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GTO sir,

Can you please elaborate the other points or point me to a link on it. Would like to know more about it as i drive a diesel.

Thanks.

I am assuming you are asking about what are the things that can be bad for a Diesel, let me start off - the Gurus can add on.

Oil Change - The recommended oil change duration is ~5000 KM or 6 months for mineral oil, and ~7500 KM for Synthetic oil. Modern Diesels invariably come with a turbo charger, which is a very high revving component (to the tune of 100,000+ RPM), and is lubricated by engine oil too. Irregular oil changes not only wear the engine down, but may also cause sludge / caking up of oils. Also important is the right quantity of oil (Hope you would have read what a bot more of oil does to Swift's DDiS engines). Make sure that your engine oil of choice meets or exceeds the specification given by the manufacturer in the user manual.

Revving the engine to red-line - A Diesel's torque curve is pretty much flat. My Getz CRDi, though redlines at 4500 RPM, generates its peak torque from about 1750-1900 RPM all the way to about 2750-2900 RPM (not sure about the exact RPMs), and will actually drop after that. Up-shifting at a max of 3000 RPM is the way to drive the car, redlining it in each gear will not give you the performance you expect, and will add to wear and tear of the sensitive internals of the heart. The best way to drive a Diesel is to upshift at the RPM the turbo starts kicking in for the 1st and 2nd gear, and then pushing her further in the 3rd / 4th / 5th.

Fuel Quality - The fuel pump, filter, common rail and the injectors are all sensitive components that work under constant pressure of ~1350 bars. Any impurity/ moisture is only going to reduce their life. And, mind you, all of them are pretty costly.

Filters - Diesel oil is not as evaporation prone as petrol. Good, right? Not really. The empty space in the fuel storage tank in the fuel station as well as in your car will be filled with air from the atmosphere, which will also contain moisture. This will mix with Diesel and will get pumped in by the fuel pump to the fuel filter. The fuel filter in modern diesels are complicated stuff, which, along with impurities, also have to filter-out moisture from Diesel before allowing it to pass in to the common rail. The air filter is critical pretty much the same way in all other engines, and so is the oil filter. Having these checked and changed as per the manufacturer's recommendation is imperative.

Idling at start / stop - It is, in general, a good habit to idle the engine for a few seconds before moving off for any vehicle. For a Diesel, it is kinda important - again for the turbo to get lubricated before it has to put in its 100% efforts in increasing thrust. And as the turbo is such a high revving component that is also lubricated by the engine oil, switching off a turbocharged engine immediately is like choking the turbo, leaving it high and dry. Allowing the engine to idle for 30 seconds or more will ensure that the turbo is spinning for longer time at normal revvs without doing any work even while getting lubricated. Switch off immediately, and you are asking for the oil to cake up at the super-hot bearings of the turbo.

In short, regular oil change / filters change / good quality fuel from a reputed fuel station, and refined driving habits will let you enjoy that torque rush for a lot longer, without a dent in your wallet. Abusing a common rail is a sure-fire recipe to spend $$$, and then call Diesels high maintenance!

@phoenix

Thanks for the reply. It was very helpful. Now i do make it a point to idle my car for a minute before and after driving.

This is one fast VDi.
Anyway this was running on Petes now its been custom mapped when I had a chance to rode shotgun.
But yes I agree with you, this is one fast car.

But of-course. That is what every mod does to the car. I guess any kind of performance mod has its own set of problems. However its the bang for the buck factor that keeps diesel tuning "fun". Be its Petes, RD or any other "box".
The sheer bhp for the rupee is unmatched if we compare to petrols.

Every component has its optimum operating range and there is also something called "margin of safety". Best example is the home LPG cylinders.
They are built to take a life time of abuse.

The way you are saying here it seems all the components in a car are running close to its designed maximum. This is not even close to the truth especially on a diesel. If the case was as what you said there would be a bunch of "blown" fiat multijets on every other road. Don't you think ?

So does this imply redlining a petrol is ok ?
Anyway who needs to redline a diesel anyway ?
On a "box" car the power delivery and more importantly the torque is so low down and linear it is simply pointless to rev the nuts off the thing.

Riju, IT IS NOT DESIRABLE TO run a box on a diesel or petrol unless optimised at factory like the AMG or BRABUS Kits.

Desirable, no. Yes I got that part Vikram sir.

However so is FFE and the "after-market / performance" filters.
Compared to all that these boxes do give value for money and bhp that is not just on paper. But simply stating that they will ruin "components" is not correct either. In that case all the folks who has a FFE job is a loon ? As its not as per the "norm" and not the optimal thing and puts stress on what not...!

We have to remember these are not just "road side" boxes. This has been developed and tested (how extensive ? I don't have a clue. But hey it does work)

No they are not "optimal".
They are not gonna blow the thing either. (As far as I know)

Anyways custom remaps are an option however its expensive and that is not really the topic here, so I'm keeping quiet.

In a lot of applications tuning boxes do not add any power to the car.

In other applications they do work and again others they do do harm.

I myself do not re-map any car unless I have run it for several runs on the rolling road (or chassis dyno). There we measure the AFR (and boost on on turbo engines). From there we can see the state of engine as well as sensors. On a recent rr day I had to send six cars back without re-mapping because they were not up to it. This the drivers did not realise.

My associates and me have designed many re-maps over the years and often upload one of our programs to find out that the specific engine needs variations in orde to get the same output (the diffrences can be as much as 15% of total power in turbo Diesels).

Being a performance tuner for many years it would be much easier to promote tuning boxes as I just need to sell them and no hard work involved and no need for the expense of a rolling road (plus premises to operate it), but I will never do this because I am professional. For this I prefer the slightly more expensive route of re-mapping.

so, does this mean that you will have no problem buying a second hand diesel running on Petes? And that if you have petes on your car, when you go to sell yours, you will let the prospective buyers know about it?

I have custom headers and K&N filter on my car. When the time comes for me to sell it, i will sell it as it is. Although my car is ten years old and you can always argue that resale value anyway is small, i can assure you that if it was newer, i still would have done the same.

Not necessarily because it is depending on other conditions too.

On the other hand when everything is done properly you can extract from some engines a lot more.

For example the 1.9JTD block in the Fiat group (also used by GM) started its live from 80bhp. It was upped to 100, 105, 115, 120 and 130bhp in the 8v configuration, which we get to about 210bhp. A lot of them are running for many years and have covered 50,000km and more without problems.

The 16v variant currently at 150bhp and 190bhp we have been able to safely extract 265bhp and over 600Nm of torque. This is without changing internals. It would never be possible to this with a tuning box.

The 1.3 M-jet started with 70bhp, was also offered as a 75bhp and 90bhp variant and is now upped to 95bhp in the 500. Fiat does have another upgrade on the shelf to make it 120bhp.

On the petrol side the 1.4 T-jet, which is currently sold ranging form 130bhp (officially 120bhp) to 215bhp is capable of 280 without changing intenals and is able to take this for a long time.

Romeo Ferraris made a long distace racer with uprated internal but the block and head remaining standard churning out 360bhp. Although it is a rac a car 1000km long distance racing is comparable to 50,000km normal use.

My CURIOSITY switch is ON today so please bear with me :D

You are talking about ECU remaps, right? But that is not what tuning boxes do (given my limited understanding). But, since you have given examples of remaps, i assume the effects of ecu remaps and tuning boxes are comparable. Yet, why do you prefer to do remaps rather than tuning boxes, even though tuning boxes are much easier to do?

Just curious to know , Peetting a new car does void the official manufacturer warranty/guarantee ?

If the car is well maintained, Yes I'll not have any problem.
If you ask me a granny style driving does more damage than pedal to the metal :D

Just an example
I've seen clutch plates of 16k run swifts that were in worse condition than my 95k run Zen's clutch. And brakes were jammed so bad, boy oh boy.

In any case 2nd hand car has its own set of good and bad bits. Personally if I had the money I'll buy a "new" car all the time.

My bike is the "living" proof for that

The following info is hear-say so accuracy is anybodies guess.
"Most" boxes play around with the fueling. Petes increases the richness which increases power. In RD they increase the fuel rail pressure.

Re-maps are essentially the same thing but the key is "custom". So what a re-map tries to achieve is a "perfect" (not really that perfect eh ?) match for the car and the set of mods its running.

Yup any kind of performance mods in most cases void the warranty. Even a simple air filter.

Why couldn't I shut up? :Frustrati

Not really.

Anyway, between a re-map and a tuning box is distinctive differences in what happens.

Tuning boxes are not able to correct the ignition timing (obviously we are talking petrol), which might not be a problem when the tuningbox is the only modification.

This is the graph of an induction I recently fitted to a Citroen C2 1.6:

[IMG]file:///C:/DOCUME%7E1/Peter/LOCALS%7E1/Temp/moz-screenshot.png[/IMG][IMG]file:///C:/DOCUME%7E1/Peter/LOCALS%7E1/Temp/moz-screenshot-1.png[/IMG]

(The green lines are torque and power before fitting and the red ones are after. You can see on the shape of the graph that re-map is benefitting perfromance.)

The amount of air that the induction allows the engine to take in is quite substantially more than with the stock induction. To get the most out of it the fueling needs adjusting (which hasn't been done on this car yet). Additionally the ignition timing needs adjusting because the only reason why the power increases because of the induction is that it leads to a higher volumetric efficiency (= higher compression - not to confuse with compression ratio) The higher the volumetric efficiency is the more the ignition timing needs altering. The tuningbox can't do this.

In the graph you see the effect of only one modification. If you have any more than this then you are way out with the ignition timing.

Now it gets even worse. Early ECUs had only one or a maximum of 2 mapping tables for each varibles, which is ignition and fueling.

The further we go the more complicated it gets. We are still talking petrol. There is now an array of tables (which I don't want to go into right now as it takes all day till we have covered everything). These tables aretailored to protect the engine via sensor evaluation. A lot of the functions are self regulating. In more modern applications the ECU can effectively override the tuningbox as it is only an add on with limited capabilities.

On turbo and turbo Diesel engines some other tables come into play that can turn out to do nasty things to the driving experience. To avoid longterm problems ti is much safer to replace the existing mapping tables by improved ones than trying to fool the system.

A modern turbo Diesel has got many tables in the map. This creates longterm problems the tuningbox (being responsible for) can't solve.

Also every engine develops a different torque characteristics. I see this often when we have single rolling road events where up to in excess of 10 cars with the same engine (in the same model) come and none is equal to the other despite them having the same engine specification.

For these reasons I rule out the use of the tuning box in favour of a re-map. But I also am not in favour of a generic map, which is the reason why we write our own maps individually to each car.

@ yzfrj - Increasing the richness is not what mapping is about in petrol applications whether n/a or forced. Mapping is a combination of fueling adjustments and ignition timing. And on modern turbos the boost pressure regulation. In many instances in the higher rpm range the manufacturers overfuel dramatically to cool down the engine, which will make you loose power. This often can be set to a slightly weaker mixture without adverse effects.

In turbo Diesel applications it is much more than increasing the fuel rail pressure, where some of the Siemens ECUs make an exception, because existent software (supplied by the code crackers) does not allow more to be done the increasing fuel rail pressure, which affects some of the 1.3 M-jet engines from the Fiat group.

I just saw what you occupation is in your profile page. So I believe ya.. :D

You are doing better than my wife.lol: (says the man who doesn't want to discuss women on the forum)

Unfortunately re-mapping is a pain. One problem the mappers and the code crackers have is that ECUs change all the time to make it difficult to impossible to change the maps. And some of the ECUs are very smart.