SEGR or GDE tune

sanuras · **Joined:** Fri Jul 06, 2012 12:41 pm **Posts:** 11

I'm a noob, so what I say maybe coming from someone who lacks some fundimental knowledge about the CRD and most of the modifications that are available for it. I own an 05 CRD with 65K miles and without F 37. I've purchased a Provent, Samco hoses and V6 airbox. Since I want to discontinue the EGR function, the next decision is to do the ORM, the SEGR or the GDE tune. Since I want to maintain the check engine light feature, the ORM is not a likely alternative. The GDE is convenient and easy but do I really need it since much, but not all, of what it does, to my understanding, is to restore what the F 37 took away and is a costlier option. The SEGR seems to be what I need, but I am unable to find a supplier for the device to purchase. Advice on the advantages of the GDE over the SEGR on a vehicle without the F 37 would be appreciated. Additionally, does anyone know where I can obtain an SEGR?

Thanking you all for the help provide thusfar.

mikey1273 · **Posted:** Fri Jul 20, 2012 9:01 pm

you can buy an SEGR from a forum member here. I believe UFO was one of the ones involved in that. I made that same decision before to. A first I got an SEGR kit that another member decided to sell I think he sold his Jeep and never built and installed the thing. I never did either after having it for near a year then i got some money and got the GDE ego tune and sold the SEGR again.

the tune does so much more than disable egr it make the thing a bit faster smoother and give some more MPG

near everyone that gets it is very happy

Hexus · **Posted:** Sat Jul 21, 2012 7:10 am

The GDE ECO Tune disables the EGR valve, disables the FCV valve, and doesn't cause a CEL problem. I've also noticed it transitions smoother, I get 6-8 more mpg on average now than I did pre-tune. The "unstoppable shudder (according to Chrylser)" shifting into your final gear at ~54-58mph is gone now. I gained some HP, Torque and it just runs better in general now.

I looked into both as well and I'm very happy that I decided to go with the Tune.

ChooChooman74 · **Posted:** Sat Jul 21, 2012 8:17 am

I went with the tune. Very happy with the results.

Sent from my DROID BIONIC using Tapatalk 2

Lancer · **Posted:** Sat Jul 21, 2012 6:42 pm

The GDE tune is a much better option. Better fuel economy, better driveability, more torque and power, it is definitely smoother.

In any event, the Ecotune (or any of the other ECU tunes) does nothing to reverse/amend the F37 flash - that was applied to the TCM. Green Diesel do offer a TCM tune which I believe does reverse the F37 ( to a point anyway).

mikey1273 · **Posted:** Sun Jul 22, 2012 10:58 am

I think if you don't want to/can't spend as much and are willing to put it together then the SEGR is good. the GDE tunes are better for all they do for the Jeep. getting the trans tune in addition to an ECU tune would be better yet but since it came out I have not. I know that at first that required sending in the trans module and being mine is needs to be driven daily its not an option. not sure if that changed yet.

Edit:
Things to think about is cost and how hands on you want to get. the SEGR kit un-built is not that expensive I think I paid about $100 from a guy that didnt want his and never built it. It does require that you fallow a load of instructions, due soldering and splicing. IF you are not in to doing that kind of electronics work or can't get a friend that knows it to help this will be not very easy. I am a computer technician and I never did mine because it was too much like work and I never felt like doing it when I got home. So I sold it when I ordered the ECO tune. if you have to pay someone to put the SEGR kit together for you and install it you can just get a GDE tune for 50-100 more and the plug in tuner he sends is so easy to use if you are capable of running a windows computer decently well and fallow the instructions the ECU tune will not be anything hard to complete.

so if you don't want to spend much and are good with being all hands on end to end with the SEGR project and don't care about the other benefits of the GDE tune then maybe that's for you. Most of us don't want to do all that work, we want to just be happy and enjoy our oil burners, so like me choose the tune now that it's an option.

DOC4444 · **Posted:** Sun Jul 22, 2012 3:48 pm

You can see from my sig that I have SEGR. I bought it before GDE started doing aftermarket tuning. It used to be the only way to drastically reduce EGR operation on a KJ CRD without having the CEL on continuously. Unless you are a real electronics/electrical wizard, you are looking at around $250 for a new one, fully assembled and at least another $200 for the install. (I believe, correct me if I am off a bit, that there are about 17 individual wires that need to be individually spliced into the wiring harness to get it to work.)

Unless you can do it for a lot less than that, the GDE tune is the only thing that makes financial sense. The GDE TCM tune offers great benefits, but I would NEVER choose it INSTEAD of an ECU tune. Add that last, and only if you drive a lot between 35 and 55 MPH and/or tow heavy (close to 5000 lb) trailers.

DOC

warp2diesel · **Posted:** Sun Jul 22, 2012 10:50 pm

SEGR=100% EGR Elimination.
GDE, EGR reduction (less than 100%) depending on how you drive.
Geordi a GDE user published his results for his driving.

DOC4444 · **Posted:** Mon Jul 23, 2012 8:15 am

Historically, this has been discussed extensively, but for the benefit of new members, GDE maintains EGR function by design. This is typical of their thorough, thoughtful and sophisticated approach. In the rare circumstance that you are hard in the throttle and suddenly get out, then violently jump right back into it, you can "overspeed" the turbo and potentially damage it.

In ONLY this rare circumstance, ALL the GDE tunes open the EGR valve, much like a wastegate. This dumps boost to try to protect the turbo from running above its design speed limit.

When I started working with GDE, I disabled my SEGR (still installed) in order to take advantage of this feature.

So, the debate is really whether there are any negatives about very occasional opening of the EGR.

When, the SEGR was first created (long before GDE came along), the general advice was to disable it a day a month to help maintain EGR functionality. Most were under factory warranty at that point. Now, few are.

My own experience after 70K miles of running various GDE tunes with the SEGR disabled, is that it takes 1000 miles of driving after an oil change (with VDDP) for the oil to start to "color" at all. It takes 5K to become pretty black, at which point I change it. (When we got the Jeep with 17K miles on it, the oil was solid black immediately after a change.)

I am about to do my TB service, at which point I will check the turbo shaft for play and report. Obviously, this will not "prove" anything, but if my turbo is still good after 100K miles, I will be pleased.

GDE recently posted about premature rocker bearing wear with the North American market versions of the 2.8 VMM. Our versions typically run with much more soot in the oil than other market versions. This is certainly at least part of the problem, but may be combined with a lot of use of Mobil 1 0W-40 oil. This may be a bit too thin and does not have all the additives to deal with soot that true "diesel" oils do.

So, if you never, ever open the EGR valve, it is hard for it to stick open and cause you trouble. If it occasionally opens, it can, plus you will get a tiny bit more soot in your oil than if it is always closed.

More collective miles may help to clarify which is the better choice, but maybe not.

DOC

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

The GDE tunes maintain the stock settings for turbo protection, ie. opening EGR valve for about a half second after a hard acceleration with throttle tip out. This bleeds off intake pressure out the exhaust, the air flow is from intake to exhaust so not soot is entering the intake manifold during this event.

The SEGR defeats the turbo protection and thus adds some stress to the turbo compressor. The turbo protection was designed by VM and Garrett (turbo manufacturer) and does help increase turbo longevity.

For customers that never want the EGR valve to open, we can accomodate, but it really makes no engineering sense to do this as it will only reduce turbo life.

ChesterCRD · **Posted:** Mon Jul 23, 2012 9:33 am

I just ordered the FT eco tune (should arrive today I think) and have been running the SEGR for a little over 70K miles. In that time I haven't disabled it, so I'm not sure how it would react to being used again or how I should go about enabling it (ie should I enable it before adding the GDE tune to allow it to open and close some, or enable it after to minimize the likelihood of a a fail open condition. )

I plan to run the FT eco tune and SEGR together to get a feel for how much of the mileage increase is a result of disabling EGR versus other tune changes. Does anyone have an experience or thoughts on this?

DOC4444 · **Posted:** Mon Jul 23, 2012 10:26 pm

Keith,

Thanks for clarifying that when a GDE tune opens the EGR valve, no exhaust gasses go into the intake.

Therefore, there really is no "dilemma" as to whether to use SEGR with one of your tunes. I'm glad that I made the "right" decision for the last 70K miles, even though I wrongly thought that by doing so, I was slightly increasing soot accumulation in my oil.

Thanks as always for all of what you do for our community.

DOC

DOC4444 · **Posted:** Mon Jul 23, 2012 10:44 pm

Chester,

You disable SEGR by installing the bypass plug you hopefully still have for it. Perhaps Keith can weigh in on your relative risk of having the EGR stick open, given that it has presumably been nailed shut for 70K.

DOC

ChesterCRD · **Posted:** Tue Jul 24, 2012 8:24 am

Thanks Doc, I have the bypass plug. My question is about avoiding a fail-open condition when it moves for the first time in 70K+ miles.

I installed GDE's FT Eco tune last night. My preliminary thoughts are that the change us subtle, but noticeable. Throttle response is different and shutdown is smoother. Around town driving is improved. I have about 150 miles of highway to cover this afternoon so I should have a feel for the highway performance and mileage after that.

DOC4444 · **Posted:** Tue Jul 24, 2012 8:37 am

I don't understand why almost nobody opts for the HOT tune anymore. We get an honest 32 mpg in 50% highway/50% local driving, albeit with my economy minded wife driving with nothing in tow. However, when towing, it is nice to have the extra power of the HOT. My chassis dyno testing showed something like 50 more lbs/ft of torque at the rear wheels over the original ECO tune.

Keith told me years ago that if you "bubble-foot" the HOT, there is almost no difference in fuel economy compared to the ECO.

Has this changed?

DOC

ChesterCRD · **Posted:** Tue Jul 24, 2012 10:49 am

DOC4444 wrote:

I don't understand why almost nobody opts for the HOT tune anymore.

I decided FT ECO tune because I'm running the original torque converter. If I had upgraded the TC I would have chosen the hot tune and obtained fuel economy with a lighter foot.

ChesterCRD · **Posted:** Tue Jul 24, 2012 10:02 pm

ChesterCRD wrote:

I installed GDE's FT Eco tune last night. My preliminary thoughts are that the change us subtle, but noticeable. Throttle response is different and shutdown is smoother. Around town driving is improved. I have about 150 miles of highway to cover this afternoon so I should have a feel for the highway performance and mileage after that.

The mileage is pretty amazing if I can trust my evic still. Prior to the flash, it was showing 27 mpg on the highway at 70 mph with the AC on. Today I averaged 34 mpg in mixed driving and the evic was showing 35.6 mpg at 70 mph with the AC on. Obviously I need to do some hand calculations to verify these numbers.

The feel of the tune is well covered by other people and my experience is similar. Most notable to me are the throttle changes, improved coasting, and smoother shut down.

For now I plan to leave my SEGR in place also. I like knowing it's closed.

DOC4444 · **Posted:** Tue Jul 24, 2012 10:21 pm

Don't, the EVIC is off (low) at least 2-3 MPG with all the GDE tunes.

If you want to keep your stock TC alive as long as possible, you bought the wrong tune. You need the "original" ECO that cleverly reduces torque just when the converter starts to lock at around 58 MPH. Then it goes back up to the same max torque as the FT. The FT has more than enough torque to cause most stock TCs to "shudder" at that critical 58 MPH point.

I am sure Keith will swap you for just shipping cost.

DOC

mdopenboater · **Joined:** Fri Aug 03, 2012 9:44 pm **Posts:** 5

I have a question about the EGR:

Isn't it just on the U.S. VM motors for emissions reasons? So closing it off shouldn't effect the turbo because they do not use the EGR in Europe, etc.

Do euro. VM crd's have a different system to protect turbo?

I just was under the impression that the best thing for performance of the diesel is to get rid of the EGR, but the issue is emissions requirements... Pre EPA they did not have them.

Can someone fill me in on this?

Thanks

SEGR or GDE tune

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