[Shimsteriom]

I read on another thread (can't remember which one) that the turbo on a td5 doesn't spool up until around 2k, but mine spools up easily at any revs over 1300.
Is this right, or have I misread or misunderstood the comments made in the other thread?

 

[Harrymattson]

Mine's up and running about 1300 too

 

[300bhp/ton]

How do you know? And what is the definition of "spool up"?

A turbo has an impeller, which is located in the exhaust system, as exhaust gases pass this, it will force it to rotate. However for the turbo to produce boost, it needs to spin at a considerable rate. This is known as boost threshold and is the thing many mistake for turbo lag (turbo lag is something completely different).

You can see in this dyno chart, there is a massive torque increase (yellow line) just after 2000rpm. This is the turbo essentially kicking in and making boost.

 

[Disco1BFG]

I read on another thread (can't remember which one) that the turbo on a td5 doesn't spool up until around 2k, but mine spools up easily at any revs over 1300.
Is this right, or have I misread or misunderstood the comments made in the other thread?

The comment in the other thread was nonsense. I saw it too. A turbocharger is actually two impellers, one driven by the exhaust gases, sharing a shaft with another which pressurises air in the inlet side of the engine - once the engine is running, the core of the blower will be turning once internal friction, and static resistance of the air in the inlet side is overcome...

I could type for a week, but its all been done before... have a nosy at:-

https://en.wikipedia.org/wiki/Turbocharger

 

[Shimsteriom]

So to say "spooling up" just means that the turbo is spinning, but not yet necessarily producing any boost?

 

[Harrymattson]

Spooled up really means that the turbo is producing boost pressure that is noticeable but not necessarily full pressure.
On every turbo engine I have owned this occurs more or less when you can hear the turbine 'whistle'.

 

[Shimsteriom]

Ok. I can here my turbo whistle at 1300rpm, so does that mean I'm actually getting boost at 1300rpm?

I'm in a pedantic mood tonight apparently!!

 

[johnlad]

my td5 starts boosting around 1250 rpm, shown on a boost gauge and rpm checked on hawkeye, full boost is only reached when booting it

 

[Shimsteriom]

Does anyone happen to have (or a link to) a power graph for a Disco TD5 running a standard ECU map?