|
I think we should get an idea of how much EGR flow we are looking at for doing something like this. I'm going to use a 1.5L engine example because that is what is in the Paseo and thats likely what I'll be doing testing on. Please correct me if you see any errors in my methods here.
The at 55mph, the Paseo is geared to be at 2600 rpm. At 2600 rpm and WOT, we are looking at the engine sucking in around 60 CFM (assuming 85% volumetric efficiency).
Now, from reading I've heard that a 40% EGR mixture is the absolute maximum that an engine can handle before misfires occur and things start to go downhill. Darin thinks he read that it is more like 20%. So, I'm going to go with the lesser of the two just to be on the safe side. Again, feel free to add any info/corrections.
20% of 60 is 12 CFM at highway cruising speeds. 40% would simply be double that, 24 CFM.
12 CFM doesn't sound like a ton to me. This is probably good because I pulled the EGR valve off the 96 Paseo I have and the hole going from the exhaust side to the valve is pretty tiny. I didn't clean it all up yet, but it looked to be around 3/16" (5mm) or so. There is no way that an orifice that small can pull 12 CFM through it without some pretty hefty pressure drop. So, it looks like the stock sided EGR valve is going to be undersized. I'm also going to assume this is similar for most vehicles out there. I sure would be nice to know what the stock EGR systems are designed to flow.
|