[hibye19013]

Hey guys,

I am taking my 335xi to the drag strip this Friday. I have never done this before. Any advice I can get would be greatly appreciated. Thanks.

[Joebie]

Watch a video on how to stage properly. Many amateur events I go to I see people pull up and have no clue how to and they just sit there for 30 seconds until an official runs out and tells them what to do. If you dont know, basically there's two sensors near the ground in the middle that sense your tires an light the prestage and stage lights on the tree. You pull up slowly until your prestage lights then let the other lane do the same, then pull up again slowly until the stage light comes one, then let you opponent do the same. Shortly after both lanes' prestage and stage lights are on, the countdown will begin.

I personally like to be the first to light the pre-stage light, let the other lane prestage, then I stage first, then they stage, then you're both off. Being the first to stage gives you that extra 1-2 seconds to prepare mentally and physically.

Also watch the race before you and see how the lights work so you know what to expect and when to go. Sometimes its "READY - GO" other times its "3 - 2 - 1 - GO". Most the time its the latter.

Also, if you've never done it before, a quarter mile is longer than you think. At least for me it was. My first run down a strip I probably let off around 800ft.

If there's a water box, drive around it. You don't HAVE to go through it and with AWD you dont want to. Many people think they have to drive through it and then start their race with cold wet tires.

Lastly, have fun! Take it easy the first few runs, there's no shame in that. Observe how you are doing and how your car is doing and step it up as you feel you can.

[hibye19013]

Thanks Joester. How about launching an xi? What are good shift points for the N55?

[Joebie]

Originally Posted by hibye19013

Thanks Joester. How about launching an xi? What are good shift points for the N55?

I drag and track motorcycles, not cars so I don't have much advice. My daily is an N52 but I used to have an N54 so I at least have a little experience driving BMW turbo 6s. On my motorcycle I have my shift light set to around 16,500rpm... but you probably shouldn't do that on your N55!

Looking at dyno graphs of the N55, you'd probably want to shift no later than 6krpm, but just do what feels right. Just looking at a dyno doesn't really tell the full story of how quick your turbos spool, how fast you are at shifting, etc etc.

[Turbod]

Originally Posted by hibye19013

Thanks Joester. How about launching an xi? What are good shift points for the N55?

All good advice listed above. One thing I will say that wasn't mentioned is deep staging. If you roll too fast into the lights and the prestage light goes off but the stage light is still on they will trigger the tree. DO NOT put it into reverse.

As for launching the car that will depend on which transmission you have. If you have an auto you will want to put it in 1st gear, with your left foot hard on the brake you will floor the gas with your right foot. When the last yellow comes on fully then let off the brake and hold the gas. If you have a manual you will need to play around with which rpm to launch. You want to let out the clutch at a slower steady pace. If you drop the clutch you will bog or stall.

Shift rpm will depend on how much boost you're running and which tune. Rule of thumb is if your tune is 13 psi or less just take the car to redline. The more boost you run the sooner you will want to shift. If the turbo is completely maxed out, 5,200 is a good shift point.

^^^ I'm sure someone will disagree with me on this. I have had my car for 3 years now and have taken it to the track from stock to now.

[Joebie]

All the N55 dyno graphs I've seen show torque dropping off rapidly after 5500, especially 6000rpm. That's why I recommended OP shift no later than 6000rpm.

But it sounds like you've been doing this for a while, you probably know better than me I just feel like you're probably losing a few tenths of a second by taking it all the way to redline, purely based off of the dynos I've seen and no real world experience whatsoever

[JLGM4]

Originally Posted by Turbod

All good advice listed above. One thing I will say that wasn't mentioned is deep staging. If you roll too fast into the lights and the prestage light goes off but the stage light is still on they will trigger the tree. DO NOT put it into reverse.

As for launching the car that will depend on which transmission you have. If you have an auto you will want to put it in 1st gear, with your left foot hard on the brake you will floor the gas with your right foot. When the last yellow comes on fully then let off the brake and hold the gas. If you have a manual you will need to play around with which rpm to launch. You want to let out the clutch at a slower steady pace. If you drop the clutch you will bog or stall.

Shift rpm will depend on how much boost you're running and which tune. Rule of thumb is if your tune is 13 psi or less just take the car to redline. The more boost you run the sooner you will want to shift. If the turbo is completely maxed out, 5,200 is a good shift point.

^^^ I'm sure someone will disagree with me on this. I have had my car for 3 years now and have taken it to the track from stock to now.

Hey since we're similar in mods, do you hold RPMs and dump the brake pedal when you're staged? I've never done a run without just flooring it and my times aren't great. I'm thinking I can maybe slam the brakes and rev it up to 2.5k or so and go

[Turbod]

Originally Posted by Joester

All the N55 dyno graphs I've seen show torque dropping off rapidly after 5500, especially 6000rpm. That's why I recommended OP shift no later than 6000rpm.

But it sounds like you've been doing this for a while, you probably know better than me I just feel like you're probably losing a few tenths of a second by taking it all the way to redline, purely based off of the dynos I've seen and no real world experience whatsoever

If you're running say 16 psi. I would shift around 5,500 - 5,800 depending on how boost falls off. The stock turbo can hold about 13 psi to redline if the tune pushes the turbo that hard at the top of the rev range. When I was running 20 psi on the stock turbo I would shift at 5,200.

Originally Posted by jgottsman11

Hey since we're similar in mods, do you hold RPMs and dump the brake pedal when you're staged? I've never done a run without just flooring it and my times aren't great. I'm thinking I can maybe slam the brakes and rev it up to 2.5k or so and go

I bought drag radials this year and went back to 1st gear launches. I was able to build 15 psi in 1st and not break the tires loose. Doing that I I held the brake down and almost completely floored it at the line. I will say that I have had better luck waiting until the 2nd yellow before flooring it. Something about sitting there with it floored caused a slower reaction when I let off the brake.

The time in my signature was last year on a 2.1 60 foot. This year I have done a 1.9 but my fuel system was crashing so my ET was not any better, 12.1@121.

[JLGM4]

I bought drag radials this year and went back to 1st gear launches. I was able to build 15 psi in 1st and not break the tires loose. Doing that I I held the brake down and almost completely floored it at the line. I will say that I have had better luck waiting until the 2nd yellow before flooring it. Something about sitting there with it floored caused a slower reaction when I let off the brake.

The time in my signature was last year on a 2.1 60 foot. This year I have done a 1.9 but my fuel system was crashing so my ET was not any better, 12.1@121.[/QUOTE]

Awesome, I'm getting port injection soon and probably a pair of radials. Gonna get things dialed in and go for some good times. I just get such slow launches with 12 psi in first gear and no boost buildup.

[Cory S]

I just get such slow launches with 12 psi in first gear and no boost buildup.[/QUOTE]

You have to build some boost, and remove any lag at the starting line. Also, on your first few runs, don't worry about the green light. When goes green, go when you're ready. A good time to hold the brake and start your brake boosting.

With my X-drive/6AT..These are my 60' averages depending on what PSI I leave at.

4psi = 1.77-1.83
5psi = 1.74-1.77
6psi = 1.72-1.74
7psi = 1.68-1.72
8psi = 1.64-1.68

I hooked solid (No scrubbing) at 8.5psi once, and cut a 1.63.

[hibye19013]

Well,

My best ET was 13.199 @ 107mph, 60' @ 2.140. I need to get my tune dialed in. A M5 beat me by a second and a Porsche 911 stomped me haha.

Cory S What tune are you running?

[NRigs]

Originally Posted by hibye19013

Well,

My best ET was 13.199 @ 107mph, 60' @ 2.140. I need to get my tune dialed in. A M5 beat me by a second and a Porsche 911 stomped me haha.

Cory S What tune are you running?

More rubber might help with that 60'. 225s on your setup definitely isn't enough.

[JETmn]

Originally Posted by hibye19013

Well,

My best ET was 13.199 @ 107mph, 60' @ 2.140. I need to get my tune dialed in. A M5 beat me by a second and a Porsche 911 stomped me haha.

Cory S What tune are you running?

Well, lets say you have lots of room for improvement. Your MPH is WAY low and your 60' should be 1.8 or lower. I am guessing you were not brake boosting, just hitting the gas when the light turned green. Read what was posted earlier about the launch, it is right on.

If you take .3 sec off your launch, that is .6 at the end of the track. Get your MPH up to 120+ where it should be and you should be in the 11's easily. What fuel were you running?

[hibye19013]

Originally Posted by JETmn

Well, lets say you have lots of room for improvement. Your MPH is WAY low and your 60' should be 1.8 or lower. I am guessing you were not brake boosting, just hitting the gas when the light turned green. Read what was posted earlier about the launch, it is right on.

If you take .3 sec off your launch, that is .6 at the end of the track. Get your MPH up to 120+ where it should be and you should be in the 11's easily. What fuel were you running?

Lots of room to improve. I was brake boosting but the car seemed a little hesitant. I was running 93oct.

[Turbod]

Originally Posted by hibye19013

Well,

My best ET was 13.199 @ 107mph, 60' @ 2.140. I need to get my tune dialed in. A M5 beat me by a second and a Porsche 911 stomped me haha.

Cory S What tune are you running?

Gotta start somewhere. I agree with all of JETmn's comments.

Cory is running the JB4 and the Cobb pump BEF.

Originally Posted by hibye19013

Lots of room to improve. I was brake boosting but the car seemed a little hesitant. I was running 93oct.

XHP had a known issue with brake boosting that should be resolved in the update that was released today. I could see a 107 trap on pump if your IATs were pretty high. I am thinking about hitting the track on 92 octane only to see what it will do on my setup.

[Bours]

Originally Posted by Turbod

Gotta start somewhere. I agree with all of JETmn's comments.

Cory is running the JB4 and the Cobb pump BEF.



XHP had a known issue with brake boosting that should be resolved in the update that was released today. I could see a 107 trap on pump if your IATs were pretty high. I am thinking about hitting the track on 92 octane only to see what it will do on my setup.

Dood where the eff are you ?