avery.whss

I'll post the dyno sheets soon..gotta scan them onto my computer...but it was a dyno dynamics machine..ran 433 stock (I have PP) and with Velos tune it ran 486...they said the open loop is kicking in to late with the tune and a few other things such as detonation with the tune (hopefully velos can fix this) but still some strong pulls..I have a few videos I'll upload in a few hours..

Are the stock #'s about right?


https://i.imgur.com/AhI8YCV.jpg
https://i.imgur.com/Yf6M0mX.jpg
https://i.imgur.com/DRQ0MMc.jpg
https://i.imgur.com/6MPXbja.jpg
https://i.imgur.com/gIVem42.jpg

Sanders27

So just curious and for clarification: the 09 PP was not a change in engine was it? I thought (and prob wrong so ignore my not knowing) but the 09 PP was LSD, brakes and speed limiter removal. I have the same tune and would be curious to your response from them.

avery.whss

it's the same engine just tuned differently from the factory.

Do you notice your car makes a weird detonation sound in 2nd-4th when in high RPMs? the dyno place noticed and so did the dyno something about the open loop not kicking in soon enough..you can kinda hear it in the video too, they said that the car should be around 12 in the air:fuel..not 10.

Sanders27

Hmmm I cannot truly say one way or the other but will run it tomorrow and keep you posted.

Even Money

Don't think so. Increased engine tune over stock didn't come until 2010 models.

avery.whss

didn't know that...i stand corrected...so whats the difference then? Is my C63 running normal numbers for stock?

Even Money

The PP offered for '09 was basically stiffer suspension, no increase in HP.

Your delta before/after seems about right, although it's def reading high, but the increase seems about right

Ingenieur

433 HP at the wheels?
that's only ~4-5% in losses

edit: graph states flywheel power so they estimated a loss factor

abcut973

How do you manage to get a stock and tuned graph?
Do you have a handheld device?

avery.whss

Yeah i do

avery.whss

You can also notice between :18 and :21 that clicking sound that happens with the tune...doesn't happen on stock file.

abcut973

yeah strange...

avery.whss

What do you mean by that? Is it 433 at the crank or wheels?

Ingenieur

In naturally aspirated engines powered by octane, maximum power is frequently reached at AFRs ranging from 12.5 to 13.3:1 or λ of 0.850 to 0.901

10;5:1 is really low
was it detonating?

avery.whss

yeah it was and does...you think it's harmful to the car? or should I go with stock file until it's fixed?.....the guys at the dyno said it should be around 12-13ish so you're right...I sent Velos a e-mail so hopefully it can be fixed.

Ingenieur

graph says flywheel
means they guesstimated a loss factor

the clicking sounds around 3500-4500 rpm

oem AF 13.7 drops to 13.2

the tune drops from 13 to less than 11.2

that clicking might be pinging?

avery.whss

Yeah it sounds more like a ping..I just wasn't sure how to describe it...it deff is running low...at one point it was like 10ish.

Sanders27

So to the question of the drop from 13.2 to < 11.2, is it harmful?

khaloof

I thought the less the number the more fuel, and the more fuel the better for the engines life.
Are you sure its detonation?

Sanders27

Please forgive my ignorance when it comes to the dyno graph but as the ratio drops, why does HP continue to climb? If there was a detonation problem wouldn't the hp/tq curve less linear?

Ingenieur

correct air/fuel ratio
higher = leaner
lower = richer

overfueling can leave deposits and fuel in the cylinder
might reignite if it hits a hot exh valve

but overly rich shouldn't increase power should it?

Ingenieur

how do they measure the AF?
a probe in the exhaust or the O2 sensor via the OBD port?

wag: the timing is too agressive and the engine knocks causing the overfueling

avery.whss

Wag? my timing is to aggressive? Not sure if it's a knock..more of a clicking sound

Ingenieur

wag=wild @$$ed guess

something is going on
you get to 3500 and the AF drops like a rock and goes off the chart at 5500 or so

I would expect it to mirror the oem curve but a ~1 point lower

perhaps the cat is over-saturated and not lighting off properly and the O2 sensor is seeing high O2 and starts fueling

perhaps the software is manipulating the lambda value to trick the ecu into increase the fueling rate

could be a many things but without knowing what the programmer did it is all a wag

I wouldn't run the software until I saw a better AF ratio