Mapping a 520D - worth it?

[ubiquity]

Looking into mapping my 520D, wondered if anyone else had bothered mapping this or similar, what were their experiences like, and was it worthwhile?

Have seen few options, from a default map to actually a blueprint. Most seem to suggest decent bhp increase and an even better torque increase, while returning better mpg.

Most interested in a small increase in power, but sorting flattening the torque curve slightly (find I often either bog down or wheelspin when trying to get onto a roundabout in bad traffic).

Also getting my swirl flaps removed, and some places have recommended I go for a blueprint after this to balance, while others have said don't bother.

Any advice would be greatly appreciated!

[DanceswithUnix]

(find I often either bog down or wheelspin when trying to get onto a roundabout in bad traffic).

I have yet to hear anyone say they regretted a remap, but in my Diesel Alfa I didn't bother as the clutch felt a bit marginal and on an oldish car the extra torque would probably have worn the clutch in no time and they aren't cheap. That on-off response just seems to be how modern turbo diesels drive though, and many people love it. I don't, so I traded the car in for one with a petrol engine

It does hike the insurance up a bit as well, though if you do a lot of miles better economy might counter that.

[Butcher]

Have seen few options, from a default map to actually a blueprint. Most seem to suggest decent bhp increase and an even better torque increase, while returning better mpg.

You won't get both more power and more mpg at the same time (due to thermodynamics), you'll have to moderate your right foot for much mpg benefit.

Most interested in a small increase in power, but sorting flattening the torque curve slightly (find I often either bog down or wheelspin when trying to get onto a roundabout in bad traffic).

That can definitely be fixed with a map, but you'll need one customised for your car, not just a default map. Most people seem to want even peakier torque curves as it makes the car feel faster, so that is what a default map is likely to be.

Also getting my swirl flaps removed, and some places have recommended I go for a blueprint after this to balance, while others have said don't bother.

It depends what they mean by a blueprint. To me a blueprint is basically rebuilding the engine which high spec parts built to a closer than usual tolerance. That's going to cost thousands, so I assume that's not what they mean.
I'd suggest mapping after any other mods to the engine you're planning to do though, so the map can take them into account, unless you're just going for an off the shelf default map as then it won't matter.

Why remove the swirl flaps incidentally? Are they causing problems?

[ubiquity]

Many thanks for the advice - much appreciated.

- Power vs mpg - appreciate that more likely to use the extra power will mean lower mpg, but just generally pottering around at same speed should result in better mpg (this is my selling point to the wife... )

- Mapping - This was what I meant by a blueprint; not just some factory map that is applied to any car with a wide tolerance, but one tailored specifically for this vehicle.

- Swirl Flaps - known issue on the Beamers, although they were strengthened in my model (57 plate e60 520D M Sport). If they fail they fall into and total the engine; even if they don't fail, they have a tendency to stick over time and remain open.
Can simply replace them with blanking plates, but obviously this does mean a modification that is not taken into account on the original mapping. Would do this first (at the same time as replacing 3 failed glow plugs!) and then look for a bespoke map to flatten the torque curve and give a bit more power (not looking for some clutch-destroying increases).

[Butcher]

In that case, I'd suggest getting it mapped properly on a dyno rather than something downloaded over the net - you'll get a much better map and you can have it customised to your taste.

[ubiquity]

Many thanks for the advise; that is what I will go for.

The garage that I am getting do to the work of replacing the glow plugs and removing the swirl flaps to replace with blanking plates suggested it would not need a re-map afterwards, but they don't offer a custom remap, so will look for other places on the South Coast that can offer this.

[kalniel]

Won't the engine just adjust correctly to the changes without needing a remap?

[DanceswithUnix]

Won't the engine just adjust correctly to the changes without needing a remap?

Yeah, I can't see why the engine would know or care if the swirl flaps are missing as they are just there to disrupt the airflow at low revs. I know someone whose BMW tried to breath them though, it was a very big bill to fix.

[Zak33]

It is viable that a remap makes you smile. All the ones I have ever had did.

But they also tend to over fuel quite heavily, and smoke under throttle. They do look mapped when being followed and will stand out against the crowd by any who knows what's what.
They can kill clutches and in the case of many cars, dual mass flywheels- i have zero knowledge of the BMW drive train, so do a little research first. Turbo wear will be higher as the boost will be higher for longer, so keep the oil changed

It's BOUND to speed up tyre wear... shock news... more power etc.

I took one off my recently aquired Skoda, for all the above reasons. It's just about choice.

[Hoonigan]

I've been looking to get my VW Golf GTD mapped. Apparently it's very reasonable to expect 220-230PS (up from 184) and in the region of 500Nm of torque (up from 380.)

Can currently manage 65MPG if you're super careful on the motorway but realistically looking at an average of 50 including city driving etc.
Waiting for a quote back from Celtic Tuning in Glasgow, and see what their fuel figures come out like.

[ubiquity]

Need to check if they use a common drive train, so possibly the 520D has same as a higher spec...

Have been doing quick and dirty changes of the oil for the turbo mid-interval, and not looking for big torque or bhp increases tbh, just a more rounded torque curve with a little more oomph!

[kalniel]

But they also tend to over fuel quite heavily, and smoke under throttle.

Isn't that insta MOT fail these days?

[Zak33]

Isn't that insta MOT fail these days?

could well be. and will be in future. Depends on the tester I think... but its more noticeable on a road when you follow someone with a mapped diesel.. it's very obvious with many of them!

New 2018 MOT test regs are:

"Your vehicle will get a major fault if the MOT tester:

can see smoke of any colour coming from the exhaust
finds evidence that the DPF has been tampered with"

[DanceswithUnix]

But they also tend to over fuel quite heavily, and smoke under throttle.

My diesel did that for a while, until I replaced the stuck open EGR valve. So that was lack of oxygen rather than over injection of fuel that caused the soot, but the effect probably looked much the same (though it will have decreased when revs were high enough that the turbo pressure could swamp the bypass left by the egr valve). So much to go wrong in a modern engine...

[MattyC]

Mapping should just bring the fueling and timing closer to what the engine wants, it might give you nothing it might give you loads. Manufactures map a selection of engines then add something like 10% to the safety margin then use it for all engines in production.

[Friesiansam]

some places have recommended I go for a blueprint after this to balance, while others have said don't bother.

What many tuners are calling "blueprinting" these days, is nothing of the sort.

This http://www.enginebasics.com/Advanced...eprinting.html gives you some idea of what true blueprinting really is.