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      08-06-2008, 10:10 AM   #45
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Can I say something that is very relevant what what TB has just said and I might add that with DCT compared to any other transmission is only partly correct is that the driver will only feel the shift's completion on S4~S6, all the other mode you do not feel the shift at all, you will notice the revs dropping but apart from that nothing else changes before/after and during the shift.

I would like someone to measure that lag on S1~S3 to see if it's as noticeable as on S5~S6, my guess is that it will be less noticeable purely because the surge isn't there to highlight the fact that the shift has been completed.
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      08-06-2008, 10:41 AM   #46
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Quote:
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For me, it is interesting to see how quickly the MDCT shifts once it initiates the shift but based on the "lag" videos we have seen for the MDCT, this metric may not be as relevant in the real world as measuring the shift from the paddle actuation. Additionally, the driver only feels the shift from paddle actuation to the resumption of acceleration.
I think that's fine. I kind of disagree with you on what the driver feels during a shift, but it's not a big deal, and I don't see the point of arguing about a definition.

However, being able to differentiate between Intervals 1 & 2 as I stated above will allow us to see differences between the different dual clutch systems. Which ones have less delay, and which ones execute the shift the fastest? Maybe they are pretty similar? Since we will be ensuring the accelerometer will be operating at the necessary frequency range, we won't have a problem determining the durations of the intervals visually from the plotted data.

Now, another question. Where should be accelerometer be mounted? Assuming it comes with a bracket, it might be best to screw it to the chassis/floor panel somehow. I was thinking about the seat mounts.
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      08-06-2008, 10:51 AM   #47
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I think part of Swamp's frustration comes from the fact that this measurement of Interval 1 (as lucid puts it) was not part of the original scope of this exercise/experiment and that it is not relevant to comparing the DCT's performance versus the competition (assuming you could even get a 430 owner to let you open up his steering column and connect a switch to his paddle wires).

That's not to say that it wouldn't be a valuable addition, because I too think it would be interesting to see what the response time on the DCT is like from one shift mode to another and from one car to another. It may not be, however, as easy as some have suggested to link up the daq with the DCT paddle shifters. Swamp, any thoughts on this?
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      08-06-2008, 10:52 AM   #48
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INow, another question. Where should be accelerometer be mounted? Assuming it comes with a bracket, it might be best to screw it to the chassis/floor panel somehow. I was thinking about the seat mounts.

I think it would be best to mount the accelerometer to the chassis itself. Putting on the seat would introduce second order noise (i.e. the seat reacting to acceleration / swaying back and forth).

But please don't actually screw the device into the metal.

EDIT: Correction....you wrote seat mounts and not seats....that seems good.
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      08-06-2008, 10:57 AM   #49
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Quote:
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Now, another question. Where should be accelerometer be mounted? Assuming it comes with a bracket, it might be best to screw it to the chassis/floor panel somehow. I was thinking about the seat mounts.
I don't have my M yet, but there may be some good mounting spots along the tranny hump (may have to remove some trim/console pieces first). If the accelerometer doesn't come with a mounting bracket, or the mounting hardward requires modification, it shouldn't be too hard to fab up a bracket out of aluminum.
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      08-06-2008, 01:38 PM   #50
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T Bone: Sorry about the attitude. Part of it may just be the difficulty of getting on the same page online. Maybe we are all on the same page here. Although not part of the original scope, I do think measuring the delay is critical and the only way to do that is the measure in some way the paddle or lever actuation. You initially disagreed with this but then later mention a switch on the paddle - this makes me think we are now on the same page. Yes a switch of some sort would work but my idea of a clamp on current probe is 100% non-destructive/non-invasive (perhaps other than popping the transmission tunnel). Once you have "interval 1" and "interval 2" as lucid named them, you clearly have ALL of the information you could ever want - the delay, clutching time and total shift time. My frustration was simply with your statement that you could get interval 1 WITHOUT instrumenting the paddle/lever in some way, which simply is not possible.

We still need cars to test! All we have are:

M3 MT
M3 M-DCT
S2000

We really need some help roping in car volunteers!

Lastly mounting the accel on a seat frame would be perfect. Lot of holes and solid metal attached very rigidly right to the chassis. I could fab a little aluminum mounting bracket.
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      08-06-2008, 03:10 PM   #51
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Is anyone here an established member of 6speedonline or brand specific online forum? If so, that could be a good way to round up volunteers.
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      08-06-2008, 06:12 PM   #52
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T Bone: Sorry about the attitude.

No probs

I can see if one of the M5 guys in SD will volunteer. When and where should I give guidance?
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      08-07-2008, 06:23 PM   #53
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swamp:

PM sent...
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      08-07-2008, 10:41 PM   #54
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Guys, OC clarified he is in for the $100 so we have $500, that is great. That will definitely buy the special accelerometer we'll need. Lucid can supply the DAQ (and is checking into a current probe, right?). Bright folks and computers are available.

We really need cars. Still we only have:

M3 M-DCT
M3 6MT
S2000

How about some GTI owners out there volunteering? We have to have a VAG DSG product MINIMALLY. Sure would like all the cars I mentioned previously.

This will be a great test. Probably suitable for publication if we wrote a good paper along with the data. The manufacturers may love it or may get pissed. Sure it is a bit of a technical pissing content among all the manufacturers but this would provide the hard data. Please help out on the car location task.
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      08-07-2008, 10:43 PM   #55
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Quote:
Originally Posted by T Bone View Post
No probs

I can see if one of the M5 guys in SD will volunteer. When and where should I give guidance?
M5 would be a decent addition to the list to test and answer our old (near) bet about SMG III vs. M-DCT. I would not consider the M5 a "must have" for the test but is a very nice "could include".

We don't have a schedule yet. Too premature without enough cars lined up.
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      08-08-2008, 11:21 AM   #56
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I'm working every angle to bring 'godzilla' to the test...


I've met fellow member 'asaulo1' before, but it never would have occurred to me that we would end up having to call on him for his help.

Caught his post here...
http://www.m3post.com/forums/showpos...3&postcount=14


Let's all keep our fingers crossed that asaulo's friend can bring the beast.

Edit: asaulo just PM'd back that he may be hangin' w/ the GT-R (and the owner) this weekend.
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      08-08-2008, 12:16 PM   #57
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Guys, to clarify, I can't ship the DAQ. It's lab equipment, and I can't use it for more than a few hours/half a day at a time. Maybe a whole day on a weekend. And I'm on travel; will be back on the 18th. I'll let you guys know about the sensors on my end when get back. I might have everything I need for an initial test.
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      08-08-2008, 01:03 PM   #58
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Ugh. I think it is going to be nearly impossible to test all the cars we want to test in a couple hours/day maximum in one city. It will be great that you could get the M3 6MT and M3 M-DCT but much of the value of the data would indeed be the comparisons. I think we are going to need multiple testers and equipment that we purchase collectively to get a lot of data.
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      08-08-2008, 04:58 PM   #59
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OK. We can buy the accelerometer required and a very inexpensive (but still pretty decent) DAQ (data acquisition system) for right around $600 ($597 with tax).

For those of you interested, my equipment selection is:

DAQ
Accel

We can then try to round up a current probe to borrow to measure the shift delay as that is likely outside the budget. Lucids borrowed equipment would save is from donations but a key to getting this done will be to MOVE the equipment around to the locations where the cars are and lucids borrowed equipment is not available for that. I am certain I could write up a little instruction sheet to anyone that is at all computer savy to take the data. These items will be owned by this group and anyone (who won't destroy the stuff) will have access to it in the future. If we get one more donor to get to $600 we will be most of the way there. Footie, enigma: How about pitching in (I'll PM you).

We still need CARS. Thanks OC for the work on the GT-R!

Last edited by swamp2; 08-15-2008 at 12:53 PM.
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      08-09-2008, 01:27 AM   #60
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Quote:
Originally Posted by swamp2 View Post
Ugh. I think it is going to be nearly impossible to test all the cars we want to test in a couple hours/day maximum in one city. It will be great that you could get the M3 6MT and M3 M-DCT but much of the value of the data would indeed be the comparisons. I think we are going to need multiple testers and equipment that we purchase collectively to get a lot of data.
Yes, I agree. That's why I suggested we buy the equipment regardless of what I can or cannot come up with.
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      08-09-2008, 02:29 AM   #61
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The DAQ and accelerometer look good to me. Now, that I see how the DAQ works, this should be very straightforward for measuring both the shift response "lag" and the shift duration.

The only feasible way of doing this seems to be to pass it around. I would suggest only sharing it to those who contribute, except in extenuating and collectively agreed circumstances.

EDIT: Another fun, but unscientific, use for this equipment would be for us 6MT guys to see who kid rip off the fastest shift times.
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      08-09-2008, 01:41 PM   #62
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Quote:
Originally Posted by TLud View Post
The DAQ and accelerometer look good to me. Now, that I see how the DAQ works, this should be very straightforward for measuring both the shift response "lag" and the shift duration.

The only feasible way of doing this seems to be to pass it around. I would suggest only sharing it to those who contribute, except in extenuating and collectively agreed circumstances.

EDIT: Another fun, but unscientific, use for this equipment would be for us 6MT guys to see who kid rip off the fastest shift times.
Agreed on all counts.

If we can make sure the software will log for long periods, the people who bought into it can check it out and take it to track to gather data for themselves after we are done with the comparison.
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      08-09-2008, 08:04 PM   #63
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If you tape or zip tie an accelerometer to the shift paddle would that give you a clear enough "shift demand" signal to record? You don't have to pull the steering column cover and it might be easier than attaching and calibrating a switch. It might also be easier to get permission from car owners.

You *might* even be able to use the same accelerometer to measure car acceleration and shift initiation. It could be messy to interpret the combined signals though.

If it's a bad idea just say bad idea and don't tear me apart for suggesting it. I'm sensitive to intellectual criticism.
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      08-10-2008, 01:53 AM   #64
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If you tape or zip tie an accelerometer to the shift paddle would that give you a clear enough "shift demand" signal to record? You don't have to pull the steering column cover and it might be easier than attaching and calibrating a switch. It might also be easier to get permission from car owners.

You *might* even be able to use the same accelerometer to measure car acceleration and shift initiation. It could be messy to interpret the combined signals though.

If it's a bad idea just say bad idea and don't tear me apart for suggesting it. I'm sensitive to intellectual criticism.
Not a terrible idea. If the lag is long enough it could work and you could see the differences between lag and shift. However, as the lag gets less and less you would have more trouble. Either way you would be needlessly complicating things and introducing a lot of uncertainty into the process. Also there would likely be some blur in the exact time of the paddle actuation based on the paddle movement and stiffness. Gathering data and taking scientific measurements should be done in cleanest, simplest and most cost effective way to get the desired data. This approach is just a bit too far on the side of cheap and cheating vs. getting the desired data and desired quality in the data. The clamp on current probe is about as non destructive as you can get to very cleanly get the paddle actuation signal and get it accurately.
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      08-10-2008, 03:10 AM   #65
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jm1234 has a point in that most folks won't want us to pull their steering column apart even though we won't be cutting into any wires with the probe. if we use a second accelerometer, which is not a bad idea, or a limit switch for that matter, there is nothing to lose (i agree that we should not use the main accelerometer for this purpose). if it records noise, we throw that channel out. and we should be able to use any cheap limit switch for that purpose since we are after a relative signal. the issue would be more related to the mechanics of paddle operation-- determining the actual "click" based on that information. if we use a switch, we can try to calibrate it so that it is activated as close to the paddle click as possible. this obviously would not be as reliable or accurate as a sensor measuring current/voltage in the wire when dealing with very small delays, but it might prove to be better than nothing. but at the same time, it might just create a lot of bad data. anyway, i guess this all depends on how sensitive people will be toward us getting into the steering column. if people are cool with that, then we don't have an issue.
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      08-10-2008, 03:30 AM   #66
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Not an electronic geek but could you not place a contact on to the back of the paddle and rig up a switch which when the paddle is flicked the two contact and create a circuit. No opening panels or messing with wiring. It mightn't give the exact point at when the signal from the paddle is sent from it's own wiring but it should be pretty close.

Just a thought.
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