Took my X6 50I to the track

[Sharpie12]

It was 55 degrees and I only did one run because there was a lot of clean up going on. Here the slip, what do you guys think?

[Sharpie12]

im on the right by the way

[LANDLORD]

Top Speed is OK but the 60 foot time is slow.

[Sharpie12]

How is that slow for a truck that weighs, what?.... 5200-5400lbs??

[audioquest]

Didn't you notice, He had the X6M. That make our X6 50i slow.

[teagueAMX]

Originally Posted by LANDLORD

Top Speed is OK but the 60 foot time is slow.

Originally Posted by Sharpie12

How is that slow for a truck that weighs, what?.... 5200-5400lbs??

LOL Sharpie12 you asked and answered your own question.

What LANDLORD was saying was that your out of the hole time at 60 feet was off. But for a truck weighing 5200-5400lbs (as you put it) you could expect your 60 foot time to be slower than the guy next to you driving who knows what, but it's likely a ford pinto with a 429 BOSS engine (just kidding)

BTW your time is good for a "5200-5400lbs truck" but don't be so sensitive when you ask for other people's opinions.

[Sharpie12]

I was just wondering what others have gotten with their 50i

[Northern X5M]

Hi, guess I will make this my first post on this forum. I have been lurking here for a while now. I took delivery of my 2011 Monte Carlo Blue X5M back in June.

Sharpie, when you ran your X6 at the track did you stall (foot brake) at the line? You will want to spool those turbos as much as the brakes will hold. With my M I have snapped off a 1.7 and a few 1.8's. Just flashing the converter i get mid to high 1.9s. Remember for every 0.1 in your 60' is good for 0.2 at the top end.

I have found with my truck manual shifting vs auto is a mixed bag. Power comes on so strong at red line it is tricky not to hit the rev limiter. My best 2 times (non launch control) are manual shifting in M mode, 2 back to back 12.80's. With launch control I have a 12.60 and a 12.79 (I think). My MPH is pretty much dead nuts 107.5. So the truck is making consistent power, I just have to get launch and shifting sorted out. All runs the density altitude was about 3500ft. The 12.60 run the DA was about 400ft. I have over 20 runs on the truck so far.

[Sharpie12]

Yes I revved to a little over 2k at the line before letting go of brake. How high can I safely rev before letting go?

[Northern X5M]

Rev till your brakes 'just' start to let go. But 2k is about right. Try shifting the transmission manually too, just before redline. Note which gear and RPM you cross the traps at as well, could be your trans is shifting to the next gear early. Holding the previous gear at the finish might gain a few 0.01's. This is my first BMW, and testing all the settings and different combos has been a task. Unfortunately race season is now over up here. Next year I would like to get into the 11's.

[aas5]

Do you guys own or lease your cars? I am asking because I always wonder if launch control has does any permanent damage to the engine?

[Northern X5M]

Originally Posted by aas5

Do you guys own or lease your cars? I am asking because I always wonder if launch control has does any permanent damage to the engine?

Mine I own... well make payments. With the launch control I know the manual says to limit its use. But I can launch the truck just about as hard without LC. With the rev limiter you can't hurt the engine, unless you mechanically over rev it. I have used LC maybe 6 times now. Other than my 12.6 & 12.7 LC runs, I have got better times manually shifting the truck and brake stalling. That being said, now that I know what the truck will do I probably won't use LC anymore.

[Sharpie12]

Great news gents!

Took the X6 to the track. Best run of the day is as follows....
I couldn't be happier. I had 4 runs 2 were 12.9 and 2 were 12.8

[LANDLORD]

That's a much better 60 foot time. Now you are getting a good launch! Next I would work on the reaction time. You can't always rely on horsepower to win a race. You may want to stage deep and give up some ET, to improve your reaction time.

The engine RPM limiter is a safety valve, but it is not good to hit it repeatedly, and expect to never do any damage. You can never predict what might happen at such high RPM's.

This is beyond the recommended RPM range, and you want to shift to place the next gear in the torque peak area around 6,000 RPM. You should be more consistent by letting the computer shift the engine in launch control mode, and avoid the possibility of hitting the rev limiter. I would always worry though about the transmission and rear differential in these maximum performance situations, especially on a sticky drag strip.
Beware of damage you may be causing that won't show up until later on.

[watoowatoo]

I remember I read somewhere in engine's technical manual that when you foot brake, after few seconds engine will reduce the turbo boost a little to prevent excess wear.

I ride 35i and I am sure the turbos on M work differently but still may be worth a try. Press the gas pedal to get your desired launch RPM right before let go of brakes (Instead of holding the RPM and brake before launch). I am getting perfect launches now, no hesitations. This will be easier on transmission as well.

[Sharpie12]

I actually held down the brake for half a second before letting go I timed it perfectly so I wouldn't have to hold it for 2 seconds or longer. I also didn't shift manually I left it in S1 so the computer would shift for me

[Sharpie12]

Watoo...I got these times with a 50I not the M.

[Northern X5M]

Personally I wouldn't worry too much about RT unless you are bracket racing. I would stage as shallow as possible to get as much roll out as possible before breaking the beams. Stage so that the 2nd stage lights just flicker on. Once you get your timing down you can still cut killer lights and stage shallow.

Your times are are incredible! Your 60' is wow! My best was 1.759(I think) and your MPH is about 1MPH off my average and only 2MPH off my best. Your MPH is more important than ET as it tells you how much power your truck is making. Still your ET is only 0.053 off my average and 0.250 off my best. Do you know the DA at the time you raced, even though your truck is F/I, DA still plays a small part. I would guess that you maybe had negative DA. From my experience with the X5M going from a DA of 3000' to 200' was good for about 0.2 seconds and 1MPH.

[Sharpie12]

I don't know how to really calculate all that but here is the info on where I was

It was 60 degrees fahrenheit at the time

http://weather.gladstonefamily.net/site/AP401

[watoowatoo]

Originally Posted by Sharpie12

Watoo...I got these times with a 50I not the M.

That's right. I was confused for a sec.

[Northern X5M]

Ok so you were at Great Lakes Raceway? I am assuming you raced yesterday? I am using the DA calculator at dragtimes.com. That way I can compare your corrected times to mine. Not sure what time of the day you raced but it was 60F at 4pm yesterday. DA was 750'.

I've read that the X6's are a bit faster than the X5's, but damn! Your 50i is almost as fast as my X5M. You stock? I just looked up gearing. The 8 speed gear ratios are slightly better than the M's.

[Sharpie12]

Tried pm'ing you Northern, but I couldn't. I have a 2010 so it's a 6 speed not 8 speed