Launch Control Slow Start

[Whitee]

Hey guys curious is anyone can help me solve my issue. I believe I have a good idea of what it is but I’m sure some of you have experienced before and can either verify or tell me I’m wrong. Car is EPL Stage 2 with DSG Tune and Roc Euro.

Here is a video of my car launching on pure 93 with 18 inch blizzaks. Notice how on launch the tranny grabs hard and the tires spin for a good amount of time.

https://youtu.be/uvdZynY5Ri8

This video is of today with my 19 inch wheels and Michelin Pilot Supersports. 39 Psi front and 35 Psi back. Notice how the car is slow off the line and I don’t get the initial hard grab like in the first video.

https://youtu.be/GiOvLRIuVLs

Now what I have realized is that this happened in the past and the difference other than the tires, is that I’m running 4 gallons of E85 in the tank. Every time I run E85 I get this issue where the car almost feels like it’s starving for fuel. Yes, I know I should log, but I’m curious is anyone else has any ideas other than mine which is that I have too much E85 in the tank and the pump can’t keep up....? No CELs or issues to mention.

Also notice I’m 1/10th slower with my PSS on, when I should be quicker compared to my soft winter tires that I blow off every time I launch.


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[YSPAIK]

I never launch my car, but it looks like it’s launching from different points in rpm range. Second video is higher and bounces more.

[kelseysautobody]

Your 18’s are probably 10lbs lighter per corner and those were two completely different launches so can’t really compare them.


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[cspcrx]

Is it possible that the 19s are a stickier tire and that is causing the car to bog, where the winter tires just spun and pulled the car along?

When I used to drag race my CRX on MT Slicks there was a sweet spot you would shoot for where the tires slipped enough to keep the revs up but not blow the tires up. Miss that low and you would bog or miss it high and go now where but make lots of smoke.

[Whitee]

All valid points but what I’m not getting is the hard clutch grab like in the first video. Hooking or spinning I should still get that neutral drop feel when launching.


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[cspcrx]

hard to tell from the video but it looks like it trys to grab but then drops. May just be the way the video looks. Also the video makes it look like you launched about 200 rpm higher than the winter tire and wheels. Have you tried 4k and see what happens?

[Whitee]

hard to tell from the video but it looks like it trys to grab but then drops. May just be the way the video looks. Also the video makes it look like you launched about 200 rpm higher than the winter tire and wheels. Have you tried 4k and see what happens?

You’re exactly right at what you’re seeing. The only difference on my summer tires is I held launch control longer, will try again.

Here is another video capturing the launch to 1/8th.

https://youtu.be/w3tmGJtL1mE

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[kelseysautobody]

You’re exactly right at what you’re seeing. The only difference on my summer tires is I held launch control longer, will try again.

Here is another video capturing the launch to 1/8th.

https://youtu.be/w3tmGJtL1mE

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Try to reload your TCU file and do the adaption after loading. I've been testing out my drag radials on a few launch RPMs files. The existing file when I first put on the DR's felt kind of sloppy and not as "crisp" as I thought it should be. After switching files this feeling went away.

[rs182]

Try to reload your TCU file and do the adaption after loading. I've been testing out my drag radials on a few launch RPMs files. The existing file when I first put on the DR's felt kind of sloppy and not as "crisp" as I thought it should be. After switching files this feeling went away.

Engine or transmission adaptation?

[kelseysautobody]

Engine or transmission adaptation?

Transmission, after flashing a TCU file. Not sure exactly what it does but EPL recommends doing this:

1. Warm Car Up
2. Flash DSG
3. Do a FULL control DTC scan and clear all codes
4. Start Car put in drive but do not release the brake for approx 60 seconds
5. Lightly accelerate and shift below 2500 rpm through gears 1-4 in manual mode

In VCDS there are also calibrations/adaptions that can reset engagement points of the clutches.
http://wiki.ross-tech.com/wiki/index.php/7-Speed_S-Tronic_Direct-Shift_Gearbox_(DSG/0B5)

[Whitee]

Transmission, after flashing a TCU file. Not sure exactly what it does but EPL recommends doing this:

1. Warm Car Up
2. Flash DSG
3. Do a FULL control DTC scan and clear all codes
4. Start Car put in drive but do not release the brake for approx 60 seconds
5. Lightly accelerate and shift below 2500 rpm through gears 1-4 in manual mode

In VCDS there are also calibrations/adaptions that can reset engagement points of the clutches.
http://wiki.ross-tech.com/wiki/index.php/7-Speed_S-Tronic_Direct-Shift_Gearbox_(DSG/0B5)

Just to be clear, I just need to reflash the tcu tune? Do I need to flash to stock than flash tcu tune or is it okay to just flash over what’s already there?


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[kelseysautobody]

Just to be clear, I just need to reflash the tcu tune? Do I need to flash to stock than flash tcu tune or is it okay to just flash over what’s already there?


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Yes reflash just the TCU tune. At the start of the flash it says "erasing tune" so 99% sure you will not need to flash the OE tune before reloading.

[Whitee]

Yes reflash just the TCU tune. At the start of the flash it says "erasing tune" so 99% sure you will not need to flash the OE tune before reloading.

I did what you recommended and the shifts are much much cleaner and also faster. Haven’t had a chance to launch yet. I wonder if EPL can chime in as to why it gets lazy over time?


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[kelseysautobody]

I did what you recommended and the shifts are much much cleaner and also faster. Haven’t had a chance to launch yet. I wonder if EPL can chime in as to why it gets lazy over time?


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When was your last DSG service? Do you do a lot of city driving?

[Whitee]

When was your last DSG service? Do you do a lot of city driving?

DSG service was done around 20k ago. Not much city stop and go at all. I did end up launching tonight after reflashing and the results sucked. Although it did short shift at 5k which seems to be happening much much more frequently on the 19s with the stickier tire. Here is the vid. Wish I could figure out what the hell is going on. I did log tonight for a full 3rd gear pull and everything looked great. Guess I need to log a launch? What parameters if any would I need to change in vcds for a lunch compared to a 3rd full pull?

https://youtu.be/ElURKAS9WLc


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[kelseysautobody]

It looks like you spun a little on that one. That can definitely cause a short shift. I'd play around with how you're setting up for the launch without actually launching. In the first video of your original post that launch is at a lower RPM with the tach slowing rising. That seems to work well for your car. The other launches you see the tach bouncing around at a higher RPM.

I like to rolling into the throttle, not too fast not too slow and getting to the kick down without depressing it. After launching then I'll get on the kick down. If I'm having issues with short shifting, right when the RPM settle I'll slide the shifter over to manual like this then launch.


https://youtu.be/kWBduzdaGJI

[Whitee]

It looks like you spun a little on that one. That can definitely cause a short shift. I'd play around with how you're setting up for the launch without actually launching. In the first video of your original post that launch is at a lower RPM with the tach slowing rising. That seems to work well for your car. The other launches you see the tach bouncing around at a higher RPM.

I like to rolling into the throttle, not too fast not too slow and getting to the kick down without depressing it. After launching then I'll get on the kick down. If I'm having issues with short shifting, right when the RPM settle I'll slide the shifter over to manual like this then launch.


https://youtu.be/kWBduzdaGJI

Will definitely give that a try, 4K seems pretty high to launch at without blowing the tires off. Your car sounds like it’s turbo!?!? What are you doing for 0-60?


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[kelseysautobody]

Will definitely give that a try, 4K seems pretty high to launch at without blowing the tires off. Your car sounds like it’s turbo!?!? What are you doing for 0-60?

Think the turbo like noise if from the window being down. Best I've got on the street is 3.20 from dragy but its usually around 3.4-3.5 because I can't get grip

[Rodizzle]

Like Kelseyautobody said ... play around with the launch . Above 3500 you tent to overspin and if by any chance you do catch 7/10 you’ll bog and short shift . Practice and more practice.
Everyone thinks it’s just just LC and your golden but it’s not truth . I still haven’t nailed the technique 100% but I’m getting there . On the streets I’m always able to launch ok but when I hit the track I get nervous and always end up spinning or short-shifting. [emoji1687]

https://m.youtube.com/watch?v=qnOpE7FJqvE


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[Whitee]

Like Kelseyautobody said ... play around with the launch . Above 3500 you tent to overspin and if by any chance you do catch 7/10 you’ll bog and short shift . Practice and more practice.
Everyone thinks it’s just just LC and your golden but it’s not truth . I still haven’t nailed the technique 100% but I’m getting there . On the streets I’m always able to launch ok but when I hit the track I get nervous and always end up spinning or short-shifting. [emoji1687]

https://m.youtube.com/watch?v=qnOpE7FJqvE


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So I attempted the method and hit 3.65 0-60 with it short shifting at 5k again lol. No idea how it was that fast when it short shifted like crazy. I just need EPL to release a lower rpm launch control or something where I can change it. 4K is too much even for my Stage 2 car.


Notice how it instantly engaged the clutch and how much harder it jumped out the hole compared to the previous videos.

https://youtu.be/W4sz1eAfvSc


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[Rodizzle]

Don’t quote me on this but almost every single tune will short shift it launched incorrectly and when I say incorrectly I just mean the transmission is picky .
You could activate launch control and then slowly pull up back on the pedal to let it hover where the RPMs you like to launch at .

There’s a clear example that it doesn’t matter what rpm’s u launch at, if the transmission doesn’t like it will just short shift
https://m.youtube.com/watch?v=2S3PmVF8CZ4


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[kelseysautobody]

So I attempted the method and hit 3.65 0-60 with it short shifting at 5k again lol. No idea how it was that fast when it short shifted like crazy. I just need EPL to release a lower rpm launch control or something where I can change it. 4K is too much even for my Stage 2 car.


Notice how it instantly engaged the clutch and how much harder it jumped out the hole compared to the previous videos.

https://youtu.be/W4sz1eAfvSc


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So this was in manual mode when you launched? Couldn’t see the display. Email Chris to see if there’s a lower launch file for your box code. They were going to move all TCU tunes down to 3500 LC at some point.

[Whitee]

So this was in manual mode when you launched? Couldn’t see the display. Email Chris to see if there’s a lower launch file for your box code. They were going to move all TCU tunes down to 3500 LC at some point.

No, this wasn’t isn’t manual. I just launched it manually by controlling the RPM is what I meant to say. I emailed Chris a few hours ago and he said they are working on it. I can’t imagine it would take much to type in 3500 where it says 4000, LOL.


Don’t quote me on this but almost every single tune will short shift it launched incorrectly and when I say incorrectly I just mean the transmission is picky .
You could activate launch control and then slowly pull up back on the pedal to let it hover where the RPMs you like to launch at .

There’s a clear example that it doesn’t matter what rpm’s u launch at, if the transmission doesn’t like it will just short shift
https://m.youtube.com/watch?v=2S3PmVF8CZ4


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Your car is wicked fast and sounds amazing. Love the sound of the IE launch control.


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