olszowa12

About a month ago I dyno'd my car and was dissapointed with the results to say the least.
The runs were done on an intertia dyno (I'm not sure if its the right name for it)

Any ideas what could be the cause?
I am planning to finally do a tune this winter and would like to sort things out beforehand.

Thanks in advance


RWHP:

Even Money

well...to start with, is the car completely stock? what size rims/tires? type gas? temp/humidity? how many fans?

also, help us out by converting to whp/tq, not sure which numbers to use from your chart..

olszowa12

Car stock with 2nd cat delete.
Temp was about 20*C / 68*F
One fan.

I edited my first post - shows WHP, temperature and torque.

Even Money

I wouldn't be too worried, especially if the car drives OK. That dyno could be like a low reading mustang dyno. I mean low compared to a dyno jet. So a dyno jet might read 360 whp for a stock c63, and a mustang dyno could read 330....or sometimes higher.

Go back for some more runs to see if it's consistent. Any other 63s use that dyno? And when you get your tune, go back again. If you have a good delta, then that's all that matters, provided the car is running right.

olszowa12

I don't know any other C63s in my area so I can't compare my results.
I know about the mustang dyno but the guy at the shop told me that the readings here are usually accurate and that 30 horses getting lost is not normal.

It seems to me that the car is running fine but it's difficult to notice the difference (-30whp) when I drive the car all the time and most of the time in the city.

khmergod

Could the cat delete be the cause?

CoolBDPhenom03

Cars can "lose" 15-20% hp on a dyno compared to engine output. It's just the nature of inefficiency to the wheels. That and all dynos read differently, as was already pointed out.

dodger63

Its most likely the adaptation's of the ecu with all you city driving

khmergod

When I did my dyno, I stomped it all the way there through every light, and didn't take shortcuts. From first to fourth run 377whp/329tq to 406whp/354tq. Each run the car got more hp. After 4th run it was getting too hot so I stopped there. Sometimes you need to re adapt the ecu.

P.S. My tires were almost bald.

prindone

How many kilometer have you car?
How many PS you have i dont found it on your dyno test?

M156Beast

Those numbers look correct. This type of dyno reads lower than a dynojet. It could have calibration issues or some other issues...dont know.


just make sure you put it on the same dyno after the tune. to see the gains


one other question, whi is the graph sloping at low RPM, were your tires slipping?

olszowa12

I will beat the 5h!t out of my car before the next dyno.
The tires were not slipping.
To be honest I am usually very skeptical about the skills of such workshops in Poland but every petrolhead I know advised me to use this dyno.

In which gear should we do the runs?
4th or 5th ?


Prindone:
The car has 146'ooo km.
The dyno showed 420PS.

M156Beast

Do the runs in 4th gear.

When you take it next time set your rear tire pressures @ 36-38PSI

Dont forget to set your C63 on Dyno Mode from your interior commands, do you know how to do that?, did you do it on your last dyno run?

olszowa12

Dyno mode was on.
I'll try in 4th gear next time- last time we did the runs in 5th gear.
The tire pressure was 40PSI.

sbce90

I wouldn't worry tbh, main things with dyno is the difference in numbers before/after tune.

ShaneN.

As in the tranny getting all slugish from the city driving? Is there anyway to reset it? I noticed in the e55 section there was a way to reset the learning/adaptions and some of those guys seem to do so, every couple days.

edit: nevermind...

https://mbworld.org/forums/c63-amg-w...ep-method.html

olszowa12

Thanks for all the input



Anyone tried this?

khmergod

Yea, run it in 4th. Run it hard before you get there. Try to get 3-4 runs or until it gets really hot.

P.S. I'm a big fan of your estate. The drop and front is *******g sick.

prindone

I Could tell you that it can be possible, mine too was about this power before i tune m'y ecu.
This Is normal m'y Audi RS4 B7 was about 370 instead of 420ps because of the oil circulation tank that Is a big problem on this car.

The car is Never about the power the manufactur say, just the GTR pass the power that Nissan say they have original! (and If they say this its just for the law like this not too much taxes in Europe)

Dyno mode??? Could someone explain more about it, im interested?

bhamg

A number of us. I felt no difference. IIRC an MB tech later confirmed it doesn't work for the C63. I have a Dinan M5 and was told to do five full-throttle runs to redline through a few gears (safely) to reset to more aggressive adaptations. Seems logical...

olszowa12

Thanks. I made it look mean, now it has to drive that way so it needs a tune


Yeah the RS4 issue is quite common.

Here is how You get into dyno mode:

Mort

I think you get the same thing as dyno mode in our C63s with the trans in M and set ESP to Off. We do not really need to use Dyno Mode.

CoolBDPhenom03

I think 5th I supposed to be the best gear.

bhamg

This. I've done runs in 4th and 5th gears with little difference, but 5th is the one.

Mort

If you dyno in 5th and do not have a tune or the speed limiter raised you run into the speed limiter at 155 mph before you reach max revs. Therefore your max hp will be low because of the lower revs. Otherwise 5th is 1:1 and is supposed to be the correct gear to dyno in.