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.

[chevota]

I got the Dragy to work for a run finally!!! Played with it for a while and triggered it a few times, so I crossed my fingers, did a run, and it worked! It still didn't record all the data it's supposed to, it's never done that, but now I have a grand total of two 0-60 runs, and one 1/8th!

It also ticked a 1/4 which read 12.19 @ 107.7. I was only trying to do an 1/8th, and couldn't stay on it any longer anyway, so I let off the gas after the 1/8th (just before the 10 second mark according to HP). So the last 2 something seconds I was decelerating. So maybe my optimistic estimated 11.7 is actually within reach.

[Schnell]

I got the Dragy to work for a run finally!!! Played with it for a while and triggered it a few times, so I crossed my fingers, did a run, and it worked! It still didn't record all the data it's supposed to, it's never done that, but now I have a grand total of two 0-60 runs, and one 1/8th!

It also ticked a 1/4 which read 12.19 @ 107.7. I was only trying to do an 1/8th, and couldn't stay on it any longer anyway, so I let off the gas after the 1/8th (just before the 10 second mark according to HP). So the last 2 something seconds I was decelerating. So maybe my optimistic estimated 11.7 is actually within reach.

What did you run in the 1/8th?

[chevota]

Guess I forgot that important detail. Per Dragy: 7.95 @ 94.94. Despite several more attempts, I have no additional data.

DA 1808, Ambient 88F
IAT at start 116. By 40mph it was 108, then at the 1/8th is was 115F. I think that's reasonable for 88F ambient? Anyone? At least it's not skyrocketing to the moon like I've seen a few cars do.

Compared to another run I did in HP, if I start at 94.94 mph and assume that was 7.95 sec, adding 4 seconds nets 121mph. Or adding time to = 11.7 sec nets 119.6 mph.
So I'm pretty sure I'm at least under 12.0, the question is by how much?

[Schnell]

Guess I forgot that important detail. Per Dragy: 7.95 @ 94.94. Despite several more attempts, I have no additional data.

DA 1808, Ambient 88F
IAT at start 116. By 40mph it was 108, then at the 1/8th is was 115F. I think that's reasonable for 88F ambient? Anyone? At least it's not skyrocketing to the moon like I've seen a few cars do.

Compared to another run I did in HP, if I start at 94.94 mph and assume that was 7.95 sec, adding 4 seconds nets 121mph. Or adding time to = 11.7 sec nets 119.6 mph.
So I'm pretty sure I'm at least under 12.0, the question is by how much?

The 1/8 trap speed should be good for 120 or 121 in the 1/4. The 7.95 ET would probably get you about a 12.1 in the 1/4. You'll need a better 60' to get in the 11s, I think. But it looks like the power is there.

[chevota]

I know the power is there, but you're right, I can't get it moving from a stop. It's not so much 60ft, it's all thru 0-60. Past 60 I have boost, and the faster I go the better I compare to other cars.
0-60 is usually 4.3 to 5. If I hook up I have crap boost and it's 4.5, if I break traction I have boost but it's not going anywhere, so more like 5.0 >:|
If I want to break 4.5 I have to have a little wheel spin to net some boost, but not too much boost that I lose it in lost traction.

If I power brake I guarantee wheel spin. I can only lean on the converter a little bit, 0 boost. Any more and it'll be all wheel spin. So usually I don't even bother, but if I want to break 4.5 I have bring the revs up a little. I don't have to worry about flashing the converter because the ECU is too slow to open the throttle.

Not sure if all us 2wd versions share this problem? I even bought some pretty sticky tires (Federal 595RS RR 265/35), and with those and a lot of luck I got one 4 sec 0-60. No way they can handle power braking/full power, but I do wonder what would happen if planted on a hot rubber drag strip? I'd love to do that...
Edit: make that two 4.0's Just did another one. I was messing with VVT to bump low rpm power so maybe it worked? Maybe just a fluke, time will tell.

I was looking at https://dragtimes.com/Mercedes-Benz-...ag-Racing.html
I can do the second half of the 1/8th quicker than any of them, and I kinda doubt any could beat me from 60 on, but my 0-60 issue seems unfixable?
The #2 spot seems closest to me, which I bet if I was on a rubber drag strip and could power brake, I could beat that 1/8th. I wonder what his 0-60 is? Probably 3.5 or some unattainable #.
The #3 spot is the best 2wd, which I can clearly beat, but I bet his 0-60 beats me too. Unless maybe I was on the track too.
Both were on a track, both 20F colder than me and lower elevation.

Speaking of traction, the new tires I have in back were sticky enough that I did something I only did one other time, ages ago, which is power brake to break the rears free on purpose, but instead it pushed the car with the fronts dragging. Not sure I want to use these tires again because they're very noisy, but if I do I'll get a size up. I wish I knew exactly what makes them noisy so I could fix it, but I can't tell by looking at them. Other than that they hook and certainly corner better than the Continental ExtremeContact Sport, of same size.
Another difference is the Conti hooked good when new, maybe even as well, but degraded per mile. These Federal are maybe half way down and have not lost traction at all. And despite the treadwear difference, 340 vs 200, the Feds seem to wear about the same. Maybe because they don't spin as much?

I've been thinking about moving my battery to the trunk, for traction, but who am I kidding, I'm way too lazy.

[chevota]

I have a 60' time: 2.15. I know little of 60' times other than my truck creams me at 1.78, and the times on that dragtimes website puts me second to last on the list, where I (barely) beat a stock '07.
So out of curiosity I plugged my # into a 60' to 1/4 mile calculator. It said it was worth 15.47 @ 85... >:| Of course I know the calculator is bs, but overall it seems my 60' sux even worse than I thought.

For the 2WD M278 people here, please share your best method for launching. I'd love to just trial and error it over an over until I get it down, but where I live even just one launch has to be planned out. Mostly the only place is to pull over on the freeway and wait for an opening.
If you have good 60' and/or better than 4.0 for 0-60, I'd love to hear about it. I'd also like to see how others boost comes up on these launches. Maybe I need to detune it so I can power brake?
So far it seems the only way to net more off the line is tweaking VVT, but then I fault out (too much boost @ part throttle) while cruising. It faults because my min turbo DC is too high, but the lower I make that the worse it runs under all other conditions. A DC of 40 works with the oem VVT. A DC of 50 is better overall, but I have to adjust VVT to prevent a fault, and that adj is in the wrong direction for launching.

Seems to me that downpipes/Cat removal wouldn't really do much for this, but I'd love to hear before/after stories of those who have done it. And things like weight, like I have >100lbs of crap in the trunk and usually >1/2 tank of gas.

[Schnell]

You're going to need a sticky tire on the street - there's no way around it. An LSD would help, too (I have one but haven't installed it). My best 60' on the street is a 1.95 on R888R tires, but that was one of only a few quick tests. Best 0-60 also on the street was 3.8 (3.6 with rollout).

If your boost comes on abruptly because of the wastegate settings, it's only going to be harder to hook. Launching off idle and bringing the throttle up gradually seems to work best. At the track, you obviously have more freedom to load up the converter a little due to prepped surface.

The 1/4 mile calculators assume everything is ideal (for example, you have perfect traction).

[chevota]

Damn. So that's power braking I assume? How much gas are you giving it, and to what rpm? I can't give it too much gas, as-is, because the brakes can't hold it.
I don't suppose you have an example run you can post for me to analyze?

I suppose I could try lowering the power <4k or so, then maybe power braking might work. Hmmm... I did notice a couple 0-60 runs improved when power overall was down. I'd make some mistake, or simply unexplained, but when I'd check the data the 0-60 improved a bit while the rest was slower. Not great 0-60 runs, just oddly better than when it made more power overall.
They were also smoother and felt slower 0-60. I'd be on it for ~2-3 seconds and I'm already thinking this tune is hozed, but somehow 0-60 wasn't. So weird.

Maybe I'll try that Wheel Torque vs VSS again. Do you use that thing? I never set it to lower than oem before, I just know the oem values do not limit it so I assumed it was another HP mistake that did nothing, or something else altogether. Oem is like 214 up to 18mph, but my torque can be way beyond that. I also wonder if it's basing that 214 on overall wheel speed, or just the front, or just the rear? The front would be the obvious choice, in my mind, but who knows what they did.
I guess I'll turn it to like half of oem and see if it responds. Thanks

Also, I never one-leg it, so no need for a posi.