Is the 2011 D40ST simply a de-tuned STX engine?

[Ihaterocks]

Wondering if some one could shed some light on this for me. I know with a chip and exhaust similar figures can be achieved. However, if it is tuning, can the ecu be re-programmed to a achieve the same output?
Have tried to search forum for an answer but am struggling a little? Sorry if this has already be discussed.

 

[Old.Tony]

Welcome to the forum.

The short answer is no.

The 2011 ST is a Thai build that should put out 140kW. The 2011 STX is a Spanish build that also puts out 140kW. I've not seen anywhere that there are any power differences between the two. Certainly the chassis rails are not the same distance apart and the mounts for the bullbar are different. The ST also lacks some of the harnesses that the Spanish builds normally have (one that I've seen myself is the ambient temp sensor harness). There is also a STX-550 which is the V6 diesel.

The new (late 2012) trucks WILL be different and it's a matter of cylinders, not tuning. The new STX will be what we know right now as the STX-550, which is a 3.0L V6 turbo diesel delivering 170kW and 550Nm. The new ST will be what we currently know as the Spanish STX, with the 140kW motor. The two will have different gearboxes and final ratios - the ST will sit on 100km/h (indicated) at 2,000rpm and the STX (V6) will sit on 100km/h at 1700rpm.

I should add that the V6 diesel is markedly smoother than the 4 cylinder. It almost accelerates effortlessly, and before you realise it the 2+tonnes of steel and mortgage repayments is breaking the speed limit.

Thai production of the D40 dual cabs should cease. They may continue to produce king cabs and the RX line, plus the entire D22 series (although some D22s are being sourced from Japan at the moment).

 

[user 1102]

Pretty sure todays Herald Sun Cars Guide said a ST had 140kW & 450Nm while the RX had 126kW & 405Nm. Anyone know the differences between these motors, is it just the tuning?

 

[wade193]

I thought the ST was 127kw and the STX 140kw.

 

[Old.Tony]

My STX is 126kW/403Nm, 2009 model. The 2010/2011 ST and STX shared the 140kW motor and the 2011 STX-550 got the V6 170kW.

It does look like the RX has less power than the ST/STX but I don't know the specific difference. The 2010/2011 ST and STX have a different head, different turbo actuator and different tune to the 2009 STX (there was no ST in 2009). I've never looked closely, or enquired about, the RX variant.

 

[Dave-D40]

My STX is 126kW/403Nm, 2009 model. The 2010/2011 ST and STX shared the 140kW motor and the 2011 STX-550 got the V6 170kW.

It does look like the RX has less power than the ST/STX but I don't know the specific difference. The 2010/2011 ST and STX have a different head, different turbo actuator and different tune to the 2009 STX (there was no ST in 2009). I've never looked closely, or enquired about, the RX variant.

I think the Thai st has only ever had the 127kw motor from memory.

 

[Old.Tony]

Nissan have updated their website to the 2012 models already so it's hard to tell. The RX is the 126kW motor, ST is the 140kW and the STX is the 170kW.

I'd spoken with a few 2010/2011 ST owners and we were all under the impression it was a 140kW engine, but that could be upselling - I can't find any reviews that give me the actual info either, although I did discover that the Navara is outselling the Toyota Hilux - not something I would have thought given the fleet buyers, but maybe they were talking non-fleet purchases (they didn't say).

The major differences between the 126kW and 140kW motors is a new head design, increased fuel rail pressure (1800 bar to 2000 bar) and a changed turbocharger control unit from vacuum to electronic. A chip would fix the second one, the 3rd I wouldn't worry too much about but I won't be touching the head. If I want an upgrade of 14kW that badly I'll go the whole hog and put a 550 in the driveway after they've sorted out the heat issues!

 

[bluessv]

The 2010 ST has the 126kw engine. I know this cause I have one. The 2010 ST has the same engine that the older 2008/2009 ST-X had (as Tony points out). The 126kw engine has been in the ST up until the latest version which I believe is referred to Series 6. A brand new, latest release 2012 model, will have the ST using the 140kw engine, the ST-X using the V6 170kw engine.

 

[joe2006]

I know the answer

But not upsetting anyone

Oh bugger! bluessv beat me too it. Actually let the cat out the bag.

 

[ONLOCK]

Haha Tony's wrong

 

[JASON-D40]

my 2 week old thai built ST has the 127kw engine, same as the RX

 

[ONLOCK]

Built In 2011? Pretty sure even some of the early 2012 models have the old engine

 

[Tappet]

I wonder what would hapen if you got the ECU out of the 140KW job and pluged it into the Thai truck. I suppose even the bloody loom plugs are different.

 

[Krankin]

I wonder what would hapen if you got the ECU out of the 140KW job and pluged it into the Thai truck. I suppose even the bloody loom plugs are different.

I'd hate to imagine what that ecu would cost

 

[nathand22]

Wondering if some one could shed some light on this for me. I know with a chip and exhaust similar figures can be achieved. However, if it is tuning, can the ecu be re-programmed to a achieve the same output?
Have tried to search forum for an answer but am struggling a little? Sorry if this has already be discussed.

The STX has a different cylinder head, with parallel ports.

A different valve in the EGR which now warms up quicker.

A new variable nozzle turbo with an electric control instead of the previous hydraulic system.

They have also added some sort of bellows type joint at the turbo outlet that helps response off idle and under acceleration.

They also increased the injection pressure up to around 2000bar or roughly 30,000psi which helps the fuel atomise.

 

[Ihaterocks]

The STX has a different cylinder head, with parallel ports.

A different valve in the EGR which now warms up quicker.

A new variable nozzle turbo with an electric control instead of the previous hydraulic system.

They have also added some sort of bellows type joint at the turbo outlet that helps response off idle and under acceleration.

They also increased the injection pressure up to around 2000bar or roughly 30,000psi which helps the fuel atomise.

Looks like its going to be exhaust and chip mods in the not to distant future. It was never going to be as simply as an ecu program. Thanks all for the feedback.