Launch control

[legacy_y_tu]

What is it? Obviously something to help get a quicker launch but is it software, hardware, a combo of both? Also does it apply to manuals only or autos as well? I've read recently in a couple of different places about Ecutek and their new launch control and it got me curious.

 

Brian

[malfeas99]

Launch control is magic.

 

I give to you:

http://www.zippyvideos.com/92767162691415.html

 

http://www.zippyvideos.com/161390166691465.html

 

Basically duplicates the launch control for cars like the Gallardo.. drop the throttle to the floor, while the clutch is disengaged, it lowers the rev limiter to a specified # (5500 in the case of that evo), drop the clutch, keep your foot down, off you go. It's especially useful with turbo cars cuz it'll let you build boost pretty much right off the line, perfectly, every time. Whee!!!!

[AWDpower]

Launch control is great! I had it on my Talon. It makes launching the car a no brainer, as long as you selected the right rpm. You build boost off the line, so you have power as soon as you release the clutch. Just beware that it can be tough on the drivetrain, since you are making a lot more torque in 1st gear. And don't do like the EVO in the video where the car was rolling slowly before he let the clutch out. That puts slack in the drivetrain, and increases the chances of breakage.

 

I don't know how well it would work on an auto. The torque converter already limits launch rpm, and you can already build some boost off the line. Maybe if you had a high stall converter and set it under the stall speed? I'm sure professional auto drag cars use launch control.

 

Jason K.

[Scotty]

Dragster don't have launch control. Launch control has been used in F1 and is being used in World Rally Championships. The launch control in F1 is much more complex. The computer figures out how fast to engage the clutch and the traction control system will cut fuel to individual cylinders to keep the tires at the optimum slip rate. I can't recall the optimum rate for race tires, but street tires is about 15% of slip for optimum acceleration and deceleration.

[JonFo]

Any recommended Torque converters for our cars?

 

And is launch control in auto basically to brake torque to stall speed then sidestep brake? or are there TCU tweaks we could do?

[nendo]

go to protourqe for upgraded convertor.

launch control is great on wrx,s but if u abuse it too much say hello to your blown tranny

[melayout]

Check out http://www.crawfordperformance.com/gallery/videos/stock_lgt.avi

 

From http://www.legacygt.com/forums/showthread.php?t=13907

 

Enjoy.

[powbmps]

Launch control was a riot in the WRX. The torque off the line was nuts! The few times I used it (UTEC stage 4 w/FP18g) I would laugh like a total moron and then feel guilty afterwards.

 

Chris S.

 

Shifting while keeping the gas floored was pretty cool too.

[AWDpower]

 

Dragster don't have launch control. Launch control has been used in F1 and is being used in World Rally Championships. The launch control in F1 is much more complex. The computer figures out how fast to engage the clutch and the traction control system will cut fuel to individual cylinders to keep the tires at the optimum slip rate. I can't recall the optimum rate for race tires, but street tires is about 15% of slip for optimum acceleration and deceleration

 

 

Sorry, your are right in that it is different from real launch control. I thought that was just what Subie guys called a selectable rev limiter. Back in DSM world it's called a Stutterbox. I don't think any of us need a real launch control, yet.

 

Jason K.

[AWDpower]

I presume that installing a launch control system in the Legacy (or in my case the Outback XT) would put lots of wear on the clutch? The system doesn't control how quickly the clutch slips in, does it?

 

People will probably argue with me on this, but I say no. I'll argue that it's easier on the clutch, because you don't need to slip it as much to launch smoothly. I've found that I can launch at a lower RPM. But if you do try to slip it, you could smoke a clutch quickly. But what about the increased torque at launch? Yes, there will be much more torque to the wheels in first gear. But as far as the clutch is concerened, it's most difficult task is managing torque in 5th gear. That's why when a clutch starts going out, it starts slipping in the upper gears first. There is much more resistance in Fifth then first.

 

Now the drivetrain is a whole nother story.

 

Jason K.

[legacy_y_tu]

Okay I'm not seeing the difference between this launch control and holding the revs at 5500 yourself and releasing the clutch. Is it simply the fact that it allows you to focus on other things instead of overrevving manually and hitting the rev limiter ?

 

Brian

[TSiWRX]

...Back in DSM world it's called a Stutterbox......

 

We don't have these things on our LGTs because, well, they "stutter/studder" by themselves.

 

-A

[AWDpower]

Okay I'm not seeing the difference between this launch control and holding the revs at 5500 yourself and releasing the clutch. Is it simply the fact that it allows you to focus on other things instead of overrevving manually and hitting the rev limiter ?

 

 

There are many advantages. One, you don't have to worry about holding at it at the right RPM. Two, it's very important to go WOT at the right time when launching, pretty much right before you let the clutch out. If you wait to long to get on the gas, the car will bog. The timing is difficult to get down, but becomes a non-issue with the launch rev limiter. Third, the car won't spool the turbo much free reving with the clutch in, because the throttle plate is just barely cracked open. But when up against the limiter with the throttle open, you can make boost on the line. And as soon as the clutch is released, the extra load means full boost comes on almost right away.

 

Jason K.

[powbmps]

Yeah, what AWDpower said. It also sounds really cool.

[legacy_y_tu]

There are many advantages. One, you don't have to worry about holding at it at the right RPM. Two, it's very important to go WOT at the right time when launching, pretty much right before you let the clutch out. If you wait to long to get on the gas, the car will bog. The timing is difficult to get down, but becomes a non-issue with the launch rev limiter. Third, the car won't spool the turbo much free reving with the clutch in, because the throttle plate is just barely cracked open. But when up against the limiter with the throttle open, you can make boost on the line. And as soon as the clutch is released, the extra load means full boost comes on almost right away.

 

Jason K.

 

All right I've got it now. thanks guys.

 

Brian

[meier motor sports]

this should be doable via ap i would think. some one agree with me please!

[Jaxx]

i have always heard it called a 2 step

to me launch control is about traction control (ala M5) boost/rpm is only half of it some versions do an ALS like fueling to spool the turbo

ecutek has said that they are working on it for the sti ecu (basicly the same as LGT ecu)

 

you don't want it in a 5 speed car .. tranny go bye bye

[powbmps]

It is a feature of the Turbo XS UTEC :

 

SPECIAL WARNING

 

The use of Launch Control WILL cause abnormal loads on your engine, exhaust system, O2 sensors, catalytic converters, clutch, gearbox and drivetrain. The use of ignition cut Launch Control WILL place abnormal loads to your valvetrain, turbocharger and exhaust system. The use of Launch Control is entirely optional and the user must be aware of the potential damage it can cause.

 

Chris S.

[meier motor sports]

any idea if this could be incorperated into a accesport map?