Thread: Should a TD5 be driven at low revs?

Originally Posted by Captain_Rightfoot

Huh? Help... it's late.. that doesn't make sense?

going off my calibrated ear I dont have a tachometer fitted to big red so by my judement...the turbo starts to drop off the boil at about 1100rpmwhen you allow the engine to slow below this RPM threshold there is no longer sufficient exhaust gas flow to adequately turn the turbine side of the turbocharger thus the compressor side of the turbocharger slows. This results in the loss of charge air pressure and a subsequent, exponential loss of engine power.


That better?

Originally Posted by Blknight.aus

going off my calibrated ear I dont have a tachometer fitted to big red so by my judement...the turbo starts to drop off the boil at about 1100rpmwhen you allow the engine to slow below this RPM threshold there is no longer sufficient exhaust gas flow to adequately turn the turbine side of the turbocharger thus the compressor side of the turbocharger slows. This results in the loss of charge air pressure and a subsequent, exponential loss of engine power.


That better?

Ok. I've got a tacho on ours. I would have said this point would have been much higher.. like 1500rpm. At 1100 it's only just off idle. I'll check but I think it idles only a few rpm below that? What's more, if you needed any significant amount of power I'd suggest anything below 2k and you're on shaky ground.

Since removing the centre muffler things are much better than they were before below 2k. Since the tomby upgrade once you hit about 2k it's all go. Below that it seems to smoke a bit. So, I try it keep it lightly loaded and between 18/20 through to 25.

boost is at about 5-6 psi then... By ear (ive never compared it to a td5 with a tacho it sounds like 1100 but i could be out...

Thanks for the info guys. Sounds like my Defender's performing as it should, and I just need to get used to it.

Cheers

Sean

Prior to intstalling my taco I thought mine was reving high too. When I had it on the Hwy I thought I was flogging it at 100km/h, now I know it was sitting around 2500rpm. It must be the way it sounds. I drive aturbo diesel 06 Triton at work at times sitting on 3500rpm on the Hwy and doesn't sound stressed. But I don't own it either

Originally Posted by Blknight.aus

going off my calibrated ear I dont have a tachometer fitted to big red so by my judement...the turbo starts to drop off the boil at about 1100rpmwhen you allow the engine to slow below this RPM threshold there is no longer sufficient exhaust gas flow to adequately turn the turbine side of the turbocharger thus the compressor side of the turbocharger slows. This results in the loss of charge air pressure and a subsequent, exponential loss of engine power.


That better?

Well the turbo on my TD5 starts to spool at around 1300 to 1400 and is at max at 1950rpm and according to the specs thats when it's supposed too, boost on a TD5 is 16 to 17 with a max of 24psi when the ECU stops it from going any higher.

Also max torque starts at 1950rpm in a TD5

Originally Posted by Captain_Rightfoot

Ok. I've got a tacho on ours. I would have said this point would have been much higher.. like 1500rpm. At 1100 it's only just off idle. I'll check but I think it idles only a few rpm below that? What's more, if you needed any significant amount of power I'd suggest anything below 2k and you're on shaky ground.

Since removing the centre muffler things are much better than they were before below 2k. Since the tomby upgrade once you hit about 2k it's all go. Below that it seems to smoke a bit. So, I try it keep it lightly loaded and between 18/20 through to 25.

Originally Posted by Blknight.aus

boost is at about 5-6 psi then... By ear (ive never compared it to a td5 with a tacho it sounds like 1100 but i could be out...

16 to 17 is the standard boost with a max of 24psi the ECU prevents it from going higher, the TD5 idles at 700 to 750rpm.

Max power is at 4200rpm.... 90Kw Def.... 102Kw Disco
Max torque is at 1950rpm.... 300Nm Def ....320Mn Disco

Any where in between these revs of 1950 to 4200rpm is safe, and this is where it should be driven, anything below is labouring the engine, anything above is over revving the engine.

Read the manual guys.

Oh Dave get your ears checked

Baz.

Yep, why would you take off in high gears and risk labouring the engine especially a diesel engine. Over time I bet it does more harm than good, even on level ground.

driving a diesel is VERY different to a petrol.

get it into a sweet spot, different for all engines and use it. You will find on a (turbo) diesel it will be from maybe 1500 to 3000.

this is what i have found.

word for the other guys who responded.