[dockishen]

hi all,
i put my e92 330i on a dyno after a remap and got some heartrending numbers!

250hp( originally 268 as per specs)
372NM( originally 300 NM)
this after a remap!!!!!

I had to have the control box changed a year ago and then had an oil service done , the car is 07 plate but has only 35 thousand miles on the clock. changed the air filter to a K&N unit.Bought new at 12000 miles

now the interesting part is the tech at the local BMW says this is perfectly acceptable.the dyno guys tell me that i need walnut blasting , the local mechanic says clean the fuel injectors ( i use redex on a regular basis ).
now personally i cannot see how a low mileage car which has been looked after well can loose enough power that the remap brings it to only 250 HP?

booked this in for a 2 day intensive fact finding mission,maybe someone here has any helpful hints or diagnosis? I need to get to the bottom of this

many thanks

dockishen

[pmmcbl]

Redex is not a good thing to put on your car. I would rather use vpower to help things a little. Are you sure the remap isn't to blame? Who did you use?

[old grey steve]

Originally Posted by dockishen

hi all,
i put my e92 330i on a dyno after a remap and got some heartrending numbers!

250hp( originally 268 as per specs)
372NM( originally 300 NM)
this after a remap!!!!!

I had to have the control box changed a year ago and then had an oil service done , the car is 07 plate but has only 35 thousand miles on the clock. changed the air filter to a K&N unit.Bought new at 12000 miles

now the interesting part is the tech at the local BMW says this is perfectly acceptable.the dyno guys tell me that i need walnut blasting , the local mechanic says clean the fuel injectors ( i use redex on a regular basis ).
now personally i cannot see how a low mileage car which has been looked after well can loose enough power that the remap brings it to only 250 HP?

booked this in for a 2 day intensive fact finding mission,maybe someone here has any helpful hints or diagnosis? I need to get to the bottom of this

many thanks

dockishen

Tough one this, first of all how healthy was the car in terms of power in the first place? In terms of power one set of rollers for instance will show a set of figures you could drive to another place carry out another rolling road test and receive back a different set of figures so raw numbers sometimes have to be looked at analysed accordingly, if that's the correct thing to say.

Re losing the power you've stated, yes I can imagine on raw figures it must have come as a bit of a surprise, afterall you'd of not set out to pay money to lose engine potentual would you.

So rewinding all the events back to zero and looking at what's going on is the right/correct way forward.

Starting with the car itself, low mileage doesn't mean as much as you'd think, some cars if they've been driven moderately don't produce the same "feel of power" thst higher mileage well exercised cars do, driven a few high mileage 330i's that feel free lively and lower mileage"town based cars" where they feel a little more reigned in and still feel tight and don't feel as responsive. And you feel this from behind the wheel and no figures will change this feeling.

You mention walnut blasting this can make a difference for sure, but not in terms of making up gaps in potentual HP loss, it'll improve throttle response, low down pickup, on/off throttle response and pickup as well as feeling slightly freer revving and smoother idling with the added bonus of being slightly more noticeable re starting from cold and idling, so it's a good move especially on a low mileage 8 year old car but thus alone won't get your HP figures where you want to see them, thsts more deep routed I think.

So looking at the remap for instance it may be discovered that this is partially responsible in terms of supplying raw data seen some mapped cars that have had their maps dicected only to discover that where it counts the fuelling, ignition has been found wanting and by adjusting it accordingly you are able to restore some unlocked potentual, you say the torque figures are up BHP appears to be down so perhaps there's some truth in the map maybe needing some tweaking.

Other items yo look at are a bit more involved, where your BMW visit may help. A change of plugs maybe a smart move forward again condition, age of plugs could have a small impact, other things to consider are injectors and HPFP's done a few HPFP's on 330's and injectors diagnosis will help here plus it will be able to look at other potentual power sapping issues and general issues such as vanished units and actuators.

Using a fuel cleaner for instance isn't a bad move but you don't have to use it that regularly decent fuels the best remedy going forward but if you've got a leaking injector then potentials being lost(mind you you'd of perhaps had this info passed to you from the dyno operator as he'd be able to spot this type of isdue-I hope)but as you e not supplied any into of your OP I'm guessing that info hasn't come your way.

The BMW dealer may we'll see an ECU fault internally due to the re map and may suggest uploading latest software re setting all parameters

In all honesty the way forward is the action you've already undertaken. Let us know what happens

[dockishen]

thanks for the replies,
@pmmcbl i agree that they may not be ideal but its only every 8000 miles i use the redex.
@steve thanks for breaking it down , the engine is very free revving and does not feel restricted at all, i used DMS who i have used before and found very good.
new spark plugs in April last year, the dyno guys didn't mention any leaking i will upload a dyno map for reference.

as i mentioned the control unit was replaced last year and new software downloaded maybe this might be at loggerheads with the remap?>>
have driven 24000 miles long distance though on slowish A roads in the last 16 months and sometimes had a bald spot when accelerating hard around 2000 rpm.
new clutch and flywheel as well, bought this from main dealer .

i know the way forward is intensive search but still heart rending

[old grey steve]

Originally Posted by dockishen

thanks for the replies,
@pmmcbl i agree that they may not be ideal but its only every 800 miles i use the redex.
@steve thanks for breaking it down , the engine is very free revving and does not feel restricted at all, i used DMS who i have used before and found very good.
new spark plugs in April last year, the dyno guys didn't mention any leaking i will upload a dyno map for reference.

as i mentioned the control unit was replaced last year and new software downloaded maybe this might be at loggerheads with the remap?>>
have driven 24000 miles long distance though on slowish A roads in the last 16 months and sometimes had a bald spot when accelerating hard around 2000 rpm.
new clutch and flywheel as well, bought this from main dealer .

i know the way forward is intensive search but still heart rending

DMS will agree will produce a decent map, Rob done my E46 330d back in the days and as they do all their stuff on site they'll of produced I suspect a decent map at least

You mention a 'bald spot' at around 2k so there's something to work on more importantly I'd say is that any peaks, troughs etc. would of I'd assumed be detectable on the rollers, if that were the case I'd of hoped the operator would of given you some indication.

So where to go. I dare say that once in BMW's hands a series of 'faults/issues'will be highlighted from here they'd be able to follow a predesignated test plan that will help pin point what's required.

Silly question but have to with the info you've got tried calling DMS to see what they feel you could be looking at? Might be worth having a go at this to get a 2nd valiuble opinion. If you've got details of the run maybe they could cost their eye over what's been done.

There are sadly many reasons fur a 'potentual' loss of power and as your title says it appears on paper to be a mystery. But with time and thought with a decent diagnosis hopefully things will be bought into the open.

[Robin330i]

There is no way that you have gained 72Nm after a remap on a NA engine!

[old grey steve]

Originally Posted by Robin330i

There is no way that you have gained 72Nm after a remap on a NA engine!

Thats what I was kind of thinking hence asking the re mapper DMS to have a look. Those sort of figures in terms of torque are 335i esq. type numbers and diesel numbers on a 330i give or take you'd be looking at say 13-18 or so BHP increase with perhaps on torque maybe 20-25NM's or thereabouts.

[AlanYoro35i]

With a remap you should only see 10% more than Stock power on bhp and torque!!!

[dockishen]

hi all attached is the dyno file ,
thanks for the interest, the dyno has been appropriately calibrated,
i did call up DMS and they were extremely busy so said they would call me back still waiting for their call

[Lawton438]

Are these figures corrected? Is it being measured at the wheel, as 250hp would be around 280-290bhp without transmission losses at the crank.

I believe your torque and bhp are meant to cross at 5250rpm.

Personally before you go on a hunt to find out what's wrong I'de take it too another dyno and get a comparison between the two as I personally think you could be chasing ghosts here.

[AlanYoro35i]

The torque curve doesn't seem right to me... all the curved lines i've seen should be a nice linear line yet your one goes up n down

[OGM2LCI]

Originally Posted by AlanYoro35i

The torque curve doesn't seem right to me... all the curved lines i've seen should be a nice linear line yet your one goes up n down

+1 should it not be a fairly straight line? Especially considering it's an NA engine??

[dockishen]

hi,
the measurement was at the wheel and yes the dyno chap did say the torque was all over the place.
Is the power output mentioned by BMW at the crank????

its also partly because of this i was puzzled .
this was one of the three runs made and i will try and see if i can get it dynoed again,

any other ideas about the wierd curve , i thought may be flash original program and dyno then remap dyno again.
good idea ? bad?

[Lawton438]

250bhp at the wheels will translate to about 280-290bhp then as there approx 15-18% transmission losses.

And yes all hp outputs by Bmw are at the crank well any car manufacturer in the UK on that note.

[vegnomeat]

Besides, a re-map on a NA engine is just wasting money,

[dockishen]

Originally Posted by vegnomeat

Besides, a re-map on a NA engine is just wasting money,

i would disagree with you on that as has been shown by the gains i seemed to have in the torque figure ,
almost 25% increase in torque is not to be sneezed at.

thanks for the clarification of the HP figures and what manfacturers quote , i didnt realise that it was at the crank!!,

so i dont need to cry??


tentatively
dockishen

[Lawton438]

Not necessarly. The c63 amg for example gains huge amounts of power just through a map.

So some n/a cars can respond well to just a map. But the majority of n/a cars don't

[Kerr]

That graph isn't right at all.

There is no way you've got that much torque either.

[vegnomeat]

Seriously, on that engine any gains will be minimal if at all. You won't be able to notice it at all.

[Robin330i]

Originally Posted by dockishen

i would disagree with you on that as has been shown by the gains i seemed to have in the torque figure ,
almost 25% increase in torque is not to be sneezed at.

thanks for the clarification of the HP figures and what manfacturers quote , i didnt realise that it was at the crank!!,

so i dont need to cry??


tentatively
dockishen

I am crying with laughter and disbelief that you think you have gained 72nm from a remap on a NA engine.

[dockishen]

Originally Posted by Robin330i

I am crying with laughter and disbelief that you think you have gained 72nm from a remap on a NA engine.

If you have anything contructive to say please do , mocking only pisses people off.

I invite criticism and i have put the numbers i got up there .if you think they are false they are your opinion ! no reason to be an A"£$£$hole.

on another note i am going to get it dynoed again in another rolling road to see if there is any change , interesting to see the result .

cheers

[djgandy]

250 might be about right. Dyno numbers are not always perfect to start with, and without a reference it's even harder to infer much.

And looking at your chart, maybe the dyno is just screwed. Because it is very unlikely that a 330i is putting out 370Nm with just a tune.
Unless you have a supercharger mounted on that engine, it isn't going to happen.

Bare in mind, that is nearly as much torque as the e92 M3 and the turbo charged 335i.

What gear did they do the run in?