Blocking EGR

[SWR Banned Find all posts View Profile Close SWR]

Hi Guys

"Providing that the EGR "is" running correctly it will reduce Nox levels and the engine will perform more stable power and engine temps.... I did mention this quite some threads back! (People should read this whole thread from beginning to end then the full picture will come light!).
http://www.pradopoint.com/showthread...l=1#post306700

This link below is to an open link on the web so i see there to be no breach of copy writes as only viewing it from its sorce!

Exhaust Gas Recirculation System EMISSION SUB SYSTEMS ...
www.autoshop101.com/forms/h61.pdf
File Format: PDF/Adobe Acrobat
performance and fuel economy can actually be enhanced when the EGR system is functioning as designed. EMISSION SUB SYSTEMS - Exhaust Gas ...


Quote diver70: Would there be any benefit in fitting an oil catch can inline here? Aren't they designed to trap most of the airborne oil, so the remaining bit of air passing through the EGR system can be burnt without fouling everything else with oil? Just seems like a simple solution that would not create any error codes or performance losses.

Answer skywalkerrun: Yeahh! "Finally"... some one read the thread and got it! ... Lol

I personally would leave the EGR alone, Fit a good oil catch can and "DO NOT" restrict or block the EGR on the 1KD-D4D's as it "Does control peak combustion temps and the D4D needs that EGR passage to dump its access turbo boost.

I will not go into detail explaining the process again as i have already written it in the past threads in great detail. (Just read the whole thread as it is only three pages!).

Cheers

PS When i am logged in there is only 3 x pages but it actually spans out to 10 x pages when logged out!....

Happy reading Lol

[xpro Lurker Find all posts View Profile Close xpro]

Xpro what you wrote is right. However, I do not agree with the theory that the EGR relieves turbo boost.

Gday,

At the start of this thread I didnt think the egr was there to relieve the excess pressure as mention by Skywalkerrun, but after some testing carried out, the Egr valve on a d4d engine appears to have two functions.
If you read the start of this thread you will see the mod i did, and by having the egr plumbed in externally i can tell you that on overrun after acceleration the excess boost is dumped via Egr. ( tested by one person reving the car while i was holding the egr intake hose). It's under vacuum when at steady revs and when let off the throttle it dumps the pressure out.
It sounds the very same as a petrol turbocharged vehicle with a dumpvalve fitted.
If you look at the system closer you will see that there is no other valves that will actually dump the boost.
Also if you hook up the diagnostics and monitor the live data you will see the egr opening when accelerator is depressed.

Cheers

[Chip It Senior Member Find all posts View Profile Close Chip It]

We have tested many vehicles, with and without the EGR system. All vehicles will make more power with the EGR plate blanked off.

A lot of websites will say the EGR makes the engine run cooler or more stabilsed (whatever that means) and they are full of the proverbial. They just regurgitating another website and another etc etc. and the original is from an engineer that reports FOR the emissions companies or for the auto industry etc. This is my take on it.

The lower temps are only at cruise as I believe SWR mentioned once before. At WOT, when you would think the cooler are temps are needed (ie that's when the engine is running the hottest EGTs, the EGR is closed. So that blows that theory out of the water.

Let me try to make a few points: Being diesels that we are discussing, they are

a) not trying to dump turbo pressure as with petrols. Petrol engines cannot have boost spikes. Diesels can as a lean mixture in a petrol is a NO NO. On a diesel, nothing is risked.

b) diesels are an air pump. ie they have no throttle to govern airflow (like a petrol). When you back off on a diesel you are removing fuel ... HOWEVER, the pistons are still pumping and the valves are still opening and air is allowed to be pumped through (just without fuel). On a petrol car when you close the throttle the butterfly stops air DEAD. The turbo cannot slow down so fast and so it still have a relatively high compressor pressure. That pressure has no where to go (forward) so it reverses and heads back out of the compressor BACKWARDS through to air intake. This action is why you hear a WHOOSH or flutter (known as turbo flutter) This is a bad thing. It is bad because the turbo is spinning at around 80,000 RPMs in the correct direction and then it has a rush of positive pressure/air flow past it trying to turn it in the reverse direction. It is bad for 2 reasons: 1) you dont want the loss of RPMs (we want that sucker to be spinning as fast as possible to maintain pressure (or build pressure) as soon as the driver demands more power. This slow down of RPMs causes turbo lag. Turbo lag is what manufacturers are trying to reduce (ie electrically driven turbos or VVT). If we slow the rotation down it takes some time to build up again. ie turbo lag. 2) some argue that the compressor having the sudden shock of trying to be spun backwards in detrimental. To overcome this, we manufacturers fit Blow Off Valves. This allows the "excess" pressure to be vented to atmosphere (or upstream of the turbo) so that the compressor has no reason to slow down. You just don't hear diesels suffering from turbo flutter since they do act as an air pump

[winniliss Avid PP Poster! Find all posts View Profile Close winniliss]

So to sum up. When I fit my chip tomorrow (thanks for the quick postage) on my 2009 D4D 120 series I can block the EGR?. Do I still need the 'catch can'?

[SWR Banned Find all posts View Profile Close SWR]

Gday ChipIt

Below is quotations of your theory on the EGR not dumping the turbo-boost for which i can not agree based on my understanding of the EGR on the 1KD-D4D (not the 1KZ) and obviously based on the Australian model due to some European D4D models having a none variable turbo.

Extracts of your Quotes: taken from the link below
http://www.pradopoint.com/showthread...l=1#post362697

chipIt Quote: We have tested many vehicles, with and without the EGR system. All vehicles will make more power with the EGR plate blanked off.

Skywalkerrun Answer: If you are doing vehicles without EGR then they are obviously old and out-dated models. You may also make power improvements by blocking EGR systems (For short periods of time) but if you block or restrict the EGR and put the engine under constant load's i am most certain your peak temps will steadily/quickly peak and error codes with CEL (Check Engine Light) will appear on the 1KD-D4D's (Australian models)!

ChipIt Quote: A lot of websites will say the EGR makes the engine run cooler or more stabilsed (whatever that means) and they are full of the proverbial.

Skywalkerrun Answer: O.. M.. G..!!! you are supposed to have an understanding on engines and yet you do not understand or acknowledge that the EGR successfully reduces cruise and mid-load temps that actually do improve fuel consumption and engine longevity providing that the EGR system is maintained properly!!! N0x is a big part for implementing EGR but not the "absolute" reason. (EGR (Exhaust Gas Recirculation) are excellent at reducing exhaust emissions and the DPF (Diesel Particulate Filter) for reducing soot particulates (Know as black smoke).

ChipIt Quote: At WOT, when you would think the cooler are temps are needed (ie that's when the engine is running the hottest EGTs, the EGR is closed. So that blows that theory out of the water.

skywalkerrun answer: "Actually"... When the engine is on full throttle "Wide open" the ECU is mapped to watch turbo boost/Fuel rail pressure/ fuel temp/ coolant temp/ Injector pulse & duration and engines RPM... With all these facts in the equation the ECU will no when the engine is on full load and providing that all of its original mapping parameters are still in play, if engine coolant temperature increases above a certain point, the standard engine management system will take some action to rectify the situation by making small adjustments to the fuel injection volume. (Toyota's engines mapped safety features in-order to help the engine protect its self).

"Approx 75 to 80% of the engines life span is at mid range and cruise!" (Un-less being raced or extreme endurance circumstances)....... Coincidentally Approximately 75 to 80% is when the EGR is at its most active!.... This is where the exhaust gases are cooled via the EGR heat-exchange (1KD not 1KZ) but more importantly these cooled EGR gases (cooler than 2500 Fahrenheit = 1371 Celsius) are inert gases which are "very effective" at suppressing "peak duration" combustion temps.

EGR gases are passed through a water-cooled jacket (Heat exchange) and then transferred to the combustion chamber to suppress the peak duration high temps.... Nox (Nitrogen Oxide) is when Nitrogen and Oxygen merge together at 2500F....... Recirculating EGR (Inert gases) suppresses these temps Hence the temp drop and not forgetting that the inert gases was also cooled via the EGR heat exchange!!!.... So would it be safe to say that the EGR "IS" making the engine run cooler!..... Inert gases will suppress high combustion temps due to the lack of oxygen but nice clean cool oxygen air would fuel the situation as a flame needs oxygen to burn.

"Yes" diesel particulates will increase when applying EGR but the engine performance and fuel consumption is not effected but enhanced with engine stability when running within its mapped parameters! (DPF was invented to combat the side effects of EGR for euro5 emissions and soon to follow euro6 emission laws).

ChipIt Quote: Turbo lag is what manufacturers are trying to reduce (ie electrically driven turbos or VVT).

Skywalkerrun Answer: I agree on the bit where you say manufacturers endure to reduce turbo lag but the variable turbo is "purly" to promote turbo spool (Turbo spin) at low rpm as well as up-top (Variable turbo has the features of both a big and small turbo without the lag or restricted performance) but of course is "nothing" to do with accepting or substituting back tracking boost!!! (That is why turbo boost is dumped via the EGR to stop/reducing turbo stall).
http://youtu.be/KgVrpiFfp8U

ChipIt Quote: The turbo cannot slow down so fast and so it still have a relatively high compressor pressure. That pressure has no where to go (forward) so it reverses and heads back out of the compressor BACKWARDS through to air intake.

Skywalkerrun answer: Hang on a minute!! You "ChipIt" said Quote: The turbo cannot slow down so fast and so it still have a relatively high compressor pressure. That pressure has no where to go (forward) so it reverses and heads back out of the compressor BACKWARDS through to air intake. This action is why you hear a WHOOSH or flutter (known as turbo flutter) This is a bad thing. Un-Quote..... As you know that if the boost back tracks it stalls the turbo and over time the turbo may fail if boost pressures are not dumped!.. This is exactly why the EGR is used to dump the boost! (On the 1KD-D4D's not 1KZ) That is why there is two solenoids that operate the EGR vacuum canister. One provides the vacuum (from the engine vacuum pump) and the other one is a switching valve. That is also why there is also a electronic vacuum solenoid on the EGR heat exchange (All 3 x are controlled by the ECU and numerous other censors also!).... There is also a micro switch on top of the EGR valve to monitor the EGR actions. This switch will throw an error code if the valve was to seez or malfunction.

Here below is your diagram but the black arrows are clearly in the wrong direction!
http://www.google.com.au/imgres?q=D4...9,r:0,s:0,i:69

If you take note of the black arrows on your diagram they are going in the wrong direction as that is the passage that the access turbo-boost takes back to the exhaust system. (Turbo waste gate path).

The white arrows are the path that the hot exhaust gases take when being directed to the inlet manifold via the heat-exchange where the exhaust gases are cooled. They are also inert gases. (Very useful for suppressing peak combustion temps at cruise and mid range).

#1 EG: When the hot exhaust gases flow through the heat exchange the flap to this port (White arrows) is wide open to let the gases flow towards the EGR valve which is also open at this point. at this point the flap for the turbo dump (Black arrows) is closed shut and the valve on the throttle body is also partially closed to increase manifold negative pressure (Vacuum) to help draw the exhaust gases into the inlet manifold.

#2 EG: When the EGR valve is closed for full boost..... then you need to dump this boost quickly the ECU then opens the EGR valve and simultaneously closes the flap on the heat-exchange (white arrows) then simultaneously the other flap opens wide (Black arrows) to dump the access boost directly back into the exhaust manifold. At this point the valve on the throttle body housing is also wide open to help let all the built-up boost drain via the EGR valve to help stop all the manifold boost back-tracking through the air-inter-cooler/ turbo-compressor/ MAF sensor then lastly the air-box which it turn causes turbo stall.

EG: #2 is the actual turbo dump process.

That is "why" when the blanking or restricting off the EGR on the 1KD-D4D's (With variable turbo) the turbo gets noticeably noisy due to the turbo stalling... As we know! turbo stall is bad for a number of reasons.

ChipIt Quote: some argue that the compressor having the sudden shock of trying to be spun backwards in detrimental.

skywalkerrun Answer: It is not an argument but a known fact.

Cheers

[Chip It Senior Member Find all posts View Profile Close Chip It]

Good for you. Glad you have done the testing. btw the arrows are not mine they are toyota's

[SWR Banned Find all posts View Profile Close SWR]

Well that's good Rob!

How about putting up there theory on the EGR as well as the diagram!

I'm willing to be corrected!

If wrong im willing to learn otherwise as am not perfect

Cheers

[Chip It Senior Member Find all posts View Profile Close Chip It]

no. not interested in brawling it out with you.. You do what you want to do, we will do what we what to do.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

no. not interested in brawling it out with you.. You do what you want to do, we will do what we what to do.

Robert,

What I would hope you to do is what's best for the customer, skywalkerrun appears to have raised some valid concerns.

Robert, would be good if you were to post up the data you have that shows he is incorrect if you believe this to be the case as I for one would like to take some action regarding fouling of the intake manifold etc without affecting the performance/longevity of the turbo and motor.

From what skywalkerrun has written, it reads that he has done a lot of real time testing and knows what his writting about, it therefore would appear the only viable option though an expensive one is a catch tank.

If you have done testing and haven proven that blocking the EGR valve will have no detrimental affect on engine/turbo performance or longevity then please post it here or simply state you don't know.

Cheers

LeighW

[Chip It Senior Member Find all posts View Profile Close Chip It]

Hi Leigh. I have already said what the EGR does. The backwards to'ing and throwing is not what we are on about. We test things. We figure out what things do. Back up the results and make decisions based on those fact. If others have a different opinion that's OK too.

I can say once more the EGR SYSTEM IS NOT THERE to cool down engine temps for longevity. Many say it is, but it is not. It is purely there to get manufactures over the emission hurdles. EGR Blanking Codes (ie P0299) only EVER come on during light throttle when the EGR is open. This is NOT the time to cool down combustion temps to increase longevity. Full stop. It is there because the Euro Drive Cycle Test and the Aussie equivalent testing regime (ADR 80 -0X) test emissions ONLY at light cruise. They do not measure ANYTHING at WOT. So manufacturers close the EGR and are allowed to make max power with max oxygenated air. These facts will never change. It is the trick of the manufacturers to pass the code.

My posts can be stripped by some but surely they have not spend $35,000 with Orbital engines looking at emissions testing as we did. It was an eye opening 3 days for many reasons. Costly?, yes. Interesting?, you bet.

I did ask SWR a week ago to give me his phone number so as to call him and have a chat about the thread and our understanding on things, however I feel there is now no point to that exercise. Guys, we are trying to get on with the job. Forums do take up a lot of time and I don't wish to come across the wrong way but we just don't have the time (or inclination) to debate what others feel is right. They came travel any road they like. Some chose to trust us, some don't. And that too is fine.

Hope this helps somewhat and I did say all this in previous posts so sorry to almost double post my point of view on EGR blanking.

Here is one dyno I have here that shows power increase due to oxygenated air being made available from blanking off the EGR System on a Nissan Navara.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Robert,

Thank you for taking the time to reply, however my query was targeted at the current Toyota D4D motors,
I can appreciate that blocking the EGR may increase power on a dyno but what about driveability on a day to basis.

If what skywalkerrun has stated, that blocking the EGR port will prevent the turbo dumping excess pressure then this will definetly have an affect on the tractabilty of the engine under normal stop start day to day driving conditions.

I don't really see how the turbo excess pressure can quickly flow back through its inlet even if the vane angle of attack is changed as the mass of air flowing through the turbo can't simply stop and reverse direction instantaneously. If it could why would Toyota employ the elaborate turbo dump system they have?

Cheers
LeighW

[Chip It Senior Member Find all posts View Profile Close Chip It]

Leigh we need to understand that a diesel engine is an air pump. Power is governed by fuel. A full air charge is drawn into the combustion chamber, not an air/fuel charge governed by a throttle as are petrol engines.

This is the reason you do not need a BOV on a diesel. We run comparatively low boost pressures and only race or high performance diesel engines receive any thought of having a BOV fitted (ie 60 - 200 psi). Remember, a BOV sits between the turbo and the throttle body. The EGR inlet sits in the intake manifold.

Lets look at 2 scenarios: If the throttle valve is closed when you remove your foot from the accelerator, the EGR, being AFTER the throttle body would not let air escape (ie would not act as a vent for the turbo pressure). If the throttle valve is open when removing the foot from a hard run (etc) the engine will just consumes the boost pressure ie back to diesels being an air pump.

Take a look at the gimmicky Diesel BOV (Blow Off Valve). They don't use pressure to open them (like a BOV on a petrol engine), they use an electronic solenoid to open them. Why? because there is no pressure upstream. (ie diesel = air pump)

Turbo Smart Diesel BOV

SUMMIT DIESEL BOV

You can see and read that they use a solenoid to open the BOV to make the pssshhhhh noise.

Read here for some another POV:

1

2

3

4

5 (the correct answer in this thread is by ckostura)

[SWR Banned Find all posts View Profile Close SWR]

Gday ChipIt

"Again" you didn't answer LeighW Questions?? Lol

I do not think He is interested in BOV but we know you are!

As far as the diesel engine goes it can still "draw" air (Not pump as the intake valve draws on induction) but you still get access turbo pressure back-tracking to the turbo so why did Toyota do a dumping process via the EGR if it is not so important??...... Also what do you think the turbo pressure switch will be telling the ECU to do when it sees all the pressure hanging around when it should have been discharged??......... How does the engine sustain max boost (14-16psi) without over-boosting? Does it purge access boost??

Your power graph is what i would call a short duration power spike... (This is a Toyota D4D thread not Nissan D22 or 7ltr truck diesels) Why not load it up constant and watch the exhaust temp climb. Mimic mid rang/cruise.

How often does a stock standard D4D throw a P0299 code?

Intake draws!

Exhaust pumps!

Would you recommend the blanking/restricting of the EGR 1KD-D4D?

I still disagree on your theory on EGR gases..... This is the "blocking EGR" thread isn't it"

Emissions and engine longevity has never been a priority on track racing but the general public do not like to jeopardize the longevity on there personal commute/pleasure vehicles.

Have you ever noticed that the newer engines are getting smaller but are cleaner burning/more fuel efficient and producing more power!... Why is that??

Cheers

[Chip It Senior Member Find all posts View Profile Close Chip It]

you can see guys why I am not interested. All it ends up being is a brawl. I have no time or inclination for this. People can believe whatever they want to. it is a free country

[SWR Banned Find all posts View Profile Close SWR]

ChipIt

It is not a brawl!! You came on this thread dictating your opinions and thoughts and i have given mine... I backed my thoughts and opinions up in detail with room for correction!

That is not brawling but a debate!

Cheers