Thread: Testing performance mods - no change?

Originally Posted by kwalikum

I've got a 2001 td5 and thought I'd give a crack at some of the recommended performance mods including "testing" any improvements. After reading a ton of posts it seems the most you can rely on is *feeling* smoother, more responsive, etc. Perhaps my engine is running cleaner or my fuel economy is better, but I was expecting some improvement in speed off the line also.

So, I picked a 0-100 test, or more specifically, a timed distance between two fixed points where my top speed is around 100km/h. I cleaned the MAP sensor before I started testing, so unfortunately that is not included.

So far I have:
1. EGR blanking kit
2. Silicone turbo hoses (wasn't really expecting anything here)
3. Removed centre muffler
4. Replaced MAF sensor

I did 2 runs after each change at about the same temperature (usually before/after tests) and noticed NO CHANGE.

I do have an outstanding MAF sensor problem. The orignal produced a "logged low" fault on the nanocom and did not change from around 50 gr/hr. The replacement (a cheapo, yes, I've read all about OEM vs. cheapo, but $50 delivered vs. several hundred convinced me to take the risk. I'm not feeling so convinced any more) tops out at about 700 gr/hr under heavy acceleration and produces a "logged high" fault. With heavy acceleration, which is when I'm testing so there's still a chance for improvement here, the reading switches to 0, but recovers when you back off the accelerator. Any assistance with this would be appreciated

As Dave said, nothing you have done is a performance mod. At best it's maintenance - with the exception of the muffler removal, which is largely an auditory mod.

The egr removal doesn't make the td5 smoother, on the contrary most people who can still hear the engine over the din of the removed centre muffler, notice a substantial increase in clatter at the light throttle openings where egr operates. I'd argue that the engine operates worse with egr removed than if you'd spent the same time and money on cleaning the egr valve and make sure the egr system was functioning correctly. What you gain is possible increased longevity.

As you discovered cheap MAFs give incorrect readings. The fix is - buy an OEM MAF.

A OEM with stock boost setting will top out at about 650. 700 is the maximum value the ECU can read. If input exceeds that it faults and rolls over to 0 as a fail safe.

Cheers
Paul

Originally Posted by bigkevg

We don't always use full power when accelerating, or I don't anyway, in theory the egr operates as you say, but hot gas, from exhaust takes up volume in the cylinder, displacing cooler clean air, therefore it must detract from performance somehow, it cannot be as efficient in either economy or power production as a clean charge.......not to mention the layer of gunk it puts into the intake when it mixes with the oil blowby.....hence my classification as a performance mod, and as I said, it's not an earth shattering one.
So yes, my apologies black night, I was incorrect, but any car, especially a diesel will run better without the egr.......IMO.

for petrol engine thinking you would be correct.


Ignoring the soot build up thing (which is why we remove the EGR on the TD5) Untill the the exhaust gas thats being recycled has displaced the o2 required for combustion its not detrimental to performance which Unlike a petrol engine where the EGR displaces o2 and upsets the Stoichiometric ratio which has a detrimental effect on performance. (this is part of one of those conversations I have probably once a fortnight with guys who have gone from mid age petrol to modern diesel vehicles)

A diesel doesnt need a complete load of clean air to run at less than full power and the EGR gasses are cooled on the TD5 (my02 and after)

lets just say that to burn 10 parts of fuel you need 100 parts of air which gets you 10 parts of oxygen, further that that is the perfect mix for burning the diesel cleanly and with maximum thermal efficiency.

If youre only asking for half power you need 5 parts of fuel, 50 parts of air, giving 5 parts of oxygen but whats going into the chamber is 100 parts of air including 10 parts of oxygen. once the diesel has done its bit with the first half of the air the leftover 50 parts of air gets turned to oxides of nitrogen because of the leftover 5 parts of oxygen. This is where the EGR comes in, it displaces all or part of the 50 parts of air that you dont need to have to support combustion with an inert gas. All good.

The problems come when it doesnt work the way its supposed to and like all other things landrover they leak and then, as a minimum, you have a non combustible gas where you need o2.

If They had one that was totally reliable, cheap to service, didnt provide a restriction to the intake air and put filtered exhaust gas into the intake manifold instead of soot I for one wouldn't reccomend removing or disabling it.

Sadly they dont so I do.

I shall now remove both feet from my mouth.....yes, I am a "petrol head" and done up plenty of petrol engines, but limited with diesel.....

I'll now shut up and bugger off.......

Thanks for taking the time to explain that in simple terms so even an old petrol head could understand mate. Cheers.

Maybe if a way to remove the oil vapour from the blowby so it was "dry" the grunge wouldn't form, the egr wouldn't clog up and leak, but even a good air/oil separator couldn't achieve that amount of oil free air I wouldn't think....without creating undue back pressure anyway.

no problem, thats what the forums here for.

have a look at provents.

diesels produce proportionally less blow by than petrols due to better sealing characteristics of the rings and higher pressures

TD5 egrs clog from the exhaust side to the oil side, sorting out the soot would solve the problem.

Diesels dont mind a little misty oil in the air, (and wow can they rev when they get a lot of oil mist in the intake air, especially turbo units) the higher combustion temps and pressures burn it off, it doesnt carbon up in the chamber and around the plugs like it does in a petrol.

Originally Posted by Blknight.aus

no problem, thats what the forums here for.

have a look at provents.

diesels produce proportionally less blow by than petrols due to better sealing characteristics of the rings and higher pressures

TD5 egrs clog from the exhaust side to the oil side, sorting out the soot would solve the problem.

Diesels dont mind a little misty oil in the air, (and wow can they rev when they get a lot of oil mist in the intake air, especially turbo units) the higher combustion temps and pressures burn it off, it doesnt carbon up in the chamber and around the plugs like it does in a petrol.

QUOTE from blacknight - have a look at provents.

Dave - you would be one of the most down to earth, funny and knowledgeable experts on this forum - hence I can't resist noting that Kev already has a provent according to his sig (accepting it doesn't necessarily mean he knows in detail what it does).

Originally Posted by gavinwibrow

QUOTE from blacknight - have a look at provents.

Dave - you would be one of the most down to earth, funny and knowledgeable experts on this forum - hence I can't resist noting that Kev already has a provent according to his sig (accepting it doesn't necessarily mean he knows in detail what it does).

Ahhh, yes I do, but I wasn't going to comment any further, Didn't want to be rude, and I've had my feet in my mouth so often my jaw hurts.....always willing to learn but......I know the provent is very good at what it is designed for, but to get truly dry air, that is air that wouldn't react with the egr, would require a much better, or different system.......I did select the provent after much research though.

Cheers
Kev

I had a thread here somewhere on the EGT improvements with a larger cooler for your info.

I'll try find it.

Cheers

Originally Posted by Disco EMU

Get onto TRS in Adelaide ... for around $650 exchange, you'll get the performance you're after.

Cheers

Craig

Hi Craig I know its probably only my vehicle but I have to disagree with you on this mod. I have a TRS job in mine and to be honest its crap. It was in my vehicle when I bought it and I'm glad I never handed over the hard earned for it. It should go a lot better than it does I believe and my last "stock I might add" Td5 would leave this chipped one for dead. Disappointed I am, well yes very!!. Very tempted to rip it out as I reckon would go better. My mechanic doesn't believe it has a chip which of coarse it has, he reckons it doesn't go like a chipped one.

So sorry mate I'm now not a TRS fan!!! just my 2c worth