Before I start I just want to say that this is an honest attempt to educate myself and hopefully contribute to the community about what seems like the never-ending debate of whether or not it is beneficial to block/unplug the EGR. I've already learned so much from the TL enthusiasts on here and I will thank ahead of time those more knowledgeable and experienced than me who will contribute to this discussion.
I didn't want to derail the other EGR thread right now and so I elected to start my own after seeing OP's request to not derail his thread since he was talking about a different/specific EGR issue as it relates to the ECU.
But after reading comments in that thread about the benefits of EGR block/unplug, I got curious and I searched the 3G TL forum for EGR threads. (I just searched thread titles with "EGR" in the 3G TL section)
Basic facts that I (think) understand about the EGR:
EGR functions mainly to reduce NOx emissions at partial/mid-range throttle
EGR does the above by letting exhaust gas recirculate into the intake, reducing cylinder temp and this reduces emissions.
EGR also has beneficial side effect of helping to protect against pre-detonation in our high CR motor (11:1) due to the lower temp
EGR is a non-issue at idle and WOT
If the EGR is intentionally blocked/unplugged/deleted. There is a difference in opinion regarding if this causes more good than bad or vice versa.
As far as I understand the debate, if EGR is deleted, it can improve mid-range/partial throttle response. However there is a counter-opinion that the ECU will notice the hotter temp and thus ECU will pull back timing to prevent knocking thereby negating any "free HP" gains. And also EGR delete may actually cause motor to be more prong to knocking unless higher octane/quality gasoline is used, thereby causing causing more headaches for the minimal, if any power gains.
Again I do not claim to be an expert, this is what I've distilled in my mind after reading several threads regarding this issue and I wanted to see what the opinion is on this issue these days.
Please feel totally free to correct any mis-understanding/mis-information in my post.
Pro EGR delete:
source: http://acurazine.com/forums/third-ge.../#post15190434
EGR not even used in certain outside countries:
source: http://acurazine.com/forums/performa.../#post10703323
Anti EGR delete:
source: http://acurazine.com/forums/performa.../#post10653840
Modern ECU's not affected by "crude" EGR delete:
source: http://acurazine.com/forums/performa.../#post10702376
ECU may need to be tuned/chipped/burned/etc. to change timing map, otherwise simple EGR delete may result in knocking:
source: http://acurazine.com/forums/performa.../#post10713304
If nothing else, it will cause annoying CEL to come on:
source: http://acurazine.com/forums/performa.../#post14891815
Annoying for those needing to pass smog tests and no real practical daily gains:
source: http://acurazine.com/forums/performa.../#post14919285
So basically my own personal question would be: If I just bought a base TL and I'm looking at something that can potentially improve partial throttle response (which will be a majority of my driving, I doubt I'll be WOT too much) then is there any practical gains to be had from deleting the EGR in the 3G TL?
And will the car need significantly higher octane/knocking protection?
Or will this not even matter because modern ECUs are too "smart" for this apparently simple and cheap trick?
Source/reference threads:
http://acurazine.com/forums/third-ge...ugging-919277/
http://acurazine.com/forums/performa...ck-off-784470/
http://acurazine.com/forums/performa...ck-off-715349/
http://acurazine.com/forums/performa...delete-905780/
http://acurazine.com/forums/performa...ye-egr-729573/
I didn't want to derail the other EGR thread right now and so I elected to start my own after seeing OP's request to not derail his thread since he was talking about a different/specific EGR issue as it relates to the ECU.
But after reading comments in that thread about the benefits of EGR block/unplug, I got curious and I searched the 3G TL forum for EGR threads. (I just searched thread titles with "EGR" in the 3G TL section)
Basic facts that I (think) understand about the EGR:
EGR functions mainly to reduce NOx emissions at partial/mid-range throttle
EGR does the above by letting exhaust gas recirculate into the intake, reducing cylinder temp and this reduces emissions.
EGR also has beneficial side effect of helping to protect against pre-detonation in our high CR motor (11:1) due to the lower temp
EGR is a non-issue at idle and WOT
If the EGR is intentionally blocked/unplugged/deleted. There is a difference in opinion regarding if this causes more good than bad or vice versa.
As far as I understand the debate, if EGR is deleted, it can improve mid-range/partial throttle response. However there is a counter-opinion that the ECU will notice the hotter temp and thus ECU will pull back timing to prevent knocking thereby negating any "free HP" gains. And also EGR delete may actually cause motor to be more prong to knocking unless higher octane/quality gasoline is used, thereby causing causing more headaches for the minimal, if any power gains.
Again I do not claim to be an expert, this is what I've distilled in my mind after reading several threads regarding this issue and I wanted to see what the opinion is on this issue these days.
Please feel totally free to correct any mis-understanding/mis-information in my post.
Pro EGR delete:
Quote:
|
The car runs much better without it. No additional knock whatsoever. Part throttle power is improved and low end torque is improved. The surging is gone and mpg improved slightly. Mine has been disabled for a year until I had to enable it for a smog check. Once I enabled it, the car was no fun to drive again on hot days. I couldn't get it smogged quick enough so I could hurry up and disable it again. I drove it last night with the EGR unplugged and it drove nice. The test was this morning when I forgot I did anything to it and noticed it was pulling so much better and smoother at part throttle. It took me a minute to remember I had disconnected it yesterday so it eliminates placebo effect. It's a HUGE improvement in drivability and low end power especially on a hot day but even on cooler mornings obviously.. I'll never run it again except for smog time. So whether the ECU sees the EGR is not functional and goes to a lower timing table or just doesn't bump the timing during normal EGR function or the fact that it requires far less throttle to make the same power that means no knocking doesn't mstter, it has no knock with no EGR. |
EGR not even used in certain outside countries:
Quote:
|
On another note, the japanese version of our cars dont even have EGRs so the removal the EGR should not do any damage if honda felt like they were fine to do without elsewhere. |
Anti EGR delete:
Quote:
|
Seriously, don't mess with this. The theory about intake temp is a nice one, but if it drops it more than 10°, tops, I will eat the intake manifold for lunch with a nice balsamic vinegarette. EGR= Exhaust Gas Recirculation. This is done for a couple of reasons- 1. Exhaust gases in the intake charge help to reduce peak cylinder temperature, reducing the formation of NOx emissions (oxides of Nitrogen- NO, NO2, etc). These are key components of smog, and the higher the engine compression, the more likely they are to occur. The TL engine is at 11:1, which is pretty high. If the engine is producing more NOx, the catalytics work harder (read hotter) to kill it (although tailpipe emissions will still go up), which ultimately shortens their life. Also, a nice side effect of lower combustion temps- less pinging. An 11:1 engine, particularly one with mild cam timing, can ping like a MF'er on all but the best pump gas. EGR goes a long way to prevent that, because the exhaust gas mixing slows the burn rate. 2. Exhaust gases help to fill up the cylinder, therefore less space is required for the intake charge. This is where you pick up the MPG- it's worth probably 0.5-1mpg on our cars, maybe even 2 at highway cruising, but that might be generous. EGR is a light-throttle only emissions control device. Importantly, EGR messes with the intake charge too much under heavy throttle, which can lead to poor charge control, etc, so the ECU shuts it down under heavy throttle. For max power, you want the cylinder filled with fresh air to the greatest extent possible, which gives you max burn-> max cylinder pressure-> max power. Still want to mess with it? |
Modern ECU's not affected by "crude" EGR delete:
Quote:
|
Well the OBD2 computers are too smart for that. when the PCM commands EGR operation, it needs a signal back from the EGR valve. and the PCM is also looking at the MAP sensor voltage to react. it will be expecting the MAP voltage to go up from the exhaust gas that is being introduced to the manifold. removing the EGR will do more damage then good to it. like T HO already said. the exhaust gas will lower combustion temp and reduce the chance of detonation/pre-ignition |
ECU may need to be tuned/chipped/burned/etc. to change timing map, otherwise simple EGR delete may result in knocking:
Quote:
|
Because the timing maps are different in cars without EGR. Every ECM I've looked into, especially on my car has a timing bump when the EGR is in effect to make up for the power you lose from the contaminated charge. This timing bump without EGR will result in detonation. You will pick up nothing from this other than a bunch of pinging unless you're prepared to run on something higher than 95 octane all the time. |
If nothing else, it will cause annoying CEL to come on:
Quote:
|
the main benefit of this mod is to help keep your intake manifold clean. thats it. you can use a block off plate. it will cause a check engine light to come on. without some sort of tune, we arent able to trick the light to go off. |
Annoying for those needing to pass smog tests and no real practical daily gains:
Quote:
|
Yes EGR is to decrease NOx emissions but also will increase fuel economy slightly. Deleting EGR on your daily driver is pointless. When you go full throttle the comp turns the EGR completely off for maximum power gains. Therefore deleting it will give you zero power gains, just a check engine light and a failed smog check in required states. |
So basically my own personal question would be: If I just bought a base TL and I'm looking at something that can potentially improve partial throttle response (which will be a majority of my driving, I doubt I'll be WOT too much) then is there any practical gains to be had from deleting the EGR in the 3G TL?
And will the car need significantly higher octane/knocking protection?
Or will this not even matter because modern ECUs are too "smart" for this apparently simple and cheap trick?
Source/reference threads:
http://acurazine.com/forums/third-ge...ugging-919277/
http://acurazine.com/forums/performa...ck-off-784470/
http://acurazine.com/forums/performa...ck-off-715349/
http://acurazine.com/forums/performa...delete-905780/
http://acurazine.com/forums/performa...ye-egr-729573/