bugger all bottom end

i've found with my d40 manual that when you take off from a standing start on a bit of a hill that you've gotta give it a boot full of acccelerater for it to take off other wise she just stalls.it seems like you have to have to get the turbo to create boost just to take off other than that it drives brilliantly.
is this normal cause it frustrates the shit out of me, it just seems a bit strange.

Hey mate i have noticed the exact same thing, i am unsure what the go is maybe because of the smaller engine, i am also researching to find the answer, so if i get any information on it i will let you know. My dad has got the 3ltD in his patrol and you can take off easy in 2nd going up a slight hill sp unsure why the 2.5 struggles.

patrol is a bit different, especially the common rail version. it has a lot more grunt down low than the 3lt navara motor has thats for sure. compared to the 2.5, the patrol 3.0 is bigger and has higher compression.

the 2.5 is a small capacity, low compression, high boost motor ( i still get conflicting reports on exact what the max boost is). if you haven't got the size you need to up the boost to be able to get the same air flow as a bigger motor.
down side of that is being able to get the boost up quick enough especially at take off where you have next to no exhaust flow to spin the turbo.

The GU spec ZD30 run's the same compression ratio as the D22 ZD30. The GU runs a Variable vane turbo so boost comes on sooner.

Ever heard the saying nothing beats Cubic Inches. Its true, the Americans have have it down pat for years. Cubic Inches give you more torque down low, the bigger CI motors last longer to. The dont work really hard.

A small motor off boost will always be a pig off boost, a chip will help but is no match for ci.

Thats just the way they are, a QD32, TD27 kills my ZD30 for down low torque. The old indirect injection diesels have compression ratio's of 22 to 1 where as direct injection motor's run 16 to 1 compression ratio.

Dave.

18:1 for ZD30, 15:1 for D40 YD25. direct injection don't need the higher compression as they don't loose so much heat through the head. even atmo direct injection is 18:1.
IDI needs 20-22:1 to make up for all the heat it loses.

also don't forget gearing. a lot of the older vehicle where a lot lower geared and that can make up for lack of power. very handy for take off and slow speed manoeuvring. just a bitch doing all 5 gears to 60km/h !
my 2.8 atmo toyota will give the navara a good contest up hills simply because you can get the exact right gear for the job and navara you can't. downside of course is the toyota does 3200rpm @ 100km/h which is not good for economy.

Same deal Blueboy. No get up and go

blue boy said:

i've found with my d40 manual that when you take off from a standing start on a bit of a hill that you've gotta give it a boot full of acccelerater for it to take off other wise she just stalls.it seems like you have to have to get the turbo to create boost just to take off other than that it drives brilliantly.
is this normal cause it frustrates the shit out of me, it just seems a bit strange.

Click to expand...

I could'nt have put it better myself. Frustrates the shit out of me too. Have a look at chipping and also have a look at the threads discussing the EGR plumbing

tweak'e said:

just a bitch doing all 5 gears to 60km/h !

Click to expand...

+1

Wish I had enough torque to skip gears comfortably.

Maybe it has nothin to do with the engine size but infact the gearing,
ie: 1st being too tall.

Try that same hill in low range and see what you think then.

Don't boot it. Ease on the accelerator slowly. Let the thing build boost and feed in diesel until the thing has a couple of revs on board.

I'm suspecting there is a significant difference in regards the deadzone below 1500rpm issue between 4 x 2 and 4 x 4 or perhaps its a recent de-tune, new emmisions regs or something - I have a 2010 plated 4 x 2 and it is a real problem. Its fine to recommend easing it up, and easing it up is nice to do most of the time but when you need to move in a hurry, maybe as a result say of a misjudgement whilst turning right across traffic, waiting for that 2 seconds ( feels like 2 millenia ) for the engine to go is infuriating and downright dangerous. Why would anybody in their right mind design a vehicle to behave like that. This thing is supposed to be able to carry a tonne and tow two. Snort. Just have to get it rolling first. I would'nt be so pissed if I thought I could buy a definate fix for it but I'm yet to see it really nailed. AND it is not just turbo lag. There is a world of difference re throttle response between when the car is sitting still and when it is rolling above 20 or 30 kph in neutral. Its a deliberate dicking with the ecu. Cant even get it re-mapped ( not in Adelaide anyway ) and even if I could it would no doubt kill the warranty - 5 years and 10 months to go. Pity about all this as the rest of the bus is great

I suspect there might be some possible improvements that could be made to the ECU, particularly down low. I don't know how well it could be improved, because the variable vane turbo in these cars doesn't spool like the fixed turbochargers - but then again, the fixed turbochargers don't provide as much boost across the range as the variable ones do.

I wonder how many of you remember the 3 turbocharged motorbikes that were on the Australian market some years ago? They really emphasised how poor turbochargers could be below boost range, and made the bikes downright dangerous.

The Honda was a piece of junk, being a slug of an engine anyway (the CX500 Shadow). Its turbo couldn't help it much, the bike was still left behind by NA bikes like the Bol D'Or (which was what I was riding at the time).

The Yamaha XJ650 was a lawn mower below boost range, which if memory serves kicked in at about 5,000rpm - below this you were better off pushing it, it performed like a shopping trolley. As the boost came on it was like the powerband in a heavily optioned chook chaser - the thing would rip your arms off - okay, not quite, but it was a surprising amount of power.

The Kawasaki 750 was the best of the bunch, providing a decent bottom end and bringing in a solid amount of power as the boost was introduced but no substantial kick in the pants.

The D22 behaves like the Kawasaki. Nice low-down power with a smooth transition into boost. Towing with the D22 is probably better for the driver than it is in the D40, which kicks like a mule once boost comes in but pulls like a dead llama until then.

I would say it's a combination of turbo choice and programming. Changing either modifies the warranty (you KNEW I was going to say that, right?) but with the amount of lag at the start, some people are going to look in that direction. Question is, can the ECU actually be modified? Is the program stored on an EEPROM that can be adjusted, has anyone done this, can we get hold of it and will Nissan notice?

When I'm driving, I do as Anthony (ants_oz) suggests, and ease the vehicle up to speed, but that's easier for me because I drive the auto. Especially when I'm towing - I don't try to race around corners or "beat the traffic". I'd rather wait a few minutes or find another path than risk losing it all because someone else wants to play stupid.

I've being trying to address this problem from day one of owning mine, Chip/hardpipe/exhaust/dump pipe/ egr mod. Still the worst 4x4 I've ever driven. Sorry I test drove only the auto before buying mine in a manual. The new jeep wrangler diesel we bought has no turbo lag what so ever. Why can't the Nissan engine be the same???
The only way I can see to overcome this problem is to throw the turbo in the bin and fit a supercharger (you'll never be able to resell or trade), change the diff ratio(none available) or bite the bullet and sell.

*Or give it plenty of right foot and invest in a heavy duty clutch!

08KINGCAB said:

I've being trying to address this problem from day one of owning mine, Chip/hardpipe/exhaust/dump pipe/ egr mod. Still the worst 4x4 I've ever driven. Sorry I test drove only the auto before buying mine in a manual. The new jeep wrangler diesel we bought has no turbo lag what so ever. Why can't the Nissan engine be the same???
The only way I can see to overcome this problem is to throw the turbo in the bin and fit a supercharger (you'll never be able to resell or trade), change the diff ratio(none available) or bite the bullet and sell.

*Or give it plenty of right foot and invest in a heavy duty clutch!

Click to expand...

Bloody hell - if all that has'nt worked then I'm knackered. And you've got more torque and power than my 4x2 in the first place. Maybe ecu re-mapping is the only thing left. Mildren Performance shop here in Adelaide tell me they have had a few enquiries but cant do it ( at the moment ) and they confirmed a remap is visible. We need someone to come up with an affordable plug and play ecu that can be popped out before a service ! That dratted warranty. And yeah - the Colorado 3 ltr has no deadzone either. Pulls from nowhere.

You might find that the variable vane turbo also has an impact. The 2.5L CR TD fitted to the D22 does not suffer lag - I've driven both the manual and auto versions of the D22, and you're hard pressed to tell the difference between the turbo diesel and a normally-aspirated petrol-powered Commodore.

If the gearing isnt right,
(different people will have different complaints),
and it never will be,
because everyone has different uses for that vehicle.
NO one vehicle will suit the entire populus.
These SMALL engines arent designed for huge power at 1200 rpm.

If you want that kind of stump pulling power/torque from idle to 1500rpm, maybe you better start looking at buying a prime mover.


Alternatively fit a "rock climber" type first gear to your cogswapper cause no exh, chip, turbo etc mod will fix your problem on these vehicles.

Remember, factory vehicles are a comprimise to try and suit the majority of driving terrains..

My first gear i find ok for general everyday driving,
but its too tall for standing start uphill on the tracks (GRRR!),
and i suspect i would have the same problem if i was towing.
Now either i rev the engine to its power range when taking off,
or,
fit a new first gear that will put the engine into its power range when taking off.

If that don't work, then the load is too heavy and or the engine is too small....horses for courses!





Above all, if all else fails, do as i do,
drop in a V8,
there aint NO substitute for Cubic Inches!

Relative gear ratios

If you want that kind of stump pulling power/torque from idle to 1500rpm, maybe you better start looking at buying a prime mover.

A prime mover or a Colorado . This thing sports a 5 spd only, has a taller bottom gear than the Navara at 4.326 vs 4.692, has the same torque figures, only 16 more kw and pulls like a demon from nowhere. And, the fuel figures are better than Navara. Go figure. Can half a litre more really do all that ?

Look the bloody Navara idles up hill in second. I'm not buying the small engine that only has power cos of the turbo argument.

A 1975 KE corolla would never idle up hill in second, probably would'nt in bottom either but it would'nt have this frikken deadzone. Rate of acceleration would be nominally proportional to throttle position.

This is not turbo lag - it is a deliberate decision to starve the engine of fuel.

Whether that be emmisions, saving the clutch, fuel figures or whatever.

Worst thing is that there appears no fix for it at any price.

Looks like I'm just going to have to grit my teeth for the next 3 years till I've paid enough off the loan to quit it with out losing my shirt

But hey I might have got used to it by then or perhaps the engine will have loosened up or something - is'nt 2012 coming soon..

no its not the diff ratio either

and BTW Colorado and Navara both pull approx 2000revs at 100kph with the overdrive ratio's being pretty close so not a lot diff ratio difference either - AND - if I had done my due diligence in the first place then yes I would have bought a Colorado so dumox me. It was the mags that got me in and the fact that Navara tub has over 1500 mm of depth. My shovels are a smidgy under 1500 - still have to cut the crowbar down tho..

I have noticed too that when taking off in first you generally get a little less smoke than once you hit second and really load it up.

I am wondering if they have starved the car of fuel in first due to clutches like in europe they were doing a remap to save the clutch.

I might start looking for a first gear torque limiting switch and see what comes up. Maybe we can disconnect this.

I know they do have different maps for different gears

4.8GU said:

I am wondering if they have starved the car of fuel in first due to clutches like in europe they were doing a remap to save the clutch.

Click to expand...

I must have that tune standard!!

you might be onto something 4.8.