[gtsussex]

Originally Posted by JD6

This is why we should get a 330d xDrive and a 335d xDrive tested together. They may still use an inappropriate correction factor for a 4wd car, but at least it cancels out.

Yup and if I do it as well, we'll have a ACS tuned 335dx figure as well (Hartge won't be different I expect).

[Tengocity]

Originally Posted by johno

My E92 active cruise (when it was working, but that's another story) was pretty good at picking up which lane the car in front was in, and that didn't have a camera. My F32 also has active cruise, but I don't think I've got the KAFAS camera, just the adaptive headlights one. I'll check when I'm back home.

Ah ok, looks like I've been fed duff info at some point! I just went out and checked and compared to the pics that Mark posted, and I can only see the one for vis pack. Looks like no Speed limit display for me then!

However, still amazed at how the system works out which is a car in front that is actually in my lane, without being able to "read" the lane markings!

[dopper99]

@NISFAN do I take it that two cars with near identical power at the wheels would have near identical performance? I know it's not quite as simple as that as it depends on the shape of the graph etc, but what does your simulator say?

[Mattt1]

Identical power at the wheels would give identical performance when rolling, but the AWD would have a better standing start.

[NISFAN]

Originally Posted by JD6

This is why we should get a 330d xDrive and a 335d xDrive tested together. They may still use an inappropriate correction factor for a 4wd car, but at least it cancels out.

At the wheels is the real figure....can't fake that by any means, not even running on flat tyres

[Andykf31]

http://www.mk5cortinaestate.co.uk/calculator4.php

253 puts the power at the crank as 313,
bang on bmw stats.

[NISFAN]

Originally Posted by dopper99

@NISFAN do I take it that two cars with near identical power at the wheels would have near identical performance? I know it's quite as simple as that as it depends on the shape of the graph etc, but what does your simulator say?

Force = mass x acceleration (what a clever guy Isaac Newton was )

or

acceleration = Force / Mass

That's the pure mathematics. Of course it is the average hp through the in gear rev range that is key. All else equal, a 300hp torquey Diesel will be faster than a 300hp peaky petrol, because it is likely to have more area under the curve despite the same top end figures.

In reality, the Diesel will most likely weigh more, so it becomes more complex than just more average hp.

[NISFAN]

Originally Posted by Mattt1

Identical power at the wheels would give identical performance when rolling, but the AWD would have a better standing start.

However, the AWD is likely to be heavier so slower once on the move.....depends on how long the race is

[johno]

Originally Posted by Tengocity

Ah ok, looks like I've been fed duff info at some point! I just went out and checked and compared to the pics that Mark posted, and I can only see the one for vis pack. Looks like no Speed limit display for me then!

However, still amazed at how the system works out which is a car in front that is actually in my lane, without being able to "read" the lane markings!

Ah, that's a shame, I was hoping you were right.

Yes, I was always impressed by the accuracy - even when going round bends. I assumed it detected the angle of my steering wheel and allowed for that when calculating which lane the other cars was in.

[Tengocity]

Originally Posted by NISFAN

Force = mass x acceleration (what a clever guy Isaac Newton was )

or

acceleration = Force / Mass

That's the pure mathematics. Of course it is the average hp through the in gear rev range that is key. All else equal, a 300hp torquey Diesel will be faster than a 300hp peaky petrol, because it is likely to have more area under the curve despite the same top end figures.

In reality, the Diesel will most likely weigh more, so it becomes more complex than just more average hp.

Depending on the increment then the more the number and speed of gear changes will come in to play...

Diesels have been deal helped by the new auto gearboxes, which have reduced the impact of the increased number of gears you need to get through.

[....,,,,..,,..]

Originally Posted by johno

Ah, that's a shame, I was hoping you were right.

Yes, I was always impressed by the accuracy - even when going round bends. I assumed it detected the angle of my steering wheel and allowed for that when calculating which lane the other cars was in.

Not sure exactly how BMW one works, however I imagine something like this.

The cruise is dependant on 2 radar feeds, one will be a wider beam width, the other narrow beam width.

Priority is likely to be given to narrow beam, this maybe by reducing power on the wider beam, therefore all narrow beam returns will give a stronger return.

Wider beam would work more on bends and support information from narrow beam returns.

Pure conjecture on my part.

EDIT:

Found a slide show thingy lol

http://www.slideshare.net/2507052220...ntrol-30621684

http://web-local.rudn.ru/web-local/p...3b3c48c334d3df

[badders74]

Originally Posted by NISFAN

Dyno can be a can of worms IF you compare the estimated crank figures.

The power at the wheels is the true figure, it cannot be cheated.....even by high pressure tyres, lol. It is an absolute un-corrected measure.

This looks to be the same dyno type that Guy and I used....yet the crank estimate is significantly higher. I don't believe the 335d xDrive loses 80hp.....high power Nissan GTR's lose about that at 500 at the wheels, and yes that is effectively a manual box, but it is still AWD, and they run 285 tyres all round.

Guy's run didn't seem to apply as much (relative to my 2WD) drivetrain loses as you might expect (was pretty much the same so you might be onto something there dopper99), so I would say the true figure is in between the two crank figures posted.

Would be good to have a group dyno day with a 320d, 335i and a 328i in the mix.

Did someone mention Mustang dyno? Those are cool.....you can do simulated 1/4 mile runs from zero ala that Audi R8 ad.

I will be mine done on a mustang RR. It should be fun Nisfan!

[SkyJawa]

Originally Posted by MarkG335

Reading the coding forum I think you need the KAFAS camera (lane departure stuff) whereas I have the 'standard' Vis pack camera. I've not managed to figure it our exactly, my camera is built into the mirror housing, the KAFA I think looks more integrated.

Taken these from the web:

My camera (speed warning not codable):

Attachment 1043969

KAFAS camera (speed warning code able - I think!)

Attachment 1043970

So if you have the correct camera I assume that means lane departure can also be coded?

[dopper99]

How did this thread end up talking about cameras.

[Pablo68]

Originally Posted by NISFAN

Force = mass x acceleration (what a clever guy Isaac Newton was )

or

acceleration = Force / Mass

That's the pure mathematics. Of course it is the average hp through the in gear rev range that is key. All else equal, a 300hp torquey Diesel will be faster than a 300hp peaky petrol, because it is likely to have more area under the curve despite the same top end figures.

In reality, the Diesel will most likely weigh more, so it becomes more complex than just more average hp.

That's a little simplistic... The area under the curve is important for as long as you can apply power, however you need to look at gear ratios, final drive ratios etc etc regardless of fuel as well. If Car A can stay in gear longer it will be applying power for longer before changing up (obviously) and so has a brief advantage every time the shorter geared Car B changes gear. One of the (many) reasons you will often see closely matched cars on paper not stay neck and neck all the time in reality in a flat out acceleration run.

So, in the above question, the extra torque of the diesel may put it ahead initially but then the petrol will keep applying the power longer and so it will pull back...so you get that see-saw effect between the two cars.

Fast changing auto boxes have reduced the effect but it still exists.

[sweels]

OP, when your car was on the rolling road, presume you (or someone with you) outside the car, such that you were able to listen to it more clearly hear the 'v8 diesel' noise. Or is that only inside the car?!

Can
Worms
Open

[Mattt1]

I don't get this whole noise issue, inside at least it sounds good for a diesel - probably better than most 4 pot petrols, but not as good as 6cyl and above petrols.

[Tengocity]

Originally Posted by dopper99

How did this thread end up talking about cameras.

Ah sorry, that was my fault!

[Pablo68]

Originally Posted by Mattt1

I don't get this whole noise issue, inside at least it sounds good for a diesel - probably better than most 4 pot petrols, but not as good as 6cyl and above petrols.

The "issue" came about because of claims it sounds like a V8 a while back which I personally consider nonsense... It sounds like a more refined (than a 4 pot), better insulated diesel from the outside, with a hint of a tuned exhaust. Recordings made inside the cabin show that in sport+ mode under hard acceleration there is a noise just like the M135 generated noise coming from the speakers area. Some members have taken umbridge at this.

[gtsussex]

Originally Posted by Pablo68

The "issue" came about because of claims it sounds like a V8 a while back which I personally consider nonsense... It sounds like a more refined (than a 4 pot), better insulated diesel from the outside, with a hint of a tuned exhaust. Recordings made inside the cabin show that in sport+ mode under hard acceleration there is a noise just like the M135 generated noise coming from the speakers area. Some members have taken umbridge at this.

Interestingly I don't think there's any difference whatsoever in the sound between foot down in Comfort, Sport or Sport +.

As said, I'm completely with you in terms of it not sounding like a V8 - it doesn't - it sounds like a straight six (which is what it is for goodness sake - not directed at you). Whether it's artificially enhanced or not (and if it is, it's nowhere near as much as in the 6 series), I really couldn't care.

I've been in a 320d for the last two days and unlike my car, I take absolutely no pleasure in putting my foot down. Forgetting fact there's a little less oomph (which is completely understandable), it just feels strained and unhappy.

That my car (and I assume the 330d as well) sound so good (for a diesel) when you plant your foot is something we should all be very happy about and celebrate.

Now please can we all just agree to disagree. Interestingly it's only a matter of days before I drive the M3 - one of the things that intrigues me is just how convincing the sound is.

[Apl440i or 335d?]

Originally Posted by Pablo68

The "issue" came about because of claims it sounds like a V8 a while back which I personally consider nonsense... It sounds like a more refined (than a 4 pot), better insulated diesel from the outside, with a hint of a tuned exhaust. Recordings made inside the cabin show that in sport+ mode under hard acceleration there is a noise just like the M135 generated noise coming from the speakers area. Some members have taken umbridge at this.

The funny thing is, i read somewhere that the 335i has active sound, and the 335d does not.

I for one can't believe this, and would stake that the 335d DOES have active sound.

FWIW I have also driven an M135i, and the sounds is very simlar to my ear.

Which ever way you cut it, I am just happy to have a nice engine note to listen too as I boot it. If it is fake, that's fine by me, as I prefer the sounds it makes to any other diesel I have heard.

[dopper99]

Anyway, if the engine in the M135i (same as 335i) sounds "so good", why do they have to pipe artificial sound to the M135i?