Thread: What happened to your Discovery 2 today?

Originally Posted by RRT

Then Sunday went for a drive to Marysville for supplies and the EGT's were hitting new highs with it approaching 700 up the steep climbs and then the whoosh was back so stopped to find the intercooler inlet was barely on and on taking out the K&N air filter found what looked like mud on the underside and the Turbo must have working hard to get the air through the system even though the boost levels were indicating good numbers.

Attachment 178223

From here, throw away only and a couple on each trip if necessary.

Thought I would try and clean the filter yesterday (yeh not much to do) and boy what a job it turned out. Tried the K&N cleaner and the first two times got out the obvious but it was truly dirty still, then hit it with P21s and it took another 5 washes and soaks until the water ran clear. Looking at the weave finally cleaned an it was quite palpable how 'thin' it is and accept the oil helps trap dirt but to my mind the mud becomes solid immovable barrier to flow.

The conditions last week were extreme no doubt, the white dust hung long in the air and did not seemingly disperse. Suppose I now surmise that a dry filter may fill up between the pleats but the upper reaches are still patent to flow as the dust is able to still float unattached and allow air to get around. There is of course a limit to disruption but in dry dusty conditions have no doubt it is a lot longer than the K&N. As I noted post, have used K&N in my road cars for decades without problem and still will, but for off road, is now throw away which I can 'recharge' at stops by shaking the bulk away.

Wonder how much impact compromised filters impact on EGT's, even though the boost numbers are 'up', does this impediment impact on the Air Fuel ratio??

Originally Posted by RRT

Wonder how much impact compromised filters impact on EGT's, even though the boost numbers are 'up', does this impediment impact on the Air Fuel ratio??

The AFR's on that tune are pretty good from memory, however you will find that with that turbo you are often running very very lean, which is great for egt and economy.

That said, the benefit of that turbo will rapidly decline when the ambient pressure drops low in the inlet before the turbo, this can make an exponential difference to egt for several reasons... And that air cleaner is clogged.

You can basically log the difference it makes to egt and performance, even with rudimentary equipment.

Cheers
James

Originally Posted by shack

The AFR's on that tune are pretty good from memory, however you will find that with that turbo you are often running very very lean, which is great for egt and economy.

That said, the benefit of that turbo will rapidly decline when the ambient pressure drops low in the inlet before the turbo, this can make an exponential difference to egt for several reasons... And that air cleaner is clogged.

You can basically log the difference it makes to egt and performance, even with rudimentary equipment.

Cheers
James

Sure hadn't had issues with the EGT's before and had noted on the previous trip had even stopped looking as they were low, very low and contained even on the long uphills. It also wasn't dusty as such much more shale where as this trip was all dust and more, maybe the serviced cleaner (before the previous trip I might add) might have had too much oil. That said the way it muddied up was disturbing, even frightening and the point of the oil actually painting an ever increasing blockage on the cotton rather than let it settle down 'uncontained' in the pleats and keeping the upper edges patent, well this makes sense to me.

As a question, if I had turned up the boost would this have improved the EGT's in the same circumstance or would it have just increased the fuel as well ? That is, is fueling an rpm function, a psi function or fluid / static combination of both?

Took the slider off (APT) (weighed it for interest and its 18.7kg. Thanks to OneBob in the "Rain water ingress" thread Rain water ingress detected at bottom of A pillar I found the drain hole and it was blocked (Cape York 2017 - red dust gets into everything). The driver's floor got wet in recent torrential rain. I have jacked up the carpet to dry. I will need to replace the A Pillar outer trim as a piece has broken off allowing a lot of water in, in heavy rain. If anyone wants to sell me the outer trim please PM me. Cheers

Originally Posted by RRT

As a question, if I had turned up the boost would this have improved the EGT's in the same circumstance or would it have just increased the fuel as well ? That is, is fueling an rpm function, a psi function or fluid / static combination of both?

That's a big question with a long answer.

However the short answer is:

All maximum fuelling rates are controlled by requested fuelling and air charge.

Air charge is regulated by requested fuelling, turbo efficiency, wastegate modulator setup/target boost levels, AAT, AAP and intercooler performance.

Egt is controlled by turbo efficiency, fuel rates AAP, AAT, intercooler performance and RPM.

Turbo efficiency is controlled by its own design, and pretty much all of the factors above, including pressure ratio.

Short story shorter, winding up the boost with a blocked filter will increase pressure ratio making intake air hotter, however the increased air flow will offset it to some degree, but of course the law of diminishing returns will bite you on the bum.

Shorter story even shorter.... No it probably wouldn't, and it could rupture your air filter and kill the engine.

And now the down low....

Get a decent air filter and keep it clean!

The tune will take care of the rest.

Cheers
James

PS. I'm not good at short answers

Originally Posted by shack

That's a big question with a long answer.

However the short answer is:

All maximum fuelling rates are controlled by requested fuelling and air charge.

Air charge is regulated by requested fuelling, turbo efficiency, wastegate modulator setup/target boost levels, AAT, AAP and intercooler performance.

Egt is controlled by turbo efficiency, fuel rates AAP, AAT, intercooler performance and RPM.

Turbo efficiency is controlled by its own design, and pretty much all of the factors above, including pressure ratio.

Short story shorter, winding up the boost with a blocked filter will increase pressure ratio making intake air hotter, however the increased air flow will offset it to some degree, but of course the law of diminishing returns will bite you on the bum.

Shorter story even shorter.... No it probably wouldn't, and it could rupture your air filter and kill the engine.

And now the down low....

Get a decent air filter and keep it clean!

The tune will take care of the rest.

Cheers
James

PS. I'm not good at short answers

Just took it out for the first time with the CLEAN filter and what a difference, the boost rises so much quicker now and obviously seat of pants thrust! The boost gauge swings rather than climbs.

The K&N came with the car and had been cleaned and treated before but not as thoroughly as the last time, the multiple soaking was eye opening as to the dirt accumulated / trapped. Still will not be using it for the tracks again I can assure you, the couple of hours cleaning with volumous water would not be capable of being done in the bush.

Have been investigating new airboxes and alternatives, this having highlighted to me that the breathing aspect can be so easily compromised and as I am also looking at putting on a snorkel, need to ensure AIR is available.

By the way, the point you make about the temps of the intake air is no more palpable as to when having to refit blown intercooler hoses, they are damn hot!

Originally Posted by RRT

Just took it out for the first time with the CLEAN filter and what a difference, the boost rises so much quicker now and obviously seat of pants thrust! The boost gauge swings rather than climbs.

The K&N came with the car and had been cleaned and treated before but not as thoroughly as the last time, the multiple soaking was eye opening as to the dirt accumulated / trapped. Still will not be using it for the tracks again I can assure you, the couple of hours cleaning with volumous water would not be capable of being done in the bush.

Have been investigating new airboxes and alternatives, this having highlighted to me that the breathing aspect can be so easily compromised and as I am also looking at putting on a snorkel, need to ensure AIR is available.

By the way, the point you make about the temps of the intake air is no more palpable as to when having to refit blown intercooler hoses, they are damn hot!

I think there are a couple of chokes in the system:
1. Between the guard (or snorkel) and the airbox
2. Hyclone in the bottom of the Td5 airbox
3. Exhaust flex - I understand the diameter is quite reduced inside the factory one. I'm not sure if this is for all of them or just the early ones. I have not checked this.
4. Possibly the metal tube between the turbo and intercooler which is crushed to make it fit.

For air filters, I don't think there is anything still which is better than a LandRover supplied one which I think is Mann Hummel????

Originally Posted by Slunnie

I think there are a couple of chokes in the system:
1. Between the guard (or snorkel) and the airbox
2. Hyclone in the bottom of the Td5 airbox
3. Exhaust flex - I understand the diameter is quite reduced inside the factory one. I'm not sure if this is for all of them or just the early ones. I have not checked this.
4. Possibly the metal tube between the turbo and intercooler which is crushed to make it fit.

For air filters, I don't think there is anything still which is better than a LandRover supplied one which I think is Mann Hummel????

It struck me as funny when I started looking at the airbox and associated piping a while ago, just moving the Bonnet Alarm pin rearward could have given straight out the guard or short pipe up at 45', this could have been been easily done with better integrity and more direct flow without that stupid woven atrocity.

Is there a problem with the Hyclone??? it seems a great idea to put about 30% impediment in the airbox which is supposed to twirl the air only to have to laminarly flow through the airfilter.

Lucky with this my DD Turbo and manifold came with custom 2.5" all the way through the down pipe, the original one certainly had a noticeably reduced diameter in this section. Suppose with a stock engine this was not much of an issue and that 3" exhausts are not considered a requisite it must have saved some $'s in manufacture.

The crush on the intercooler pipe, more surface area to heat the PS and ACE fluid with rather than single touch point, LR must have a reason I suppose??

Sometime ago someone posted re the Airbox and mentioned the GU Patrol box, or should I say cylinder. Have checked the dimensions of the space and it is approx W 25cms * L 25cm's * D 30cm's which should comfortably fit it - this is an aftermarket one;

4x4 Universal Cold Air Box Filter Kit Black Finish for Universal Set Up | eBay

It will require some modding but am looking now at something similar to how they show it with the Navara but imbedding a 4" pipe along the panel. It will probably require a relocation of the bonnet alarm or at least mod of the attachment but at the moment seems the most expedient solution short of a complete makeup of a unit.

Navara.jpg

The attachment idea of the base at the moment is to cut away the base of the stock unit and attach this to the bottom bracket, again some modding will be required but at least that way the original mountings are used - if not, rivnuts.