Dynamic EGR Control for TDIs

[Mark@MaloneTuning]

Background: I permanently turned down EGR as far as the ECU could manage in my 2006 TDI. I immediately noticed a difference in 8C/46F weather:

• With EGR turned off right from the start, my engine took significantly longer to warm up. A cold engine is bad for longevity and fuel economy.
• I was losing coolant heat during traffic stops because heat from the exhaust was not being recycled. Even if the coolant temperature was optimal @ 90C (194F), I could see my temperature needle drop below 40C (104F) whenever I tried to leech engine heat for my interior comfort.

After putting the EGR settings back to stock, the TDI is able to build and retain heat with much less effort. I enjoy better MPG too.

Some people with EGR delete report lower MPG during short commutes, and better MPG during long trips. Here's an example from a 2005 PD 1.9L BEW TDI customer in Los Angeles:

City/Highway Mix:

All Stock: 42 mpg
Stock, EGR OFF: 34 mpg
Tuned, EGR OFF: 35 mpg
Tuned, EGR ON: 43mpg​

Highway:

All Stock: 46 mpg (trip to Vegas)
Stock, EGR OFF: 44 mpg (trip to San Francisco)
Tuned, EGR OFF: 47 mpg (trip to Seattle)​

He later re-installed his EGR components and his fuel economy shot up back to normal.

I get requests every week to delete EGR completely so I developed a Dynamic EGR tune that may be an attractive alternative for the following reasons:

Reduced Wear and Tear

Cold engines have greater engine wear and it is exacerbated by EGR delete because of slower warm-up time. Even if you live in a hot climate, a little increased wear every day will add up.

Mercedes Benz has also documented increased engine wear caused by EGR (soot abrasion in cylinders), and by minimizing EGR once the engine is warmed (EGR is minimized for the majority of engine run-time), you further reduce overall wear & tear.

Optimal Fuel Economy

Cold diesel engines have a lot of blow-by and once the engine is warmed up, the engine seals tighter and gets better fuel economy. By reducing your engine warm-up time with EGR, you reach optimal fuel economy sooner in every drive.

Emissions

Emissions with a cold engine is especially dirty. Normal EGR operation during warm-up can significantly reduce your annual emissions compared to a full EGR delete.

Runaway Engine Protection

If a turbo leaks oil into your EGR-deleted intake, the engine may start running on its own. Shutting off the "ignition" key will not stop it because the oil self-burns. It will continue to rev high until potential damage occurs. Or until you shift into a high gear and stand on the brakes to stall the engine. If you get the timing right you'll probably save the engine. Otherwise you're out of luck, especially if you have an automatic transmission.

The EGR has a valve that can block airflow from entering into the intake once you turn the key off, thus suppressing the oil burn and stopping the runaway.

Smoother Engine Stop

This may not be a big deal to some people, but the engine will shake noticeably when turned off, if the intake valves are removed. Retaining the EGR valve (especially for ALH TDIs that don't have an IMF) will maintain smooth engine shut-offs.

Smoother Idle

Some customers have reported smoother idle with Dynamic EGR compared to stock EGR. If your TDI occasionally has a slight "miss" while idling, Dynamic EGR may reduce or eliminate that issue.

Improved Performance

Some customers who still have their stock performance tune have noticed slightly improved low RPM response, especially off the line. That's with only Dynamic EGR as their only modification.

Cleaner Intake

With Dynamic EGR, EGR is activated only during the short warm-up period. It's turned down as far as possible for the rest of your drive. Your intake will be free of soot build-up much longer, perhaps even the lifetime of your vehicle.

The Dynamic EGR feature has been in use for a year with no issues. It requires custom tuning price (about $50-100 more than standard). Other features are available with custom tuning: Dynamic idle control, left-foot brake fix, and glow plug duration & strength change.

 

[blizzard60]

Mark, I find this VERY interesting. Here's a question for you though (of course, it's me ): what about BEW, etc customers that have gone do an ARL/PD150 intake and therefore only have the option for a vacuum EGR now. Can you re-map the software to work the valve for the intake flapper as an EGR or something?!

This is something that I probably want to take you up on depending exactly how it can work for the above situation!

Cheers,
-Chris

 

[Bob_Fout]

This looks pretty cool Mark!

 

[Vesparide]

I've got a question regarding how the dynamic EGR control would work with an egt probe and a EGR block off plate as my next upgrade will be a boost/egt gauge.
I currently have the EGR delete and I have always wondered why everyone was getting mileage into the 40's with their car and I would be lucky if I got over the mid 30's and now I know.
And if it is doable with the probe and block off plate, count me in.

 

[foxracer1]

I kinda wish i would have left the egr on my dads 98 now just for warm up!

If you turn it off after it warms up would you still need the EGR cooler? I might put the intake mani back on for this function but don't really have room for the cooler with current turbo setup.

 

[UFO]

I'm all in favor of reducing EGR, but is this legal? The EGR system is an emissions device installed to meet Federally mandated NOx emissions after all...

 

[Mark@MaloneTuning]

Vesparide: An EGR block-off plate will permanently stop EGR flow, so this tune won't apply.

blizzard60: Using the intake valve control for EGR control is a pretty unusual request but I'll look into it

UFO: Everything still looks normal with all EGR components installed. However even just changing the muffler is frowned upon by some authorities because it is part of an emissions equipment.

You may be surprised to know how many TDI owners request full EGR delete tunes. I get several requests a week. The Dynamic EGR is an attractive alternative as it's cleaner for the environment, speeds up engine warm-up in the winter, and potentially improves fuel economy.

Disclaimer: Any kind of modification to emissions equipment, including this Dynamic EGR tune, should be for off-road use only.

 

[m1ketdi]

Is this another one that can be done in all TDI generation ecu's?
Much more complex to implement than the dynamic idle mapping, although I have some ideas how it might work, no sleep for me .

Can't wait to see what you come up with later in the tear.

 

[Mark@MaloneTuning]

If you turn it off after it warms up would you still need the EGR cooler?

The EGR cooler transfers exhaust heat into the coolant, which contributes to faster warmup. You'll probably want to keep the EGR cooler.

 

[foxracer1]

Oh yup didn't think of that. I'd have to redesign my setup.

 

[turbocharged798]

Of course Malone posts this thread the day I rip out my EGR cooler and plumbing.

My EGR valve was toast (peeing oil everwhere)and I do not think I want to shell out the money for a new one anyway.

 

[2footbraker]

Cool concept.

 

[smltwnguy30]

This may seem like a newb question here, but I was moments away (literally) from ordering an EGR/EGR Cooler delete for my TDI when I read this. I have to ask a few questions to get a better feel for what all of this means.

1. I have a Frost Heater in my TDI. If that is used properly for keeping the coolant in the block warm, during the cold months, then is deleting the EGR and Cooler still a bad idea?

2. Would this be more practical to continue to use the EGR Cooler inconjunction with the Frost Heater and still delete the EGR? Thus with the cooler intact there would still be moderate thermal exchange helping to keep the coolant warm on cold days but decreasing the soot and increasing air flow by eliminating the EGR?

3. You mentioned MPG drop for a customer on short trips but how long were the trips? What was the temp outside during this time period?

4. Do you have any Dyno runs, or know of any that show what the end result of the EGR and Cooler delete vs EGR delete vs an installed EGR of a car ran when the car was at its regular operating temperatures?

5. The EGR adds hot exhaust gas into the intake mixture, yet we use intercoolers to cool it down to get a more dense air charge for combustion. Eliminating the EGR should increase density by limiting that thermal exchange and therefore make more power??? So... If one uses their Frost heater to warm the block before driving, is there any need for using this tune option instead of deleting the EGR?

 

[jgeppelt]

Malone Tuning, I am in need of a full egr delete tune. Please PM me what you would charge to do this for me and what your turn around time is.

thanks

 

[Mark@MaloneTuning]

This may seem like a newb question here, but I was moments away (literally) from ordering an EGR/EGR Cooler delete for my TDI when I read this. I have to ask a few questions to get a better feel for what all of this means.

1. I have a Frost Heater in my TDI. If that is used properly for keeping the coolant in the block warm, during the cold months, then is deleting the EGR and Cooler still a bad idea?

Using a coolant heater shortens the warm-up period substantially. However, if for example your startup temperature is 100F (38C) then EGR will still bring it to optimal temp quicker. It'll also minimize or eliminate temperature drop while idling outside in really cold weather (especially 5C / 41F or below).

2. Would this be more practical to continue to use the EGR Cooler inconjunction with the Frost Heater and still delete the EGR? Thus with the cooler intact there would still be moderate thermal exchange helping to keep the coolant warm on cold days but decreasing the soot and increasing air flow by eliminating the EGR?

I assume that you're asking about letting your exhaust gas reach your EGR cooler, but not your EGR valve/intake manifold. It sounds a bit odd and I have not seen someone try it, so I can't tell you if it'll be useful.

3. You mentioned MPG drop for a customer on short trips but how long were the trips? What was the temp outside during this time period?

The commute is 45 miles each way. It was April in Los Angeles. I don't know the exact outside temperature but it isn't terribly cold in LA.

4. Do you have any Dyno runs, or know of any that show what the end result of the EGR and Cooler delete vs EGR delete vs an installed EGR of a car ran when the car was at its regular operating temperatures?

I don't know of any before/after dyno runs for EGR delete.

5. The EGR adds hot exhaust gas into the intake mixture, yet we use intercoolers to cool it down to get a more dense air charge for combustion. Eliminating the EGR should increase density by limiting that thermal exchange and therefore make more power??? So... If one uses their Frost heater to warm the block before driving, is there any need for using this tune option instead of deleting the EGR?

When you apply full power and need as much fresh air as you can get, the EGR valve blocks exhaust flow as much as it can, so it's not like EGR is always pumping hot air into your engine.

 

[2footbraker]

When the egr is in "off" mode, does the anti-shudder valve and n75 valve still act as though the egr is functional?

 

[amd is the best]

Does this include CR's?

 

[smltwnguy30]

Thanks for taking the time to answer my questions!

I do have another question though, when the EGR is deleted and the computer shows a code for that is it detrimental to anything else or just turns on the CEL? I guess my real question is If I drive for a while before getting the tune is it going to hurt my car or mileage?

I appreciate your time, and I plan on ordering a custom tune from you at some point in the near future! Hopefully before TDI Fest!!!

 

[timirving]

Just ordered my first tune.....

I went with the dynamic EGR; I'm excited about it as a full EGR delete worried me with regards to warm up time. My MKIV Jetta is a daily driver and keeping it running strong for the next 300,000 miles trumps my need for performance

I too am looking forward to the functions in development Mark. When I upgrade my nozzles and possibly a turbo....oh, and then a clutch, I'll be contacting you to tweak my tune. I am hoping for "dynamic hovercraft mode" soon.... that's just a little ECU tweak right?

 

[UHF]

I'm supposed to get my ecu back with stage II tune from Malone today with EGR delete to go with my exhaust that is also in the mail. Did I make a mistake?

 

[Mark@MaloneTuning]

I'm supposed to get my ecu back with stage II tune from Malone today with EGR delete to go with my exhaust that is also in the mail. Did I make a mistake?

If this is Lorne and if you're changing your mind about EGR delete, then I'll re-tune your ECU at no extra cost.

E-mail me at info@malonetuning.com and we'll talk further.

Cheers,
Mark

 

[UHF]

Email sent.

 

[boertje]

I got the dynamic EGR with stage 1.5. Great job Mark!

 

[NewOwner]

I got the dynamic EGR with stage 1.5. Great job Mark!

Do you mind posting your experience with dynamic EGR? Does the weather conditions has any effect? Any mileage improvements and etc? Much appreciated. Thank you.

 

[boertje]

I have had it on my bug now for 2 months and I can get 48 mpg average going 70-75 all day long even with head wind on my 1000 mile trips. This is on the interstate with mountain driving. I believe the EGR only comes on until the engine is 150*F and then shuts off and is just to help the engine warm faster. In fact I just ordered stage 2 dynamic EGR for my Jetta and will upgrade my bug from stage 1.5 to 2. North Idaho can get somewhat nippy in the winter and that is also a reason I did it and it leaves the EGR intact for those officials that might get nosy in the future.

 

[glitdi]

Thanks again Mark for the tune, with the new turbo setup I have and the dynamic egr the car has loads of power and I don't have to worry about emissions testing...I am having my cake and eating it too!!

 

[hubbie36]

Hello Mark - I too was just about to click the order button on a Race Pipe and EGR Cooler Delete kit. My issue is that I live in Nova Scotia, Canada and although its 85F out today, come January it will be in the -30s, so warming the engine is a major priority. I have had my EGR fail three times in the past 8 years on my 2002 Jetta TDI and I just wanted to eliminate this system all together but I am interested in your dynamic EGR tune. Can you provide some more information keeping in mind I am fairly new to tuning (but an expert in EGRs)... Any other recommendations I could use for maximizing MPG as I am barley breaking 35. Cheers!

 

[Mark@MaloneTuning]

What kind of information would you like? Quite a lot of information is already posted on the first page of this thread. There is normally no difference in warm-up times between standard EGR and Dynamic EGR. Many of my customers however reported longer warm-up times and lower MPG with EGR delete, which is probably not what you want in NS Winter. Three EGR failures is a lot though! What part of it failed?

 

[hubbie36]

The EGR unit itself clogged to the point of failure (it literally had a cardiac arrest). It was replaced in 2005 and then clogged again in 2007. It was then cleaned and failed again just last week. I have no idea why my car is accumulating so much crud as I maintain this car by the book and dive it every day. The only add-ons I have are a K&N air filter and I use a diesel additive for lubrication:

http://www.canadiantire.ca/AST/browse/4/Auto/3/AutoFluidsChemicals/DieselAdditives/PRDOVR~0380766P/Diesel%252BKleen%252Bwith%252BCetane%252BBoost.jsp?locale=en

My frustration got the better of me this season and I would like to just trash the unit all together but I don’t want to sacrifice MPG and I also need the reliability for those -40c Canadian mornings. If you can provide me anything that won’t sacrifice reliability but will give me that extra oomph I know this engine can produce, I would be grateful. Thanks so much for your expertise.

 

[G60ING]

Why are they replacing the whole EGR if its just clogged? Are they cleaning the whole intake manifold too? What about the inlet ports on the head?

Maybe you car needs to have the EGR duty cycle turned down with Vag-Com.