18+ Launch Control...do you use it at the track?

[fubar569]

I'm currently foot braking the car to anywhere between 1500 and roughly 2,000 before it starts to push through. Times are decently consistent. No real complaints other than maybe wanting to try to streamline a process to get as repeatable/close to 10.0 as possible.

Background: I have ran 10.35's on the flex tune with E71 and a 2.95 pulley. 10.15's on the E85 track tune with a 2.79 with 85% in the tank...and 9.84/9.87 with a 2.50 on the track tune with 85%. All footbraked with varying burnouts and no 60ft better than a 1.47-1.49...usually 1.50's - my last 5 passes at Empire I pretty much dead hooked all 5 runs. Couldn't force the car to get loose if I wanted to.

Car is a 110% full weight taxi cab with a 10" sub in the trunk and usually some garbage on the floorboard.

It COULD be faster. But I'm not ashamed of towing a trailer in, going 9.8's and towing it back home.

I am again set for HRDW in the street machine eliminator class which is a 10.0 index and #1 last year was a 6spd GT500 that went 10.030 average. I'm not that good. But top 10 was somewhere in the 10.3's and top 5 was like 10.28...

What is your experience with using launch control? On the 2.79 with LC set at 1500 I am building 6psi off the hit. I have never tried it at the track before. CCI driveshaft, stock axles, DIRS/Race brace with cradle lockouts.

What settings for drive modes and TC do you find to be the Quickest & most consistent? How do you prefer to warm up your drag pack? (MT ET-R'S 315/50/17 on D5 Beadlock here)

Figured I'd see if maybe I could pick anything up from anyone before test & tune on friday.

 

[Unholy707]

launch control will kill your time with traction control if it senses ANYZ slip

 

[SilverBillet]

I'm currently foot braking the car to anywhere between 1500 and roughly 2,000 before it starts to push through. Times are decently consistent. No real complaints other than maybe wanting to try to streamline a process to get as repeatable/close to 10.0 as possible.

Background: I have ran 10.35's on the flex tune with E71 and a 2.95 pulley. 10.15's on the E85 track tune with a 2.79 with 85% in the tank...and 9.84/9.87 with a 2.50 on the track tune with 85%. All footbraked with varying burnouts and no 60ft better than a 1.47-1.49...usually 1.50's - my last 5 passes at Empire I pretty much dead hooked all 5 runs. Couldn't force the car to get loose if I wanted to.

Car is a 110% full weight taxi cab with a 10" sub in the trunk and usually some garbage on the floorboard.

It COULD be faster. But I'm not ashamed of towing a trailer in, going 9.8's and towing it back home.

I am again set for HRDW in the street machine eliminator class which is a 10.0 index and #1 last year was a 6spd GT500 that went 10.030 average. I'm not that good. But top 10 was somewhere in the 10.3's and top 5 was like 10.28...

What is your experience with using launch control? On the 2.79 with LC set at 1500 I am building 6psi off the hit. I have never tried it at the track before. CCI driveshaft, stock axles, DIRS/Race brace with cradle lockouts.

What settings for drive modes and TC do you find to be the Quickest & most consistent? How do you prefer to warm up your drag pack? (MT ET-R'S 315/50/17 on D5 Beadlock here)

Figured I'd see if maybe I could pick anything up from anyone before test & tune on friday.

It seems you should have faster 60’s with that setup and those times if it’s dead hooking?

 

[Unholy707]

If it’s dead hooking and you’re already foot braking to the stall of the converter then you need more power to get a better 60’

 

[Unholy707]

I get a 1.4 just by stomping on it, no raising the rpm lol

 

[SilverBillet]

What’s your mph @fubar569?

 

[vortecd]

I like to get the rpm enough to take the slack out of the drivetrain and hit it. I know some that say stalling it up worked best for them so maybe no clear answer. I don't use the launch control

Need to keep records on DA, temp, humidity every time you are at the track to compare times. When my car was stock in 0 DA I could run 10.5 but in 3000 DA could be 10.9

Take out what you can when going to the track. Getting some skinnies will save 50ish pounds alone

I go through 3 gears on my burnout. TC off, trans in track, traction in sport, suspension in street

 

[fubar569]

It seems you should have faster 60’s with that setup and those times if it’s dead hooking?

I would think the car is capable of more but I don't have any issues really to speak of. It's consistent enough for the local tracks and overall pretty reliable.

It felt like a dead hook. I know I couldn't really feel any spin at all. Maybe I'm just not being aggressive enough with the throttle off the line even though I'm stalling it up?

I like to get the rpm enough to take the slack out of the drivetrain and hit it. I know some that say stalling it up worked best for them so maybe no clear answer. I don't use the launch control

Need to keep records on DA, temp, humidity every time you are at the track to compare times. When my car was stock in 0 DA I could run 10.5 but in 3000 DA could be 10.9

Take out what you can when going to the track. Getting some skinnies will save 50ish pounds alone

I go through 3 gears on my burnout. TC off, trans in track, traction in sport, suspension in street

One thing I don't do is keep good enough data. But that's my fault. I tried to get three gears but sometimes in using the taser for line lock it doesn't always hold.

I have skinnies but I'm trying to Pare down what I take with me basically just to simplify the whole operation. If I were going for all Glory runs I would definitely take the skinnies.

What’s your mph @fubar569?

Anywhere from 135 to 142 depending on track & pulley. I'm faster at numidia vs empire by about 3.5-4mph average which doesn't make sense.

 

[vortecd]

I would think the car is capable of more but I don't have any issues really to speak of. It's consistent enough for the local tracks and overall pretty reliable.

It felt like a dead hook. I know I couldn't really feel any spin at all. Maybe I'm just not being aggressive enough with the throttle off the line even though I'm stalling it up?



One thing I don't do is keep good enough data. But that's my fault. I tried to get three gears but sometimes in using the taser for line lock it doesn't always hold.

I have skinnies but I'm trying to Pare down what I take with me basically just to simplify the whole operation. If I were going for all Glory runs I would definitely take the skinnies.



Anywhere from 135 to 142 depending on track & pulley. I'm faster at numidia vs empire by about 3.5-4mph average which doesn't make sense.

Not sure why the line lock not holding unless the rpm coming down to low. I have never had an issue with that. DA makes a huge difference.

With e85 2900 DA 2.65 pulley 4650 lbs I went 9.96 so you are in the ball park unless it was 0 DA. I never ran that combo in better weather since I switched to a whipple. I think in 0 DA I would have been around 9.6-9.7

I have a book I record what I can in there so I can go back and compare times. When trying to remember DA and such it will be hard to remember so I have a written record

 

[fubar569]

Went to the track Friday night and made 6 runs. 4 of which gave any useful data. 2 on the foot brake and 2 on launch control.

Foot brake off idle-ish (TC fully off) went 10.22 on a ~1.59 60.
Foot brake til probably 2000 (TC fully off) went 10.19 on a ~1.59 60.

middle pass was me going ZOMGWTFBBQ why isn't LC working. Smoked em for 200ft and about pegged the wall. Oops.

Launch Control (traction in sport) at 1300/1400 went 10.15 on a ~1.55 60.
Launch Control (traction in sport) at 1700 went 10.14 on a ~1.55 60.

All passes were red key, "707", trans track, suspension street, and traction either off on the foot brake or sport for the LC passes (must be enabled in some form for LC to activate).

I've been in this specific ballpark 2 different outings with similar weather conditions resulting in very similar 60's and ET's. Foot Brake seems to be effective enough by itself and LC/sport traction is at least comparable if not a hair more consistent...which I did not expect.

I believe I'm probably pulley or tune limited right now. The more boost I feed it under the curve the more it picks up in all areas. The 2.79 resulted in right at or just over 16psi at 6500rpm so in theory I COULD just run the flex tune all week (went 10.31 on the 2.95 pulley on said flex tune). I'd need to send data off to verify but I intended to pay for track support for the entire event so...

I'll probably get one more outing just to take some more life off the Mickey Thompson's before I put a fresh set on for drag week. Based on last year's final results even a consistent 10.15 would Place me in the top five. That would be an enormous victory for a first time event if I managed to finish all 5 days.

I will have a total of 16 days off between now and drag week so you could say it's crunch time. Especially considering work has me flying into North Dakota for the time being.

 

[Unholy707]

So launch control didn’t ruin your run once you lost traction?

 

[Speedy!]

I'll be curious to see input on this. On my 2016 Hellcat, launch control was useless. SRT "said" it would control wheel spin to maximize forward momentum but that was never my experience. It'd just launch at the given RPM and immediately blow the tires off. I was always interested in it as a reaction time aid, but it never got off the line.

In the 170 I've not tried launch control yet, but did use the trans brake and it worked as advertised. I pulled 300ft/lbs at the launch and gradually fed power back in and ran my best time in the car on a basically unprepped track.

I'm wondering if some improvements were made on 2018+ programming to LC that make it work better. Ideally if it can work as advertised you'd already be WOT, boost building in the blower, staged, and all you're doing is taking your foot off the brake which would greatly improve RT.

 

[fubar569]

So launch control didn’t ruin your run once you lost traction?

Nope. If anything the opposite.

Can't say the track wasn't prepped either:

I'll be curious to see input on this. On my 2016 Hellcat, launch control was useless. SRT "said" it would control wheel spin to maximize forward momentum but that was never my experience. It'd just launch at the given RPM and immediately blow the tires off. I was always interested in it as a reaction time aid, but it never got off the line.

In the 170 I've not tried launch control yet, but did use the trans brake and it worked as advertised. I pulled 300ft/lbs at the launch and gradually fed power back in and ran my best time in the car on a basically unprepped track.

I'm wondering if some improvements were made on 2018+ programming to LC that make it work better. Ideally if it can work as advertised you'd already be WOT, boost building in the blower, staged, and all you're doing is taking your foot off the brake which would greatly improve RT.

I have heard the 18+ had the logic improved but I've never been able to try. I was building 4-5psi at ~1700rpm on the launch control. It's been as high as 6 during testing in my driveway. LOL. Much more than probably 1800 I'd imagine it would push thru. I know 2000 absolutely did.

 

[Unholy707]

I think track prep makes all the difference. Maybe I’ll try launch control if I can hit all the buttons. Then again I have a 15 so probably junk. Supposed mine still works with the auto swap but launch rpm is definitely lower than with the manual. Due to torque converter stall I’m sure

 

[Unholy707]

Wonder if @zhc can chime in on the launch control/torque reserve

 

[2ndAmend]

I am a low level amateur so I have been using Launch. It seems to work well for someone like me that has no clue. I have done launches from 2000 with no spin. When I try 2300, the car surges forward when I activate it and breaks the beam! I watched someone else do the same thing, it's not the brakes, it's the flexing of the tires!!!

 

[fubar569]

I am a low level amateur so I have been using Launch. It seems to work well for someone like me that has no clue. I have done launches from 2000 with no spin. When I try 2300, the car surges forward when I activate it and breaks the beam! I watched someone else do the same thing, it's not the brakes, it's the flexing of the tires!!!

It's not the tires here. Start getting over 2000 on mine it will push right thru the brakes on LC. I want to say last time I experimented 2000 pushed thru. 2300 was a nice burnout on a two step. Anything else up to max was HAHA OLOLOLOLOLOL!!!

I'll have to try them all again and see where it definitively will push straight thru.

For science. Of course.

 

[Unholy707]

I just gave up on it when it would kick you out of it and kill all timing and be pointless. I don’t foot brake at the track I just stab it from idle. Maybe this would get me a better 60’ (1.45)

 

[fubar569]

I just gave up on it when it would kick you out of it and kill all timing and be pointless. I don’t foot brake at the track I just stab it from idle. Maybe this would get me a better 60’ (1.45)

1.45 is awesome.

At 1.45 I'd be in the extremely high 9's as it sits.

The guys that pull in the 1.3's are in a whole other world IMO.

 

[Unholy707]

That’s what I run, non stop. Need to do more work. At least the car is dead consistent