Request for gents with a data logger:

[Sims]

Afraid not, they generally frown on people putting their car on rolling roads as it is. One time with my S4 one dealer even said it may invalidate my warranty running it on a r/r because it is 'abnormal driving conditions'.

I can see their viewpoint, just as they are not keen on launch controls.
But surely Audi will use RR's, and will know how best to get the optimum result.

[ArthurPE]

as P_G noted, although you can set the torque split (used more for calculating the power) the car may/will still detect slip, and cut power...

the only way I know to alleviate this is to use a load vs inertia dyno...
that way the load can be adjusted to ~40:60 and wheel speeds can be matched by varying the load...can't won't see slip...
and if you go this route, run a steady state test vs ramp/accel..

[pippyrips]

Afraid not, they generally frown on people putting their car on rolling roads as it is. One time with my S4 one dealer even said it may invalidate my warranty running it on a r/r because it is 'abnormal driving conditions'.

I can see their viewpoint, just as they are not keen on launch controls.
But surely Audi will use RR's, and will know how best to get the optimum result.

Audi definitely use rolling roads. Those that watched the documentary on the making of the R8 will have seen the engines being bench tested prior to build & each car being dyno'ed just before they come of the production line.

It would be interesting to know if this procedure is done on all RS models and what difference in figures there is between bench testing and dyno (as well the factors they apply on the RR.)

[P_G]

I'm sure Audi do use dynos but don't like their customers doing so to 'recreate the experience' Why would you need to, they have done it for you already. Don't you believe them?

[Sims]

... Don't you believe them?

Don't start that one again please.

[ArthurPE]

Audi definitely use rolling roads. Those that watched the documentary on the making of the R8 will have seen the engines being bench tested prior to build & each car being dyno'ed just before they come of the production line.

It would be interesting to know if this procedure is done on all RS models and what difference in figures there is between bench testing and dyno (as well the factors they apply on the RR.)

now that is a heck of a question!

[S2tuner]

as P_G noted, although you can set the torque split (used more for calculating the power) the car may/will still detect slip, and cut power...

the only way I know to alleviate this is to use a load vs inertia dyno...
that way the load can be adjusted to ~40:60 and wheel speeds can be matched by varying the load...can't won't see slip...
and if you go this route, run a steady state test vs ramp/accel..

Maybe you could READ what we say when we say we have a braked (load)dyno and don't dyno cars in inertia mode, because inertia dynos just make up for a nice "toy" for people to be impressed with in a workshop, not a tuning TOOL. We run ramp brake runs which usually take around the same amount of time in gear on the dyno as on the road in the same gear, so that surely won't be an inertia run?

[ArthurPE]

maybe you could check the attitude...

what brand/model of dyno do you use?
it's a CarTec correct? website?
I thought they were inertia type?
the ramp time is to provide a baseline for the calcs ~ the same time range as on the road...
if it's a load dyno there will be a large bank of radiators (or resistors) somewhere with cooling fans on them...

an inertia dyno can be braked, but is not the same as a load dyno (electric motor, eddy current, water or hydraulic pump, etc.)
if the time is measure to calc power it's inertia, a load type will measure some variable (pressure, current,etc.) directly proportional to torque...

not saying what yours is, but interested in reading about it...


edit: found their website, looks like a nice machine, associated with snap-on

Maybe you could READ what we say when we say we have a braked (load)dyno and don't dyno cars in inertia mode, because inertia dynos just make up for a nice "toy" for people to be impressed with in a workshop, not a tuning TOOL. We run ramp brake runs which usually take around the same amount of time in gear on the dyno as on the road in the same gear, so that surely won't be an inertia run?

[S2tuner]

The attitude is only because you keep bashing our dy

[S2tuner]

The attitude is only because you kept bashing our dyno (it calculates losses and doesn't measure them, it's an inertia dyno, it can't take 40-60% torque split, etc) until you got to read about it. It has eddy current brakes that can hold 460kW (that's 625wHP) on each axle set, so yes it it is a proper brake dyno. I'm glad you've read a bit about it and don't think it's an inertia dyno anymore

[ArthurPE]

The attitude is only because you keep bashing our dy

'bashing' or being skeptical?
this is a discussion forum, where both sides are required to for it to be of any value...

if sonny's car actually ran 7.5 (corrected) that is impressive
I have no reason to believe it didn't

but that has nothing to do with deposits (or their removal) and was achieved by the cats, manifold, exhaust & software...

it also indicates (by my reckonong) a 6-7% HP boost at peak, and ~ the same across the torque band...but not a 370 to 440 increase ~20%
or even 370 to 413...11%

I do believe you raised stock power ~415 to 440+

your dyno measures losses?
you measure each axle speed?
or use a tach pick-up signal?
you adjust each load to acheive a 40:60 power split and identical drum speeds?

[S2tuner]

The attitude is only because you keep bashing our dy

'bashing' or being skeptical?
this is a discussion forum, where both sides are required to be of value...

if sonny's car actually ran 7.5 (corrected) that is impressive
I have no rerason to believe it didn't

but that nothing to do with deposits (or their removal) and was achieved by the cats, manifold & software, etc.

it also indicates (by my reckonong) a 6-7% HP boost at peak, and ~ the same across the torque band...but not a 370 to 440 increase ~20%
or even 370 to 413...11%

I do believe you raised stock power ~415 to 440+

After cleaning, the car was showing 404 PS I think

[ArthurPE]

After cleaning, the car was showing 404 PS I think

so ONLY 34 HP or 9%+ ?

no way, no how...

[Sims]

After cleaning, the car was showing 404 PS I think

so ONLY 34 HP or 9%+ ?

no way, no how...

I am curious, how can you be so sure from your vantage point?

[ArthurPE]

After cleaning, the car was showing 404 PS I think

so ONLY 34 HP or 9%+ ?

no way, no how...

I am curious, how can you be so sure from your vantage point?

I dwell in a place called 'reality' where we are bound by the laws of 'physics'

not only 'sure', absolutely positive to a 100% degree of certainty...