0-100 pass and est 1/4 mile for my E550

[chevota]

I finally managed to get a 0-100 run, and despite a soggy launch it did it in 8.7 sec.

Time and speed is based on the HP scanner so I'm not sure how accurate that is, but it's all have. I started counting when the front wheel speed was .01, and my speed up top is pretty much spot on, per my gps, since I have larger tires in back to compensate for the oem error.
Using a different run a couple weeks ago, which was from ~85-130, I added that to estimate 1/4 mile. It does 0-120 in 11.71 sec, and comparing to some E550 runs I found online, like one car that that did 11.708 @ 119.22, it seems like my time would also be 11.7. Fingers crossed the HP Scanner is accurate enough for this sort of thing...

I think that's pretty good considering it was likely a 15sec car before I started messing with it, thanks to some serious mystery issue.
Stock is supposed to 13.0 @ 108, per automobile-catalog.com/make/mercedes-benz/207_e_class_sports/c207_2/2016.html
Now I hits 108 in 9.77, and in 13 sec I'm at 126.7.
Other than the HP Tuning I did, the only mod is K&N Filters and I'm running 50% Ethanol. All orig parts excluding new coils, plugs & IC pump.

The last month I started documenting time it takes to get to each 10mph increment, and what speed I hit after one second starting at each 10mph increment.
Eg; 90-100 takes 1.17, and 90 +1 second is 98.8.
I was hoping other M278 drivers have saved similar data to compare? Anyone use HP at the strip to see how it compares? Or compared to a Dragy? I'm aware 11.7 seems like a stretch, especially considering my launches are weak and 60ft times are no doubt 2sec. So I'll take any info, data or input anyone has.

[Kendalld13]

I use Dragy fairly often. It is pretty accurate from the times I've used it.

[chevota]

I have a Dragy, but it's Bluetooth and Bluetooth doesn't work for me as a general rule. Like a super power, they won't work in my vicinity.

So you're saying that the Dragy and HP Scanner read basically the same?

[outlaw_50]

I would go Dragy path as time is calculated using GPS signal but Bluetooth is only used as a communication between your phone and Dragy to display time.

Better numbers with this platform could be achieved by TCU tune

[Kendalld13]

No, I would not say they are the same. As outlaw mentioned the bluetooth is to connect to your device, the unit is based off of gps. Unless you have poor signal(which it will let you know) this would be the time that you may receive incorrect data but it will also label the pass as in-valid.

[chevota]

Now I'm confused. I'll rephrase the question: If anyone has used HP and Dragy at the same time, or HP and a drag strip, how did the time stamps in HP compare?
Or, is HP consistantly delayed, or consistantly inconsistant and therefore useless?

Bluetooth usually connects to it, as almost all BT devices do for me, its data thats the problem. So I setup for a run, and its ready and waiting. I gas it, but nothing happens.
Based on what outlaw said, a person could setup Dragy for a run, then turn the phone completely off, make the pass, then reconnect phone to dragy and get the data? I had previously assumed Dragy was mainly the app, plus a better gps antenna and/or accelerometer. Because a typical phone has gps and an accelerometer, so what coud the Dragy box really do other than have better sensors?

[outlaw_50]

you could read more about dragy to understand how it works and calculates time

[chevota]

I researched it before I bought it and it was vague. No mention of accelerometer or phone. It gave the impression it only uses satellites. This is why I didnt buy it long ago because I don't see how it could be accurate without an accelerometer. But everyone raves about it so I got one, only to be more than dissapointed.

[Schnell]

Dragy is quite accurate, always well under a tenth of a second off in my experience. I just reviewed some VCM scanner logs from the drag strip and it was kind of a pain to match up with timeslips.

Are you turning on GPS along with bluetooth? And enabling permissions in your phone for the Dragy app to use location data?

[chevota]

The way I do time with HP is; Ctrl+Right Arrow moves it 1 second, Right Arrow is 1/100th a second. Pretty handy...
The front wheel speed is the only thing I have to start the count with. The question is; does it read that front wheel speed right away, or is there a delay? Of course there is a delay, but I guess the question is it delayed by the same amount through the run and ends up being accurate? It seems to read fine when I start slow, to see if it works, but that means little. For example, I can stop at a sign or light and the speed shows I never stopped. Is the car or HP causing that error?

Dragy won't let me start the app unless I have location on, and Bluetooth is a must, obviously. When loading the Dragy program it says "Sending Sat Data to Dragy". Maybe it doesn't save sat data? Or maybe it assumes my phone is already connected to them? I dunno.
Sat data takes a while so best to do this before I leave the house. Once done with that there is no indication it's ready to make a pass, no "Ready" light, nothing, I just have to assume it'll work.
Since you asked about Location and Bt, I just discovered I can then turn location and bluetooth off, and there is no change. No indication that anything is wrong. In fact, when I click status, it's says both are still connected and two dots of signal strength on each. I can then click back to the main screen and it still looks no different, no clue anything is wrong.
So it's possible that it's simply losing the connection before I can make a pass? I dunno, hard to tell when there is no indication that the thing is ready to make a pass or not, or connected or not.

[Schnell]

Are you tapping on the "Go" tab in the app?

[chevota]

It defaults to that tab when I run the app. But yes, that it where I have it when I try to make a run.
It would be nice if there was some indication that it is in fact ready to record a run.