Thread: Throttle response modification.

Originally Posted by Tins

Let's face it, the things are designed for, and usually work well with, modern common rail diesels. The TD5, fortunately IMO, is not a common rail diesel.

No.... But it nearly is

Originally Posted by shack

No.... But it nearly is

Better, IMO. No danger from the obscenely high pressures in the rail, but with pretty much most of the advantages. I maintain that the TD5 was a great design.

Originally Posted by Tins

Better, IMO. No danger from the obscenely high pressures in the rail, but with pretty much most of the advantages. I maintain that the TD5 was a great design.

They are definitely more foolproof and less problematic, cheaper to repair etc...

However, a 2.7 runs at a maximum of 1650 bar whereas a TD5 - EU3 version runs at 1750 bar.

I think the 3.0 sdv6 is 2000 Bar.

Where the common rail wins out I guess is it's ability to deliver multiple injects per cycle, I think things like post inject , from memory up to 3 or 5 post inject events , help massively cleaning up emissions.

The TD5 would have a limited efficient crank angle° inject range from being charged by cam lobes.

Originally Posted by shack

They are definitely more foolproof and less problematic, cheaper to repair etc...

However, a 2.7 runs at a maximum of 1650 bar whereas a TD5 - EU3 version runs at 1750 bar.

I think the 3.0 sdv6 is 2000 Bar.

Where the common rail wins out I guess is it's ability to deliver multiple injects per cycle, I think things like post inject , from memory up to 3 or 5 post inject events , help massively cleaning up emissions.

The TD5 would have a limited efficient crank angle° inject range from being charged by cam lobes.

You've moved out of my area here, apart from the repairability bit. But my understanding is that TD5 is EUI, and therefore the pressure is at the injector only, and not system wide. I don't see the 'cam driven' injection as a negative on such an efficient engine, and I would have liked to see where it could have gone. The TD5 has none of the traps for the unwary that CR does when cracking fuel pipes.

Originally Posted by Tins

You've moved out of my area here, apart from the repairability bit. But my understanding is that TD5 is EUI, and therefore the pressure is at the injector only, and not system wide. I don't see the 'cam driven' injection as a negative on such an efficient engine, and I would have liked to see where it could have gone. The TD5 has none of the traps for the unwary that CR does when cracking fuel pipes.

The "rail" on a TD5 certainly has much less pressure, ironically it's the rail or fuel gallery on a TD5 that is the weak point.

On a common rail it's not the rail that's the issue, it's the hpfp and injectors!

The cam driven injectors do have some draw backs, one being they are much harder to calibrate as fuel delivery varies so much based on SOI and engine speed

I love TD5's though, don't get me wrong!

They can go fast too.....

Originally Posted by Tins

Let's face it, the things are designed for, and usually work well with, modern common rail diesels. The TD5, fortunately IMO, is not a common rail diesel.

Actually the throttle controllers are less to do with the common rail injection, and more to do with the fly-by-wire throttle potentiometer, 2 and 3 wire types on TD5's IIRC.

Originally Posted by RANDLOVER

Actually the throttle controllers are less to do with the common rail injection, and more to do with the fly-by-wire throttle potentiometer, 2 and 3 wire types on TD5's IIRC.

OK, so they could work? Info is hard to find. There's a bloke who sometimes features on that 4wd/247 channel that does them. Maybe I'll ask him.

Originally Posted by Tins

OK, so they could work? Info is hard to find. There's a bloke who sometimes features on that 4wd/247 channel that does them. Maybe I'll ask him.

Maybe not as I have one on my D3 and it is great and I never looked into it when I had the D2 but Gavin has (see quote below), which might be why one of the earlier posts looked like the guy had just developed a D2 specific one.

Originally Posted by gavinwibrow

Not sure if this is the best place, but some related info.

I have an i-Drive in my 2.7L D4, and it is transformational for pickup speeds, so thought ummm, D2 has fly by wire accelerator, so should fit there too and be a cheap way of getting extra pickup performance.

So I contacted them and unfortunately

"Thanks for your enquiry. Unfortunately we have made every effort to create a throttle controller that operated within the correct parameters for the Discovery 2 TD5, however we have not had any luck this far."