SS Manual Launch Control

[4WDlifeform]

With all nannies off, if I do not put the pedal to the floor (say I bring it up to 4k slowly), will the computer still pull the throttle back to attempt maximum grip after launch? I just installed the Hurst Line Lock. When I go to burn out, I suppose I have to pop the clutch without flooring it.

I like that it can act like a two-step, but I do not like the computer pulling the throttle back. Is there a way to modify 'something' so after launch, full throttle is truly full throttle?

What if I only turn off traction control, leave stabilitrack on. Would it let me do burn out and race without influence of the computer? From what I read, stabilitrack only senses if the car goes sideways. In a drag race, the plan is to not let that happen anyway, so it should not influence throttle?

Maybe I just need more time toying with the car. I am taking it to the track tonight to see if I can get closer to 13 seconds (all stock). I have the line lock to experiment with and I might mess with the traction settings a bit too.

Curious to hear thoughts/procedures you guys use with the manual trans. Need some ideas to play with tonight. I am a novice so I have much to learn. Cheers!!

[acammer]

If you have everything off (long press the button for like 5 seconds) then you should not have any traction control intervention at all. In competitive mode, you get the factory "launch control", and the computer will modulate the throttle on the release/roll out.

I'm not sure about traction control off and stabilitrack on - it makes sense to me that this would give you some nannies if you get way out of shape, but should allow for a good burnout and no throttle intervention as long as you're pointed mostly straight. For me, I just turn it all off and let the computer between my ears do the work.

Here are a couple of videos to give you some ideas on drag racing. Note a couple of things. First, I drive around the water, and then back in. Treaded street tires will pick up a bunch of water, so if you drive your fronts through that, you'll be trailing water all the way up to the starting line. This will hurt your launch, and you won't make friends with the guy that has to use that lane after you. So, go around, and back in.

You'll see I put the car into second gear for the burnout - this will give you more wheel speed. I have a 4.10 rear, so I really need it. A stock geared car might be fine in first, you can experiment and see what you like - for me second is nice, I don't have to rev it's guts out, and a I get a good burnout. I let the car roll out of the water spinning the tires, then I hold it briefly with the brakes to make a little heat, and then roll out again and step on the clutch BEFORE it hooks back up. Just easier on the drive line than hooking under power. For street tires you don't need a massive long burnout, they'll just get greasy. Some street tires just want to be cleaned up, ie very short burnout, for me I found these tires worked best with a little heat in them. 25 psi hot was working good, you'll probably want to experiment with that as well.

Then I roll up and take the pre-stage beam. Once I have pre-stage lit I grab the emergency brake - I'm going to use that to stop the car when I pull up into the full stage beam. Etiquette is to light just your pre-stage beam, and then wait for the other lane before going full stage.

Once I'm fully staged, I hold the car with a decent amount of emergency brake, increase RPM to my launch RPM, and then ever so slightly begin to release the clutch till it just starts to drag. This technique builds pre-load in the drive-line, every component, the dual mass flywheel, the driveshaft, the rear end, the axles, all the bushings in the rear suspension, subframe, and differential mount all have slack and will act like a springs against the torque of the car when you release the clutch. If you take up that slack you won't shock those components so hard, they're already pre-loaded. This does two things - you reduce the opportunity for breakage on the launch, and you reduce the potential for wheelhop. When the light goes green (before it really, but that's more advanced stuff you don't need to worry about until you're really racing the lane next to you) I make a smooth and quick clutch release while rolling the throttle down, and smoothly release the emergency brake. It's all smooth, there is no side-stepping the clutch, no smashing the throttle. It happens very quick, but it's not abrupt.

If the track prep is good and you have a stock-ish car, it should hook pretty decent like that. I never change my launch technique - you want to develop something very repeatable and consistent. If I'm having traction issues I lower the launch RPM. If it's hooking good I'll raise it some till I find the limit. With 4.10s and street tires my best launches were coming around 3000rpm. With the stock 3.45s it needed more like 4500rpm. Now that I'm on a real tire it wants 5000+rpm - I'm still figuring out what it needs.

So, then you just need to make all your shifts cleanly. Clean shifts > fast shifts 100% of the time. You want them fast, but if you're missing gears, back it down till you're consistent, and then build up the speed. My car will not tolerate a full "power-shift" from 1 to 2, I have to make a conscious lift on the throttle and not rush that shift. My 2-3 and 3-4 I can go as aggressive as I want with though.

With stock gearing, depending on how fast the car is trapping, you may not need to go to 4th gear. I recommend trying to stay with 3rd. If the car hits the limiter before the finish line beams, then you need to go to 4th. If it doesn't, then definitely stay in 3rd. It's close when these things are stock-ish. Mine would run into the limiter about 1100' when it was full bolt ons with stock 3.45 gears, so I had to make the shift. If I had new tires, the extra tire height may have been enough to get me through the traps without the shift. Stock, it would have been fine in 3rd.

Always pay close attention when making the turn onto the return road - don't cut in front of a car in the other lane, wait on him and let him make the turn first if it's on his side, even if he's behind you. Last thing you need is somebody trying to come through your drivers door because they lost their brakes.

Hood open between runs, you want to keep the car as cool as possible. If you can tolerate it, run the heat in the staging lanes to pull heat out of the car. Try to idle as little as possible in the staging lanes - I don't start my car till the line is moving, and if it isn't moving fast, I'll shut it off after I move up a few spots.

Hope that helps. Let us know how it goes.



And here is a daylight view of the e-brake launch technique. This isn't a great launch, it bogs some, but there is a enough light to see what's going on. I still managed to leave super late and turn on the win light against the Mustang, so it's not totally shameful. Note this is with stock 3.45 gears - you'll see where I have to grab 4th just before the beams. This was trapping like 112 - it would go 111 through the beams if I kept it in third. The tires were stock size, but really worn so quite a bit shorter than a fully treaded set.

[4WDlifeform]

@acammer Thank you for all the tips! I appreciate you taking the time to put all that together.

So holding the button for 5sec turns EVERYTHING off? Even the launch control? I have always just pressed it twice for competitive mode, did not know there was another option!

This will be my second time to the track. I have tried the e-brake launch before. I have also tried letting the computer do the throttle limit (launch control) and all my times were right around 13.3 to 13.5 (car is stock, only NPP and CAI). My best time was with no e-brake, no launch control. I am going to try pre-loading tonight with the line-lock. Releasing the push button should be easier/faster than working the brake lever. I might ignore the tree like you did in your video, and just focus on the launch technique and 60ft time. Trying to do all that at once as a newbie is a bit overwhelming. Once I am comfortable with a consistent technique, then I'll work on reaction times....

I can not avoid the water box at this track, they soak the whole lane. AWD cars walk right though it, no burn out at all. No one seems to make a fuss. Heck, could probably leave the A/C on!

I did have to shift into 4th for the last couple 100ft or so. I do not have a shift light, and I did run into my limiter a few times my first time out.

[acammer]

Originally Posted by 4WDlifeform

@acammer Thank you for all the tips! I appreciate you taking the time to put all that together.

So holding the button for 5sec turns EVERYTHING off? Even the launch control? I have always just pressed it twice for competitive mode, did not know there was another option!

This will be my second time to the track. I have tried the e-brake launch before. I have also tried letting the computer do the throttle limit (launch control) and all my times were right around 13.3 to 13.5 (car is stock, only NPP and CAI). My best time was with no e-brake, no launch control. I am going to try pre-loading tonight with the line-lock. Releasing the push button should be easier/faster than working the brake lever. I might ignore the tree like you did in your video, and just focus on the launch technique and 60ft time. Trying to do all that at once as a newbie is a bit overwhelming. Once I am comfortable with a consistent technique, then I'll work on reaction times....

I can not avoid the water box at this track, they soak the whole lane. AWD cars walk right though it, no burn out at all. No one seems to make a fuss. Heck, could probably leave the A/C on!

I did have to shift into 4th for the last couple 100ft or so. I do not have a shift light, and I did run into my limiter a few times my first time out.

Yea, you'll know you have it all off when both the traction control off and stabilitrac off lights are both on. No launch control, no traction control, no stabilitrac, you get whatever you give the car. Preload with the line lock should work just fine, agree it's easier to release the that work the lever.

Definitely forget about cutting lights - just work on getting your launch technique down and consistent. Then you just start tuning your rpm to where it needs to be to give you a good hook.

It's too bad they drag so much water up to the line - no wonder it's hard to launch there.

[4WDlifeform]

Well, had an "OK" night. I did all passes with all nannies completely off. Best run was 13.214 @ 108.91, it was the only good launch I got, 60ft was 2.132. My best prior to the line lock was 2.3ish.

1st run I spun out of the hole pretty bad. No grip :-/... But I tried running through without hitting 4th gear, and made it. My trap speed was 109.8.

2nd run spun again, shifted into 4th, 109.5mph

3rd run, my clutch pedal didn't come all the way out!?? Pretty sure I smoked the clutch a bit... that was quite frustrating. Kinda worried me as I finished the pass, but shifted fine since. Not really sure what happend? Only thing I can think was my RPMs might have been quite high (try only listen to motor and watch tree, but my competitor that run was pretty loud!) I think I was reading that can cause the clutch to stick?? Still researching.

4th run was great, line lock held as I started slipping the clutch, button out, quick and smooth clutch release as I worked into WOT. I believe I shifted into 4th.

Tricky launching this thing. Definitely need to practice practice. Some stickies back there would be very helpful! I want to mount a camera in the cab so I can see/remember everything I did.

Until next time. Thanks again for your comments!!

[acammer]

Originally Posted by 4WDlifeform

Well, had an "OK" night. I did all passes with all nannies completely off. Best run was 13.214 @ 108.91, it was the only good launch I got, 60ft was 2.132. My best prior to the line lock was 2.3ish.

1st run I spun out of the hole pretty bad. No grip :-/... But I tried running through without hitting 4th gear, and made it. My trap speed was 109.8.

2nd run spun again, shifted into 4th, 109.5mph

3rd run, my clutch pedal didn't come all the way out!?? Pretty sure I smoked the clutch a bit... that was quite frustrating. Kinda worried me as I finished the pass, but shifted fine since. Not really sure what happend? Only thing I can think was my RPMs might have been quite high (try only listen to motor and watch tree, but my competitor that run was pretty loud!) I think I was reading that can cause the clutch to stick?? Still researching.

4th run was great, line lock held as I started slipping the clutch, button out, quick and smooth clutch release as I worked into WOT. I believe I shifted into 4th.

Tricky launching this thing. Definitely need to practice practice. Some stickies back there would be very helpful! I want to mount a camera in the cab so I can see/remember everything I did.

Until next time. Thanks again for your comments!!

Sounds like you're doing things right - slow and steady improvement.

The clutch staying on the floor is a common issue, which can usually be improved/solved with fresh/clean fluid. I have an Ideal Garage clutch master cylinder, dedicated clutch fluid reservoir, removed stock clutch spring, and a light linear pull return spring. That all translates to a better high rpm shift, and better clutch feel. I would start with a fluid flush - run it a week, and then flush it again. The other thing to avoid is "hot-lapping" the car - making passes without some cool down time in between. Some cars just won't tolerate that, and you may just need more cool down time between runs.

Stickies will definitely help get the times down - but I recommend continuing to work on getting all you can out of your street tires before moving on to the drag radials. Once you have sticky tires on the car the risk to the whole driveline goes up substantially, so the more experience you have before you start that higher risk stuff, the better.

Something to consider at some point might be a shift light. I have one now, and I absolutely love it. The stock tach, with 4.10s in the rear and a healthy cam only build cannot keep up with the engines rate of acceleration in 1st gear, so I was having to anticipate the shift quite a bit. Now, I have a programmable light where I can set a trigger RPM for each gear, so I can have a little more anticipation on the 1-2, and then get the other shifts closer to my target shift rpm. It also has a launch mode, it turns the light on when the car isn't moving when I hit a pre-set rpm. If I exceed that RPM, it starts flashing. Just gives me something easy to aim for while trying to watch the tree, my competitor, etc.

[4WDlifeform]

Thanks again @acammer. I have been looking into the clutch pedal issue since Friday, and finding quite a range of opinions on what the root problem is, and what fixes it.

From what I have been reading, 30k is a good point to flush the fluid. In process of installing the line lock I ordered a power bleeder, so I may try and get under to bleed the clutch fluid. Suppose DOT4 fluid is a good choice for more aggressive use?

I like the idea of a shift light. Especially one where you can program a launch RPM and a shift RPM separately. Can you share a pic of how you installed yours? Let me know model number too, may look into this. Thanks again!

[acammer]

Originally Posted by 4WDlifeform

Thanks again @acammer. I have been looking into the clutch pedal issue since Friday, and finding quite a range of opinions on what the root problem is, and what fixes it.

From what I have been reading, 30k is a good point to flush the fluid. In process of installing the line lock I ordered a power bleeder, so I may try and get under to bleed the clutch fluid. Suppose DOT4 fluid is a good choice for more aggressive use?

I like the idea of a shift light. Especially one where you can program a launch RPM and a shift RPM separately. Can you share a pic of how you installed yours? Let me know model number too, may look into this. Thanks again!

I like Motul RFB600 for the clutch fluid - has worked well for me. Bleeding the clutch is a real pain in the butt - the valve is INSIDE the bell-housing. If you ever have to pull the trans, do yourself a favor and put a remote bleeder.

I don't have any pictures of the install, it's pretty simple though - the wire drops down into the drivers side fuse panel, and then on down to the OBDII plug. It's pretty straightforward, just pop the fuse panel off and you can see right where to route it. I have my OBDII plug un-mounted from the bottom of the dash, so I can stuff it up inside there rather than bumping it constantly with my clutch foot.

I do have a video of it that gives a rough idea of where I placed it. My 6 year old shot the video from the passengers seat - he wanted to make a hit and record the light. What kind of good father wouldn't agree to that!?

[Taylortoons]

You boiled your brake/clutch fluid. I did the same not long ago. Use the Ranger method to replace the fluid. I did this 3 times and my clutch is like new. No more sticking to the floor.

[race24x]

What is the Ranger method. THis happened to my clutch the other day. How do you get to the bleeder inside the bell housing

[Taylortoons]

I read about it somewhere on here then googled it. Watched a few YouTube videos and it looked simple enough. I used a mini hand held syphon pump from Napa.

[Pete G]

Originally Posted by acammer

If you have everything off (long press the button for like 5 seconds) then you should not have any traction control intervention at all. In competitive mode, you get the factory "launch control", and the computer will modulate the throttle on the release/roll out.

I'm not sure about traction control off and stabilitrack on - it makes sense to me that this would give you some nannies if you get way out of shape, but should allow for a good burnout and no throttle intervention as long as you're pointed mostly straight. For me, I just turn it all off and let the computer between my ears do the work.

Here are a couple of videos to give you some ideas on drag racing. Note a couple of things. First, I drive around the water, and then back in. Treaded street tires will pick up a bunch of water, so if you drive your fronts through that, you'll be trailing water all the way up to the starting line. This will hurt your launch, and you won't make friends with the guy that has to use that lane after you. So, go around, and back in.

You'll see I put the car into second gear for the burnout - this will give you more wheel speed. I have a 4.10 rear, so I really need it. A stock geared car might be fine in first, you can experiment and see what you like - for me second is nice, I don't have to rev it's guts out, and a I get a good burnout. I let the car roll out of the water spinning the tires, then I hold it briefly with the brakes to make a little heat, and then roll out again and step on the clutch BEFORE it hooks back up. Just easier on the drive line than hooking under power. For street tires you don't need a massive long burnout, they'll just get greasy. Some street tires just want to be cleaned up, ie very short burnout, for me I found these tires worked best with a little heat in them. 25 psi hot was working good, you'll probably want to experiment with that as well.

Then I roll up and take the pre-stage beam. Once I have pre-stage lit I grab the emergency brake - I'm going to use that to stop the car when I pull up into the full stage beam. Etiquette is to light just your pre-stage beam, and then wait for the other lane before going full stage.

Once I'm fully staged, I hold the car with a decent amount of emergency brake, increase RPM to my launch RPM, and then ever so slightly begin to release the clutch till it just starts to drag. This technique builds pre-load in the drive-line, every component, the dual mass flywheel, the driveshaft, the rear end, the axles, all the bushings in the rear suspension, subframe, and differential mount all have slack and will act like a springs against the torque of the car when you release the clutch. If you take up that slack you won't shock those components so hard, they're already pre-loaded. This does two things - you reduce the opportunity for breakage on the launch, and you reduce the potential for wheelhop. When the light goes green (before it really, but that's more advanced stuff you don't need to worry about until you're really racing the lane next to you) I make a smooth and quick clutch release while rolling the throttle down, and smoothly release the emergency brake. It's all smooth, there is no side-stepping the clutch, no smashing the throttle. It happens very quick, but it's not abrupt.

If the track prep is good and you have a stock-ish car, it should hook pretty decent like that. I never change my launch technique - you want to develop something very repeatable and consistent. If I'm having traction issues I lower the launch RPM. If it's hooking good I'll raise it some till I find the limit. With 4.10s and street tires my best launches were coming around 3000rpm. With the stock 3.45s it needed more like 4500rpm. Now that I'm on a real tire it wants 5000+rpm - I'm still figuring out what it needs.

So, then you just need to make all your shifts cleanly. Clean shifts > fast shifts 100% of the time. You want them fast, but if you're missing gears, back it down till you're consistent, and then build up the speed. My car will not tolerate a full "power-shift" from 1 to 2, I have to make a conscious lift on the throttle and not rush that shift. My 2-3 and 3-4 I can go as aggressive as I want with though.

With stock gearing, depending on how fast the car is trapping, you may not need to go to 4th gear. I recommend trying to stay with 3rd. If the car hits the limiter before the finish line beams, then you need to go to 4th. If it doesn't, then definitely stay in 3rd. It's close when these things are stock-ish. Mine would run into the limiter about 1100' when it was full bolt ons with stock 3.45 gears, so I had to make the shift. If I had new tires, the extra tire height may have been enough to get me through the traps without the shift. Stock, it would have been fine in 3rd.

Always pay close attention when making the turn onto the return road - don't cut in front of a car in the other lane, wait on him and let him make the turn first if it's on his side, even if he's behind you. Last thing you need is somebody trying to come through your drivers door because they lost their brakes.

Hood open between runs, you want to keep the car as cool as possible. If you can tolerate it, run the heat in the staging lanes to pull heat out of the car. Try to idle as little as possible in the staging lanes - I don't start my car till the line is moving, and if it isn't moving fast, I'll shut it off after I move up a few spots.

Hope that helps. Let us know how it goes.



And here is a daylight view of the e-brake launch technique. This isn't a great launch, it bogs some, but there is a enough light to see what's going on. I still managed to leave super late and turn on the win light against the Mustang, so it's not totally shameful. Note this is with stock 3.45 gears - you'll see where I have to grab 4th just before the beams. This was trapping like 112 - it would go 111 through the beams if I kept it in third. The tires were stock size, but really worn so quite a bit shorter than a fully treaded set.

Nice write up! I always wondered how guys would load the driveline with a manual and no line lock. On my streetbike or even motocross I would engage the clutch just enough that I could use my feet to hold back or of course use the front brake.

[acammer]

Originally Posted by Pete G

Nice write up! I always wondered how guys would load the driveline with a manual and no line lock. On my streetbike or even motocross I would engage the clutch just enough that I could use my feet to hold back or of course use the front brake.

That little bit of preload really helps cut back on wheelhop and breakage.

[frankwjr]

http://www.rangeracceleration.com/Clutch_Care.html