What's the appeal of diesel?

[jarrus]

Correct gear ratio's and correct turbo selection should make up for the lack of rev's any day

[HDi fun]

Originally Posted by jarrus

Correct gear ratio's and correct turbo selection should make up for the lack of rev's any day

They are certainly interchangeable. As we've said before it's roadwheel torque which accelerates the car.

So a petrol engine with less flywheel torque can take advantage of its higher revving nature by using lower gears.

All that gear ratios do is to exchange revs for torque. The actual power in the system is exactly the same either side of the box.

But then diesels will pull hard from 1500rpm or lower in some cases so can therefore pull longer gears.

It's more down to preferred driving style now more than anything else.

There's no hard and fast rules

[Yugguy]

The appeal of diesel these days is that you don't need an enormous V8 petrol to have some power. Yeah, the V8 might be more fun,more satisfying, but if you can't afford 20mpg or less or the 900 quid a year car tax or the shafting off the chancellor if it's a company car then a modern diesel married to a good autobox makes sense.

[geraint13]

Originally Posted by Yugguy

The appeal of diesel these days is that you don't need an enormous V8 petrol to have some power. Yeah, the V8 might be more fun,more satisfying, but if you can't afford 20mpg or less or the 900 quid a year car tax or the shafting off the chancellor if it's a company car then a modern diesel married to a good autobox makes sense.

sounds good to me !!!!!

[HDi fun]

Originally Posted by Yugguy

The appeal of diesel these days is that you don't need an enormous V8 petrol to have some power. Yeah, the V8 might be more fun,more satisfying, but if you can't afford 20mpg or less or the 900 quid a year car tax or the shafting off the chancellor if it's a company car then a modern diesel married to a good autobox makes sense.

What you say is pretty accurate. With over 300lbft on offer from below 2000rpm with a diesel engine you do get that urgent feel that comes from a 4 litre plus V8 petrol engine.

Of course, you won't get the 300+bhp at the top end because it won't rev to 6500+rpm but in general driving up to 3500-4000rpm the in gear muscle is much the same.

[jarrus]

Indeed, agreed that has to be the appeal for me as well
but it has to be a manuel though

[HDi fun]

Originally Posted by jarrus

Indeed, agreed that has to be the appeal for me as well
but it has to be a manuel though

I'll always take a decent automatic over any manual. Diesel engines for years didn't really cut it with automatic transmission simply because they lacked (and still do lack) the ability to rev much past 4000rpm.

Many go higher now (my 406 red-lined at 5300 and the limiter only invaded at 5500) but they don't really do much in performance terms at those engine speeds.

The advent of automatics with 5, 6 or more true gear ratios during the last ten years or so has made the automatic diesel option a likeable choice.

[jarrus]

The limiting factor on that engine was the fact it had a tiny turbo,

it had a gt15 which really is a little small if you rev past 4k, even on my engine a gt15 is too small past 4k rpm (mine has the KKK equalivilant a K14)

I reckon if I did undertake a 2.2 hdi 306 a gt22 would make it produce power up the top quite easy (useable power that is)

[ronniecalcutta]

Diesel, Diesel, Diesel. Off course with Common Rail Direct Injection & equipped with a turbo...I like the growl of CI engine...

[jarrus]

Some diesels can sound very nice indeed,

I've posted some video link somewhere in the thread I think,
But the other day on the way to Alton Towers my friend was giving his Alfa 156 1.9 8v jtd the beans and it sounded rather nice, especially over 3k rpm was almost a petrol sound but still had the nice rough edged diesel sound in there, it was actually a nice mix...

[ronniecalcutta]

Exactly Jarrus, the sound is mesmerizing ... especially when I drive the Mahindra Scorpio MHawk of my friend... http://www.mahindrascorpio.com/

[HDi fun]

My 2.2 had a Garrett T3 turbocharger.

It sounded brilliant when overtaking, more like a jet engine with the turbo scream than a piston engine.

[jarrus]

just looked it up, was a GT1549P, the t3 is a very old turbo charger by today standards and even then, the old t series turbos weren't variable vane with the exception of the VNT25 which was made for Dodge and was also used in the 405 T16 really nice engine that....

DI diesel engines need far less air to produce a good amount of power/torque

They don't list a 49 compressor on the garrett website on the gt15 frame,

but from what I can gather it was good for up to 200 hp (going on the bases of the 48 compressor)

[one in a million]

diesels are now being made to actually look nice, im not a diesel person at all but i give it to them they do save your money when travelling.

[HDi fun]

Originally Posted by one in a million

diesels are now being made to actually look nice, im not a diesel person at all but i give it to them they do save your money when travelling.

They don't when it comes to routine maintenance though.

[HDi fun]

Originally Posted by jarrus

just looked it up, was a GT1549P, the t3 is a very old turbo charger by today standards and even then, the old t series turbos weren't variable vane with the exception of the VNT25 which was made for Dodge and was also used in the 405 T16 really nice engine that....

DI diesel engines need far less air to produce a good amount of power/torque

They don't list a 49 compressor on the garrett website on the gt15 frame,

but from what I can gather it was good for up to 200 hp (going on the bases of the 48 compressor)

It is indeed a very old unit.

DI engines don't so much need less air as such, they just are better able to make us of huge amounts of the stuff

[jarrus]

Indeed,

for example, my car uses a similar turbo charger to what the 2.2 was running,

about the most my engine can muster out of it is about 170 hp tops, the hdi should be able to get 200 hp from it,

Turbodynamics make a hybrid unit for the 1.9 td using a t2 turbine hosing and a t25 compressor wheel and hosing (the 60 mm housing) and the most i've seen from that is about 213 hp and from the size of the housing and the fact that he was running about 35 psi that just outrageous lengths to go to for such a little gain

I've finially come to realise that the xud as great as they are, are useless for making big power (well 213 hp isn't bad) but that was with 245 lbft torque which is laughable for a diesel with that kind of power so I've abandoned the idea of making a big power xud as I can see there will be many problems

I'm either going to buy a Renault sport Megane 175 dci or an Vauxhall Astra SRI 1.9cdti sport hatch 150, or drop a 2.2 hdi into a 306(I would quite like to find a 3 door shell maybe), or i've found a low mileage black GTI6 on the trader which I've inquired about, it's not 100% standard but nothing that can't be easily undone

[metalonmetal]

you can have bags of torque from a petrol.

I get 270lbs-ft at the wheels (so probs over 300lb-ft at the crank) at 2500rpm in mine, and very little lag.

Big shove comes in from 2000 and runs cleanly pulling right through to 6500.

[HDi fun]

Originally Posted by metalonmetal

you can have bags of torque from a petrol.

I get 270lbs-ft at the wheels (so probs over 300lb-ft at the crank) at 2500rpm in mine, and very little lag.

Big shove comes in from 2000 and runs cleanly pulling right through to 6500.

Oh yeah, there are not hard and fast rules. With diesel you'd probably be well
under way from 1300rpm but obviously the show's over by 5000 at the latest.

270lbft is not remarkable compared to the latest high performance diesels from BMW and Mercedes Benz.

[jarrus]

I looked on celtic for the remapped power output of a BMW 335d and it was just monstrous,

345 hp.....it is a lot but not mega by todays standards, but..................................but.......... ...........this is where the lunacy starts it has........... 511 lbft torque?!?!?!

thats enough to up root my house!!!!

and considering they can only get 360 hp out of the 335i, out of the 2 I'd take the diesel every time.....

[HDi fun]

Originally Posted by jarrus

I looked on celtic for the remapped power output of a BMW 335d and it was just monstrous,

345 hp.....it is a lot but not mega by todays standards, but..................................but.......... ...........this is where the lunacy starts it has........... 511 lbft torque?!?!?!

thats enough to up root my house!!!!

and considering they can only get 360 hp out of the 335i, out of the 2 I'd take the diesel every time.....

So would I, without hesitation.

[LuxuryMotorShow]

much depends on the type of car and the type of journeys its going to be used for.... e.g. a 2 seater convertible vs an estate car or city car vs long distance cruises.

Personally, I think there isnt much difference and I would rather have a petrol myself - although some diesels are very sporty and torquey!

[Big Fat Fatty]

No amount of torque can overcome the noise from the tailpipe!

[HDi fun]

Can't say I've noticed that one.

[Big Fat Fatty]

you won't have done from inside them, it's the people outside who have to put up with it.