|I'd love to
you've been up to...
Tell me all.
interested in stories or pix...
Show me the Data!
|So what about
Show me the Data of the Van!
I like reading the conclusion first
Inspired by the MLM dyno-day/shootout, Eric Lange, of Dutch Mini Mailinglist (DMM) fame organized a meet at BCCP to (finally) get an idea if all the efforts to make our small beasts go faster had been as effective as we hoped.
I'd arranged to pick up Marcel, a friend of mine, early in the
morning (7:30 am!), as BCCP isn't what you'd call 'around the
corner' of my place.
Those that know me have already seen the problem in the former sentence... And I indeed didn't wake up till 8am :)
After rushing over to Marcel, and enjoying a cup of tea with him and his dad (no matter how much in a hurry you are, there's always time for a cup of tea or coffee), we headed towards BCCP.
Obviously we arrived there late and had missed the
introduction by the operator, Hans, and the first session, which
featured Sander's MPi Cooper.
After saying hi to the some old, some new to me (and some I didn't recognize at first :) fellow listers we watched the next Mini in line, Taeke & Kim's Estate be put through the motions.
The graphs of the first bunch of Mini's were interesting, but Hans was glad that my Van also took part, as this showed some real problems, which makes it that much more interesting. Apart from the 'plopping' sound in my exhaust, a result of an 'afterburn' in the tailpipe, I don't experience the problem(s) found during 'normal' (pretty fast) driving. The afterburner again is a result of high levels of gas and oxygen leaving the engine unused. I'm told that instead of the smoke seen coming out of other Mini's during the test, the Van produced a nice 'rolling' flame out of it's tailpipe :)
The session for each Mini consisted of 4 runs. The 1st was a
run in 3rd gear, the 2nd a run in 4th gear, the 3rd a run in All
gears ('change up') and the last a Fast acceleration test were
the engine is accelerated about 500rpm, then released for about
1000rpm and then again accelerated.
The whole idea behind a dyno-test, also called a rolling-road, is to test the car like it was actually driving on the road, but having it stationary while doing so.
This way the actual behavior of the car can be tested while it stays in one place.
Most sites on rolling road test warn you about the fact that
it can be quite gruesome. In my experience there's not much to
worry about; as long as you don't do foolish things that you
wouldn't do on the road either, your car should have no problems
in the test-bench.
The only exception might be the fact that during testing the throttle is released suddenly a number of times. And, as some Mini's showed, that may caused some smoke-problems on engines that are not in top shape anymore.
Another point made on mentioned websites is to prepare for a rolling road test. It's fairly obvious that you'd check the state of you engine and it's fluids, as well as make sure stuff like the air-filters etc are clean. Ok, it may be obvious, but I simply hadn't had the time to even look at my Van since I'd returned from my trip to Austtria the week before. The Van had performed fine during that trip, so it was in decent shape. I did have time to check the oil while waiting for my turn though, but that was about it.
As the Van had never been tested before, and all 'tuning' was
done based on gut-feeling, it would be interesting to see how
much of the advertised 92bhp (@ flywheel) actually got to the
street. My estimate was that it wouldn't be putting out much over
70bhp, which meant about 50bhp on the road. This is based on the
knowledge that in a 'normal' helical gearbox about 30% of the
power is lost.
This knowledge is based on a myth though, as Hans had explained, but was more than happy to explain again to the late-comers.
And the argument he made sounded good to me; Imagine having an engine putting out 300bhp. Losing 30% of that would mean 100bhp would be absorbed by the box. Given the amount of energy that gets lost and the heat that would produce, this would simply fry the box, which doesn't happen.
He said that in his experience a Mini-gearbox 'absorbs' about 12-13bhp (there is a way to test/calculate accurate loss I'm told, which how the corrected numbers on the MLM shootout are calculated). As the measurements on rolling road tests are done at the wheels and most listed bhp-numbers are at the flywheel, this meant we had to add about 12bhp to our numbers to get flywheel-numbers.
All in all Hans and his colleagues were very helpful, always willing to answer any questions and just plain friendly. That alone is a big plus; it makes doing the test so much more fun. I think that all of those there that day learned a lot, not just about their Mini's, but cars, engines and tuning in general. Based on the responses since, most look like they're hoping to return soon, even though a rolling road test can be a tad expensive, especially when next to the testing (as was all that we did this time around), actual tuning is done.
Apart from the data and thus (possible :) information gathered from the test-session, one of the biggest eye-openers for me that day was that when you have a test done, be sure to included a 4-gas-test, preferably with a unit linked to the test-system, as this will give you so much more information if there is any room for improvement.
Anyhow, as mentioned; fun was had, expectancies were either
met,shattered or exceeded and we all got nice graphs to take home
and show around :)
As a (IMO very big) bonus, we also got the test-data emailed later that week, which can be analyzed with an app from the people that made the test-bench. Most of the graphs you see on the next pages are derived from that application. It also means that if you'd like to see another graph, all you have to do is ask (and probably wait a while :).
So, who where there ? Have a look:
|Mark assists||Mark's engine||It's a
gas gas gas
|Mark's off||Rolling||Rolling||Rolling||Headphones save lives|
And last but not least, some pix to show the laid back atmosphere of the day:
Ok, enough with the story and pix, let's get to the hard data and graphs!