Put the Plus on a dyno

[MoRS6+]

how do I upload the graph? Its a pdf and its too big to attach?

Mine was a pdf as well. I opened it in Adobe Reader, then used Faststone screen capture 5.3 (the last freeware version they did) to do a scrolling capture (as it goes off the screen). You now have a screen capture which you can either just save as a .jpg (this is the default save option anyway) or edit before you save (I blocked out the number plate and added the title, all done from within Faststone). HTH.

You can get it here: http://www.oldapps.com/fast_stone_capture.php

[paul_23]

Interesting - a few of you say N75 boost solenoid was replaced to get the power. Apart from lower dyno output, what characteristics did you notice before it was changed as I have been logging block 115 and checking boost levels and not sure if the N75 is to blame for its behaviour so would appreciate others feedback (my N75 was changed just over a year ago so should these be swapped out every 12 months??).

Cheers

[spurtle]

+1 on how to diagnose N75 problems (tho' sorry for the off-topic - no disrespect dk!)

[HYFR]

+1 on how to diagnose N75 problems (tho' sorry for the off-topic - no disrespect dk!)

no worries, its ON topic, as I needed an N75 to hit 481PS ... feck knows that a N75 is thou ... I just paid the man !

[MoRS6+]

Any chance of getting that graph up Dave? Would really like to compare ours as they are both standard plusses and both done on the same dyno. I fear my N75 may be causing too much boost somehow

[HYFR]

I tried that screen capture thingy ... It just made a video? Pm me ur email and I'll send it

[MoRS6+]

I tried that screen capture thingy ... It just made a video? Pm me ur email and I'll send it

Weird. It should d/l a zip file and just unzip or unrar it to a folder where it will put the fscapture.exe file. There is no installation for it, just the fscapture.exe which you can just put straight on the desktop. Dead handy to have it in the quick launch icons as well.

On the d/l page I posted above, click where it says FastStone Capture 5.3 in the left box and then in the right-hand box, scroll down to where it says

Download FastStone Capture 5.3:

FastStone Capture 5.3 (1.2 MB) <click this on that page

Then, unzip the fscapture.exe to either a folder or to the desktop.

When you click it, it will launch a small rectangular box with different capture options - the sixth icon along is 'scrolling capture' for when you want to capture something that goes off the screen (such as a large pdf for example).

Anyway, will pm email and I could do the capture and post both together for comparison.

[MoRS6+]

Righteo then, the 2 runs together:




They look pretty similar to be honest, I'm missing that tiny bit at the top end just on that penultimate peak at about 5650rpm.

But I still wanna know what's going on with my torque?? Why is it reading that high for a stock car??

[batty]

my opinion on the early torque spike...
at the start of a power run on a rolling road, the operator floors the throttle at low revs.
during this sudden demand for power, the torque converter allows slip and then assumes a locking-up phase.
i'm not sure why an auto-box is designed this way - either to portect the gearbox from a sudden spike, or to give the occupants a more refined ride.
during the short time of slip then lock-up, there is a false torque spike sent to the wheels due to the inertia of the engine.
the rolling road is very sensitive to recording these spikes, hence the graph shows a false torque spike at low revs.

I had my plus rolling-roaded last year, and i noticed this false torque spike.
You could assume that the reading on an auto car is only correct during full TC lock-up i.e. after around 3k revs.
The other thing that puzzled me, was the figures from Audi stated max torque from as low as 1950rpm, but you can never see this on a rolling road, as the TC will not lock-up after a sudden power demand (flooring of the throttle) until way after this engine speed.
The figures from Audi must be tested on a dyno directly from the engine i.e. without torque converter.

[Doug_S2]

The majority of standard RS6s always <beep> timing a lot so the ecu is always controlling timing so it is hard to get repetetive runs that match each other. Tuned cars usually are a lot more repetitive becasue the timing is adjusted to that car.

wastegtes are so weak on the RS6s you get a big difference in boost control with the N75 operating only slightly different between cars