Dyno Day Saturday 1st June!

[bix]

For all those that don't ordinarily visit the competition part of the forum and those who haven't seen the posting, dyno day is this coming Saturday!

Whether you drive a Mini or an Il Mostro, come on down to Beninca's to check out the power and the glory (with a bbq lunch). Bookings essential and details can be found here: http://www.alfaclubvic.org.au/forum/index.php?topic=10698.0

Please PM me for a booking.

[bix]

Still taking bookings for the Dyno day, with 1 day to go! PM me to reserve a spot.

[Steve S]

Is there any problem if it is raining?

[bix]

Hi Steve,
There shouldn't be any issues if it is raining. We'll place the bbq under cover. You might want to bring a raincoat or umbrella getting to and from your car.

[AikenDrum105]

Great day put on by the club,  lots of myths dispelled and horses escaped - big thanks to the organisers !

I (badly) synced a video of the MS3 ECU log from the super with the wobbly video I took...  here it is in case it's of interest

A couple of things you can see - the Air/Fuel ratio of the wideband sensor in the exhaust (yellow line, top graph)  shows the fuelling map is taking the engine far too rich the further into the top end it goes - which matches up with the increasing soot you can see out the exhaust,  it tops out at about 12.5 (quite rich)  just before the limiter kicks in...

Also,  the white line in the lower graph (spark advance)  shows a peculiar retardation at 5900 rpm onwards (up to 12 deg.)  ...  this was a conservative soft limit I enabled prior to Winton last year (my first track day) which I promptly forgot about.  you can see a dent in the dyno curves as it happens..  the spark cut limiter drops 4 of every 5 spark events at 6600, and there's a hard fuel pressure cut at 6700.

Wonder if there's more HP up there with the right AFR and correct spark advance or if it's just teasing me...

[bix]

Thanks for everyone's participation in the 2013 Dyno day! The weather was looking more like a train wreck early in the morning, but fined up and turned out to be very enjoyable, with a good turnout. Thanks to Colin's skills in managing the cars and street traffic. Thanks to John H for cooking some fine lunch to the hungry masses.

Here are the results. Only the names have been changed to protect the innocent:

[redsky]

Thanks for organising such an enjoyable day Paul. It was great to meet some new people, see some nice cars and go home with a good result from the dyno for the 75.

Cheers Darren.

[John Hanslow]

Thanks for your good work.  It was a great morning and lunch too.

[Garibaldi]

Paul, thanks for a great day. John, the lunch was fantastic. Thanks to everybody that attended, I really enjoyed your cars.

[Neil Choi]

Interesting results.

Also from the readings and I did a quick look up, the rwbhp seems to correlates +/- 10bhp to the advertised kW at the flywheel.  Therefore about 20-25% loss of power through drivetrain.  So if your sales brochure is selling you 184kW, then you should expect about 184(+/-10)bhp at the wheel, ie GTA.

I looked up the specific kW of the M5, GTA, JTS, 75TS (on carsales) as a quick comparison to the rwbhp results, they seem to match up.

Now don't get on my case about difference in dyno's, the day, the weather etc etc.

[Victor Lee]

As a very rough estimate, Neil's observation is correct.  RWBHP = Engine kW  And rear wheel drive powertrain loss is obviously more than front wheel drive. 

That's why these Dyno Days are great (btw, well done Paul & John!), as it compares cars on the same day on the same dyno.  Dyno results are accurate only to themselves.  I reckon if we would've driven all the cars to another Dyno, the RWBHP results would be different but the comparisons between each car would've been the same.

In saying that, I reckon the Beninca dyno must be well calibrated as the M5's numbers were nearly identical from the last time we had a Dyno Day.  It lost 0.4 hp between 28/08/10 and last Saturday.  I mentioned this to Joe and he seemed quite pleased about that his Dyno had maintained good calibration!

[hmd]

You don't need to go to another dyno to get different figures, how you tie the cars down and tyre pressure etc... can all have effect on the readings.

[Victor Lee]

You don't need to go to another dyno to get different figures, how you tie the cars down and tyre pressure etc... can all have effect on the readings.

That may be the case, but on Saturday, there was no playing with tyre pressures, tie downs etc.  Joe treated each car the same: He drove each car on, settled it in, did one dyno run for HP and torque, finished, and drove the car off.  What I'm saying is if each car was also tested the same way at another Dyno, the results between each car would be similar, but the actual HP numbers between the Beninca Dyno and the other Dyno would be different.

[colcol]

As much as people HATE front wheel drives the more compact packaging and better fuel consumption is the reason the way Car Makers are heading, having said that you are entitled to HATE front wheel drive, as its YOUR choice and your money, just don't say that Manufacturers are complete Dickheads for going the front wheel drive, Colin.

[Evan Bottcher]

I found this article on transmission losses interesting:
http://www.modified.com/tech/modp-1005-drivetrain-power-loss/viewall.html