Gde tune

[Sharpee64]

Hi there

Has anyone had a green diesel engineering tune on there jk? I'm looking at getting one for my 08. Does anyone know if they can tune for a straight through exhaust system with no cat? My jk is currently having over boost issues and throwing engine lights ever sines I had the exhaust modified. Apparently the reason why it's over boosting is because the exhaust is more free flowing so it spools the turbo quicker and changing the air fuel ratios and that's why it needs a tune.

Cheers

[mick666]

Here is what I have experienced so far in my 07 2.8 auto.
bought stock standard at 100000ks use. Removed rear muffler, not much difference in sound and power. Later on there was a clunking noise. Found a HUGE crack where turbo dump meets cat, removed cat. Thanks AEV. I had to remove your RHS geometry correction brackets to do this. Made a Stainless dump pipe with flexi joint in the middle...Sounded FARQUING horrid, like a GQ patrol, so I welded a short 100 CPI ss cat and straight thru ss hotdog in.
Sounds nice. At NO TIME did ANY ERRORS come up.
Would like to hear more about GDE tune too, especially regarding noise, idle speed and EGT
Cheers, Mick

[Iconian]

There has been multiple threads on this.

I have the GDE tune on '07 JK. It has a hi flow 200 cell catalytic converter with a small straight through muffler. From the back of the turbo to the exhaust tip there are no restrictions or bends that are not mandrel bends, The exhaust was restricted behind the turbo so the exhaust shop opened this up to the same diameter as the exhaust. A pyrometer was also fitted.

The previous owner tested the GDE tunes on the dyno after exhaust mods were complete. The max EGT limit was 500deg. 9 runs altogether were undertaken to get a good average: 3x Runs in STD, 3x Runs in ECO, 3x Runs in HOT.

Dyno sheet is below, but results were as follows:

HOT (red on graph) 114.8KW / 490NM
ECO (green on graph) 113.4KW / 480NM
STD (pink on graph) 89.4KW / 370NM

From the dyno results it was concluded that the hot and eco tunes are almost the same except for one big difference, the exhaust temp in HOT is up to 500deg C and rises very quickly when accelerating, so it's pouring in more fuel for just 1.4KW power increase which doesn't seem like it was worth stressing the motor for

Post the dyno test, the previous owner ran it in ECO obviously and I am still running in it ECO. I haven't had any engine lights thrown.

The other usual question is if it's worth it? Outside of the performance and apparent economy improvements (I've only ever know the economy based on the GDE tune, so I don't really have anything to compare it too. Other can probably weigh in?), I think it is purely worth it for engine health avoiding most of the exhaust gas recirculation

[redrock]

I love my GDE tune, JKU hammers with 35's. And has never run smoother. Speak to Stuart at Murchison in QLD. He's a legend.

[Sharpee64]

Have tried contacting murchison but have gotten no response also pmd Crdstu on this forum and no reply

[Purds]

I bought mine from Murchison and they were great to deal with. Very friendly and was purchased over the phone. Had to ring them up a second time and was put straight through to Stuart. I uploaded my new tune onto the Jeep last night and seems to be going well.

I don't really know about economy gains yet (08 CRD manual runs very economical anyway - 8.6L/100km). The turbo seems to spool earlier and i get a bit more low down. One of the main reasons I got it was to turn the EGR off for engine longevity.

I am not sure it will fix your issues with the exhaust though as it is more or less a one size fits all tune. It is not tuned to your custom exhaust but rather just matched to your stock vehicle specs.

[mick666]

Hi Jono

"The exhaust was restricted behind the turbo so the exhaust shop opened this up to the same diameter as the exhaust. A pyrometer was also fitted."

The exhaust diameter is 2.5 inches, and the orifice coming out of the back of the turbo casting where it bolts on to the flange is less than 2 inches.... did the exhaust shop remove the turbo and machine the casting out to 2.5 inches?

How is your idle speed and diesel rattle at idle?

Cheers, Mick