japanese spec 86-88 Turbos all never came with them

 

my appologies you are right only s4 us came with egr. the primary purpose of any egr is no for emissions. It is used to recirculate exhaust gas back into the combustion chamber to cool it and in doing so this prevents, to an extent, knock.

 

Cooling down the combustion prevents excessive NOX generation as well as knock.

Most cars (that I've seen anyway) don't have much EGR lift at WOT. You'll find that most cars totally switch off their emissions controls at WOT anyway...