Thread: 700Nm puma ???

700Nm of Torque or Talk???

Originally Posted by uninformed

Personally I will never buy another copy of anything 4wd action. I bought a copy with a modded defender on the front. I knew the vehicle. I read the artical and it was utter BS. I made a post about it on another forum, copped a flogging from all the sheep and even the editor. I kept to my guns knowing better. In the end the original owner posted and backed up what I had said all along....it went unoticed. The biggest thing that ****ed me off was the editor just hand balling the resposnibilty while talking out both sides of his mouth at once.

not worth using as toilet paper

yeah exactly....i pretty much only get it to have a look at pictures as everything else is just dribble and the "gurus" just hound you for saying something which as you said you knew the vehicle in person...i must say i did come across a fella that posts in the magazine who is Andrew from AXT turbos he has been a very helpfull and genuine bloke....

Originally Posted by TimNZ

700Nm of Torque or Talk???

LOL

Originally Posted by c.h.i.e.f

Yep I find the mags funny how the nissota owners get in there saying about there heaps good turbo and there heaps high exhaust temps at around 550* etc etc where I've frequently pushed out 800+ (not that that's good) its also amusing one article mentioned a td42 running high boost (16psi) and then it stuffed the fuel pump I shook my head and thought a $15 CAV would have fixed the problem !!!

16 psi that's throu the roof you tell a toyboata owner how much boost a 300 runs and they call bull**** on it every time. I had a 100 series in last week aftermarket turbo on 4.2 diesel. You wouldent even know it had a turbo on it when I drove it . How ever I have driven some real crackers too but mostly td42 patrols in my opinion a better donk then the Toyboata 1hz and don't get me started on the torque of toyboatas v8 diesel poor realy considering the size of the donk

Originally Posted by TimNZ

700Nm of Torque or Talk???

I'm guessing 420Nm of Torque and 280Nm of Talk.

Originally Posted by Dougal

I'm guessing 420Nm of Torque and 280Nm of Talk.

Hahaha yes...

Originally Posted by 460cixy

16 psi that's throu the roof you tell a toyboata owner how much boost a 300 runs and they call bull**** on it every time. I had a 100 series in last week aftermarket turbo on 4.2 diesel. You wouldent even know it had a turbo on it when I drove it . How ever I have driven some real crackers too but mostly td42 patrols in my opinion a better donk then the Toyboata 1hz and don't get me started on the torque of toyboatas v8 diesel poor realy considering the size of the donk

Yep they always question our boost figures likes its the end of the world...having said that I have only been in one turboed 1hz that goes "alright" that's after we modified the pump and run 15psi it still ain't a patch on the Isuzu but as for td42 I like them and have read that they can get good figures but I have never taken my mates ones for a test as they usually are out of action due to bad panel damage I agree with the v8 Cruisers statement too as you suggested 4.5L of not much with a terrible turbo setup IMO

Given 140kW and 700Nm, but not knowing at what rpm. It does look like 700Nm is an error (as discussed in some posts above).

Power is force x velocity (linear motion) or when converted to circular motion terms and SI units, Power (watts) = 2 x pi x Torque (Nm) x revs per second. If power is in kW then use torque in kNm.

If the peak power is developed at say 3000 rpm, i.e. 50 rev per sec, then:
Torque (kNm) = 140 (kW) / [2 x 3.14 x 50 rev/s] = 446 Nm

That torque value is most likely on the high side for a Puma engine as the peak power is most likely achieved at higher rpm.

Now if the peak torque is developed at 2000 rpm, i.e. 33.3 rev per sec, then:
Power (kW) = 2 x 3.14 x 0.7 kNm x 33.3 rev/s = 146.6 kW

Once again that power is most likely too high at those rpm for a Puma engine.

The conventional engineering measure for comparing performance of different engines, of the same type but different displacement, is BMEP (brake mean effective pressure).

BMEP is the equivalent average pressure acting on a piston over the thermodynamic cycle (2 revs for a 4 stroke engine) and is calculated from the torque measured on a dynamometer (dynos were commonly called brakes because a method of braking is used to apply a load on the engine), divided by the engine displacement.

Pressure is produced by heating the air in the combustion chamber from burning fuel (more pressure requires more fuel to be burnt) and by basing it on the torque from a dyno, BMEP takes all engine losses, friction, etc. into account.

BMEP (Pa) = 2 x pi x Torque (Nm) x rev per cycle / displacement (cubic metre)

For a 4 stroke engine and converting displacement to litres this can be simplified to:
BMEP (Pa) = 12566 x Torque (Nm) / displacement (litre)

Now for a 2.4 litre Puma, to produce a torque of 700 Nm then:

BMEP = 12566 x 700 (Nm) / 2.4 (litre) = 3665 kPa or 36.65 bar



A quick search of the internet produced typical figures of :

• 7 to 9 bar for a NA diesel
• 14 to 18 bar for a turbo diesel
• 14.6 bar for a 755 HP, 2.4 litre, V8 race car engine
• 80 to 100 for top fuel dragsters

It would be interesting to see some figures for a range of modern common rail diesels.

So 36.6 bar from a Puma is not too scruffy. IMHO it ain't going to happen because peak cylinder pressures and temperatures will be far too high for the piston material to withstand.