Weird problem

[benzboy]

Hey all, did a dyno run with the C36 today, sounded great on the dyno btw.

I got the plot and looked at the power, 200whp... should be more than that, talked to the dyno guys and looked at the A/F plot, it was a crazy zigzag like you get for closed loop... as it was not coming out of closed loop for some reason.

Wondering if anyone has had this problem before, my guess is throttle position sensor?

Thanks
Tom
http://www.butseriouslynow.com/hosted/tom/P6100014.JPG

[irieite]

Hmm. Good question. I'm not sure whether or not these cars are supposed to come out of "closed loop" at WOT like the old CIS-E cars..

I would try posting this question (along with the photo of the results) on the MercedesShop forum as well. There are allot of knowledgeable techno geeks there who will probably jump on this one.

[benzboy]

Thanks, posted up there, as far as I was aware every car goes open loop at WOT, all 20 odd cars at the dyno day did

[irieite]

Originally posted by benzboy
Thanks, posted up there, as far as I was aware every car goes open loop at WOT, all 20 odd cars at the dyno day did

I'll keep an eye on the thread. I'd like to know whether or not they do as well. If that is the case, then I would suspect any switch that monitors WOT either at the pedal or throttle body. Are your floor mats getting in the way? ;)

[benzboy]

Hahaha, nope, but I have always thought it was a lot quicker at WOT when I first got it, I thought I had just gotten used to it but always had in the back of my mind that something was wrong

[benzboy]

On second thoughts maybe there isnt anything wrong, did a timed 0-100 run in the pouring rain yesterday and still managed a 7.5 second run, be interesting to try a 0-100 in the dry now.

Heh, the traction control doesnt really help the car that much when you try to launch it in the wet, was fishtailing through first and most of second gear.

Also got the traction control light issue sorted... someone had pulled the bulb.

And last but not least, changed the colour of the temp, clock and odometer in the weekend to blue, and goin to change the illuminating numbers on the tach and speedo and such to blue soon too.

[Pagz]

hmmm...it should be reading off maps only at WOT for sure...mine does.
Ratios hitting the mid 16's at WOT will be killing power...it should be way back,and alot more consistant.



...ONLY 18.5KW more than mine stock at the wheels same dyno:D:D:D...you needa get that sorted;)

[benzboy]

Hmm, which brings me back to the throttle again, as ilde is a little bit lumpy as well as seemingly not going into WOT... does anyone know if the C36 throttle is the same as the C280, or if its bigger?

Thanks
Tom

[Pagz]

Na man i dont got one,last time i had mine checked at couTts,cost like $75 for 45 mins...there are a few others around aux with the tools i believe.
it maybe cheaper in the long run just to pay up and have it done!...

[benzboy]

Looks like I might have to get it done, damn it, haha, only had the car for a few weeks too

[benzboy]

Hey All

Good news, dynoed again today, came out of closed loop this time, and A/F ratio is perfect, nice straight line enrichening a little at 4000rpm then staying flat again the whole way.

160kw at the wheels this time (215rwhp) which is a big improvement.

One thing still a little confused about is I heard it hit the limiter and I know it pulls strongly to limiter on the road but power seemed to completely drop off after 5500 rpm.

Oh and the traction control light was flashing the whole time too, haha, I guess these cars dont really like being dynoed.

Still, was one of the most powerful cars there, was only beaten by a 750il BMW 190kw (255rwhp) and a 560SEC 167kw (223rwhp)

Comparing to those cars stats and supposed flywheel power it puts my car about right... chip did stuff all, maybe 5-10 bhp max

[Pagz]

Hey man,
I completely forgot about the dyno day!!(had to work today anyhow)

Good to hear its all running right now!,160@wheels is not bad!,whats the factory spec?

could you not turn the ASR off completely??

[benzboy]

Nope, no ASR button for mine, haha, 206 kw standard, reckon mines ever so slightly more than that, but the a/f ratios and throttle respones from chip is great.

Just very very pleased that it came out of closed loop this time.

Had exhaust sorted yesterday too, sounded like crap with just rear muffler, now its got a foot long resy in it and sounds great, taken all the tinniness out of it.

Sounded awesome on they dyno

[benzboy]

Hmm, I think it may actualy have more power, looks like somehow the limiter came on at 5600 RPM and it didnt even hit the peak of 5750.... this may have something to do with ASR, speed sensors on front wheels (speedo didnt register) or something.

I dont think Mercedes ever intended for this car to be dynoed, haha