Maximize your launch - Better your 0-60!

kujo · 02-01-2007, 12:32 AM

I have a VBox Performance box.
It's a GPS system that all the car mags use.

M1, DTC/DSC off, power brake the car to 1,600 rpm, let go of brake and feather the gas to the floor, not hitting the kick down.
Shift at about 6,400 rpm as torque starts dropping at 5,800 or there abouts.
This will give you 4.78 to 4.85 to 60 ALL DAY LONG AND RELIABLE, until you starte getting heat soak.

I tried all scenarios with the VBox.
D and gas it.
DS and gas it.
D and Power brake
DS and power brake
M and power brake
And, all with DSC and DTC off seperately and together.

All gave different times and everytime the car didn't have all traction nannies off, the time were slower.

Sure, it's not scientific fact, but the way I posted gave me the most consistent times, over and over again.

Fastest was 4.78 !!!!!!!!!!! Bone Stock with RFTs.

going to try again with new T1Rs and see what happens.

The LSD will really transform this car.

Happy clutch / Torque Converter Frying !!!

kj

bimmerlex · 02-01-2007, 05:21 PM

Quote:

Originally Posted by AndrewAZ

It wont do anything unless it over heats, its perfectly safe to do it all day long assuming that the temperature of the transmission says within normal operating temperature, but it wont after a few in a row.

What if you have a tranny cooler?

FirstClass · 02-01-2007, 09:24 PM

Quote:

Originally Posted by kujo

I have a VBox Performance box.
It's a GPS system that all the car mags use.

Did you pay for it or how did you get it? Aren't they like $10k?

MDman · 02-01-2007, 11:45 PM

Quote:

Originally Posted by kujo

I have a VBox Performance box.
It's a GPS system that all the car mags use.

M1, DTC/DSC off, power brake the car to 1,600 rpm, let go of brake and feather the gas to the floor, not hitting the kick down.
Shift at about 6,400 rpm as torque starts dropping at 5,800 or there abouts.
This will give you 4.78 to 4.85 to 60 ALL DAY LONG AND RELIABLE, until you starte getting heat soak.

I tried all scenarios with the VBox.
D and gas it.
DS and gas it.
D and Power brake
DS and power brake
M and power brake
And, all with DSC and DTC off seperately and together.

All gave different times and everytime the car didn't have all traction nannies off, the time were slower.

Sure, it's not scientific fact, but the way I posted gave me the most consistent times, over and over again.

Fastest was 4.78 !!!!!!!!!!! Bone Stock with RFTs.

going to try again with new T1Rs and see what happens.

The LSD will really transform this car.

Happy clutch / Torque Converter Frying !!!

kj

kujo, what time did you get when gassing it on DS mode with DSC and DTC off?

kujo · 02-02-2007, 02:35 AM

Just gassing off the line in DS mode made mostly consistent 5.0's.
People say that DS starts in 1st gear, but I don't think it does.
in DS with a tiny bit of brake torquing got hi 4.9s occasionally.

Anything launched at over 1,800 rpm just got far too much wheels spin to get good times.
But, launching at 2K got some fun fish tails......
2K launches with an LSD will equate to some fun, tire eating donuts when approriate !! :-)

They are not 10K anymore.......

kj

MDman · 02-02-2007, 01:35 PM

Quote:

Originally Posted by kujo

Just gassing off the line in DS mode made mostly consistent 5.0's.
People say that DS starts in 1st gear, but I don't think it does.
in DS with a tiny bit of brake torquing got hi 4.9s occasionally.

Anything launched at over 1,800 rpm just got far too much wheels spin to get good times.
But, launching at 2K got some fun fish tails......
2K launches with an LSD will equate to some fun, tire eating donuts when approriate !! :-)

They are not 10K anymore.......

kj

Thanks for the info.

kujo · 02-03-2007, 03:23 AM

no problem.
I'm going to do some more runs this weekend, as the custom/prototype exhaust went on today, so we'll see if I can pick up a 1/10th or two.

kj

Mr.Marvelous · 02-03-2007, 01:42 PM

Wait a minute...

You guys are saying that giving some throttle while holding down the foot brake is safe? doesn't the car try to move forward while brakes are trying to stop it?

I never done such thing because I thought it d kill the car instantly...

FirstClass · 02-03-2007, 04:47 PM

Quote:

Originally Posted by Mr.Marvelous

Wait a minute...

You guys are saying that giving some throttle while holding down the foot brake is safe? doesn't the car try to move forward while brakes are trying to stop it?

I never done such thing because I thought it d kill the car instantly...

If you have an automatic, this is called "torque braking" and is how you get the fastest acceleration times. But if you do it too much it will cook the transmission.

Mr.Marvelous · 02-03-2007, 05:03 PM

and what happens if I cook the transmission? dies or continues to work after cooling down?

I m asking this because I still cant imagine the mechanic behind this torque breaking

FirstClass · 02-03-2007, 05:14 PM

Quote:

Originally Posted by Mr.Marvelous

and what happens if I cook the transmission? dies or continues to work after cooling down?

I m asking this because I still cant imagine the mechanic behind this torque breaking

I'm not sure. I think it dies. Overheating the transmission is like overheating the engine, a very bad thing.

The mechanic is this: The RPMs are higher when you start and therefore you have more power. It also keeps the engine from bogging as much and in the case of 335i owners the turbos are already spooled up when you go.

Simple1 · 02-03-2007, 06:21 PM

Just to add to this debate, DS ALWAYS starts in 2nd unless you shift down yourself and when coming to a stop comp will only shift down to 2nd as others have said and you have to manually shift to 1st gear. I have 6000 miles to prove I know what i'm saying, lol

GTGeo96 · 02-03-2007, 08:30 PM

you guys are overthinking this TQ. Braking thing way too much. There is No clutch in an auto...instead it works on a converter that as it spins innertia fills it with fluid, after it gets a certain ammount of fluid in it, it will start to grip, after a certain amount of fluid, it will lock completely. The key to Tq.Braking or "powerbraking" is holding the car at the point where the converter is starting to engage so that when it takes off, it will lock faster and accellerate faster. doing this WILL NOT OVERHEAT your transmition, because it only takes 2 seconds at most to get it at the right rpm. it doesnt have time to overheat the trans. Compare it to just dumping the clutch on a manual...its not going to harm anything...it just puts high levels of strain on the trans, because you are subjecting it to more agressive driving. However, if anything is weak in the system, that weak part will let go with the stress, but thats the part itself thats at fault...if you baby the car everywhere you go, this part that is defective may never see enough stress to fail. If you are afraid to do this, you should be afraid to go WOT anyway...because that also produces higher levels of stress on the engine than normal. Anything wrong with the engine, will most likely fail at that time.

ulises 335i · 02-24-2007, 11:55 PM

i did a 0-60 in 4.9 with my 335i sedan auto, i measured it with my gtech pro. launching @ 2,000 rpm.... with alot of wheel spin. i think some drag tires ill do a 4.7 easy

musc · 02-25-2007, 01:15 AM

If you sit there and hold the RPMs up (torque braking) for long periods of time, it will build up some heat, but doing this periodically while racing isn't going to be a big issue. If you make it a habit at every stoplight, then sure, it can lead to premature tranny failure.

Another thing to keep in mind, is the converter is still going to 'flash' to a set point. Typically, things happen so quick, its hard to see it happen. The converter doesn't act as a lock up until you are a steady speeds. I am not sure what the maximum flash point is with the 335i AT, but probably between 2000-2500. I doubt you can power brake it to 3K. So regardless if you launch at 800 or 1800, its still going to flash. The big difference with this car is that you are building boost while torque braking. Good for DRs, bad for street tires.

So trying to keep pushing the RPMs up while torque braking has a point of diminishing returns. 1600-1800 is a good range. You shouldn't really push it any farther than when you feel the back of the car start to 'lift up'. At that point, the chassis is starting to unload, and it just makes you more prone to wheel spin, even with DRs or slicks. I typically would just test this on some back road. Powerbrake it until you feel the wheels start to spin...and that is your max RPM, or flash. Then note when powerbraking, at what RPM you feel the rearend start to lift up...your powerbrake RPM should be about 200 rpm before you feel that lift.

Also keep in mind that the more torque you make, the different the torque converter will act. So PROcede guys may find that you can torque brake a higher RPM.

Like this particular set up. The converter is a 3500 stall, but with this particular engine, flashed to about 4000K confirmed with with a recordable tachometer. But I only launched at 1200. I could powerbrake to about 2800 before the chassis started to unload. Cant argue with 1.50 60fts

http://m3.musc.us/nova.wmv

02-01-2007, 12:32 AM	#45
kujo Major 151 Rep 1,153 Posts Drives: BMW Join Date: May 2006 Location: LA, CA USA iTrader: (1)	I have a VBox Performance box. It's a GPS system that all the car mags use. M1, DTC/DSC off, power brake the car to 1,600 rpm, let go of brake and feather the gas to the floor, not hitting the kick down. Shift at about 6,400 rpm as torque starts dropping at 5,800 or there abouts. This will give you 4.78 to 4.85 to 60 ALL DAY LONG AND RELIABLE, until you starte getting heat soak. I tried all scenarios with the VBox. D and gas it. DS and gas it. D and Power brake DS and power brake M and power brake And, all with DSC and DTC off seperately and together. All gave different times and everytime the car didn't have all traction nannies off, the time were slower. Sure, it's not scientific fact, but the way I posted gave me the most consistent times, over and over again. Fastest was 4.78 !!!!!!!!!!! Bone Stock with RFTs. going to try again with new T1Rs and see what happens. The LSD will really transform this car. Happy clutch / Torque Converter Frying !!! kj
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02-02-2007, 02:35 AM	#49
kujo Major 151 Rep 1,153 Posts Drives: BMW Join Date: May 2006 Location: LA, CA USA iTrader: (1)	Just gassing off the line in DS mode made mostly consistent 5.0's. People say that DS starts in 1st gear, but I don't think it does. in DS with a tiny bit of brake torquing got hi 4.9s occasionally. Anything launched at over 1,800 rpm just got far too much wheels spin to get good times. But, launching at 2K got some fun fish tails...... 2K launches with an LSD will equate to some fun, tire eating donuts when approriate !! :-) They are not 10K anymore....... kj
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02-03-2007, 03:23 AM	#51
kujo Major 151 Rep 1,153 Posts Drives: BMW Join Date: May 2006 Location: LA, CA USA iTrader: (1)	no problem. I'm going to do some more runs this weekend, as the custom/prototype exhaust went on today, so we'll see if I can pick up a 1/10th or two. kj
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02-03-2007, 01:42 PM	#52
Mr.Marvelous the name says it all... 72 Rep 269 Posts Drives: F30 BMW 320i Sport Line Join Date: Oct 2006 Location: Turkey iTrader: (0)	Wait a minute... You guys are saying that giving some throttle while holding down the foot brake is safe? doesn't the car try to move forward while brakes are trying to stop it? I never done such thing because I thought it d kill the car instantly... __________________ Join Driven: The Ultimate Car App http://www.getdrivenapp.com/
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02-03-2007, 05:03 PM	#54
Mr.Marvelous the name says it all... 72 Rep 269 Posts Drives: F30 BMW 320i Sport Line Join Date: Oct 2006 Location: Turkey iTrader: (0)	and what happens if I cook the transmission? dies or continues to work after cooling down? I m asking this because I still cant imagine the mechanic behind this torque breaking __________________ Join Driven: The Ultimate Car App http://www.getdrivenapp.com/
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02-03-2007, 06:21 PM	#56
Simple1 Major 137 Rep 1,060 Posts Drives: G05 X5 40i M Sport Join Date: Mar 2005 Location: Earth iTrader: (1)	Just to add to this debate, DS ALWAYS starts in 2nd unless you shift down yourself and when coming to a stop comp will only shift down to 2nd as others have said and you have to manually shift to 1st gear. I have 6000 miles to prove I know what i'm saying, lol __________________ G05 X40M Sport F80 M3 Euro Delivered = Gone too Soon e90 335i debadged = Gone but not forgotten
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02-03-2007, 08:30 PM	#57
GTGeo96 Private 4 Rep 94 Posts Drives: Montego Blue 335i Join Date: Jan 2007 Location: Newark NJ iTrader: (0) Garage List 2007 335i [0.00]	you guys are overthinking this TQ. Braking thing way too much. There is No clutch in an auto...instead it works on a converter that as it spins innertia fills it with fluid, after it gets a certain ammount of fluid in it, it will start to grip, after a certain amount of fluid, it will lock completely. The key to Tq.Braking or "powerbraking" is holding the car at the point where the converter is starting to engage so that when it takes off, it will lock faster and accellerate faster. doing this WILL NOT OVERHEAT your transmition, because it only takes 2 seconds at most to get it at the right rpm. it doesnt have time to overheat the trans. Compare it to just dumping the clutch on a manual...its not going to harm anything...it just puts high levels of strain on the trans, because you are subjecting it to more agressive driving. However, if anything is weak in the system, that weak part will let go with the stress, but thats the part itself thats at fault...if you baby the car everywhere you go, this part that is defective may never see enough stress to fail. If you are afraid to do this, you should be afraid to go WOT anyway...because that also produces higher levels of stress on the engine than normal. Anything wrong with the engine, will most likely fail at that time.
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02-24-2007, 11:55 PM	#58
ulises 335i these cars waste alot of fucking gas 52 Rep 992 Posts Drives: 335i montego blue Join Date: Jan 2007 Location: el monte, c.a. iTrader: (3)	i did a 0-60 in 4.9 with my 335i sedan auto, i measured it with my gtech pro. launching @ 2,000 rpm.... with alot of wheel spin. i think some drag tires ill do a 4.7 easy
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02-25-2007, 01:15 AM	#59
musc Free T_e_r_r_Y :) 223 Rep 1,706 Posts Drives: X3MC, Audi TTRS MK3, 335is DCT Join Date: Dec 2006 Location: Charleston, SC iTrader: (9) Garage List 2023 BMW X3MC [10.00] 2011 BMW 335is [10.00]	If you sit there and hold the RPMs up (torque braking) for long periods of time, it will build up some heat, but doing this periodically while racing isn't going to be a big issue. If you make it a habit at every stoplight, then sure, it can lead to premature tranny failure. Another thing to keep in mind, is the converter is still going to 'flash' to a set point. Typically, things happen so quick, its hard to see it happen. The converter doesn't act as a lock up until you are a steady speeds. I am not sure what the maximum flash point is with the 335i AT, but probably between 2000-2500. I doubt you can power brake it to 3K. So regardless if you launch at 800 or 1800, its still going to flash. The big difference with this car is that you are building boost while torque braking. Good for DRs, bad for street tires. So trying to keep pushing the RPMs up while torque braking has a point of diminishing returns. 1600-1800 is a good range. You shouldn't really push it any farther than when you feel the back of the car start to 'lift up'. At that point, the chassis is starting to unload, and it just makes you more prone to wheel spin, even with DRs or slicks. I typically would just test this on some back road. Powerbrake it until you feel the wheels start to spin...and that is your max RPM, or flash. Then note when powerbraking, at what RPM you feel the rearend start to lift up...your powerbrake RPM should be about 200 rpm before you feel that lift. Also keep in mind that the more torque you make, the different the torque converter will act. So PROcede guys may find that you can torque brake a higher RPM. Like this particular set up. The converter is a 3500 stall, but with this particular engine, flashed to about 4000K confirmed with with a recordable tachometer. But I only launched at 1200. I could powerbrake to about 2800 before the chassis started to unload. Cant argue with 1.50 60fts http://m3.musc.us/nova.wmv
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