[wolves]

^ Nice run!

[CalCarNut]

Originally Posted by XenaBimmer

Ran a 13.6@101 in my 328 w/ BMS stage 1 even with a bad 2.1 60 foot. This was my first time ever taking this car down the track as well, and didn't get to do any other runs
I'm on the stock run flat tires and launched pretty easy brake torquing to 2k rpms.
Sub 13.5's should be do-able with more practice!

It takes a lot to knock off 1/10th. Your 60' is pretty damn good and your trap speed too.

[F30 Epal]

What's the best possible way to launch the 6-speed? Hold the rpm at 2k or 2.5k or maybe 3k rpm with the DTC off?

[jamoka3]

This was my 7th run at the track with the Active 8 piggy back. It was set at the stock set point a MAP 6. I have the 93 Octane tune. My car has the N26 engine (got car in New Jersey.)
At time of run outside air was 71 degrees. I had the car in Sport + and in Sport shift mode. *Launch control was activated at start.

[CalCarNut]

NIce...puts a x28 in the 14.1-14.2 range (stock) though. hmm.

[jamoka3]

Originally Posted by SoCalDave

NIce...puts a x28 in the 14.1-14.2 range (stock) though. hmm.

Outside air temps about 72 degrees. Completely bone stock N26 engine.And I'm xdrive and auto...

[XenaBimmer]

The 60 ft sure is improved with the x drive, I would have thought that the et and trap would be better with the Active tune though

[jamoka3]

Originally Posted by XenaBimmer

The 60 ft sure is improved with the x drive, I would have thought that the et and trap would be better with the Active tune though

I had the AA8 box set at the stock map6 it can go up to map 9. With a few more bolt on's we'll see what it really can do! I'm pretty happy tho considering I have the N26 engine and my times have improved.

[jamoka3]

Max Well over at the X3 forum has developed an acceleration model for the X3 and several other BMW model types. He has dedicated a lot of his time and has been plotting drag times vs the simulation for actual dragway slips.
He has offered to run my 1/4 times and some 0-60 times in real world numbers...He should be completed soon and post a graph to help solve some more questions, we may have about RT, Trap speed and 60' information.

[Max Well]

Originally Posted by jamoka3

Max Well over at the X3 forum has developed an acceleration model for the X3 and several other BMW model types. He has dedicated a lot of his time and has been plotting drag times vs the simulation for actual dragway slips.
He has offered to run my 1/4 times and some 0-60 times in real world numbers...He should be completed soon and post a graph to help solve some more questions, we may have about RT, Trap speed and 60' information.

Greetings, all,

Jamoka3 joined a number of other forum members at Island Dragway 21 Aug 2015 and ROBNYC shared a few of his slips with me. As the folks on the X3 forum know, I have no background in Physics, engineering, or automobiles at all, but have always been fascinated with the performance of our BMWs over the years. Last year, after reading about how the new series X5s actually had better highway mileage than our smaller and lighter X3s I researched the mechanisms behind such.

I initially analyzed the HP required to maintain constant speed across the range of all of BMW’s line. It quickly became clear how important Cd (coefficient of drag) and frontal surface area are in allowing vehicles to slip through the air. If anyone is interested in that initial project, it can be found at: ‘Horsepower and Speed – the graph’ [http://x3.xbimmers.com/forums/showthread.php?t=1004702 ]

As we in the X3 realm are looking forward to the new G01 models to be released next year (to also include 40i and true M variants), I began wondering how the aerodynamic and HP changes they are planning might affect the X3’s performance, but I couldn’t find any information online.

After a fair amount of research I found a Master’s Thesis from 2002 by Matthew Snare in which he and his Professors developed a series of equations to allow a ‘Dynamics Model for Predicting Maximum Acceleration Rates of Passenger Cars’. So I developed Excel spreadsheets using their equations to allow one to change parameters of the equations unique to each model type. Although my initial studies were mainly on the X3, it seemed reasonable the simulation’s construct should work for any vehicle (as Matthew Snare validated with 13 different vehicles in his initial research), as long as one has the correct data such as Cd, frontal surface area, weight, HP, etc., ... If one is interested in the particulars the main thread can be found at: ‘!X3 Acceleration Files – Master List!’ [http://x3.xbimmers.com/forums/showthread.php?t=1149189 ] .

With that as a brief background, jamoka3 asked in a PM if there was a way to look at his 0-60 mph times, as Island’s drag slips don’t provide such (only the eighth and qtr mile times provide the speed). By superimposing the Distance and the Speed charts one can at least get a rough idea if one’s curves can be extrapolated by following the simulation’s curve as a rough guide. I’m attaching the summation chart here at jamoka3’s request, as well as a chart summarizing his drag slip times. As can be seen, his tuned runs closely approximate the simulation’s curve, so it would seem reasonable to suggest he ran about 0.5 sec faster on the 0-60 mph time, or around 5.5 sec, c/w the ‘stock’ time of roughly 6.0 sec.

Apologies for the length of the post, but to just place a chart here without any background seemed a disservice, and I hope it provides some assistance to jamoka3’s question. For more focused 1/8th mile and ¼ mile views of his ‘stock’ and ‘tuned’ runs, those can be found in the Master List thread.

[FSociety]

Thank you Max Well jamoka3 K320

We need more F30 N20/N26 to test

[Max Well]

Happy to help out, Rob.

As one more way of analyzing the data, I took the model's 328i xDr construct and ran it with different permutations of HP in 10 HP increments. From the base of 241 HP down to 191 HP and up to 291. That allows a series of curves to be generated showing how HP may affect the slope of a vehicle's performance graph in this estimated simulation.

These 'reference curves' (I use that term loosely) thus allow one to make a rough extrapolation of the HP differences between runs in those two short time intervals. In Jamoka's example at the 8.4-9.9 sec interval, his stock run data point is -31 HP from the model's stock 328i curve, whereas his best run is at +2 HP in c/w the simulation's stock curve. So it would seem reasonable to conclude, in this small sample of one stock run and 2 tuned runs, his 'tune' allowed a 33 HP increase in that narrow time (and speed) interval. I would leave it to the statisticians to determine how many runs of stock vs tuned one would need to reach statistical significance, but that is not the point of this layman's analysis. This is simply a chance for those of us without dynos and high-end software to be able to put at least some science behind the performance of our vehicles.

I'm also including the chart for the 13-14.6 sec interval where it would appear the increase is about 27 HP.

[Max Well]

Although many probably already have worksheets to use at the strips, as I made this template for the X3 folks thought I would share here. I'm also including a blank template of the simulation's 328i xDr acceleration curves through the 1/8 and 1/4 mile time frames which should make it easy to plot one's times while at the track to see how between-run modifications may affect the performance if desired.

[Max Well]

A summary of this thread’s drag slips was made for reference then plotted against the sim. The sim’s curves have been set at sea level for continuity. References suggest up to 1200 feet altitude doesn’t have a major effect on the performance of turbocharged engines, which may be why correction factors below this altitude aren’t common. http://wallaceracing.com/altitudecorrection.htm

I have included split times for the intervals to allow a more detailed look at performance as it removes rollout differences, (a summary of their usefulness can be found at http://www.motorsportsvillage.com/timeslip.html ).

I’m also including a template graph for the 60 mph interval. By identifying the estimated reference HP curve for the 660’ and 1320’ times, 0-60 mph times can be approximated. Examples – K320 and XenaBimmer are roughly at +25 HP for both distances, so that would put their time around 5.250 sec on the 60 mph graph. Jamoka3 tuned is around the sim’s stock line, so that run appears close to 5.525 sec, whereas his stock was at the -30 HP reference line which would equate to 5.975 sec.

Considering the number of variables which can influence the end result (temp, barometric pressure, altitude, weight, tires, track ...) if a stock run can be obtained before tuned runs a reference point for that individual day it might prove helpful when trying to assess tune changes or comparing runs on different days.

[Max Well]

In response to Trekk's question as to how 100 lbs weight difference might affect the 0-60 mph time of the 328i xDr in his thread 'Dinantronics 328 vs stock 335' [ http://f30.bimmerpost.com/forums/sho...1081631&page=2 ], I ran the simulation at varying weights. Here are the graphs of the 0-60 mph and 13-15 sec intervals:

[jamoka3]

Went back to the track on 10/16/15 with the bimmerpost crew.
Im running the 2014 328i Xdrive, auto, N26 engine. Bone stock!.

CAR #384
Only upgrade is the Active Autowerkes Active 8 Module.
*Used 8 gallons of 101 Octane Race fuel made with race-gas Racing fuel Concentrate and 93 octane base Shell V power fuel.
http://race-gas.com/

[jamoka3]

Best run of the night was 13.210 in the 1/4 mile, very happy with this!

Also I had NO issues and no malfunction indicators or drive train malfunctions.
Map 6 -I used daily with 93 Octane.
Map 7- Used at track with 101 Octane, shifted great and felt very fast!
Map 8 - Used with 101 Octane,(got best 1/4 times!), but the shifts felt a little harsh? (Maybe hit torque limit in trans?)
I did not try MAP 9- ran out of time at track and a little worried about running on bone stock intake, charge pipes, and exhaust...

[Max Well]

Thanks for sharing your data, jamoka3. You have presented a clear and concise documentation for others to review. I quickly plotted your data in a chart which shows your split times. From a personal perspective I find the analysis of split times a more intriguing aspect of how tunes and adjustments affect performance. Excel has highlighted in the light purple your fastest split times for each interval.

Did you have a chance to plot your times on the HP curves? I won't have a chance to do so right now but it would be interesting to see how they fared vs your earlier runs.

Thanks again for your excellent documentation of the data.

[Max Well]

Here is jamoka3's data from Friday night plotted at the 1/8th and 1/4 mile time intervals. Certainly a difference compared with the earlier year runs. The cooler air temp, 101 Octane, and less weight of a half tank vs full tank may be contributing, but this time the simulation clearly couldn't keep up.

For clarification, does MAP 6 take you back to 'stock' settings (so in essence Runs 1 and 5 were your reference stock runs)?

[koryrykman]

Mine is a 2012 sport. 45k miles. Lowered w/ h&r and big ass 20" heavy wheels.
JB4 - map 2 which allowed 30% e85 and the rest premium 93.
Sport +, and sport trans. 3000k launch. Shot out like a bullet!
You have to get the jb4.

13.316 at 103mph. Smoked an SS sedan 3 times! haha, with a 4 cylinder bimmer.

[TomDenmark]

koryrykman, Do you lose traction at anypoint? launch control? If I torque break to 3000rpm I will get nothing but smoke. anything more than 1800rpm is too much.

I think I always get overboost in 1. gear and lose traction from around 3.5k rpm if I just slam it form idle. Maybe its just the stock R17225 pirelli runflats that don't have enough grip.

Just curious if its normal and if others have same problem and use boost limit setting on the JB4 to avoid this?

[XenaBimmer]

Nice run; you picked up .3 and a couple mph with the JB4 compared to my stage 1. You should be able to drop another tenth or more with a better 60 ft as well