C230K Dyno Run - Take II

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GrahamC230K

MB Enthusiast
Joined
Jul 14, 2002
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9,755
Car
Audi A3 & S4 quattro
It's along one, make sure you have a drink.

He he. Been at it again. Haven't done any mods yet and I'm on my 2nd Dyno session!

Wanted to clear up some of the bugging questions I had after my 1st experience -

www.mbclub.co.uk/forums/showthread....d.php?s=&threadid=500&perpage=15&pagenumber=1

So, today I wasted another 50 notes here:

www.g-force-motorsport.co.uk/rolling.html

This has to be the most hi-tech rolling road I have ever seen. The whole thing is housed in a air temperature controlled "cell". I was allowed in behind a viewing screen and the whole experience was amazing.

The car was strapped down, wired up and off we went. The size of the fan was rediculous - almost blew me over. With the bonnet down but not latched, it made it flap about like a weak piece of plastic!!

We did 4 power runs in total after calibration. All were the same apart from tenths of a HP. The runs were done in 3rd gear as the dyno was configured to read peak BHP at about 80mph.

With my ASR OFF (but this still brakes the wheels just does not cut engine power) it still flashed on the whole way through the runs however - relevance comes later. I'm sure I was not actually wheel spinning as the dyno is designed and has had 1000+ BHP cars on it, but the ASR certainly was kicking in.

So, to the charts.

1 - Showing the 166.8 BHP @ the wheels plotted against Supercharger Boost Pressure.

bhp_boost.jpg


Now the Flywheel BHP is estimated to be 203.4 BHP. YES, this is estimated not measured. We have assumed a 18% transmission loss which is what the technician said is expected for a Front engine rear wheel drive car, such as a Mercedes or any German make. He said jap cars would be less as they just dont make the transmission drivetrain as heavy duty as the Germans! He advised after my prompting Autos would have about 7% more losses - about 25% in total. We used this assumption as my transmission losses measured rediculously high - giving a total 226BHP if you were to believe them. We think they were inflated as the ASR was kicking in giving an additional resistance which was not real. This possibly also explains the 218BHP figure from my previous session.

Note how BHP peaks and tails off, whilst boost pressure is still rising nicely? Can only be explained by a valve of some sort releasing pressure - perhaps controlled by ECU - that would be a nice one to tweak!


2. - BHP against air/fuel (Lammda sensor)

bhp_airfuel.jpg


Apparently as you can see the fuel is relatively lean near peak BHP - this is where chips can exploit a few extra BHP.


3. - BHP against torque.

Now on the actual graph the curve is meaured in lb, not lb/ft but the torque curve shape is correct.

I have the equation if you want it, but this converts to 207 lb/ft torque.

bhp_torque.jpg



I am happy with these results as even taking the worst case scenario with transmission losses I am still up on power without any mods. I have a much better understanding and am content.

As for now I am all dyno'd out as if nothing else its a bit costly, so hopefully I wont see my car on another one unless it gets really sick.

One thing I did learn: If you want to compare cars - Real wheel BHP is the only measure to concern with and you really need to use the same dyno too!

Any one still awake?
 
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Book me in on Saturday we both go for a day out.
 
Graham - I might be interested in Saturday as well if I manage to get my tuning box sorted by then - it will hopefully be installed Friday latest.

Would they do us an hourly rate or something ? I'd want to run it with and without the tuning box attached.

S.
 
Originally posted by sym
Graham - I might be interested in Saturday as well if I manage to get my tuning box sorted by then - it will hopefully be installed Friday latest.

Would they do us an hourly rate or something ? I'd want to run it with and without the tuning box attached.

S.

I got about 45 minutes for my money. I'm sure you could do a quick alteration of your chip - I did 4 power runs.

Call them and book in - they are friendly people. I may or may not be available Saturday - I have an EBAY buyer collecting their goods.
 
I would like to come too but it would have to be early on Saturday.
 
Originally posted by GrahamC230K

Note how BHP peaks and tails off, whilst boost pressure is still rising nicely? Can only be explained by a valve of some sort releasing pressure - perhaps controlled by ECU - that would be a nice one to tweak!


I have emailed Upsolute HQ today to quiz them if they have ANY control over boost at all - the only way I can believe there 39BHP claimed increase - so lets see what they have to say.


I would recommend anyone to go to G-Force to use their dyno as they measure boost and the lamda (air/fuel) which is exactley what a chip will alter so you can really tell the difference - but.

I was comparing the two dyno results I have - they are not as far out as you may think.


GForce Results

166.8 BHP @ the wheels
ASSUMED 18% trans loss (professional opinion)

166.8/0.82 = 203.4 BHP @ flywheel


Hi-Tech Results

176.8 BHP @ the wheels
MEASURED 40.8BHP Transmission loss
176.8+40.8 = 217.6 @ the Flywheel

A difference yes?

However 18% of 217.6 is 39.1, which is near enough spot on the 40.8BHP transmission losses measured. All the numbers tally, the only difference is that the Hi-Tech dyno measured 10BHP at the wheels more on the day.

From what I understand of Dyno's this unfortunately is not unusual to see such a difference. Could also be down to one was done in a open air workshop, the other in a temperature controlled cell with "dyno correction". Whether it corrects the readings to an environment of average temp, humidity etc I don't know exactley but it does something along those lines as they measured the air temp in my air filter intake for the correction reading.

Basically - the figures are not as wild as you think once you understand the science.
 
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Re: Re: C230K Dyno Run - Take II

Originally posted by GrahamC230K
I have emailed Upsolute HQ today to quiz them if they have ANY control over boost at all - the only way I can believe there 39BHP claimed increase - so lets see what they have to say.


The ECU controls the clutch on the Kompressor, I think Upsolute take advantage of this.. would be nice to know any hardcore facts.
 
C230K Upsolute Chipping

OK, despite issues with the Upsolute.com forum (they have upgraded the forum and some hits you get the new forum, some hit you get the old one - threads not identical on both!) I have some news.


From the horses mouth (ie Upsolute staff) I have found out the 39BHP increase stated on the Upsolute database is for a chip AND pulley!!

How misleading is that?? I am stunned.

The Upsolute chip alone gives approx 20BHP if you are lucky. They also have Dyno graphs on their site for a C230K showing this clearly.

So Upsolute is no more of an advantage of any other chip as far as I can see..............
 
TD tuning can supply a tuning box and pulley kit to give 42bhp. But the tuning box only gives 17bhp!!
 
Originally posted by jimmy
TD tuning can supply a tuning box and pulley kit to give 42bhp. But the tuning box only gives 17bhp!!


Amazingly similar to Upsolute.
 
I now know ASR flashes when "off" but does not acutually assist after approx 50mph max. so that wont have affected my figures. It measures speed from front wheels so will have thought I had mondo wheelspin!

The previous RR (the one that read 176.8 BHP @ the wheels, 218BHP @ flywheel) measured an 18% transmission loss too, so the only difference was it just over read, and with the trans losses being proportional, it just inflated things more. No more confusion!
 
The guys from scoobynet will love me (I mean shoot me) for this, but take a look at these numbers for some comparison.

Look at the Paw (Power at Wheels) numbers..........my 166.8 not so bad!


I guess four wheel drive and 3 diffs means big trans losses.....


http://dyno.scoobynet.co.uk/indexps.htm
 

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