disable ESP for dyno mode

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Jul 15, 2006 | 08:40 PM

#21 (permalink)

woody

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Joined: Sep 2004

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From: Leicester UK

Re: disable ESP for dyno mode

Quote:

Originally Posted by feets

oopsie! I forgot about the 6 speed thing.

On the rollers, that was an incomplete thought. I am wondering how close the speeds must be between the front and rear speed sensors to relieve the problem.
I wonder if there's not an easy way to mount a second set of speed sensors on the rear wheels.
When I converted the hot rod to EFI, I was going to need a second crank position sensor at an exact distance from the first. It was only firing half the engine because it was set up for a dual rotor RX-7.

I've got a machine shop at home where the garage used to be. Fabbing something up would be no biggie but I haven't taken the wheels off the car yet.

I had thought about a box with a motor with and a couple of sensors fitted to a toothed wheel too, but just figured it would be easier and cheaper with electronics. I guess its a case of each of us using whatever facilities and expertise we have to hand. How closely the speeds have to match may be an issue like you mention, but I will be taking the speed signal from a rear wheel sensor so the replicated front sensor signal will exactly track the rear just as it would on the road. The mechanical method may need you to try and track the motor speed manually as the car is run up on the rollers. The system definitely needs to see 4 good wheel signals above 30k km/h (I think from memory) to reset the ESP/ABS system after reconnecting any of the sensors. Which suggests the speeds need to be within the bounds of what is expected to occur in real world conditions.

Jul 16, 2006 | 06:50 AM

#22 (permalink)

bobs

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Joined: Oct 2005

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From: Richmond, VA

Re: disable ESP for dyno mode

Guys, one other thing to take into consideration. I read an article a while back about some guys that were trying to dyno a car (I can't remember if it was a 'Benz or a BMW) and they were having trouble getting full engine output because there was a sensor that measured the amount of ram air hitting the front of the car. Basically the car knew that it was being run on a dyno rather then being driven on the open road and cut back the power, supposedly to reduce cooling requirements.

I don't know if our cars have this or not, but since you all are tearing into the ECU programming, it might be worth having a look.

Jul 16, 2006 | 12:53 PM

#23 (permalink)

HDDP

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Joined: May 2004

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From: Charleston, SC

Re: disable ESP for dyno mode

Thanks Bobs, it's not that the RPM's are pulled back, It completely cuts out, like turning off the key at 5,000 rpm.

Jul 26, 2006 | 04:23 PM

#24 (permalink)

HDDP

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Joined: May 2004

Posts: 4,094

Likes: 8

From: Charleston, SC

Re: disable ESP for dyno mode

Quote:

Originally Posted by feets

I know that a couple folks are trying a work around to get the cars into dyno mode and it's peaked my interest.
I've arranged to have one of our Mercedes shop foremen plug into my SRT to see what can be done. Assuming it works, I've got a few things I'd like to try.

1) does it completely disable ESP/BAS/ABS/ETC or do those functions still work.
2) will the vehicle stay in dyno mode after multiple restarts.
3) can we map the steps necessary and repeat them on a hand held scanner instead of the Mercedes diagnostic equipment.
4) are there any visible indications when the car is in dyno mode.

HDDP: do you want ESP to remain active in it's reduced "off" mode or would you prefer it to be disabled?

What other things would you guys care to look at?

Did you find anything out ? Did you try anything ? Did you speak with your Mercedes Guru ? Or was your post just a bunch of hot air ? Updates !!!

May 29, 2010 | 04:40 AM

#25 (permalink)

firemen

Joined: Apr 2010

Posts: 46

Likes: 0

Re: disable ESP for dyno mode

Quote:

Originally Posted by feets

I haven't dug into the 170 (SLK) and 193 (Crossfire) electrical systems very deeply. Perhaps I should start.

The M112 engine has both a crank sensor and cam sensor. Be sure you're reading the correct one.
Most tranny speed sensors on MBs read only the turbine input and output speed. Other sensors monitor pressure and then you've got the full solenoid pack. Communication is made through the cable connection with two white O rings that tend to leak. The left front wheel speed sensor is often used as a vehicle speed sensor.
Again, I haven't dug deeply into the 170/193 cars.
Did the speedometer read correctly during dyno runs? It may be looking at the output speed sensor and still function correctly on the dyno.

I'd be interested in spinning up a front wheel via electric motor while the car was on the dyno. It would require either a robust dual roller stand or a serious stand for the car to rest on as it moves around on the dyno.

*EDIT*
Something just came to mind. I don't know if it will help or not, but I can try digging around in the tech library at work and see what I can find on the SLK for a test or other obscure mode. We haven't hooked up to a SLK to try it on them either. If it works, it may give us a road map to use

This generator stores energy each time the vehicle breaks. I suppose it’ll only do it once then, seeing as the vehicle has to break for the flywheel to gain energy.

Last edited by firemen; May 29, 2010 at 05:37 AM.