D40 2.5 vs D22 2.5

[Dunkly]

I own a D22 2.5 and today I drove a D40 2.5 at work, even to my car is chipped the D40 still feels that little bit quicker, so I wanna know is there alot of work involved to change the D22 2.5 into the D40 version? Is it just a new computer? Or new fuel pump or heads? Where's all the extra power come from?

 

[Raczy]

There is a totally different turbo setup, basically the turbo on the d40 is controlled electronically and provides more efficiant and boost earlier on through the rev range.

EGR mod, Chip, Exhaust, boost and good tune should see the same power.
The autos in the D40 also make it drive quicker.

 

[gazza414]

I drove the d40 STX and the difference is like day and night--plus the d40 is a step change

 

[mitch92]

different turbo, head and computer. basically, to do it would probably be cheaper to buy a d40 if it is what you want.

 

[austingtir]

^^ Not entirely true the limiting factor in the d22 is the turbo and computer. The head intake and the rest of it doesnt make a huge difference. Nissan fitted a super tiny turbo which even if you add boost and fuel it doesnt make a huge difference the turbo is just to small for anything more. Nissan did this on purpose to limit the d22's as obviously you cant have them performing close to a d40.

I fitted a tf035hm 13t to my direct injection 2.5 navara with a no limit chip to suit a zd30 divorced dump into 3" exhaust and it works pretty well. Infact i think i could go to a td04 15t and that might be better still as im still on the verge of running hot egt's with the 13t turbo.

I have had the 13t upto 1.3 bar and the thing moves along very well for the weight of the truck. I have a water injection kit im still fiddling with and then i can probably make the higher boost setting a bit more permanent.

 

[mitch92]

I will happily admit i know nothing about boost pressures etc. and intercooling and the likes, nor to be honest care. I am considering a new exhaust, but have my reasons for this.

The three things i said are what all the differences are from my own research. I believe the 126kw d40 had the variable blade turbo and obviously the computer to match, and the 140kw version had the heads as well.

What can be done to the 2.5 d22 to get up there in power, i don't know (besides chip of course, which still isn't as high). I personally have no interest in making mine a speed machine, hence why i don't have interest in learning of boost and crap.

Cheers
Mitch

 

[Dunkly]

It's not about speed and power, it's about torque. Something you can never have too much of

 

[andyrobertson]

As well as the engine differences, the weight difference also probably makes the D40 quicker, I think they come in about 2200kg where as my D22 tops the scales at a little under 2800kg.

 

[gazza414]

As well as the engine differences, the weight difference also probably makes the D40 quicker, I think they come in about 2200kg where as my D22 tops the scales at a little under 2800kg.

You might be best to look at those numbers again.

 

[gazza414]

^^ Not entirely true the limiting factor in the d22 is the turbo and computer. The head intake and the rest of it doesnt make a huge difference. Nissan fitted a super tiny turbo which even if you add boost and fuel it doesnt make a huge difference the turbo is just to small for anything more. Nissan did this on purpose to limit the d22's as obviously you cant have them performing close to a d40.

I fitted a tf035hm 13t to my direct injection 2.5 navara with a no limit chip to suit a zd30 divorced dump into 3" exhaust and it works pretty well. Infact i think i could go to a td04 15t and that might be better still as im still on the verge of running hot egt's with the 13t turbo.

I have had the 13t upto 1.3 bar and the thing moves along very well for the weight of the truck. I have a water injection kit im still fiddling with and then i can probably make the higher boost setting a bit more permanent.

Interesting post...have you ventured down this path anymore that you can share ? with your findings ?

 

[Krankin]

Yep.....some enlighting posts and figures......thank god for the navara forum.

 

[Old.Tony]

I think there is some truth in the turbo observation. The D22s pack about what, 8-9psi standard boost? The D40s pull 19psi stock. You could probably crank the D22 out to 14-15psi but you can crank the D40 out to about 26psi and BlueNavara runs his at 36psi although I suspect his turbo isn't stock.

Different heads DO make a difference - the exact amount could be determined on a dyno with oodles of money and time and I have neither! What I do know is that the 2009 D40 (like mine) develops 126kW. The 2010 D40 STX (not the Thai ST) develops 140kW and the differences are MOSTLY in the head and ECU programming. They did change the actuator mechanism on the turbos but I believe the turbos themselves are still the same.

The intercoolers for the 2009/2010 STX are the same, but I'm not sure if they've done anything with the injectors (getting part numbers for the injectors for the two models from Nissan would help). If they raised the fuel rail pressure while making the injector aperture smaller, you'd get the same amount of fuel in but with the higher input pressure it would atomise better, thus mix and then burn better, providing yet another boost of power. Let's see if Fatboy can give us part numbers for the injectors - that'll answer that.

And the D40 injectors are BOUND to be different to the D22s, with similar variations in fuel pressure etc.

 

[Krankin]

after all that....chip the '22 and you can get great power/torque results....
yes the '22 turbo is smaller but it has more in reserve...as in its not at it limit...and furthermore, it uses ball bearings for the shaft bearing..thats a PLUS for me, and I'm talking about the 2.5CRTD.