High Mileage B7 Dyno Results

[HYFR]

so i get this right....

78k mapped RS 4 gets 302ps on the dyno (corrected)

my 74k RS 4 got 371ps on the same dyno (corrected)

was yours cleaned?
or mapped?

my car was stock and never cleaned

given mine got 70ps more on the same dyno with the same mileage....i come to these conclusions; either:

- My car is great
- His car is crap
- Dyno's are not accurate

[HYFR]

Its good job I put my car on the dyno, otherwise the carbon 'believers' would have you thinking once the car gets "high" mileage (>70k) it starts to produce 300ps !!

[ArthurPE]

one set of comments before I bow out of this so it doesn't deteriorate into 'one of those'
I do believe there is something to be learned from this, but not relating to deposits, but rather flaps

who here actually thinks on a car >60k miles that cleaning alone will yield 90 HP (100 - 10 for the porting), maybe more since this had sw?
90+ HP?
that equates to 2 sec and 12 mph in the 1/4...

I noticed you changed the mass flow numbers? they were twice that before and a ~13% difference...now there is a 33.3333.... difference...
the perfect engine (100% vol eff) should flow:
7500 rev/min x 1/60 min/sec x 4.163 l x 1/2 (banks) x 1/2 (duty cycle, ie, per rev 1/2 cylinders are intake) x 1.210 g/sec (1010 mbar 20C)
~ 157 g/sec, real world, 140+/bank, 285 total...
but even using your numbers a 33% air/fuel increase will yeild at ~50% efficiency power of 16% or 32 HP on a 200 HP basis, NOT 90+

but as I have shown, deposits have <5% impact on flow, ~2% power...max, worse case...

what mechanism retards the timing?
how does something outside the cylinder do this?
can't be 'mixture' homogeneity, ref my post on what is going on, 1500 psi injection, low air spped to begin with, compression efficiency...
so what induces detonation to <beep> timing?

so is it mass Q or timing/detonation? or both? but how?

I am not here to argue like others - they are the results from that specific car.

questioning the results as presented is 'arguing'?
or scientific debate?
one is healthy, the other is not

it's hard to reconcile 90 HP from cleaning alone... (figure 10 for the port)

[Doug_S2]

I had entered 338 and 384 not 138 and 184

[P_G]

there were other issues at play here, most likely the flaps...there is an SIB out on them
won't set a code, only impact performance

I'm not so sure about that Arthur. It may not set a fault code in the ECU log but may do on the OBDII memory. Reason I say this is my EPC fault P2020 was not stored in the standard fault logs but in the OBD II. Only when it had accumulated so many codes did it communicate to the ECU fault log to resgiuter it as a fault code there and then the engine management light came on.

Now I believe that there is a fault with my potentiomemeter on bank 2 but I do wonder whether it could be a combnination of the sensor and the flaps.

Doug, then you tested the movement of the flaps did you do this thorugh VAG-COM? On Audi diagnostic it shows % of movement of the flaps and mine on bank 2 started at anywhere between 6% and 10% and moved through the range to 99%, but upon physical comparison with bank one the white colored arms that you modulate moved through the same range on both banks.

Now I've had the EPC light come on again since having them cleared but Audi Roadside but revving up to 7000 rpm in 3rd or 4th and then allowing the car to decelerate of its own accord will cancel the light, almost as if the airflow past the flaps pushes them back into their zero position and therefore allows the potentiometer to read zero so it thinks there is no longer a fault.

Perhaps carbon build up can occasionally inhibit the tumble flaps full range of movement and the potentiometer readings translated back to the ECU 'turn the wick' down? However the carbon may not permanently adhere and can be cleared by high air flow? Or the heat of air and engine make the carbon soft enough to be malleable and not inhibit the flaps. My EPC light occured at temps less than 10 degrees celcius. I wonder if there is an optimum temperature for carbon build up as a combination of air and engine block temperature.

Just some unproven theories.

[ArthurPE]

I think the reason why the codes clear when rev'ed to 7000 and allowed to return is sort of a calibration or initialization procedure
the e46M3 fly by wire throttle had a similar function
akin to window up/down initialization...

could be airlfow pressure/force, but it is very small, <5 " wc...

as far as carbon inhibiting the flaps, and that initiating some sort of 'limp mode', that sounds plausible

[2manytoys]

Doug, did you check timimg adance before and after the cleaning?

Before mine was cleaned I was only running 9-13 degrees timing. I've since found out that the power boost at 5500/6000 rpm is small at 20-22 degrees but is massive (standard for the car I'd say) at 30 degrees.

Audi are working on my car AGAIN. It's back to 20 degrees (it's not flaps, my whole manifold has been replaced). This time Audi will be looking at why the timing has been pulled back.

[mark758]

Mapping does not fix the issue of restricted flow in the ports - if it does not flow the air or it does not run more timing then you don't get gains.

Does that mean that if a car makes good gains following a simple re-map , say 18bhp, it is probable there are no issues from carbon build up?

[mark758]

my car was stock and never cleaned

given mine got 70ps more on the same dyno with the same mileage....i come to these conclusions; either:

- My car is great
- His car is crap
- Dyno's are not accurate

[Doug_S2]

i have logs of timing before and after this car was down at 20 to 23 degrees before and 28 to 31 degrees after cleaning. The main issue with this car was the air flow was low - 134 versus 184 g/s peak per back - so 100g/s extra in total.

Timing of 9-13 is silly low - I would log maf, <beep>, fuel pressure and mixture for each bank and see what the car is doing. Are you sure that is overall timing or is that each bank timing <beep>?

If you make gains by mapping then you have headroom left - so it either runs more timing and leaner, and/or flows more. A stock car is throttle limited in low gears so even if you don't make peak gains you get more torque in low gears. A lot of maps increase the throttle maps so it feels faster part throttle but is not actually faster at all.

[2manytoys]

Yeah, pretty sure it was done properly. The carbon was pretty bad at the time, and the car was pinging quite a bit too. Here is a pic of what mine looked like at the time:




It's good to see you have noticed the same issue with the timing. At the moment, I'm back down to 20 degrees timing with intake temps around 33 degrees C (outside air temp is as low as 13 degrees C). I'm not sure it's carbon this time, as the build up doesn't look too bad, but who knows?? It's looks roughly like this at the moment (this is of my valves again, after about 2000kms from when they were cleaned).

[Doug_S2]

20 degrees peak ? what peak maf readings do you have? log 003, 031 and 020 in turbo mode in a 3rd or preferably 4th gear run and send me an an email.

[Cornishmoocher]

This probably a daft question........

Why would you log in turbo mode?

mooch.

[Doug_S2]

you get better resolution logging it in turbo mode (nothing to do with turbos on the car)

[Cornishmoocher]

AHHh- See, told you it was a daft question!

Thanks

Mooch