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Discussion Starter #1
I wanna know what is your best technique for aggressive-moderate launching without hurting the clutch? DCS and SPORTS on-off?. I tried the way I know but it jerks hard sometimes ( the clutch is not fully engaged...
Looking forward to getting the best input from the fellows here cherrsagai
 

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Your goal is to balance (in a very quick fashion) clutch engagement versus power supplied. That balance occurs during the initial engagement that creates the weight transfer to the rear. As the weight shifts to the rear you can quickly get the process done and be rocketing out of the hole with a hooked up clutch and hooked up tires. The devil is in the details of this of course. ;)

DSC has to be off of course or you can't even come close to a strong launch. Hence the reason you are only doing this on a closed course (autocross, dragstip) or your own property.

If you don't have previous experience with maximum launching of a RWD car, it would be ideal to practice such on a different car since the M5's clutch does not care much for a ham-fisted driver burning a few hundred HP through it when it isn't fully hooked up.

There are two big variables on traction during the launch. The first one is that initial weight transfer you create before you go for the whole launch. It's a very quick process, but it is critical to getting the most out of the rear tire's abilities. Mastering it just right will greatly increase "launchability". Take a look at the start here in this video of me driving at a BMW club autocross at the Performance Center. It's the only in-car video I have of a launch. Note the very small elapsed time between my initial engagement (the car lifting up), and then clutch hooked up and full power (almost) out of the hole with just a bit of wheelspin. This particular launch above is a perfect segue into the second and biggest variable: tire traction.

The above was done on R-comp tires in warm weather, so traction was superb. However, depending on the number of heat cycles your tires have done, the ambient temperature and the tire type, your launch parameters (starting rpm, rate of engagement and power application) will vary (perhaps dramatically for well heat cycled tires on cold pavement!). Not much more to be said here except brand new tires (after you have worn off the mold release compound) with few heat cycles will always have a ton more grip than well heat cycled tires. This last fact is what always makes me chuckle when I see a review of how great some new tire brand is compared to someone's old tires they just finished using up.

Some specifics to try... If the ambient temperature is reasonable and you have relatively fresh tires, shoot for a starting rpm between about 1800 to 2200 rpm. Use the throttle to balance the clutch engagement during that brief initial weight transfer period, and once you get weight starting to shift fully to the rear, use a LOT more clutch engagement coupled with more throttle. If you do this just right, you won't overdrive the rear tires but instead will be able to manage tire hook-up with the throttle while the clutch is fully out. On a hot track with R-comps, you can aggressively get into the throttle without too much wheelspin worry (as in video), but on street tires you have to be much more judicious with the throttle. As ambient temperatures fall below 60F, you have to be “exponentially” more careful, seriously.

The key to grip on launch is to NOT overdrive the rear tires. Once you loose that sweet spot of about 10-15% slip at the tire's contact patch, you'll have to really get out of the throttle to regain grip and the launch is blown. Practice feeling that weight transfer, developing the feel for how you can progressively (but very quickly) get the clutch engaged and the power down. A perfect launch will not be a wild, smoking mess (which the M5 is easily capable of doing), but will result in a brief small amount of wheel spin (maybe 1 to 2 car lengths on relatively fresh, high quality street tires) and a totally hooked feeling from behind the wheel.

Start small and work your way up. Work on clutch engagement. Get the feel for throttle response. Etc.. If you ever mess up and start putting too much power through the clutch before you have it hooked up, GET OUT OF THE THROTTLE IMMEDIATELY. Let the clutch cool and try again later. By the way, if you are trying multiple launches within a short period of time, you'll find that the clutch engagement capabilities will vary as its temperature rises, so give it some time to cool off.

That's all I can think of at the moment other than you're of course doing all of this at an autocross, the track or on your own property. At the strip, you'll have the additional variable of how the launch area is prepared which can make a HUGE difference in traction and how you manage this whole process.
 

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agree

M5 clutch is "pretty weak" (we all have our opinions), so getting complete link as quickly as possible is priority #1, then pour on the power w/o burning rubber is priority #2.
 

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Your goal is to balance (in a very quick fashion) clutch engagement versus power supplied. That balance occurs during the initial engagement that creates the weight transfer to the rear. As the weight shifts to the rear you can quickly get the process done and be rocketing out of the hole with a hooked up clutch and hooked up tires. The devil is in the details of this of course. ;)

DSC has to be off of course or you can't even come close to a strong launch. Hence the reason you are only doing this on a closed course (autocross, dragstip) or your own property.

If you don't have previous experience with maximum launching of a RWD car, it would be ideal to practice such on a different car since the M5's clutch does not care much for a ham-fisted driver burning a few hundred HP through it when it isn't fully hooked up.

There are two big variables on traction during the launch. The first one is that initial weight transfer you create before you go for the whole launch. It's a very quick process, but it is critical to getting the most out of the rear tire's abilities. Mastering it just right will greatly increase "launchability". Take a look at the start here in this video of me driving at a BMW club autocross at the Performance Center. It's the only in-car video I have of a launch. Note the very small elapsed time between my initial engagement (the car lifting up), and then clutch hooked up and full power (almost) out of the hole with just a bit of wheelspin. This particular launch above is a perfect segue into the second and biggest variable: tire traction.

The above was done on R-comp tires in warm weather, so traction was superb. However, depending on the number of heat cycles your tires have done, the ambient temperature and the tire type, your launch parameters (starting rpm, rate of engagement and power application) will vary (perhaps dramatically for well heat cycled tires on cold pavement!). Not much more to be said here except brand new tires (after you have worn off the mold release compound) with few heat cycles will always have a ton more grip than well heat cycled tires. This last fact is what always makes me chuckle when I see a review of how great some new tire brand is compared to someone's old tires they just finished using up.

Some specifics to try... If the ambient temperature is reasonable and you have relatively fresh tires, shoot for a starting rpm between about 1800 to 2200 rpm. Use the throttle to balance the clutch engagement during that brief initial weight transfer period, and once you get weight starting to shift fully to the rear, use a LOT more clutch engagement coupled with more throttle. If you do this just right, you won't overdrive the rear tires but instead will be able to manage tire hook-up with the throttle while the clutch is fully out. On a hot track with R-comps, you can aggressively get into the throttle without too much wheelspin worry (as in video), but on street tires you have to be much more judicious with the throttle. As ambient temperatures fall below 60F, you have to be “exponentially” more careful, seriously.

The key to grip on launch is to NOT overdrive the rear tires. Once you loose that sweet spot of about 10-15% slip at the tire's contact patch, you'll have to really get out of the throttle to regain grip and the launch is blown. Practice feeling that weight transfer, developing the feel for how you can progressively (but very quickly) get the clutch engaged and the power down. A perfect launch will not be a wild, smoking mess (which the M5 is easily capable of doing), but will result in a brief small amount of wheel spin (maybe 1 to 2 car lengths on relatively fresh, high quality street tires) and a totally hooked feeling from behind the wheel.

Start small and work your way up. Work on clutch engagement. Get the feel for throttle response. Etc.. If you ever mess up and start putting too much power through the clutch before you have it hooked up, GET OUT OF THE THROTTLE IMMEDIATELY. Let the clutch cool and try again later. By the way, if you are trying multiple launches within a short period of time, you'll find that the clutch engagement capabilities will vary as its temperature rises, so give it some time to cool off.

That's all I can think of at the moment other than you're of course doing all of this at an autocross, the track or on your own property. At the strip, you'll have the additional variable of how the launch area is prepared which can make a HUGE difference in traction and how you manage this whole process.
As good a tutorial as I have seen!:applause: Mods, consideration as a sticky?
Regards,
Jerry
 

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It takes time to perfect. find a streth of road and work it. becarful not to apply to much throttle and try not to overheat the clutch. basically do a few launchs then drive a while to let the clutch cool then try somemore.

What you what to do is get the weight to trnsferto the rear tires and moving before you mash the gas.

IMHO if you do not have expeirence buy a set of drag radials. I actually have a set for sale... but when installed on my S2 i would get 0 wheel spin on a launch. It is so nice to pull from a dead stop every single time. they last about 15k as long as your not doing smokey burn outs....

I think everyone here should invest in a set of Dr's, great for the summer!

Ryan
 

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Discussion Starter #8 (Edited)
So to sum it all up, besides all the variables ( road condition, tires, temperature, clutch condition..etc
1- DSC OFF
2- RPM between 1800-2200
3- To release the clutch in two stages:
3a transferring the load to the rear tires,THE SENSITIVE STAGE
3b fully engaging the clutch,with balancing press on the throttle,THE FAST STAGE.Noticing that the clutch pedal SHOULD be fully released BEFORE full throttle.
4- Shifting to 2nd on 6000 RPM-1ST TO ITS PEAK-the way explained in 3b
5- Practice, practice and practice...

Now whats peeling? clutch pumping?. Is there anymore terms pros use regarding this matter?

Also I found this link,but it seems to be not working,anybody has similar vids for the footwork?. Welcome to Virtual M5 Driving School!

Regards,
 

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I don't understand your #3 about shifting to 2nd. If you're going for all-out acceleration, you rev 1st right to its peak.

On another note, for newbies to the M5, the tach needle is damped, and it will not keep up with the engine rpm rate of change in 1st gear. Hence you have to shift somewhere around 6k rpm or so to prevent hitting the rev limiter. In 2nd gear and higher the rate of change of rpm is slower, so this isn't an issue.

Chuck
 

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Discussion Starter #10
I don't understand your #3 about shifting to 2nd. If you're going for all-out acceleration, you rev 1st right to its peak.

On another note, for newbies to the M5, the tach needle is damped, and it will not keep up with the engine rpm rate of change in 1st gear. Hence you have to shift somewhere around 6k rpm or so to prevent hitting the rev limiter. In 2nd gear and higher the rate of change of rpm is slower, so this isn't an issue.

Chuck
I thought this is the optimum RPM to shift into 2nd and avoid the jerking I used to get. I stand corrected,and will edit it..:typing:
 

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I thought this is the optimum RPM to shift into 2nd and avoid the jerking I used to get. I stand corrected,and will edit it..:typing:
Ah, yeah, all my comments above were in regard to an all-out launch giving the best possible acceleration. General street driving with moderate launching is a bit different. By the way, one thing I never use anymore is sport mode since it makes the throttles way too sensitive to fine modulation, especially at an autocross or track event.
 

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Yes you can powershift. yes it is effective and helps et's and may help you get that nose on the local vette, porsche or tuner. It is not good for the transmission. Ask me how I know....

Do not powershift the tranny! Do not have any pressure on the accelerator during a shift. Make sure you are fully out of the gas when you shift and ensure you are 100% in gear before you press the gas pedal. Trust me!

If you are doing any other high driving IE HPDE's I highly recommend double clutching. The E39 m5 transmission is a very strong tranny and some guys are running 600-800whp through the stock tranny without incident. The gear sets are extremely strong but the syncros are weak. DO NOT power shift your car. If you are looking for the extra tenth or two... install drag radial's. Do not compromise your shifts for a tad quicker time, again ask me how I know... if you have a spare tranny and you do not care then by all means powershift the hell out of it. If not, do not do it as used trannys are hard to find again ask me how I know and it gets expensive.

If you continue power shift you wont be doing this.... :M5launch:
Ryan

Would anyone recommend power shifting? What damage will it do besides give the clutch a hard time?
 

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Yes you can powershift. yes it is effective and helps et's and may help you get that nose on the local vette, porsche or tuner. It is not good for the transmission. Ask me how I know....

Do not powershift the tranny! Do not have any pressure on the accelerator during a shift. Make sure you are fully out of the gas when you shift and ensure you are 100% in gear before you press the gas pedal. Trust me!

If you are doing any other high driving IE HPDE's I highly recommend double clutching. The E39 m5 transmission is a very strong tranny and some guys are running 600-800whp through the stock tranny without incident. The gear sets are extremely strong but the syncros are weak. DO NOT power shift your car. If you are looking for the extra tenth or two... install drag radial's. Do not compromise your shifts for a tad quicker time, again ask me how I know... if you have a spare tranny and you do not care then by all means powershift the hell out of it. If not, do not do it as used trannys are hard to find again ask me how I know and it gets expensive.

If you continue power shift you wont be doing this.... :M5launch:
Ryan
thanks - that answers an open question in my mind.
i already made 2 clutch mistakes:

1. dont dump the clutch from 2nd gear.
i have a UUC V12 performance organic clutch. burnouts were too fast/easy/shortlived in 1st gear, so i thought i would try it starting in 2nd gear. it didnt hold. the clutch fried under that pressure.

2. dont try to keep the wheels spinning from 2nd gear to 3rd.
i didn't even power shift it, but the clutch couldn't handle the power and weight of the car, and it is hard to tell whether it is the clutch or wheels spinning on that shift. unfortunately, it was the clutch again.

the good news is that the clutch is still holding strong, but i must have shortened most of it's life!
 

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Discussion Starter #14 (Edited)
Ah, yeah, all my comments above were in regard to an all-out launch giving the best possible acceleration. General street driving with moderate launching is a bit different. By the way, one thing I never use anymore is sport mode since it makes the throttles way too sensitive to fine modulation, especially at an autocross or track event.
I tried it today and WOW !! DSC & SPORTS both off and launching from 1500 RPM ,link then press and shift to 2nd from 5000 RPM. Among like 10 launches I had 4-5 very much what I want-strong yet very smooth,no wheels spinning nor power loss or jerking when shifting. I tried different seat positions till I figured the optimum one-I figured it is an important factor. Seriously small details make a difference,the X factor is how moving the weight then pouring the power to be done as one vast and confident step..
This car is a blast to drive :1:
 

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Discussion Starter #16

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damn 1-2 upshift

My goal is a little bit different; I want to execute a hard launch from a rolling start. Since I'm street driving, I leave the DSC on at all times. I find it to be difficult to consistently execute a 1-2 shift under maximum acceleration; meaning the gas pedal is floored until I hit 6K RPM and execute the shift. If the clutch is let out too quickly, in a best case scenario there is a lurch and in the worst scenario a neck jerking bunny hop, both resulting in the guibo and motor mounts taking a tremendous beating. If the clutch is let out too slow then you are slipping it (which eats up the clutch) and you still get a slightly jerky upshift. Based on posts I have read on the forum (KBK and ARD addressed this) it would seem that the remedy is that some gas must be applied while the clutch is engaging. The problem is consistently finding the right amount; too much and you eat up the clutch.

The worst part is that even though I have been driving a manual tranny for 12 years, I'm scared sh!tless that I'm going to eat up my clutch. Kind of takes away the fun of driving when you are worried about a $3,000 repair bill.

Practice makes perfect, but its hard when you are nervous about destroying your clutch and also don't have a safe place for practicing launches. Very frustrating....grrrrrrr
 

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Ryan,

I keep the DSC on because I don't want to run the risk of the tires breaking loose on public roads. Running the risk of losing control is one thing if you are on a track or drag strip but all together different when just driving around. You could say that I want to safely push the car to its limit with out damaging it or myself.

My expectation is to be able to consistently and safely perform a 1-2 upshift at maxium power w/out damaging the clutch (2-3 and on at max power are no problem). It seems to me that the issue is tactfull use of the throttle when getting the clutch to hook up that is the trick but perhaps I'm missing something.

I can see how DSC would effect the power getting to the wheels off the line, but wow does the DSC figure into smooth upshifts once the car is rolling? How does it help or hurt the situation?

Thanks,

Justin
 
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