what boost psi does the 3 lt turbo diesal gu wagons run stoc

[hayde]

just wondering if any ones got the 3lttd gu wagon like 04 model with a boost gauge i need to settle an argument with a mate i rekon that there lie over 18psi he thinks there like running about 4 psi i need to prove hes full of it can you guys help me

[RAY185]

They run about 300psi standard right before they blow up.

I don't know for sure what stock psi is but I think your mate is closer than you are. I reckon it would be somewhere around the 6-10psi. Did you bet your virginity?

[ISUZUROVER]

max is around 20psi apparently. Average 14-15 psi.

Standard for a modern diesel. No new diesels run low boost anymore.

[-Nemesis-]

No idea, but both guesses seem at the extreme ends of wrong. I'd guess somewhere in between.

[bogged]

http://www.patrol4x4.com/forum/

[ISUZUROVER]

My god this place is full of nuffys...

Just because the TD42 only runs 8psi of boost doesn't mean that anything above that is high.

The LR 300TDi engine runs 17psi stock. All newer LR engines run more. All modern diesels I am aware of run 15 or greater max psi from the factory. Many run as high as 30 or 40 psi (these are usually truck diesels).

Back onto the 3.0TD (ZD30).

Factory spec is 18 psi max

http://www.4wdmonthly.com.au/forum/sitemap/t-26548.html

maximum boost which around town easy driving was >21 psi.

ZD30 boost level questions
After fitting a boost gauge to my truck, I notice the following boost levels:
- Flat bikkies (WOT): 15PSI,
- Largest momentary spike due to VNT actuation: 22PSI,
- Highway crusing: varies between 4PSI and 15PSI - sometimes creeping up to just over 15PSI before dropping down to around 4 or 5 PSI even on flat road.

I have my gauge fitted between the turbo compressor and the inlet of the intercooler. I also have a TaipanXP exhaust and a DTronic chip installed. From memory, the WOT boost figure was the same 15PSI with the standard exhaust. EGT gauge is coming so no data on that at present. Boost gauge accuracy seems to be OK as the same levels were reported when the guys from TaipanXP used their gauge after the exhaust install.

Do these values sound OK? Or should I be adjusting the boost down? I have had no success in testing for the overboost condition . . . perhaps because I have an automatic.
__________________
2002 GU 3.0-litre Auto Wagon

http://www.patrol4x4.com/forum/showthread.php?t=16062

g'day,
i have a gu 3.0 with auto tranny, standard exhaust, egr blocked and adjusted vnt, at WOT 1st gear boost shoots up to 23psi for a second and drops to 14 and creeps up to 15-16 psi, 2nd gear (WOT) 15psi... cruising at 80 kph - 7psi, 100kph i- 11psi, 120kph - 11psi then drops to 5 psi (depends on throttle position) 140kph - 14 - 15 psi. i dont experience the nissan overboost safety feature. Before blocking the egr and adjusting the vnt it took me 3 maf sensors getting fouled... this is my 4th Maf sensor so im hoping to get it right this time...

[DR Frankenstine]

they would deffinately have over 11lb boost. there's no point running an intercooler under 11 lb.

[ISUZUROVER]

they would deffinately have over 11lb boost. there's no point running an intercooler under 11 lb.

Thanks, we need even more uninformed nuffys in this thread. Any proof of that??? thought not... you will find it is more like 6psi boost where an intercooler makes no difference...

[DR Frankenstine]

they would deffinately have over 11lb boost. there's no point running an intercooler under 11 lb.

Thanks, we need even more uninformed nuffys in this thread. Any proof of that??? thought not... you will find it is more like 6psi boost where an intercooler makes no difference...

Your obviously an expert on everything. The act of compressing air causes heat build up and at about 11lb of boost the cooling compressed air will atomise and form water particals which of course get forced into the combustion chamber. We all know what happens then. This helps to keep the temps down which is why people do water injection. compressing air to 6lbs of boost doesnt create enough heat from compression to warrant an intercooler so you are only cooling the air thats heated from the exhaust/turbo temps not compression so this has no real benifit. How about keeping your personal attacks to yourself. typical landrover owner gets around with his head up his arse chocka block full of his own importance. Hows that for a personal attack.
Today your the statue

[bogged]

just wondering if any ones got the 3lttd gu wagon like 04 model with a boost gauge i need to settle an argument with a mate i rekon that there lie over 18psi he thinks there like running about 4 psi i need to prove hes full of it can you guys help me

Pre or Post hole in the piston?

[dumbdunce]

intercooling (although we're really taking about aftercooling) at any boost level is advantageous. engines work across a temperature difference. the greater the difference between the hot side and the cold side, the more efficient that engine is. the colder the air you suck in, the more "space" you have to heat it up before you reach the limits of the materials in the engine (metals, ceramics, coolants and lubricants etc), and the limits of allowable emissions (especially NOX in the case of diesel engines). at low boost levels (6psi, 11psi, 15psi, 3psi, let's say under about 1 atmosphere to keep it civil), the cost of intercooling probably exceeds the benefits available specially in terms of power production and engine protection. As a handy bonus, cooler air is more dense so for a given charge pressure, a greater mass of fuel and air can be combusted per cycle. the advantage available from intercooling increases as boost levels increase and given current turbo diesel boost levels and emissions requirements, aftercooling is necessary - but there is still gain to be had in aftercooling an older engine running modest boost.

I believe the original question has already been adequately answered.

as for peak boost levels in diesel engines? Caterpillar ACERT engines have been fiddled to run up to around 70psi boost, (although the factory level is around 45psi). Most 4 cylinder passenger turbo diesels are in the 20 - 30psi region now, in factory trim. 20ish psi in the ZD30 is no longer considered "high" boost - the ZD30 is a bit of a dinosaur now, most manufacturers offerings in the same class have more of everything.

feel the love, brothers

[ISUZUROVER]

intercooling (although we're really taking about aftercooling) at any boost level is advantageous. engines work across a temperature difference. the greater the difference between the hot side and the cold side, the more efficient that engine is. the colder the air you suck in, the more "space" you have to heat it up before you reach the limits of the materials in the engine (metals, ceramics, coolants and lubricants etc), and the limits of allowable emissions (especially NOX in the case of diesel engines). at low boost levels (6psi, 11psi, 15psi, 3psi, let's say under about 1 atmosphere to keep it civil), the cost of intercooling probably exceeds the benefits available specially in terms of power production and engine protection. As a handy bonus, cooler air is more dense so for a given charge pressure, a greater mass of fuel and air can be combusted per cycle. the advantage available from intercooling increases as boost levels increase and given current turbo diesel boost levels and emissions requirements, aftercooling is necessary - but there is still gain to be had in aftercooling an older engine running modest boost.

I believe the original question has already been adequately answered.

as for peak boost levels in diesel engines? Caterpillar ACERT engines have been fiddled to run up to around 70psi boost, (although the factory level is around 45psi). Most 4 cylinder passenger turbo diesels are in the 20 - 30psi region now, in factory trim. 20ish psi in the ZD30 is no longer considered "high" boost - the ZD30 is a bit of a dinosaur now, most manufacturers offerings in the same class have more of everything.

feel the love, brothers

What he said...

DR frankenstein - perhaps you should remove the "dr" from your name Sorry if I was a bit harsh, but I was p'd off by all the idiots who had no idea posting their (incorrect) opinions. But I spose this is OL

I actually ran the calcs a long time ago. You need to get down to 5-6 psi and be running a reasonably inefficient intercooler for the intercooler to have no effect.

Condensation of water vapour doesn't come into the equation. NFI what you are talking about there.


From the other thread a few years ago...

Edit - god I posted some crap the other day - don't know what came over me.

Damian - I agree with everything you say. It seems the "rule of thumb" I quoted was a bit off - However - the relative benefit of an intercooler is proportional to the boost that the engine is running. And thanks for reminding me of some of the thermodynamics so I could check what the real relationship was (see below).

Here is a useful intercooler design spreadsheet I posted a link to a few days ago.
http://www.outerlimits4x4.com/PHP_Modul ... hp?t=67402

Now - I have finally gone back over the thermodynamics I had forgotten so I can explain what I was talking about in the first place.

The adiabatic heating of air during compression is approximately:
T2=T1*(P2/P1)^0.283

where T1 is the compressor inlet temp, T2 the compressor outlet temp, and P1 and P2 the inlet and outlet temps respectively.

The final Temp of the air leaving the compressor is:
T3=T1+(T2-T1)/CE

where CE is compressor efficiency. The coolling provided by the intercooler is basically the same equation.

If the wastegate is controlled by a pressure sensor on the inlet manifold, the peak boost pressure reaching the engine can be assumed to be constant, only the temperature changes. But the intercooler induces an extra pressure drop on the system, which means the turbo has to work harder to maintain the same boost pressure at the manifold.

If you run through the calc above for the same system with and without a charge cooler (intercooler), you can work out the temperature difference in the air reaching the engine (with and without an intercooler), which is proportional to the mass difference in the air, which is proportional to the increase in engine performance. Anyone see any problems with that so far???

So, to see how much difference an intercooler makes, I picked some typical values for the calcs:
T1 = 373.15K (30°C)
P1 = 1 atm
delta P for the intercooler is 20% of the boost pressure (not really realistic for 15psi and above)
Compressor Efficiency = 70% (typical range 55-95%)
Intercooler Efficiency = 65% (typical range 50-90%)

If you look at the graph below, you can see that for a reasonable efficient intercooler setup you get about a 5% inlet temperature decrease over the same setup without an intercooler at 10psi. Naturally if you had a more effective intercooler (e.g. water to air) with a lower pressure drop you could get more of an increase. But I think the numbers are reasonably representative of what happens in reality. If you work out the power and torque increase for an intercooler with equivalent pressure drop in the intercooler design spreadsheet above, you get about a 5% increase in power and torque (for a 4L diesel at 2500rpm).

The bottom line is - if your setup is running reasonably low boost, bolting come random (probably inappropriately sized) intercooler on is unlikely to make a noticeable difference. But if you already have a free intercooler, why not suck-it-and-see.

[RAY185]

Wow Ben, you're almost foaming at the mouth.

This thread was in gen shit shat when I replied and was moved here sometime after. If it was here to start with I probably wouldn't have replied without actually knowing for sure what boost they run (I've had nothing to do with late model diesels and based my suggestion on the 4.2TD). Being in gen shit shat I didn't give a rats arse as to the accuracy of my reply and didn't expect the scrutiny you have afforded it.

cheers,

Nuffy

[hayde]

ok then thanks