#82727, "EGR questions and Injector Duty Cycle ?'s"
First off yes i searched for this and i did find somethings about both but i couldn't find a straight answer. First off the i found out that blocking off the EGR is safe according to some posts. But the point of the EGR is to reduce Oxides of Nitrogen (NOx) emmisions which occurs when the burning fuel mixture exceeds 2500 degrees F. This is when oxides of nitrogen (NOx) occurs the most in cylinders so manufactures use the EGR to recirculate the gas back into the cylinders to reduce the tempature of the peak flame in the cylinders and thus reduce NOx emmisions. Also the EGR does not recirculate burnt gasses back into the cylinnders at idle or WOT. So the lack of an EGR would actually produce an increase of NOx emmisions and peak flame tempature in the cylinder. So heres my question has anyone who has done this "mod" noticed an increase in power or smother operation? Also i have seen posts about how it is better for turboed cars how so? Is it because the manifold actually has a pressure instead of vacuum and causes the EGR not to work since our EGR works off of manifold vacuum?? And does anyone know the duty cycle at which our stock injectors operate during WOT? And the flow rate of our stock injectors? Thanks in advance.
#82728, "RE: EGR questions and Injector Duty Cycle ?'s" In response to Reply # 0
I recently blocked off my EGR when I replaced a cracked piston. I haven't noticed any real differences. Blocking EGR is known for being good for turbo'd cars because it reduces intake air temperture without those hot gases being recirculated into the manifold, which drops EGT's to a safer level.
#82731, "RE: EGR questions and Injector Duty Cycle ?'s" In response to Reply # 1
Originally posted by sike Blocking EGR is known for being good for turbo'd cars because it reduces intake air temperture without those hot gases being recirculated into the manifold, which drops EGT's to a safer level.
How does it drop off EGT's if the point of the EGR is actually to reduce the peak flame tempature by putting in an inernt gas that doesnt burn into the cylinder thus reducing the total ammout of air being burnt and causing the peak flame tempature to be less than 2500 degrees F so NOx isn't produced? (I'm not trying to sound rude i just want to have a better understanding of why it's better not to have EGR if you are using some sort of forced induction.)
#82732, "RE: EGR questions and Injector Duty Cycle ?'s" In response to Reply # 2
Not trying to be an ass here either, but how dont you understand it? I see your number calculations and what not, but its easy to understand. The EGR recirculates """HOT""" gases into the intake manny. If you remove the EGR and block it off on the intake manny and head, you are NOT sucking any more shit hot gases into your intake manifold thus making it better for you in the long run and reducing EGT's becuz they arent any more of those HOT gases going back into the motor.
#82733, "RE: EGR questions and Injector Duty Cycle ?'s" In response to Reply # 2
Originally posted by Quadman313
Originally posted by sike Blocking EGR is known for being good for turbo'd cars because it reduces intake air temperture without those hot gases being recirculated into the manifold, which drops EGT's to a safer level.
How does it drop off EGT's if the point of the EGR is actually to reduce the peak flame tempature by putting in an inernt gas that doesnt burn into the cylinder thus reducing the total ammout of air being burnt and causing the peak flame tempature to be less than 2500 degrees F so NOx isn't produced? (I'm not trying to sound rude i just want to have a better understanding of why it's better not to have EGR if you are using some sort of forced induction.)
Not sure. I understand what you are saying, but theres a little too much science there. Blocking EGR has proven to drop egts by up to 100º.
#82735, "RE: EGR questions and Injector Duty Cycle ?'s" In response to Reply # 4 Nov-15-04 01:52 PM by Quadman313
Ok i know that it reciculates hot gasses back into the manifold but i was thinking that the fact that it is used to reduce the peak flame tempature would override the fact that it is hot gasses but mabye not. I was just looking for a scientific soultion/answer not just its hot gasses recirculated, Oh well thanks for the responses though mabye ill ask my automotive teacher tommrow. And if it does really lower the EGT's by a 100 degrees it sounds like a worthy mod as well as the fact that it doesn't allow any more carbon deposits in the manifold.
Oh and does anyone know about the injector questions?
#82729, "RE: EGR questions and Injector Duty Cycle ?'s" In response to Reply # 0
Its good for n/a or turbo cars. By removing it, you are'nt putting any more hot gases into your intake manny, your putting nothing in. By doing so, since you dont have hot shit coming in any more, yuor CAI or turbo or what not and suck in better cooler air for better gains. I did a lot of search into that damn little thing of metal to block it off, and before I blew up my shit motor on a lousy 5psi, i felt decent gain with out the egr there (keep in mind I also added a venom intake manny and i am turbo'd too). but for the most part, a $10 product off of ebay wont hurt you in anyway, if anything, help you! Also remember that when you remove the egr, your going to have a CEL all the time, but if you dont mind like me, go for it bro!
#82741, "RE: EGR questions and Injector Duty Cycle ?'s" In response to Reply # 0 Nov-15-04 04:18 PM by ner947
I disabled my EGR system because:
1. It keeps the intake manifold cleaner 2. The EGR pipe can't melt any wires when the EGR pipe is in a box in my garage
As far as I'm concerned, the performance benefits are a wash. I didn't notice a change in peak boost pressure, boost response, or EGT when I disabled the thing a long time ago.
#82745, "RE: EGR questions and Injector Duty Cycle ?'s" In response to Reply # 9
1. The EGR pipe melts wiring harnesses very frequently. 2. The EGR valve will not make a perfect seal under forced induction and high exhaust manifold pressures. 3. It doesn't work at WOT anyway, which is the only time the concerns posted above apply. 4. No one cares about both emissions and performance except the OEM, and we call them Satan for a reason. 5. At over ~10psi, you'll blow the actuator off the valve assembly and melt it. 6. No more nasty carbon/unburnt gas/sludge deposits on the intake manifold and throttle body. 7. Why not? it doesn't help you. it doesn't necessarily hurt you either. Why leave unnecessary complications in an already complicated system?
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#82755, "RE: EGR questions and Injector Duty Cycle ?'s" In response to Reply # 0
Originally posted by Quadman313 But the point of the EGR is to reduce Oxides of Nitrogen (NOx) emmisions which occurs when the burning fuel mixture exceeds 2500 degrees F. This is when oxides of nitrogen (NOx) occurs the most in cylinders so manufactures use the EGR to recirculate the gas back into the cylinders to reduce the tempature of the peak flame in the cylinders and thus reduce NOx emmisions. Also the EGR does not recirculate burnt gasses back into the cylinnders at idle or WOT. So the lack of an EGR would actually produce an increase of NOx emmisions and peak flame tempature in the cylinder.
This is correct. The increase in peak flame temperature will increase your chances of experiencing knock. Like you said, that only applies at part throttle, so its not entirely important from a max performance perspective. Additionally, exhaust gas recirculation at part throttle forces you to open the throttle plate further to maintain the same engine power as if there was no EGR. Opening the throttle plate further will reduce pumping losses associated with the intake air hitting the throttle plate. This results in a increase in efficiency...saving you fuel.
As for removal of the EGR system decreasing EGT's at WOT, I don't really believe it. If the EGR system does not operate at WOT, then it might as well not be there at WOT. Perhaps there is some leakage past the EGR valve that contributes to increased EGT's at WOT. Or maybe people see what they want to see. I'd remove it all just to keep from melting wires and building up crap in the intake.
I don't think anyone really knows our max injector duty cycle at WOT. Perhaps someone with an E-manage hooked up to the stock injectors could provide some data. The stock injector flow rate is 235 cc/min. Check out the data sheet below:
Corbin
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