[OzBMR]

Originally Posted by Glemm1970

This is where you can always catch on in the evening.

Nice test road

[boosted]

Originally Posted by B58togo

That is beautiful. Where is it?

Vladivostok, Russia

[Glemm1970]

Originally Posted by Glemm1970

This is where you can always catch on in the evening.

Russia. Vladivostok city.

[M140_BCS]

440i F36 Auto -

MHD Stage 1 93Oct
No mods, bone stock.
100-200kph - 10.1

[M140_BCS]

MHD Stage 2 93 Oct, xHP Stage 3, BCS 100 Cell DP, NGK 94201

100-200kph 8.4

[IMS-340C]

Dude were u on a mountain or something? your slope looks like a roller coaster

Originally Posted by M140_BCS

440i F36 Auto -

MHD Stage 1 93Oct
No mods, bone stock.
100-200kph - 10.1

[M140_BCS]

Originally Posted by IMS-340MP

Dude were u on a mountain or something? your slope looks like a roller coaster

The road looked flat to me....

[IMS-340C]

RWD 340i MPPSK 87 oct downhill run.

Mods: Catless downpipe.

[Lego864]

Originally Posted by IMS-340MP

RWD 340i MPPSK 87 oct downhill run.

87 octane!? I hope that's not by choice

[IMS-340C]

Of course not and it's very frustrating, that's the highest octane I have in my country.

Also BMW has different engines for low octane countries so officially we are allowed to use 87 octane.

Originally Posted by Lego864

87 octane!? I hope that's not by choice

[trescuarenta]

Done some dragy test in my my bone stock 340i xDrive.

0-100 4.88
100-200 12.45
1/4 mile 12.96 (let off a bit too early, think i can get a 12.8 aswell.

I'd say not too bad for a heavy stock car, although that 100-200 needs to be improved drastically.

[yokata]

Originally Posted by trescuarenta

Done some dragy test in my my bone stock 340i xDrive.

0-100 4.88
100-200 12.45
1/4 mile 12.96 (let off a bit too early, think i can get a 12.8 aswell.

I'd say not too bad for a heavy stock car, although that 100-200 needs to be improved drastically.

100-200 have to be around 11.6-8 i think, what gas do you use?

[IMS-340C]

xdrive is slower than RWD after launch but yeah it should do better than 12.45 100-200.

What was the slope on that 100-200 run?

Originally Posted by trescuarenta

Done some dragy test in my my bone stock 340i xDrive.

0-100 4.88
100-200 12.45
1/4 mile 12.96 (let off a bit too early, think i can get a 12.8 aswell.

I'd say not too bad for a heavy stock car, although that 100-200 needs to be improved drastically.

Originally Posted by yokata

100-200 have to be around 11.6-8 i think, what gas do you use?

[yokata]

Originally Posted by IMS-340MP

xdrive is slower than RWD after launch but yeah it should do better than 12.45 100-200.

What was the slope on that 100-200 run?

Yeah mine is also xdrive with full options and i live in sofia which is around 600 meters above sea level and times stock was around 11.8...

[IMS-340C]

Wow, the difference between MHD stage 1 and stage 2 almost 2 seconds 100-200!!

MHD stage 1 93 oct should run easily in low to mid 9s.

Originally Posted by M140_BCS

440i F36 Auto -

MHD Stage 1 93Oct
No mods, bone stock.
100-200kph - 10.1

Originally Posted by M140_BCS

MHD Stage 2 93 Oct, xHP Stage 3, BCS 100 Cell DP, NGK 94201

100-200kph 8.4

[trescuarenta]

Originally Posted by yokata

100-200 have to be around 11.6-8 i think, what gas do you use?

Run was done op RON98. Only tried once.

Originally Posted by IMS-340MP

xdrive is slower than RWD after launch but yeah it should do better than 12.45 100-200.

What was the slope on that 100-200 run?

+1.34% slope. Only tried once, will try again soon.

[IMS-340C]

+1.34% is too much uphill which explain the slow 100-200.

On a flat road you should be in the high 11s.

Originally Posted by trescuarenta

Run was done op RON98. Only tried once.



+1.34% slope. Only tried once, will try again soon.

[Skyhigh]

Guys has anyone done a direct comparison between BMW Laptimer and Dragy? I got quite significant deviations - both in the 0-100 time but also in the acceleration (g).

I have not yet however used Laptimer and Dragy at the same time. They were used one at a time in different session. I also used an app called "Race timer" which gave consistent results with Laptimer. Both are based on iPhone GPS though.

BMW Latimer consistently measured approximately 0,4 sec better time than Dragy. This cannot be just due to GPS sampling inaccuracy...!
It also measured slightly higher peak acceleration. This should be coming from the car sensors, which are accurate.

Where does Dragy get the acceleration from? The Dragy GPS module has no in-built accelerometers, as far as I know and shown on various disassembly videos. The acceleration graph in Dragy is also very unstable, which makes no sense to me. I would certainly feel if my car accelerates with 0,8g one second and 0,5g the next and then back to 0,7g (and not during gear shifts)...

Now, it could be that I (or the car) completely messed up the last seven 0-100 runs, done with Dragy (I hope so ), but still 0,4 sec delta between Laptimer and Dragy is something I find no explanation for...

[IMS-340C]

Definitely 0.4 to 100 Km/h is a lot but don't forget that BMW speedometers are calibrated to read around 3% less than real speed.

In my car 100 is 97, 200 is 195, 250 is 243.

Try a custom run in Dragy 0 to 97 Km/h and see if it's the the same.

Originally Posted by Skyhigh

Guys has anyone done a direct comparison between BMW Laptimer and Dragy? I got quite significant deviations - both in the 0-100 time but also in the acceleration (g).

I have not yet however used Laptimer and Dragy at the same time. They were used one at a time in different session. I also used an app called "Race timer" which gave consistent results with Laptimer. Both are based on iPhone GPS though.

BMW Latimer consistently measured approximately 0,4 sec better time than Dragy. This cannot be just due to GPS sampling inaccuracy...!
It also measured slightly higher peak acceleration. This should be coming from the car sensors, which are accurate.

Where does Dragy get the acceleration from? The Dragy GPS module has no in-built accelerometers, as far as I know and shown on various disassembly videos. The acceleration graph in Dragy is also very unstable, which makes no sense to me. I would certainly feel if my car accelerates with 0,8g one second and 0,5g the next and then back to 0,7g (and not during gear shifts)...

Now, it could be that I (or the car) completely messed up the last seven 0-100 runs, done with Dragy (I hope so ), but still 0,4 sec delta between Laptimer and Dragy is something I find no explanation for...

[Skyhigh]

The speedometer itself has nothing to do with it - Laptimer measures speed and time based on GPS in combination with data (e.g. lateral and longitudinal acceleration, gas pedal %, etc) coming from the car.

Try using it as well and see what it gives you. It actually provides a lot more data for analysis than Dragy and since it is a BMW app, it is nicely integrated with your BMW iDrive to give you some additional displays. The only disadvantage is that it uses your phone GPS.

Race Timer is in turn a third-party stand-alone app for iphone, using (phone) GPS only. Both gave consistent results.

Dragy on the other hand consistently (in a separate run session) yields roughly 0,4 sec higher times.

The only hardware difference between the 2 sessions is lowering suspension springs. Exact same road and place. Maybe 5-8 degrees Celsius temperature difference.

Next time I will run both in parallel.

[IMS-340C]

In that case BMW laptimer uses your mobile GPS which for most mobiles is 1 Hz, the Dragy uses a 10 Hz receiver which is by far more accurate.

[Skyhigh]

That is true and not true at the same time. Looking at the graph from laptimer, augmented data (incl. speed) is collected every millisecond (10Hz). The consistent results from nearly 10 runs confirm that there is no deviation as high as 1 second in the measured 0-100 (which 1 Hz would hypothetically allow). Pretty much all runs gave +/- 0,1s time. I think it is fair to assume that Laptimer gives an accuracy based on 10 Hz sampling, whereas Dragy claims 100Hz (Combination of 10Hz actual GPS, multiple satellite types and data analysis).

I don't disagree that Dragy is or should be the more accurate. I just find no reasonable explanation for consistent ~ 0.4 sec difference between the two...