[DpG Venom]

Morning gents.

As you will have guessed from the title I got the 320 remapped during the week and got some low figures. Does anyone know if the f31 has an engine safe mode or power cut if it realises the front wheels are not turning? I'm 30bhp down on what I was expecting.

Car is a 2015 with 43k miles on the clock. It's possible that the engine has adapted to short journeys and very little high speed runs.

The extra torque is very noticeable and I've already noticed an extra 2mpg on my daily drives.

[Hooded]

Yes it’s Definitely low on power, your figures are closer to an E46 320d before and after runs.
Who did the remap and before and after dyno runs?
Has anyone checked it over for anything obvious like a boost leak etc?

[robbiep]

It's not a 320d ED is it ?

They have a base of 163PS = 160HP

[DpG Venom]

Haven't checked the turbo or anything as didn't notice any issues. Mate of mine has a dyno and the tune was done by him using Monster Tuning software. Custom map after the engineer saw my first dyno run.

It's a 320d M Sport + so I'm down about 30bhp. Not that it means much as I only drive 18 miles per day!

[fantanas]

Originally Posted by DpG Venom

Haven't checked the turbo or anything as didn't notice any issues. Mate of mine has a dyno and the tune was done by him using Monster Tuning software. Custom map after the engineer saw my first dyno run.

It's a 320d M Sport + so I'm down about 30bhp. Not that it means much as I only drive 18 miles per day!

Maybe your DPF is clogged? Restricting air flow hence power. Check it's condition...

Do you hear any whistling noises? Maybe a boost leak?

How is your air filter? Maybe it needs replacing.

Or maybe their dyno is reading low... what gear did they use for the power run?

I would go for a long drive with some additive in the fuel tank to clean things up a bit. Clean the dpf and injectors.

No safety to cut power off.

[HighlandPete]

Originally Posted by DpG Venom

It's a 320d M Sport + so I'm down about 30bhp. Not that it means much as I only drive 18 miles per day!

I wonder if you have a bit more than the usual amount of carbon matter in the inlet side of the engine, possibly due to lots of short trips.

[fantanas]

Originally Posted by HighlandPete

I wonder if you have a bit more than the usual amount of carbon matter in the inlet side of the engine, possibly due to lots of short trips.

He is down 30hp. It is a lot for just some excess carbon buildup

[DpG Venom]

Originally Posted by fantanas

Maybe your DPF is clogged? Restricting air flow hence power. Check it's condition...

Do you hear any whistling noises? Maybe a boost leak?

How is your air filter? Maybe it needs replacing.

Or maybe their dyno is reading low... what gear did they use for the power run?

I would go for a long drive with some additive in the fuel tank to clean things up a bit. Clean the dpf and injectors.

No safety to cut power off.

Run was done in 4th gear (I've an auto box so it was put into sport + and gear stick across in manual).

No whistling that I can hear. I'll get the DPF looked at and I'll try putting additive into the fuel tank. Air filter was new in July so it shouldn't be that but worth checking.

Thanks fantana.

[fantanas]

Originally Posted by DpG Venom

Run was done in 4th gear (I've an auto box so it was put into sport + and gear stick across in manual).

No whistling that I can hear. I'll get the DPF looked at and I'll try putting additive into the fuel tank. Air filter was new in July so it shouldn't be that but worth checking.

Thanks fantana.

Let us know how it goes

[HighlandPete]

Originally Posted by fantanas

He is down 30hp. It is a lot for just some excess carbon buildup

May be extreme, but don't under estimate the power drop from a choked set of inlet ports. Have to eliminate these sort of issues from the check sheet, when an engine appears to be working normally.

[fantanas]

Originally Posted by HighlandPete

May be extreme, but don't under estimate the power drop from a choked set of inlet ports. Have to eliminate these sort of issues from the check sheet, when an engine appears to be working normally.

I wouldn't expect much from a 43k miles engine. If they are clogged up that much, then there is another underlying cause that is a bigger issue.

Worth checking I guess.

[HighlandPete]

Originally Posted by fantanas

I wouldn't expect much from a 43k miles engine. If they are clogged up that much, then there is another underlying cause that is a bigger issue.

Worth checking I guess.

Agree, if it is that bad, and carbon is excessive, there is more to examine.

[Watsey]

Originally Posted by DpG Venom

Run was done in 4th gear (I've an auto box so it was put into sport + and gear stick across in manual).

No whistling that I can hear. I'll get the DPF looked at and I'll try putting additive into the fuel tank. Air filter was new in July so it shouldn't be that but worth checking.

Thanks fantana.

If it's the ZF 8AT dyno runs should be done in 5th.

[Hooded]

Originally Posted by Watsey

If it's the ZF 8AT dyno runs should be done in 5th.

For some reason Jason at BW Chiptune uses 3rd gear on these auto boxes

[Watsey]

Originally Posted by Hooded

For some reason Jason at BW Chiptune uses 3rd gear on these auto boxes

I've had my car dynoed at BW Chiptune. They told me they use 3rd because their dyno won't go above100mph.

Seemed odd, considering everyone else (where I've been, and Web research) seems to use 5th (iwhich s close to a 1:1 ratio).

3rd and 6th are torque-limited, so using 3rd makes no sense.

[Hooded]

Originally Posted by Watsey

I've had my car dynoed at BW Chiptune. They told me they use 3rd because their dyno won't go above100mph.

Seemed odd, considering everyone else (where I've been, and Web research) seems to use 5th (iwhich s close to a 1:1 ratio).

3rd and 6th are torque-limited, so using 3rd makes no sense.

Jason told me these cars make closest to the BMW quoted stock power figures when tested in 3rd gear on his dyno.

[Watsey]

Sounds like he's told different things to different people.

A dyno should be set up to give an accurate reading of the true output as a starting point, rather than a theoretical published output.

I do think it's strange he uses 3rd when 3rd is torque limited by the TCU.

Anyway, ETTO their own on that one.

[Hooded]

Originally Posted by Watsey

Sounds like he's told different things to different people.

A dyno should be set up to give an accurate reading of the true output as a starting point, rather than a theoretical published output.

I do think it's strange he uses 3rd when 3rd is torque limited by the TCU.

Anyway, ETTO their own on that one.

Yes it does seem that way.

I think we can agree though at least from the example I posted above which was tested in 3rd gear, it does make roughly the power you would expect from both stock (268) and PPK (295) so the remap reading (328) is likely to also be fairly accurate.

I get the point you make about the torque limit in 3rd though.

[Eddamoo]

Originally Posted by Watsey

Sounds like he's told different things to different people.

A dyno should be set up to give an accurate reading of the true output as a starting point, rather than a theoretical published output.

I do think it's strange he uses 3rd when 3rd is torque limited by the TCU.

Anyway, ETTO their own on that one.

The problem is a wheel driven dyno can only estimate Flywheel figures - it cannot be calculated accurately. Especially Dyno Dynamics ones that dont even do a coast-down (which only manage to estimate losses after the gearbox). They should always be run 1:1 (5th Gear in the 8HP) as the gearbox is 5%+ less efficient in 3rd i believe.

There does seem to be a torque flatspot at ~3000-3500rpm both before and after the remap which doesn't seem to be common to the N47. I would try to see if anyone has done any MAF & Boost logs to compare them to your own.

[HighlandPete]

ZF 8HP gearbox, 6th gear is 1:1 ratio.

[Watsey]

Originally Posted by HighlandPete

ZF 8HP gearbox, 6th gear is 1:1 ratio.

6th is also torque-limited though. I think that's why most remappers use 5th : close to 1:1 and full torque available (up to the gearbox limits anyway).

[doncarlyon]

Why would 6th be torque limited?