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Diesel Chips / Diesel Engine Tuning: How its done

147K views 190 replies 62 participants last post by  bansalrehana 
#1 · (Edited)
#8 · (Edited)
Yes mate, and one additional factor.
When the fuel is injected, which is the biggest advantage to have in tuning any car.

Boost is necessary. You must increase the oxygen content to burn more fuel safely.
If the engine could have burnt more fuel safely and maintain emissions, the OEM Manufacturer would have loved the chance to be class leader in power/torque.
IPW is a handy thing as the ecu wont register and fault codes or go into limp mode with this adjustment.
Fuel pressure is handy - better atomisation of the fuel helps to burn it more effectively.
Is the chip your using made by DTE in germany?

Hi DieselTuner and others,

I have been trying to work out for a while how these systems work. I have a question of two that you may be able to add to your list of things to answer.

You mentions two types of chips: Pressure Increaser and Injector Extender.

I understand the mechanism behind the Pressure Increaser and how it increases the rail pressure (as explained in your first post).

How does the Injector Extender type chip actually extend the injector pulse length? Is the Chip wired in between the ECU injector output and the injector? this sounds a bit crude and I assume this is not how it is done.

Also many of the chips seem to only connect to the engine via a 3-wire CAN-BUS interface. Is this how the Injector Extender works? What exactly is the chip talking to over CAN-BUS and how does it adjust the performance? As far as I can tell the ECU doesn't have a CAN-BUS connection (I am talking about ZD30 CRD specifically here).

Can the Injector Extender chip move the start of the injector pulse forward in time or is it only extending the end of the injector pulse.

I have been talking to a particular chip manufacturer/seller and I got the impression that they were developing a chip that wired into the injectors directly, replacing the existing injector wires. Does this sound plausible and can you provide any insight into how this would work.

Also it would be useful if we could compile a list of the major chip brands and the type of control they use.


Thanks

Phil
I will put more detailed info in my post regarding exactly how the injector extender works.
I wanted to keep it simple and as brief as possible (i know its already very big) because if it turns out to be a novel, few people will take the time to read it.

As for your question regarding canbus. I have had a large number of customers contact me this year regarding the exact question you have asked.

I have seen claims from one vendor that their chip controls boost/timing/injectors and fuel pressure through canbus control - even though the chip used is just a re badged DTE chip that clearly is only a fuel pressure chip. It is absolute garbage. Look at where the chip in question plugs into. The fuel pressure sensor. That is the only sensor it is modifying.

Unichip can and does use canbus control on some vehicles for things like road speed limiter removal, and spill valve control on certain diesels such as holden rodeo.
Any canbus system is 2 wires anyway. Can-hi and can-low, So if you are to modify anything on the canbus system you need 4 wires Can-hi in/out can-low in/out.
 
#13 ·
As far as I know DTE are the only company to offer injector extend + fuel pressure increase in the one chip and they are very cheap also.
They also have boost control as an option and rpm pickup from crank angle sensor on some chips.

Unichip also does both, but we use an external driver for the injector control. So you could say its an additional chip I guess.
 
#14 · (Edited)
First, thanks for the excellent and thorough explanations. Really interesting and I'm sure most people will read all of it.

A bit more that could be added to the intercoolers section is that more boost does not neccesarily mean more air if it is very hot. air density is what we want. People get very fixated on a boost pressure figure while forgetting about IAT which can be several hundred degrees above ambient. Until you calculate the temperature of air compressed to 1/3rd its volume at 30 psi you will never believe how hot it can be. You can actually melt the paint off your hot side piping.

Exhaust sizing: is that why two stroke motorbike exhausts are that distinctive shape? I assume the optimum large intenstine shape would be dependent on egt, rpm, displacement, boost, and probably some acoustic effects too.

If people DO start making genuine canbus chips they would be potentially very dangerous. I cannot see a reputable company taking this risk, however remote. I would go as far as saying I dont think we will ever see a genuine canbus chip. If it is intercepting the canbus signals then it has to be a store-and-forward type operation, it will read everything and decide if it has to change it. So it will have a measurable delay which means the airbag and seatbelt pretentioner timing will be off.

WHat about particulate filters on modern diesels, how much of a performance cost are they? I've seen some enormous units under medium sized trucks and there just isnt space in passenger cars for an appropriately scaled version for 3 litre engines. The VW V12 diesel Le mans car I saw pictures of had TWO particulate filters bigger than a 30 block of beer.

The comments on EGT Vs coolant temp are interesting I think I can see what youre getting at. Surely oil temperature would be even better than coolant to monitor since its being sprayed all over the bottom of the pistons to cool them and there isn't a thermostat in the circuit (usually).
 
#15 ·
I did mention air temp and pressure at the start but you are right, I will put some more detailed info under the inertcooler subheading mate.

The two stroke exhaust actually runs on a different but similar design.
The exhaust gas is allowed to expand rapidly which will create a pressure wave, helping to draw more exhaust out of the engine.
Similar in principal to good intake manifold tuning and achieving positive pressure at the valves without turbo/supercharging.
Dan's Motorcycle "Two Stroke Motorcycle Exhaust Pipes" - Good read up with a diagram of how it works.

There is a chip that does canbus already, but as I said its never used for engine control anyway.
The things I control with canbus is road speed removal mainly, and on pre CR engines some of them have the AFM through the canbus which allows easy mixture changes while not having to adjust the spill valve directly.
Generally speaking, there is no delay in signal when modifying it if the chip runs a good processor.

DPF's are a tricky one. They are restrictive, but highly depend on the size of them.
On the latest v6 navara's we have achieved about 2psi less exhaust backpressure by removing it. That it is considerable amount of pressure released, considerint the whole system only had just over 3psi standard.

Oil temp would be another good option for controlling fueling. It doesnt react as fast though as its specific heat capacity is much lower than the cooling system.
So for a given temperature, it does not rise as high or fast.
 
#17 ·
Im so sorry people. I have had to remove all info from one of the suppliers mentioned due to threats/warning's that I was misleading with what I posted.

Instead of just providing me with the info I needed to correct my statement as asked (if it was actually untrue) I was asked to remove all mention of their company, all information of their product and never speak of them again in future posts.

I apologise to the general reader population for this mishap and potential knowledge of the product they will never receive due to the company's strict policy on not letting anybody know what they actually do with their products or how they achieve it.
 
#19 ·
Yeah unichip is still there mate, as are all others apart from one.
I think each got a fair and equal mention to be honest, none more so than any other.

I have taken evidence, facts, data and general information of 4 chip reseller/manufacturers out of all that I have put up in there that needed changes to their info sheet.
I have made those changes without question as they provided more than enough information to show in which area I was wrong, and exactly HOW they do it so I could provide factual information.

Only 1 remains that has shown no evidence no facts, no data and zero general info on what I should change or how I should change it apart from saying 'Dont talk about our products'.
 
#20 ·
Great read.
Some of it 'gobbly ****' to my non technical brain - but simple enough to gain enough of an insight of what makes what tick when I turn the key and start applying right foot pressure.

Are there any of the chips that you would run in your CRD? Of those which is the 1 you would prefer?

Cheers
Guido
 
#21 ·
Sorry for the quick semi hijack

My 3.0 Gu 4 2005 model just crapped itself. Short story:

Rebuilt engine, new injectors,glow plugs and other bits, having injector pump assessed.

I had a safari dtronic chip in he car when. Bought it.

Question: do I remove the dtronic chip prior to starting and running in the engine and then reinstall it, or do I leave it installed for he whole process?
 
#23 ·
It died well - with it's boots on.

Actually it was driving fine - went through a round about - shuddered. Blew white smoke - drove on a bit then shuddered to a halt.

When my mate (mechanic) and i pulled the glow plugs out the 3&4 th had melted to stumps.

The 3rd and 4th cylinders are a mess. Easier to swap for a remanufactured engine than pull mine apart.

You are only supposed to get 120K Km from a diesel aren't you?:mad:

oh well - it is only money - lots of money.
 
#24 ·
Noting the general unreliability of the Dtronic units, I wouldn't be surprised if it might have had something to do with the failure. I had a Dtronic for around seven years, but when I got the first unit it didn't do a thing. I went back to ARB and they had shelf loads that were DoA and I had to ferret through something like five new units before I found one that made a material difference. The DPChip, by comparison, provided a significant improvement over the Dtronic. I believe that ARB eventually they stopped selling them, because they were so problematic.

Cheers

Ray
 
#25 ·
It is actually the harness that were used that were the problem.
100% of all those chips you saw would have been in perfect working order.

Until Dastek took control of their own harness manufacturing company, none of the looms that used to be used were reliable (something like 15% fail rate)

I still wire in Dtronic's that have problematic looms to this day. Soon as its taken out of the picture, no more problems.

Sounds like the glow plugs continue to cause issues for ZD30 owners.
 
#27 ·
Good to see an unbiased explanation of how all the chips work and what they do exactly to benefit. but the question I have and I'm sure many people are asking them selves is which one do I buy? If the cost of the chip is not an issue and power/torque/realiabilty is what I want, I was always under the impression that you should try go with the company closest to you, not for the sake of service but more so because the chips are tuned to the climate in which they are in. For example I am about to purchase a chip and I have a manufacturer that has developed their chip within the town I live in. So to me it was the obvious choice. I will certainly be asking them the above mentioned questions regarding before and after results of the physical data. But I'm wondering weather a different chip may be the one for me. As I said cost is not an issue (within reason) If the results of one chip greatly better then results of another for the sake of a few hundred dollars more then I will pay the extra money. At the end of the day everyone wants the best out of the vehicles and nobody likes breakin down on the side of the road. Or worse. Hundreds of klms from any help.
Another quick question, one such manufacture promises boost increases for the di 3.0L patrols from 16 psi to 22psi. Yet the zd30 ddti engine has a vnt turbo an you said you should not increase more then 1-2 psi. So it gets me wondering weather that I should stay clear of them.
Sorry for the long post but tuning is something that has always interested me but never had it explained like you have done. So thanks alot!!! Been a real help.
 
#29 ·
The 3.0L DI runs about 14psi standard. Taking this up to 17-18psi is not a worry, but anything past 20 and I would begin to question the longevity of the turbo.

As you have said though, ask the questions, shop around and go with who you are most comfortable with.
 
#30 ·
If you were going to buy a chip would it be worthwhile having the car (in this case a patrol CRD) dyno tuned before the chip went in or after, or both?
It seems like just having the car dyno tuned without the installation of a chip can be quite beneficial because factory tunes are not geared for power/torque. So would having a well tuned engine as a base be better for chipping?
 
#31 ·
There is no way to tune the engine without installing an aftermarket chip.
Only by reflashing, but that is very rarely done anyhow on Nissan diesels.

Installing just a pressure chip allows you to adjust fuel pressure only.
Injector extension allows you to adjust close of injector point only.
So neither of them are really helping with engine efficiency, they are just pumping in more fuel.

A chip that does boost control, very beneficial, more air helps the fuel burn.
A chip that controls start of injection point and all the other stuff is obviously going to get you alot more torque and economy than the more basic chips.

So really to call it 'Tuning the engine' You have to have access to alot more than just one aspect (fuel pressure)
You need access to how much fuel, when its injected, how much air, and compensation based off other sensors.
 
#32 ·
There is no way to tune the engine without installing an aftermarket chip.
Only by reflashing, but that is very rarely done anyhow on Nissan diesels.

Installing just a pressure chip allows you to adjust fuel pressure only.
Injector extension allows you to adjust close of injector point only.
So neither of them are really helping with engine efficiency, they are just pumping in more fuel.

A chip that does boost control, very beneficial, more air helps the fuel burn.
A chip that controls start of injection point and all the other stuff is obviously going to get you alot more torque and economy than the more basic chips.

So really to call it 'Tuning the engine' You have to have access to alot more than just one aspect (fuel pressure)
You need access to how much fuel, when its injected, how much air, and compensation based off other sensors.
Gday mate,

With all this in mind, would you recommend installing a unichip?
If so where are they sold?
 
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