Tuning a diesel a bit disappointing

[F4Phantom]

All this time I thought when I get some spare $ together I will take it down and get the diesel tuned. I have read here and else where you can tune a diesel pump to get more power and better economy. I dont know how they are tuned but I figure there is much more to it than just a fuel screw. I would have thought in and out air could be adjusted and fuel could be put in at a different time, perhaps a little more along with the turbo putting out a bit more pressure all working better to make the engine 'optimised'.

So I go into a diesel tuner and he asks the problem, I say there is no problem but I would like to get the engine tuned and 'optimised'. He says he can do the injectors but I have already done them. He says he can wind up the fuel screw but that may melt pistons. He recons thats about it. I asked about an intercooler and he says they dont do much either.

So in the end there is nothing I can get done except a pump rebuild for no reason or injectors redone. All to manufactures specs but no improvements. Of course if it was common rail with elecs then there is a lot that can be done he says.

What a let down, I actually had been looking forward to doing this eventually.

any opinions?

[isuzurover]

Firstly, what engine do you have? I assume a Tdi?

Air is unregulated on a diesel, so the only thing you can do for more air is to increase the boost.

You can safely increase the fuelling, but you need to install an EGT guage first.

It sounds as if the guy you went to is not very experienced with your engine. You can get substantial gains by increasing boost and fuelling - and fitting a larger or more efficient intercooler. However - fit an EGT guage first.

[F4Phantom]

Firstly, what engine do you have? I assume a Tdi?

Air is unregulated on a diesel, so the only thing you can do for more air is to increase the boost.

You can safely increase the fuelling, but you need to install an EGT guage first.

It sounds as if the guy you went to is not very experienced with your engine. You can get substantial gains by increasing boost and fuelling - and fitting a larger or more efficient intercooler. However - fit an EGT guage first.



No I have an FD35T from a nissan. Its a nissan version of the 3.9 Isuzu. Anything which can be done to the isuzu would be able to be done to mine.

I will read into EGT guages.

[rovercare]

All this time I thought when I get some spare $ together I will take it down and get the diesel tuned. I have read here and else where you can tune a diesel pump to get more power and better economy. I dont know how they are tuned but I figure there is much more to it than just a fuel screw. I would have thought in and out air could be adjusted and fuel could be put in at a different time, perhaps a little more along with the turbo putting out a bit more pressure all working better to make the engine 'optimised'.

So I go into a diesel tuner and he asks the problem, I say there is no problem but I would like to get the engine tuned and 'optimised'. He says he can do the injectors but I have already done them. He says he can wind up the fuel screw but that may melt pistons. He recons thats about it. I asked about an intercooler and he says they dont do much either.

So in the end there is nothing I can get done except a pump rebuild for no reason or injectors redone. All to manufactures specs but no improvements. Of course if it was common rail with elecs then there is a lot that can be done he says.

What a let down, I actually had been looking forward to doing this eventually.

any opinions?

Your thinking far to much into it

Increase boost pressure, to the high end of the efficiency range of the turbo, increase fuelling till exhaust gas temps are at the high end of acceptable levels, you will not be dissappointed

You will however require a boost gauge and EGT gauge

Intercoolers don't do much?, dude is a ******:D

[rovercare]

Oh, don't be expecting much in the way of improved fuel economy;)

[waz]

I don't know where you are, but these guys did a 2 friends' 300Tdi Discos with fantastic results both in power and fuel consumption.

Diesel Care - Home Page (http://www.dieselcare.com.au/)

Waz

[isuzurover]

The FD35T runs the same (diesel kiki) injector pump as the 4BD1. So it is simply a matter of fitting an EGT and turning up the max fuel screw.

If it is built like the 4BD1T it can probably also handle a lot more boost.

[F4Phantom]

yes it is a diesel kiki pump. I have worked with the isuzu and they look very similar. I Also called nissan and they tell me the engine with oil changes on time will do around 800, 1m k's without dramas.

Even as is I went up the steep incline out of dargo and passed two LCs, a pajero, a jeep a navara, and two patrols all up the hill! So it goes ok, but I want it to be all it can be. Right now boost does not go over 5psi.

[rovercare]

yes it is a diesel kiki pump. I have worked with the isuzu and they look very similar. I Also called nissan and they tell me the engine with oil changes on time will do around 800, 1m k's without dramas.

Even as is I went up the steep incline out of dargo and passed two LCs, a pajero, a jeep a navara, and two patrols all up the hill! So it goes ok, but I want it to be all it can be. Right now boost does not go over 5psi.

5psi, well, you have plenty of room to move;)

[loanrangie]

5psi, well, you have plenty of room to move;)

**** i can fart harder than that :p.

[lardy]

**** i can fart harder than that :p.

So can I .......but i usually follow through around 7 psi:p

[klappers]

So can I .......but i usually follow through around 7 psi:p

:Rolling::Rolling::whistling:

You know that if you follow through you are out??

[Bigbjorn]

:Rolling::Rolling::whistling:

You know that if you follow through you are out??

There is an audio CD titled "The World Farting Championships" done in the hushed tones used by the commentator on "Pot Black".

According to this, wet farts are instant disqualification.

For those interested in competition, the reigning world champion was reputed to train on a diet of green cabbage and mushy peas.

[F4Phantom]

just though I would give a quick update. I put in a boost controller today and as I paid a lot more attention to what was going on I realised the engine was running in absolute minimum boost before the controller. The needle was barely getting off 0psi and moved 2 - 5 under max load. So I now have it going up to 8psi under max load which I think is still fairly conservative. the big change though? Acceleration. It really has transformed the drive. It was as good as mentioned in my earlier post up hills, but now its is quite quick. I also looked at pyrometers which are about $300 for a basic model. I will get one as well and then an intercooler.

[Benny_IIA]

So can I .......but i usually follow through around 7 psi:p


Waste gate opens :angel:

[steveG]

just though I would give a quick update. I put in a boost controller today and as I paid a lot more attention to what was going on I realised the engine was running in absolute minimum boost before the controller. The needle was barely getting off 0psi and moved 2 - 5 under max load. So I now have it going up to 8psi under max load which I think is still fairly conservative. the big change though? Acceleration. It really has transformed the drive. It was as good as mentioned in my earlier post up hills, but now its is quite quick. I also looked at pyrometers which are about $300 for a basic model. I will get one as well and then an intercooler.

You can get a pyro/EGT gauge for a lot less than $300.
Have a look at the Auberins ones I used for my Disco http://www.aulro.com/afvb/projects-tutorials/85153-d1-300tdi-egt-gauge.html

Steve

[F4Phantom]

You can get a pyro/EGT gauge for a lot less than $300.
Have a look at the Auberins ones I used for my Disco http://www.aulro.com/afvb/projects-tutorials/85153-d1-300tdi-egt-gauge.html

Steve

cheaper by a long shot, thanks for the tip. good thread

[Bush65]

just though I would give a quick update. I put in a boost controller today and as I paid a lot more attention to what was going on I realised the engine was running in absolute minimum boost before the controller. The needle was barely getting off 0psi and moved 2 - 5 under max load. So I now have it going up to 8psi under max load which I think is still fairly conservative. the big change though? Acceleration. It really has transformed the drive. It was as good as mentioned in my earlier post up hills, but now its is quite quick. I also looked at pyrometers which are about $300 for a basic model. I will get one as well and then an intercooler.
Unless you are going to up the boost pressure a good bit more (I would) then you will most likely not see a good improvement in performance for the $$$ by fitting an intercooler (unless you get a good deal).

[F4Phantom]

Unless you are going to up the boost pressure a good bit more (I would) then you will most likely not see a good improvement in performance for the $$$ by fitting an intercooler (unless you get a good deal).

Longevity is an important issue for me and I dont want to get more performance and then have to rebuild the engine.

I do however want to optimise the engine to get good power.

I think I will fit an intercooler to make me feel better.

BTW under proper conditions with a pyro what would you go to in psi and still feel comfortable?

[Blknight.aus]

install a pyro and a boost gauge.

then tweak it as hard as you like.

so long as you dont over boost too much or push the pyro too hard your fuel economy need not change. Turbo diesels only burn as much fuel as they need to to make the power you ask of them

you can get a stock TDI300 out to about the same power output as a stock base model td5 if you only ask it to make tdi 300 power you get tdi300 economy, you ask it to make td5 power and you get v8 economy.

[F4Phantom]

install a pyro and a boost gauge.

then tweak it as hard as you like.

so long as you dont over boost too much or push the pyro too hard your fuel economy need not change. Turbo diesels only burn as much fuel as they need to to make the power you ask of them

you can get a stock TDI300 out to about the same power output as a stock base model td5 if you only ask it to make tdi 300 power you get tdi300 economy, you ask it to make td5 power and you get v8 economy.

thanks, I do have a boost guage so pyro is next on the list.

[Bigbjorn]

thanks, I do have a boost guage so pyro is next on the list.

Isspro make a very nice combined boost gauge and pyrometer. You may even find one at a truck wreckers. Common fitment to US origin heavy trucks, KW, Western Star, Mack etc.

[Bush65]

Longevity is an important issue for me and I dont want to get more performance and then have to rebuild the engine.

I do however want to optimise the engine to get good power.

I think I will fit an intercooler to make me feel better.

BTW under proper conditions with a pyro what would you go to in psi and still feel comfortable?
I don't know about your Nissan engine, but you compared it to an Isuzu 4BD1 - that would seem a reasonable comparison because AFAIK they are both truck engines so built for similar duty.

EGT is a comparative measure of how much heat the engine is producing, it increases as the governor on the injection pump adds more fuel to maintain engine rpm with increased load or when you ask it to go faster. At or near full load the air/fuel ratio decreases and egt increases rapidly.

To keep EGT in control at high loads, more air is required - turbos are a very good way to increase the air flow. Increasing boost pressure will, so long as the compressor is operating with reasonable efficiency, make your engine run cooler and more importantly will reduce the EGT. If boost pressure is greater than say 10psi, then an intercooler will start to be beneficial - above say 15 psi it is highly recommended.

You have to keep in mind what Blknight.aus said above - you will not be running high boost or EGT all of the time. Off road in lower gears, your boost will be low and at low speeds on/off road your intercooler will be less effective.

With low boost pressure like you have, the intercooler might even result in a loss of performance because it will cause pressure drop and the poor cooling benefit may not compensate enough.

[F4Phantom]

I don't know about your Nissan engine, but you compared it to an Isuzu 4BD1 - that would seem a reasonable comparison because AFAIK they are both truck engines so built for similar duty.

EGT is a comparative measure of how much heat the engine is producing, it increases as the governor on the injection pump adds more fuel to maintain engine rpm with increased load or when you ask it to go faster. At or near full load the air/fuel ratio decreases and egt increases rapidly.

To keep EGT in control at high loads, more air is required - turbos are a very good way to increase the air flow. Increasing boost pressure will, so long as the compressor is operating with reasonable efficiency, make your engine run cooler and more importantly will reduce the EGT. If boost pressure is greater than say 10psi, then an intercooler will start to be beneficial - above say 15 psi it is highly recommended.

You have to keep in mind what Blknight.aus said above - you will not be running high boost or EGT all of the time. Off road in lower gears, your boost will be low and at low speeds on/off road your intercooler will be less effective.

With low boost pressure like you have, the intercooler might even result in a loss of performance because it will cause pressure drop and the poor cooling benefit may not compensate enough.

thanks mate, another very informative post. Yes I am not trying to hang off the coat tails of the much loved (around here) isuzu 3.9 but as far as I know most jap and american companies made a roughly 4 cylinder 4L TD direct injection engine. Cummins also do a good one. LR could have used any one of these and mine is no different, its a full mech set up with a kiki pump (I think the isuzu uses a kiki as well) and direct injection. They are all great engines because parts are cheap, they are easy to work on, loads of torque, and can have good power gains. Also very efficient, I average 9.8L around town.

These engines are built for carting around more than the weight of a RR. BUT and this is why they dont get used on cars, they are very loud and rattly. My mates 4.2 GQ diesel feels silky smooth compared with mine. That is the only advantage of the 6 over the 4, smoothness. His cant match mine for torque or economy. Mine also it a bit chewy on gear boxes I think because of the rattling.

The latest incarnation of these engines now have intercoolers and are common rail. I would love to get a P38A RR and put in a brand new mitsu or whatever 4.0L CRD hooked to an auto trans would be amazing. Heaps of power and economy, they may also be smoother than my clunker. Makes more sense than a tdi conversion to me.