Rolling road - BHP well down. Won't rev past 6000rpm.

[E46ACS]

Had my car on a Dyno today, only made 288bhp at the flywheel.

Car would not rev past 6000rpm. Took it out on the road, all fine, revs all the way round like it should. Put it back on the dyno, same again.

According to Dyno Dynamics, the car knows its on a rolling road so a soft limiter kicks in and prevents it going past 6000rpm. Apparantly I can get the dealer to put the car in 'dynamic' mode, and this will prevent this.

Anyone else had this? Or heard of this? Is this right?

Fortunatly I didn't pay for today as it was a friends place who is having a new website and wanted some photos of a proper car on the dyno!!!

[cslbecks]

This wasnt the Evolve dyno day was it???

[SpineOnABap]

Yeah, it's normal. Try it when stationary in neutral - it'll only rev to 6,000.

I thought most reputable tuners/dyno operator types would know how to get round it though!

[E46ACS]

No it wasn't a the evlove dyno day.

What is the way round it? Is to get the dealer to set the car in dynamic mode?

[david]

I had the same problem on a local dyno, coudn't get over 6000rpm and had bad results (around 250hp at the wheels) joined an over dyno little more miles away and got it dyno correcty, 297Hp at the wheels for 347hp at the flyingwheel.

it's mostly because the "dyno operator" doesn't know how to bypass the ECU-DME Bmw system when it cut's at 5850rpm.

last dyno gave me 320.9hp with full SS + remap at rear the wheels (at TMS) and got it dyno again a few day's later in France, same results +/-peanuts

[E46ACS]

Yeah, it's normal. Try it when stationary in neutral - it'll only rev to 6,000.

I thought most reputable tuners/dyno operator types would know how to get round it though!

I don't think he knows too much about BMW's. Will have to find another one that does.!!!

But does anyone know how to get round this though?

[david]

tuner/dyno wont give you the answer, they keep it for them, it a argument to have more clients comming to them.

from what I heard, you nead to plugg in the computer, disconnect a electronic parameter, simulate a fake mesur.

[Thorney]

There are a variety of ways to get round it but yes, its something we've spent time understanding the systems and not something we would openly share on a forum.

[sailorbaz]

I've got a Dyno day on the 1st March coming up locally, will have to find out if yer man knows about this 6K limit thing and knows of a way to get round it.

Its a Sunday, otherwise I'd be giving him your number John to tell him to get round it :whistle:

[Mark CSL]

I know this but not sure how it is exactly.
It is along the lines of run the car on the road drive it on the rollers .
Then switch off engine then hold sport or dsc button for 2 sec / min.
Then run the car on the rollers you get about 3 runs i think it was.

I shall try and find it again the exact way of doing it
:whistle:

[DazBlackCSL]

I know this but not sure how it is exactly.
It is along the lines of run the car on the road drive it on the rollers .
Then switch off engine then hold sport or dsc button for 2 sec / min.
Then run the car on the rollers you get about 3 runs i think it was.

I shall try and find it again the exact way of doing it
:whistle:


Dont forget you also must , have one trouser leg rolled up , stand dead straight with you arms out like a tree , and hum the theme tune to the A team , and then hey presto it should work fine :smt026

[SpineOnABap]

I wouldn't worry about silly rolling roads - just go on how it goes in real-life. You'll know if it's got a problem or not. And if it's fine then all a RR is going to tell you is that by their estimation it produces what you thought it would anyway.

[alexk]

The procedure (I didn't invest more than 30 mins, unlike JT that did and he cannot share on a forum...) is :

1) car off
2) turn key to position 2 (everything on but engine off)
3) press DSC button for 2-6 seconds
4) press sport mode
5) start the car
6) rev car to limiter (it will stop at 6.5k, still)
7) turn off car
8) repeat 1) to 5). The car will now be able to rev all the way to 8k


Alternatively, with the BMW GT1 :

DMS-> Test plan -> Service Functions -> 12. Dyno/Rolling Road function.

I will be able to confirm the above with a video soon that I will dyno the CSL in Sportec http://www.sportec.ch (http://www.sportec.ch/) which is 10 mins from my home ;)

[_Nathan_]

GT1 is the easiest way! few clicks and no wondering if you got it right or not.