Thread: The end of my Discovery.

Originally Posted by DazzaTD5

its actually lower than that as the 2.7 is 27xx cc slightly over

its bull**** anyway, ive fitted up a 2.7 as 3.0lt in d4 model, clocked more on a dyno than plenty of 3.0 ones.

a 2.7 is also slightly higher compression.

my project 2.7 in a D3 (my mates car now) pulls dam close if not better than a 3.0 D4 without the lag, I havent had the chance to go head to head.

Well ... the compression is silly. It's like saying the V8 4.5 litre Cruiser diesel has higher compression than the Cruiser V6 3.3 diesel. Which is the case. But compression is not the issue in a motor that has forced induction, where lower compression results in better performance.

You're saying Ford was stupid in not putting the 2.7 litre instead of the twin turbo into the Ranger/Everest? And for a short time the F150? Even Toyota with their 3.34 litre V6 diesel has gone to the duel small/large turbo setup, which was the most obvious reason why the 3 litre increased its performance. Variable - expensive, setup issues and maybe less reliable; twin scroll - cheaper but not as efficient; duel - cheap and efficient.

Anyway thought that the Lion 3 litre and the current Ford 3 V6 D lacking of take off performance from first and second gears was due to protecting the drivetrain. But since the straight six goes hard at take off, I must have been wrong.

A higher compression ratio is not silly at all on a turbo diesel.

Higher cr allows for lower boost , which considering the 2.7 only has 1 turbo, is important at lower RPM, to maintain higher peak cylinder pressure. This in turn should lower the perceived turbo lag.

The 2.7 motor whilst not bullet proof, would seem to be more robust by a reasonable amount than the 3.0.

A properly tuned 2.7 can be a pretty slippery thing, ours hasn't been on a dyno but as many of you know, I tune TD5s and I believe I'm pretty competent, but I don't think I can get a TD5 to pull like our 2.7 without a fair bit of hardware upgrades.

In fairness some of the upgrades would be the Auto box.

There will be/is some drivetrain protection, but I don't think that will be the cause the the slow getaway.

I'm interested to see what Daz response is to all this, I'm happy to be corrected.

Originally Posted by Melbourne Park

Well ... the compression is silly. It's like saying the V8 4.5 litre Cruiser diesel has higher compression than the Cruiser V6 3.3 diesel. Which is the case. But compression is not the issue in a motor that has forced induction, where lower compression results in better performance.

You're saying Ford was stupid in not putting the 2.7 litre instead of the twin turbo into the Ranger/Everest? And for a short time the F150? Even Toyota with their 3.34 litre V6 diesel has gone to the duel small/large turbo setup, which was the most obvious reason why the 3 litre increased its performance. Variable - expensive, setup issues and maybe less reliable; twin scroll - cheaper but not as efficient; duel - cheap and efficient.

Anyway thought that the Lion 3 litre and the current Ford 3 V6 D lacking of take off performance from first and second gears was due to protecting the drivetrain. But since the straight six goes hard at take off, I must have been wrong.

That remark is silly, and wrong, higher compression means the gas flowing through the turbine is able to spin it up quicker = less lag.

It's getting the correct compression for the overall efficiency and suitability of purpose that matters, later hybrid / mild hybrid vehicles are able to cheat somewhat to overcome the lag of a late model lardy 4x4.

As for the "duel" turbos, well, if they were using jousting sticks, the large one would probably win, but if it was Pistols my money would be on the small one.

The last sentence is an example of both silly and wrong.

Originally Posted by shack

A higher compression ratio is not silly at all on a turbo diesel.

Higher cr allows for lower boost , which considering the 2.7 only has 1 turbo, is important at lower RPM, to maintain higher peak cylinder pressure. This in turn should lower the perceived turbo lag.

The 2.7 motor whilst not bullet proof, would seem to be more robust by a reasonable amount than the 3.0.

A properly tuned 2.7 can be a pretty slippery thing, ours hasn't been on a dyno but as many of you know, I tune TD5s and I believe I'm pretty competent, but I don't think I can get a TD5 to pull like our 2.7 without a fair bit of hardware upgrades.

In fairness some of the upgrades would be the Auto box.

There will be/is some drivetrain protection, but I don't think that will be the cause the the slow getaway.

I'm interested to see what Daz response is to all this, I'm happy to be corrected.

James, I didn't see your post until after I had posted ( in between other things

but spot on. ( Edit, well, apart from the TD5 not pulling as hard as the 2.7 bit )

Cheers

Originally Posted by discorevy

James, I didn't see your post until after I had posted ( in between other things

but spot on. ( Edit, well, apart from the TD5 not pulling as hard as the 2.7 bit )

Cheers

Does your TD5 pull as hard as a tuned 2.7?

IIRC, I read somewhere that the 2.7 compression ratio was lowered slightly so that it runs more quietly, which seems to ring true to me as I can often hear other car diesel engines rattling away over the noise of mine in traffic with the windows up!

Originally Posted by shack

Does your TD5 pull as hard as a tuned 2.7?

Well it was the Auto D2a (I've only run the manual against the 3.0 D4) and it's only "Dragged" 3x tuned 2.7's (1 was mine).

The D4 3.0 reeled the TD5 in after about 15 seconds.

Another was one that had been tuned on the dyno via Dazza on here, and we did 6 runs all up ( owner couldn't believe it the first few times ) I even let it spool up and take off before me a couple of times and the TD5 was between 8-12 car lengths ahead after 400 metres.

They do have a weight advantage..

Apologies to O.P. for off topic and loss of your engine

Originally Posted by RANDLOVER

IIRC, I read somewhere that the 2.7 compression ratio was lowered slightly so that it runs more quietly, which seems to ring true to me as I can often hear other car diesel engines rattling away over the noise of mine in traffic with the windows up!

Yes they are very quiet, my wife rarely hears me leave in the morning and i park not that far from our bedroom window.
You definitely hear jap diesels pull up beside you.