Piwoslaw's Peugeot 307sw modding thread

[nichols735]

dragging up some thing way way back in this thread, but EGR = BAD for FE!

EGR is for NOx emissions, not for FE. It often has very little moving parts itself because airflow through it is regulated by a throttle someplace else on the engine. If you have EGR, get rid of it, if you dont DONT ADD IT.

by the way, the adjustable grille is awesome. I am going to "borrow" some ideas from that.

[Christ]

Originally Posted by nichols735

dragging up some thing way way back in this thread, but EGR = BAD for FE!

EGR is for NOx emissions, not for FE. It often has very little moving parts itself because airflow through it is regulated by a throttle someplace else on the engine. If you have EGR, get rid of it, if you dont DONT ADD IT.

by the way, the adjustable grille is awesome. I am going to "borrow" some ideas from that.

This is a pretty strong first post... Do you have any references to back up your claims?

Edit: Clearly, you're referring only to EGR on a diesel engine, correct? If that is, in fact, the case, disregard my call for references.

[euromodder]

Originally Posted by nichols735

If you have EGR, get rid of it, if you dont DONT ADD IT.

NOx is far worse than a slight decrease in FE.

Have you forgotten about the acid rain, dead trees, or have you never seen them ?

Despite EGR, we still get better FE than maybe 95% of the US ...

[Piwoslaw]

Since installing the EGR cooler last autumn I haven't noticed much of a difference in milage. The newer versions of my turbodiesel have a restriction in the intake manifold that helps suck in more EGR, and not only are they cleaner (EURO 4 and EURO 5), but also more fuel efficient (lower consumption by 0.1-0.4 l/100km). Of course, this may not be because of EGR, but in spite of it, yet it shows that it is possible to increase EGR in a diesel without sacrificing FE.
Reading how people have removed/blocked the EGR valve in their diesels, some report a subjective 20% improvement while others reported worse fuel consumption and performance.

[RRC]

Originally Posted by Piwoslaw

(...)
You wouldn't happen to be from around Warsaw, would you?

Yup

[Arragonis]

PW - apologies for jumping in again to ask questions - before the intake changes did you record before and after intake temps ? Do you monitor them now and if so what do you get ?

Thanks.

[nichols735]

Originally Posted by euromodder

NOx is far worse than a slight decrease in FE.

Have you forgotten about the acid rain, dead trees, or have you never seen them ?

Despite EGR, we still get better FE than maybe 95% of the US ...

Well, people sometimes forget that if you increase your mileage because of it then you total emissions per mile is lower, i.e. NET lower emissions. It all varies depends on speed/load, but your net emissions will most likey be higher w/o EGR, even with increased mileage.

back to the car in question, PIWOSLAWany update on coolant temp with the adjustable grille block?

[PaleMelanesian]

A friend last year had a plugged EGR valve in his Chevy V6. It dropped his mileage about 20%. Fixing it restored the mileage.

Our theory: exhaust gas is already oxygen depleted, so acts as an inert gas in the combustion event. Adding more of this inert gas means less of the active fuel-air mix in the cylinder. Basically, it makes your engine act as if it's smaller than it is. You get lower power, but also lower fuel consumption.

[Piwoslaw]

Originally Posted by Arragonis

PW - apologies for jumping in again to ask questions - before the intake changes did you record before and after intake temps ? Do you monitor them now and if so what do you get ?

My intake temperature sensor is before the turbo, so it doesn't register any change between blocked and unblocked intercooler. As for blocking the hole between radiator and intake scoop - it's too early to tell, but I doubt that I'd notice. This is because the intake duct snakes around the engine like a heat exchanger, good if it was a gasser and I wanted a WAI, but since it's a diesel I wonder about the sanity of PSA's engineers More details here: More efficient air intake (1.6HDi) - ideas.

What really increased engine and intake temperatures was the upper grille block and engine insulation.

Nichols735: Just the lower grille block doesn't effect coolant temps when driving in flat terrain - it stays at 78°C. Adding the upper grille block kept temperatures closer to 88°-92°C, with ambient temps at or below freezing.
Driving uphill brings the temps up (85°-95°C) and then I open the lower grille block.
I hardly ever hear my fan turn on (only when the A/C is on), but this is what happens when you hypermile a turbodiesel

[Piwoslaw]

While inspecting how dirty the car is today, I noticed a tiny detail on the rear lamp:

Can you see it? It's the thin vertical line of dust, just left of the center on the picture. Nothing fancy unless you know that this is the point at which the airflow starts to separate, that's why it's relatively clean ahead of that line. Here's another view:

So what? Well, maybe I could glue clear plastic at that point, extending a few cm to the rear. This would create a lip or minikammback with a sharp trailing edge. I'd do the same to the rounded corners of the rear bumper. Probably not worth any mpg's, but who knows?