Longranger1 wrote:Sierra, if you have an Ultraguage you can see in real time what the EGR valve opening percentages are. Yes, it is exactly as you say - the EGR valve opening percentages and consequent gas flow. There is also an Ultraguage function which shows the percentage of error in relation to the throttle valve. The throttle valve and the EGR valve work together and if one is out of step with the other then this will show as a percentage of error.
sierra wrote:Longranger1 wrote:Sierra, if you have an Ultraguage you can see in real time what the EGR valve opening percentages are. Yes, it is exactly as you say - the EGR valve opening percentages and consequent gas flow. There is also an Ultraguage function which shows the percentage of error in relation to the throttle valve. The throttle valve and the EGR valve work together and if one is out of step with the other then this will show as a percentage of error.
I set my Scanguage to read the throttle position, TPS. There's nothing I can see that reads the EGR valve and I thought that was either open or shut?
Anyway, it was wide open, 99%, up to 55c coolant temp and then at 20% up to 1/4 accelerator pedal and 99% above that to full a/pedal. Also 99% on no a/pedal and including idle. It never went below 19% and rarely showed anything inbetween 20% and 99% as it changed. On shutdown it stayed at 99% interestingly.
It makes sense the throttle valve mustn't close, hence the 20% minimum.
Different result to yours!
Longranger1 wrote:Mate, that's because you have one of those overpriced Scanguages. I can assure you that this is an egr dedicated guage function. The Ultraguage also has the function you describe
srb wrote:LR is correct about the Ultragauge function and the EGR valve function working with the throttle flap. This is how the EGR and clean air are mixed... Your readings are of the percentage of throttle flap opening, so when your throttle flap is only open at 20% it means the EGR valve will be open close to 80%. But with the blank plate there will be 0% EGR flow. This is why we are getting the vacuum spike in the intake manifold I assume.
And to answer your last question why LR and myself are interested in the EGR valve opening %? This is because of LR's stage 2 bypass. We have plumbed the boosted clean air from the intercooler through the EGR valve while leaving the EGR gasses blocked at the EGR cooler. So while the throttle body is partially closed at 20% there will be air pressure to travel down the bypass to the EGR valve that is open at say 80%
TUFF TROOP wrote:Just leave it how it is . As you may drop another bolt and be stuck Again.. Which wouldn't be good haha! ,
odie602r wrote:Okay, first half of my longer trip is done, post full EGR blank. 639.6kms, of which approx 525kms at highway cruising @100km/h, rest city driving. Used 63.15 L fuel, so economy of 9.87L/100kms.
That is after the inaugural EGR blank installed trip where it had used 11.02l/100kms.
So in other words, this leg of the trip saw me gain my equal 2nd best economy figure, only 0.4L/100kms off it's best at highway cruising (still not as good as I think it should be mind you).
Was planning to pull out EGR blank and block off one way valve for return leg, but now not so sure. Maybe it's worth doing a back to back with EGR blank in, to see it's maintained for the return leg. Return leg won't have the city driving component (well only 30-40kms) so not as much as the leg I just did.
What do think - evaluate the second leg with EGR blank still in, or pull it out?
Longranger1 wrote:"The other LR mod I can see offers benefit in raising the MAP reading in the 0-25% AP range and could be increasing the fuel."
By this do you mean fuel consumption increase? The fuelling at steady speeds wouldn't vary - if it did then you would actually be accelerating. Of course fuelling is going to be increased off idle because with the blank in manifold pressure is depressed. I found with only the blank in and no other mod's, torque down low was pathetic. As well as laggy as hell.
On your non-VGT engine Sierra, things are a little different, so what works on the VGT engine may not carry across to yours or for that matter the 3.2 engine. Theory says it would, though the proof is in the the trialling of it.
To cut a long story short, the 2 mod's work very well together and has little in the way of downsides apart from being obvious.
Another thing to consider is that the VGT set up will always have an exhaust back pressure pre-turbo higher than boost pressure - it cannot be any other way, as then you would have air pushed backwards into the exhaust manifold under conditions that the EGR is in play.
While I have found both mod's work extremely well, I understand that this isn't for everyone. Modifications to your vehicle are done at your own risk, whatever those modifications may be.
odie602r wrote:Okay, first half of my longer trip is done, post full EGR blank. 639.6kms, of which approx 525kms at highway cruising @100km/h, rest city driving. Used 63.15 L fuel, so economy of 9.87L/100kms.
That is after the inaugural EGR blank installed trip where it had used 11.02l/100kms.
So in other words, this leg of the trip saw me gain my equal 2nd best economy figure, only 0.4L/100kms off it's best at highway cruising (still not as good as I think it should be mind you).
Was planning to pull out EGR blank and block off one way valve for return leg, but now not so sure. Maybe it's worth doing a back to back with EGR blank in, to see it's maintained for the return leg. Return leg won't have the city driving component (well only 30-40kms) so not as much as the leg I just did.
What do think - evaluate the second leg with EGR blank still in, or pull it out?
srb wrote:Yeah I see what your saying regarding whether there is too much restriction through the EGR valve to be worth doing the mod. This may be true but there is some benefit in the AP range like you said, not sure how much yet cause most of my driving is stop start around town, it should show its benefits on the highway hopefully. Having said that... I can defiantly feel like something is different though. Seem to be less engine rattle at Idle and smoother running. This of course could be the placebo effect thingy though?
In regards to the dealer seeing it... If I ever have any warranty concerns with the engine then all I do is remove the bypass hose and screw plugs into the couplings and say it was for gas analyse test. That was LR's Idea!
I don't really hide anything from my dealer anymore.. The new service manager there agrees with all my mod's. He's into modified cars him self and is aware of all the carbon problems with the new diesels.
sierra wrote: I agree that theory and trial results can often be quite different. Disappointing, as expected or inspiring. I should imagine you are inspired. I'm still trying to figure out where the gains from the second mod come from?
sierra wrote:This is major surgery. There has to be a simpler way, after all just unplugging the throttle valve will achieve the same result and more, since there is a full flow of fresh air all the time with the blank in and the conditions also removed that cause the low pressure MAP code.
The only problem with that is a lumpy shut down.
srb wrote:Hay a bit off topic Sierra but I've never tried the 2 stroke before and to be honest I don't know much about it. I would have to look into it myself before I tried it... Can you point me in the right direction regarding info on this? I'm happy to try anything as long as I know for sure It wont damage anything.
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