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Discussion Starter · #1 ·
I recently got an STI and have been having a lot of fun learning about it and especially driving it. one thing I’m curious about is the best way to actually launch it if I wanted to take off. I don’t drive incredibly aggressive and am usually a pretty defensive driver but I want to have some fun every now and then;)

I’ve done some research on the subject but have a few remaining questions:
1) is it always best to launch in 1st gear? Seems like second would allow more speed initially
2) how bad is it to do this if I’m driving it daily and want to maintain it in the long run (only has 40k miles) i.e. Once a week/month/ etc

Thanks in advance


Specs:
Blouch 20g turbo
Stage 2 Cobb tune
Larger TMIC
Injectors

Not sure if that helps but figured I would throw them in there.
 

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On stis especially you will want to preload your drivetrain so there is less shock when the clutch is released and the car will launch smoother. Launching even if you do it right is still very hard on drivetrain components.
 

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How do you preload? Sounds like the definition of clutch wear . . :)
 

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By essentially using your handbrake as a staging brake, letting the car tense up with the brake holding it then you launch.
 

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Yes :)
 

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I've launched my 05 a LOT. Literally hundreds of times -- almost all autocross racing, which is more abusive than doing it on the street most of the time due to running much stickier tires than standard street tires. If you do it right, you should be okay. Biggest thing I've seen happen is breaking axles because of wheel hop, though luckily that hasn't happened to me yet.

I'm of the opinion that using launch control via an Accessport or other tuning software is the best, as it lets you build more boost before launching. It takes a little longer and might not be as good for the street (I tend to hold it on 2-step for a full second or two to build boost) but you have more power right when you drop the clutch which gives more consistent wheelspin so you don't risk getting wheel hop as much.

Best way to launch -- it's all in the clutch release. You want to release it fast... you want a bit of wheelspin. Launching is inherently hard on the car -- you're putting a ton of energy into your whole driveline all at once. If you get wheelspin, then you let the tires take the brunt of that. If you don't spin the wheels, that energy stays in the driveline and gets taken by your transmission, diffs, and axles. Additionally... if you don't get wheelspin it's a lot more likely you'll bog the car. The biggest advantage that launching gives you is it lets you start from a dead stop with the turbo spooled and you never drop out of boost. Keeping the RPM up after dropping the clutch is part of that and the way to do that is through wheelspin.

So, how to release the clutch? The best way is to think of it like you just stepped in dog poo. Try it now while you're reading this. It's not as fast as a complete sidestep... but it's pretty fast. I don't hold the handbrake or anything unless I'm on a sloped surface. You're sending a ton of stress towards your driveline regardless and it just gives you one more thing to think about and possibly mess up. Might be better, might not be -- I've never bothered with it.

So, if you're using launch control, it's foot flat to the floor, I usually use between 4500 and 5500 for RPM (depending on tires and surface, you'll want to experiment a bit to find what works best), hold it there long enough that you build boost. Watch your boost gauge and wait until it stabilizes (usually is around 10psi for me on a vf39), then drop the clutch like you just stepped in dog poo. Don't lift at all -- keep the pedal to the floor the whole time.

If you aren't using launch control (I didn't for a long time), give it a couple quick revs, then floor it. Right before you hit redline, drop the clutch like you just stepped in dog poo. Don't lift at all, keep the pedal to the floor the whole time.

Ideally, you'll spin all 4 tires for a good bit through the gear and catch full traction around 4000-4500 rpm at which point you'll be fully in boost and feeling like a rocketship.

Final advice -- the worst thing you can do (both for speed and for your car) is to try to baby it. You're doing something abusive... but the car is built to handle it. Embrace it and send it. 50% commitment to a launch is FAR worse for the car than 100% commitment.

Have fun!
 

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If you're gonna do it, do it right :) :) :)
 

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Discussion Starter · #8 ·
I've launched my 05 a LOT. Literally hundreds of times -- almost all autocross racing, which is more abusive than doing it on the street most of the time due to running much stickier tires than standard street tires. If you do it right, you should be okay. Biggest thing I've seen happen is breaking axles because of wheel hop, though luckily that hasn't happened to me yet.

I'm of the opinion that using launch control via an Accessport or other tuning software is the best, as it lets you build more boost before launching. It takes a little longer and might not be as good for the street (I tend to hold it on 2-step for a full second or two to build boost) but you have more power right when you drop the clutch which gives more consistent wheelspin so you don't risk getting wheel hop as much.

Best way to launch -- it's all in the clutch release. You want to release it fast... you want a bit of wheelspin. Launching is inherently hard on the car -- you're putting a ton of energy into your whole driveline all at once. If you get wheelspin, then you let the tires take the brunt of that. If you don't spin the wheels, that energy stays in the driveline and gets taken by your transmission, diffs, and axles. Additionally... if you don't get wheelspin it's a lot more likely you'll bog the car. The biggest advantage that launching gives you is it lets you start from a dead stop with the turbo spooled and you never drop out of boost. Keeping the RPM up after dropping the clutch is part of that and the way to do that is through wheelspin.

So, how to release the clutch? The best way is to think of it like you just stepped in dog poo. Try it now while you're reading this. It's not as fast as a complete sidestep... but it's pretty fast. I don't hold the handbrake or anything unless I'm on a sloped surface. You're sending a ton of stress towards your driveline regardless and it just gives you one more thing to think about and possibly mess up. Might be better, might not be -- I've never bothered with it.

So, if you're using launch control, it's foot flat to the floor, I usually use between 4500 and 5500 for RPM (depending on tires and surface, you'll want to experiment a bit to find what works best), hold it there long enough that you build boost. Watch your boost gauge and wait until it stabilizes (usually is around 10psi for me on a vf39), then drop the clutch like you just stepped in dog poo. Don't lift at all -- keep the pedal to the floor the whole time.

If you aren't using launch control (I didn't for a long time), give it a couple quick revs, then floor it. Right before you hit redline, drop the clutch like you just stepped in dog poo. Don't lift at all, keep the pedal to the floor the whole time.

Ideally, you'll spin all 4 tires for a good bit through the gear and catch full traction around 4000-4500 rpm at which point you'll be fully in boost and feeling like a rocketship.

Final advice -- the worst thing you can do (both for speed and for your car) is to try to baby it. You're doing something abusive... but the car is built to handle it. Embrace it and send it. 50% commitment to a launch is FAR worse for the car than 100% commitment.

Have fun!
Thank you so much for your input and advice! I will take a lot of this to mind! One more question: is it best to be in first gear for all of this? Sounds silly but it feels like second just gets you going quicker and 1 has too many rpms to begin with on take off...idk lol
Cheers
 

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Thank you so much for your input and advice! I will take a lot of this to mind! One more question: is it best to be in first gear for all of this? Sounds silly but it feels like second just gets you going quicker and 1 has too many rpms to begin with on take off...idk lol
Cheers
Think about 2nd gear though, when do you start to really hit full boost? 4k ish rpm so about 40ish mph. You'd have to get off the line hard enough that by the time the tires gripped fully you were going at least that fast. If you think you can spin all 4 tires off the line up to 40mph then I could maybe see it being better, but most likely you'll bog.
FWIW, a friend of mine that I race autox with has an 06 STi putting about 650whp down and he still launches in 1st...
 

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the write up brapp did is perfect. I have launched my 06 easily over 100x, probably closer to 3-400 in all honesty (over 8 years). i have done this both on a stock turbo and my current 20g. i build about 8psi sitting still with it currently. i was building closer to 14 wheni had a stock vf turbo.

i have never once tried launching in second. although because first is so short that 1-2 shift is always tough to hit perfectly.

i use the accessport launch control. on the street i launch at 4500 (ap setting, actual is closer to 4700). and i have had it on a drag strip launching at 6k, but that was a prepped strip where 4500 would bog down.
 
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