Turbo boost

[craig Member Find all posts View Profile Close craig]

Has any body thought about increasing the boost coming out of the turbo?
I was speaking to a guy at the camping and 4x4 show and he had done it, he has increased it to about 13psi, he also had a power chip too and he reckons it did make some improvement

[Stitch Junior Member Find all posts View Profile Close Stitch]

From what I understand is that running higher boost - shortens the engines life apparently....

[jeff s Avid PP Poster! Find all posts View Profile Close jeff s]

Hi Craig.

I have read that even with just the chip the (old type) diesel will come up close to the new D4D?


Jeff.

[waifamily Junior Member Find all posts View Profile Close waifamily]

with the dtronic for the 96kw engine it only takes it to 118kw. The new D4D is 127kw standard commonrail. to drive both the D4D still pulls after 100kph right up to 175kph while the 96kw engine with the chip struggles after 130kph.

[DaveO Junior Member Find all posts View Profile Close DaveO]

From what I understand is that running higher boost - shortens the engines life apparently....

Comparitively (ie driving both the same) would make little difference if the chip and exhaust are engineered correctly. You would still be extracting the similar power from the same size engine.

Higher boost will result in lower EGT under load. This is a good thing. You can get accurate readings with a digital EGT gauge like this pyrometer, and it even has provision for an audible alarm incase you are too busy watching were you are driving

[DaveO Junior Member Find all posts View Profile Close DaveO]

with the dtronic for the 96kw engine it only takes it to 118kw. The new D4D is 127kw standard commonrail. to drive both the D4D still pulls after 100kph right up to 175kph while the 96kw engine with the chip struggles after 130kph.

Thats mainly because the 1KZ-TE power tends to go flat and the turbo becomes less efficient while the VGT on the 1KD engine maintains its efficiency.

A good exhaust system and a diesel tuning module will make a difference across the whole rev range, and its cheaper than a trade up by about $22K, and make with a few simple mods will provide very similar power.

[Guest Close Guest]

From what I have been told the engine management starts to cause issues if you go over 7-8 pounds of boost?
This is from a Toyota dealer (rural) that modifies heaps of them for the local guys).

[Drew Advanced Member Find all posts View Profile Close Drew]

The other factors contributing to the D4-D's power advantage are the twin camshafts with VVT, 4 valves per cylinder, and electronic throttle. I reckon you'd need some miraculous engineering to bring the old girl up the the performance of the technology packed D4-D.

Drew.

[craig Member Find all posts View Profile Close craig]

I am not trying to chase the same power as the D4-D, I am just trying to get some more power out of the 1KZ engine.
From what I have found out I could boost the turbo for about $300 or but a 2 1/2 exhaust on for the around the same price.
These are cheaper options as I could always change the size of my intercooler and go to a liquid cooled intercooler also

[Guest Close Guest]

You can up the boost on the factory turbo by fitting a (Appox) 4mm spacer on the wastegate mount. This is how the guy I mentioned above does it.
You will need to remove a few bits to get to it, but it is easily done.

[DaveO Junior Member Find all posts View Profile Close DaveO]

Improving the exhaust system would be my first improvement (and was the first performance improvement). This is bad for the factory cast dump housing. That match box wont go in any further!

Bumping the boost will cause the turbo to fight the back pressure, and unduly heat the incoming charge further. This adds to higher EGT and engine tempertures. Starting with the exhaust will also improve efficiency. High EGT's will lead to turbo damage.

Add a diesel tuning module and up the boost after the exhaust system. Upping the boost alone will only provide minor power increases (comparitively) by itself.

Here is a reference to some diesel engine basics and diesel performance topics that I used. Its not about how a diesel works, but about why and improving performance.

[craig Member Find all posts View Profile Close craig]

DaveO
What size exhaust have you got fitted to your prado, and where did you get it from?

[DaveO Junior Member Find all posts View Profile Close DaveO]

From what I have been told the engine management starts to cause issues if you go over 7-8 pounds of boost?
This is from a Toyota dealer (rural) that modifies heaps of them for the local guys).

Guys,
not directed at anybody, but there is some mis-information here - perhaps the dealer does not want anybody to actually adj the boost??

The refefence to factory boost pressures is not quite correct, because;
a. the factory spec is higher than this (7.4->9.7PSI)
b. I've measured mine (with different meters) at higher boost
c. with the wastegate line clamped boost will go over 12PSI easily around 2800RPM BUT IAT takes off causing higher EGT - Thats one reason why its not a good idea with an improved exhaust system.

This is because the turbo is trying to suck air in thru the restrictions of the snorkel, air filter, ducting AND force it thru the intercooler and ducting ( even throttle plate on later models). That means the differential is closer to 14PSI referenced to snorkel intake and back of valve head - all causing the tubo to work a lot harder than first might be considered, heating the induction air even further.

For the spec check the TC section of the factory manual (about TC-3)

Perhaps the dealer isnt quite sure what they are doing - they do have the factory manual dont they???. Sorry to burst your bubble, but the 1KZ-TE will produce over 40% more power with sensible mods - other than boost adjustments.

BUT this is only from experience in having done that.

PS: I dont care if you agree or disagree - I have the extra KW under foot :-) PERHAPS you have??

[DaveO Junior Member Find all posts View Profile Close DaveO]

The other factors contributing to the D4-D's power advantage are the twin camshafts with VVT, 4 valves per cylinder, and electronic throttle. I reckon you'd need some miraculous engineering to bring the old girl up the the performance of the technology packed D4-D.

Drew.

The bigest effective difference is the VGT and extra valve area. This makes it easier to get max boost at a wide range of engine revs with max efficiency. This reduces the IAT for cooler engine operation and EGT at the same power levels.

1KZ-TE has electronic throttle on Australian delivered Prado too. AT WOT the difference is minimum. The throttle is primarily to reduce emissions, not control the engine as on a petrol engine.

Anybody remember driving a torana 6 with 35/75 cam and triple SU's - around 250HP but not street drivable in traffic - no VVT in those days.
First 1KD engines did not have VVT technology - its a recent enhancement.
By itself it wont create more power - it will create more power across a wider rev range - making for a much more drivable engine.

Still, the 1KD engine is a nicer starting point, but it could be a +$30K hit to the wallet :cry:

[Guest Close Guest]

Info came from the dealer that had been modifying them, and was also quite happy to modify the particular diesel prado we were discussing (One of my mates that is a S L U G ! ).
All info was passed in general conversation over the course of a weekend at an event attended by us all.
As he is a Toyota dealer I am quite sure he knows what he is doing. He has done dozens of them.
Mind you there was umm numerous amber fluids consumed that particular weekend too ops: .
So much infact I just gave him a call to chat about it! Your right, boost as shown on page 13-2 of the manual (Yes he has one ) :wink: He stated boost is between 7.4-9.7 Psi. He ups them to around 9-14psi.
The conversation apparently went that he has seen some as low as 3, and average is about 7ish. (Thats where I went wrong!)

Now boost can be dependent on weather conditions, air density etc.
For instance the Rally car I team with was pulling up to 27 psi the other day at a Rally in Mt Gambier (Very moist cold air). More boost than we have ever seen and amazing power.
Went great until the last stage, Ate the exhaust turbine, spun it off and shat it down the exhaust :cry:
3 other vehicles that normally run similar boost (15-17psi) were doing the same, all overboosting and all destroyed the turbos.........



Has anyone else noticed how much of a bitch it is to find boost in the manual!
Did find a bit that states: NEVER apply more than 21.3 PSI to the actuator (Wastegate). So would be intersting to see these boosted up to around 19 Psi!
The 1KD is apparently running about 14.5 Psi max boost stock.

Hmmm, You got extra Kw, Yeah I can play too :lol: I got one car sitting in the carport running about 390kw currently.. Does good skids...