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      04-02-2012, 10:42 PM   #23
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Quote:
Originally Posted by kmarei
Not sure how pencil geek reached that it has lower power train losses
Here's your answer...

The short answer is...he never did and never said that. The longer version goes more like this...but before we go there, if we're going to drag up a 2 year-old thread, then let's make sure to give you get some updates to it as well. I think most of the deleted content wasn't in this thread, but in PG's own thread that started it all. That thread is now gone along with all of the analysis that went along with it.

In this thread, the OP compared different dyno brands to each other (mustang+dynojet+dyno dynamics, etc) before collating his data. He didn't restrict it to one dyno type and one gasoline octane rating. Most people will read that and realize the basic data collection was flawed because it included too many variables that affect the outcome in rather significant ways (different dyno brands and different octane ratings). The OP ended up conceding this point in PG's thread and later conceded the point that PG's data collection method was more accurate and so was the analysis that went along with it. The OP never said PG was correct...but that his analysis ended up being more accurate.

It's important to understand why PG made the comparison in the first place. It wasn't to prove the DCT had more or less DT loss than the 6MT, it was to settle a dyno cheating allegation that occurred on a Dynojet with California 91 octane gas. That's why it was so important to make the comparison on a Dynojet with 91 octane gas and ignore other dyno's like Dyno Dynamics and Mustang and Dynapack. The vendor was trying to claim that a 6MT with 5.0 PSI boost was making the same power as a DCT with 7.5 PSI boost -- mostly due to DCT drive train losses. With 2.5PSI more boost, that would mean about 60whp worth of DT losses due to the DCT. Most people would never believe that, so PG went to the DynoDB and looked at bone stock cars -- as that's the only way to make a valid comparison that isn't influenced by later modifications.

So PG compared all of the bone stock cars in the dyno database, 6MT and DCT, on 91 octane California gas. Many of the tests came from the same dyno, and some of them were even done on the same dyno on the same day. When you collect the data correctly, those results showed very clearly that the DCT on average, on a DYNOJET, had about 7-10whp more than the 6MT. The original comparison included fourteen dynos to compare, seven DCT and seven 6MT; four of the results were on the same dyno; and two of those were on the same dyno and same day. The entire data set was consistent, and there were no outliers in any of the data. Even the lowest bone stock DCT was still about 2whp higher than the highest 6MT. Two years later, there are even more DCT and 6MT entries in the DynoDB from Cali-91 gas, and to this day, the same statistics hold true. You're welcome to visit the DynoDB yourself and filter to bone stock entries on 91 octane and you will see if you come up with the same results.

That's all PG was saying...was on a Dynojet where the dyno cheating allegation was made, the DCT makes more power than the 6MT on 91 octane Cali gas.

It's worth mentioning that Sal @ Evolve supplied PG a set of data from the Dyno Dynamics which showed the opposite results. On a DD, the DCT had less power than the 6MT. So on a Dynojet, the DCT averages higher, but on a Dyno Dynamics, the 6MT averages higher.

PG's real dyno of choice is the Dynapack -- identical operation as the RRI dyno tests in Europe. That's the dyno that would tell the real truth aside from vendor politics. There just weren't and still aren't enough results on the Dynapack to know one way or the other. I hear a Maha dyno was just installed in Cali, so maybe we can get some results out of that one pretty soon and get a better picture. BMW uses a Maha.
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