Why do these dirty Diesels have to be so damn fast??
Discussion
yonex said:
Modern diesels are rapid. But they don't rev, sound nothing like a decent engine does and are generally coupled to auto boxes.
This is a good thing though because without an auto-box trying to "make progress" in a diesel is more akin to one handed rowing. Incidentally and back on subject it appears my petrol car is equally as fast as a Golf GTD. Which given that it's about 200Kg more than a GTD and a damn sight bigger is not too shabby. Although I then start thinking about remaps...
shielsy said:
Soov535 said:
I have the F10 535D and it's standard.
329bhp, loads of torque. Same performance as the old six cylinder M5 and 45mpg.
Incredible.
With a remap and a zorst they are insane.
Not really incredible is it. 329bhp, loads of torque. Same performance as the old six cylinder M5 and 45mpg.
Incredible.
With a remap and a zorst they are insane.
New twin turbo 3.0 diesel 5 series goes just as fast as 1989 3.6 litre N/A petrol 5 series. Shocker.
Fastdruid said:
This is a good thing though because without an auto-box trying to "make progress" in a diesel is more akin to one handed rowing.
Not this AGAIN!Listen, a modern diesel revs a bit lower than a modern gasoline engine, but to compensate, the manufacturers handly fit them with numerically lower ratio final drive ratio! (a higher ratio ie engine turns a lesser number of turns for one rev of the back wheels).
THIS ought to be obvious, otherwise Diesels would have to have a large number of ratios' in their gearboxes but they don't. As such a Diesel 5 series does 155mph and has 8 gears, and a petrol 5 series does 155mph and also has 8 gears.
And of course, because VGT is much more common on modern pressure charged compression ignition engines than on spark ignition ones (due to the lower EGT's as a result of the numerically higher compression ratio), in fact, the torque curve is broader when referenced to vehicle speed by the final drive ratio. (ie longitudinal acceleration is higher across a wider band of vehicle speed in any given gear)
f1nn said:
In the interests of fairness, and as an ex owner of an E90 330D which was remapped, I don't have much difficulty believing that a 280bhp old Saab would be there or there abouts in a hypothetical drag race.
I've had a Saab, a 9-3 Aero HOT, which was dynamically the worst car I've ever owned, shockingly s
t in some areas, but they can be made to go fast in a straight line.
I've had a Saab, a 9-3 Aero HOT, which was dynamically the worst car I've ever owned, shockingly s
t in some areas, but they can be made to go fast in a straight line.
indeed.Trying to take a corner at speed is like trying to steer a holed supertanker in a storm
Im no fan of diesel, but i cant help but grin at all the willy waving on here
I doubt anyone will argue a diesel can sound as lovely as a proper 6+ cilinder highly strung N/A petrol, but what is the problem with them being fast? They have their advantages and uses, and a good diesel engine can be a nice thing to drive.
Why not let every driver decide what they like, and respect their taste?
I doubt anyone will argue a diesel can sound as lovely as a proper 6+ cilinder highly strung N/A petrol, but what is the problem with them being fast? They have their advantages and uses, and a good diesel engine can be a nice thing to drive.
Why not let every driver decide what they like, and respect their taste?
daveco said:
PowerslideSWE said:
A friend of mine has a remapped 535d e60 with bigger injectors and removed DPF and you need something very brisk to keep up with that thing on the motorway.
It's probably putting out well over 350hp 
How is the gearbox and engine coping with the extra torque?
its under warranty from merc and according to brabus makes 365bhp and 575lb/foot
it does feel like a quick car, but perhaps now AS quick as the numbers would suggest
Some interesting comparisons going on here. I've owned both an E92 335d and an E34 M5 3.8, and below 100 mph there actually wasn't an awful lot in it. The shorter rev-range of the diesel being compensated for by an auto-box that kept the car accelerating seamlessly
However, by the time they both hit about 100mph the old warhorse's S38 was just coming on song and it would power forward relentlessly, while there was a noticeable drop in shove from the newer car, seemingly getting a bit wheezy
However, by the time they both hit about 100mph the old warhorse's S38 was just coming on song and it would power forward relentlessly, while there was a noticeable drop in shove from the newer car, seemingly getting a bit wheezy
I had a 335d, it was a disappointment TBH, it never felt or was any faster than any other 286hp car, it's maybe because I drive my petrol cars properly or that they were turbo too giving similar levels of power low down.
It's not being diesel, it's the turbo that makes them effortless. Petrol turbos go just as well.
I did have a jaunt against an e60 lci 535d saloon in my old 550i touring, i closed in on it quite quickly. HP always wins when you're in the right gear.
It's not being diesel, it's the turbo that makes them effortless. Petrol turbos go just as well.
I did have a jaunt against an e60 lci 535d saloon in my old 550i touring, i closed in on it quite quickly. HP always wins when you're in the right gear.
philmots said:
I had a 335d, it was a disappointment TBH, it never felt or was any faster than any other 286hp car, it's maybe because I drive my petrol cars properly or that they were turbo too giving similar levels of power low down.
It's not being diesel, it's the turbo that makes them effortless. Petrol turbos go just as well.
I did have a jaunt against an e60 lci 535d saloon in my old 550i touring, i closed in on it quite quickly. HP always wins when you're in the right gear.
It's not being diesel, it's the turbo that makes them effortless. Petrol turbos go just as well.
I did have a jaunt against an e60 lci 535d saloon in my old 550i touring, i closed in on it quite quickly. HP always wins when you're in the right gear.
The old n/a diesels never seemed that impressive
Leins said:
Some interesting comparisons going on here. I've owned both an E92 335d and an E34 M5 3.8, and below 100 mph there actually wasn't an awful lot in it. The shorter rev-range of the diesel being compensated for by an auto-box that kept the car accelerating seamlessly
However, by the time they both hit about 100mph the old warhorse's S38 was just coming on song and it would power forward relentlessly, while there was a noticeable drop in shove from the newer car, seemingly getting a bit wheezy
I disagree, sorry! ;-)However, by the time they both hit about 100mph the old warhorse's S38 was just coming on song and it would power forward relentlessly, while there was a noticeable drop in shove from the newer car, seemingly getting a bit wheezy
ime, the heavily pressure charged 35d engines are better above 100mph, because two things happen:
1) once into >4th gear, the transmission torque limit is removed
and
2) in the taller gears, the turbo(s) has a chance to catch up and actually hit the target boost, and hence the engine actually makes peak BMEP (in the lower gears, the engine accelerates too fast for the turbo (and to some extend 'lecy VGT actuator) to keep up).
Above about 130mph, then yes, drag gets the better of the relatively meager power figure, but i wouldn't say a 35d feels wheezy, sorry!
also i, suspect, if you actually put the cars side by side, the 35d would be a faster car under most conditions. (E35 N5 1750kg, 400Nm @4750, 340bhp @ 6900 (228Nm/t & 194bhp/t) vs 1645kg, 580Nm @ 1750, 286bhp @ 4400rpm (351Nm/t & 174bhp/t) not to mention my but dyno tells me that 286bhp is the lowest a 35d makes on a hot day, on the poorest fuel, and i also suspect the real number is significantly higher........
I know which one sounds better though ;-)
philmots said:
I had a 335d, it was a disappointment TBH, it never felt or was any faster than any other 286hp car.
ime, the 35d feels SLOW! This is because due to the staged turbo's it actually has a very wide, very flat torque curve. This means it doesn't suddenly come on boost, and without that JERK it means it feels slower than it is.You tend to find yourself using a lot of the performance a lot of the time, hence you get used to feeling the steady, but un-thrilling longitudinal accel of the car. However, if you forget, and then look at the speedo, you can find rather illegally large numbers showing when you didn't really expect them!
Also, at around 1650kg, the absolute power to weight ratio is just around 175bhp/tonne, which these days is nowhere near "exciting" ;-)
Max_Torque said:
Leins said:
Some interesting comparisons going on here. I've owned both an E92 335d and an E34 M5 3.8, and below 100 mph there actually wasn't an awful lot in it. The shorter rev-range of the diesel being compensated for by an auto-box that kept the car accelerating seamlessly
However, by the time they both hit about 100mph the old warhorse's S38 was just coming on song and it would power forward relentlessly, while there was a noticeable drop in shove from the newer car, seemingly getting a bit wheezy
I disagree, sorry! ;-)However, by the time they both hit about 100mph the old warhorse's S38 was just coming on song and it would power forward relentlessly, while there was a noticeable drop in shove from the newer car, seemingly getting a bit wheezy
ime, the heavily pressure charged 35d engines are better above 100mph, because two things happen:
1) once into >4th gear, the transmission torque limit is removed
and
2) in the taller gears, the turbo(s) has a chance to catch up and actually hit the target boost, and hence the engine actually makes peak BMEP (in the lower gears, the engine accelerates too fast for the turbo (and to some extend 'lecy VGT actuator) to keep up).
Above about 130mph, then yes, drag gets the better of the relatively meager power figure, but i wouldn't say a 35d feels wheezy, sorry!
also i, suspect, if you actually put the cars side by side, the 35d would be a faster car under most conditions. (E35 N5 1750kg, 400Nm @4750, 340bhp @ 6900 (228Nm/t & 194bhp/t) vs 1645kg, 580Nm @ 1750, 286bhp @ 4400rpm (351Nm/t & 174bhp/t) not to mention my but dyno tells me that 286bhp is the lowest a 35d makes on a hot day, on the poorest fuel, and i also suspect the real number is significantly higher........
I know which one sounds better though ;-)
The M5 was very impressive from 100-130 though, with performance the diesel just couldn't live with IME. Even the S54 in my old CSL didn't seem much stronger at this point
f1nn said:
But I think the point being that a 286bhp diesel will generally be more fuel efficient than a 286 bhp petrol, given the same use.
And that's important to some people.
Yep, couldn't agree more.And that's important to some people.
IMO the only reason to have a diesel over petrol is mpg, and even then you need to be doing some proper mileage for it to make sense. Again IMO.
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