[mickyboy]

What is the best revs to launch at?
I got blown away the other day by a subaru forester 2.5l turbo.
Mind you, I didn't know he was going to race me, so I couldn't make up much ground. The Ars*&&^%^ then waved as he turned off down the road. Next time I will be ready!!!! :headshake:
Need someone with experience to give advice!

 

[lionking]

If you want a good launch - get an auto!

Check out the 1/4 mile 60' times on another thread here. We had a night at the drags recently. The auto launched flawlessly but the manuals were a bit tricky. There was a bit of discussion about the best way to launch. A lot of it is really dependant on surface grip and controlled slipping of the clutch.

Get out to the strip and have some fun practicing!

 

[mchapman]

Enthusiasts wave.

 

[mickyboy]

Too late I already have the 6MT for the next 3 yrs. I did test drive both trans but decided on the manual because the engine is so torquey that you barely have to change gears in traffic. Also the manual gives you great control when weaving in and out of traffic!
Next time guys in Sydney are going to the track I will go.
Will keep a track of the posts for the info.

 

[davidm]

What is the best revs to launch at?

It totaly depends on the conditions and road surface and therefore there is no such thing as 'magic revs'. It will be somewhere between 2,000 and 3,500rpm though. Ideally you need to learn to adopt and feed the power depending on the conditions.

I got blown away the other day by a subaru forester 2.5l turbo.
Mind you, I didn't know he was going to race me, so I couldn't make up much ground.

Even if a Barina gets a couple car-lengths jump on you, then I don't think you'll catchup to it before you hit 60kph. On the street, he who goes first wins unless you're racing to something 160kph speeds.

Still, like LK said, auto is by far the quickest thing in day today driving. When I'm driving my fathers auto HSV R8, there's nothing that can keep up with me off the lights ... not even bikes when you accelerate only to the speed-limit.

Look at the the '400m times' thread, and notice not only the 60' time that the auto could manage, but also the reaction time that you have at your disposal with auto box. With a manual you're lucky to get within 1/2sec of it, and you'll never make up that 1/2sec difference before you hit 60kph (or so) ... no matter what car you have.

 

[mchapman]

Its also worth noting that a 2.5L Turbo 4WD car can potentially be a force to be recokoned with. For reference the Au-Spec WRX has a 2.0L Turbo motor.

 

[jetpilot718]

Ehh, who cares about the subie, your car looked better losing than his did winning!

Besides, catch him out of first gear on a 5mph roll, and you will WALK his ass hard.

 

[Perth 350z]

Originally posted by DavidM@Nov 25 2004, 04:45 AM
What is the best revs to launch at?

It totaly depends on the conditions and road surface and therefore there is no such thing as 'magic revs'. It will be somewhere between 2,000 and 3,500rpm though. Ideally you need to learn to adopt and feed the power depending on the conditions.

So, is there much difference between having traction control on or off?? As I was wondering the other day what the difference is between "launch control" (on the new BMW M5) and traction control.

 

[harryw]

Perthy, Im not sure about traction control but with the **** we got it makes a huge difference.

Once the wheels show any sign of spinning the computer kills the motor!

As always

H

 

[mchapman]

Traction control will slow you down.

 

[davidm]

So, is there much difference between having traction control on or off??

Like the others said - it will slow you down. When it kicks in it will cut the power and feels not unlike fuel-surge ... so in that 1/2sec or so, it's like you lifted off.

The TC will also kick-in when you make a quick gear-change ... in particluar 1st-to-2nd, and again llose you another 1/2sec or so.

 

[scathing]

What launch control in the BMWs do is actually countermand the traction control.

Normally if the ABS sensors detect wheelspin it'll cut power (and maybe grab the brakes, I can't remember if BMWs do this) but if you've enabled launch control, it'll permit wheelspin from the standing start.


As people have said, there's no ideal launch RPM as it depends on your tyres and the surface. The other thing is, it depends on how good you are at feeding the clutch in.

The ideal launch is with a little wheelspin, to keep the revs up, while not sitting there doing a burnout. Of course on the street this attracts unwarranted attention, so you'll have to adjust your style again.

 

[mr rizk]

On a side note I ran my mates 05 WRX from a stand still. Quite amusing actually as the first time the VDC was on. Man I looked like a dick. The car lunged forward and then basically all power was cut and the SLIP light was going mad. Anyway second run made sure VDC was off. Launched at 2000 and then my ass end stepped out. By this time my mates about a 2 car lengths in front and I’m still going sideways, take 2nd gear and the car flicks the other way but still going sideways, 3rd flicks the other way still losing traction and then finally grabs. By this time his long gone and I have coved 100m going sideways. This was with new S03’s so looks like I need 275’s now. All he saw in his rear view mirror was Z driving like a crab !!

With the additional torque I need to re evaluate my launch methods with a bit of clutch slip :biggrin:

 

[Perth 350z]

Thanks for the input everyone.

I've got an auto, so I don't have to worry about gear changes however, I have had that wonderful sideways feeling from launching at around 2000rpm and watching my opponent run away from me with lots of traction.

Was fun, but would have been better if I actually had some grip to give him a run for his money.

 

[davidm]

On a side note I ran my mates 05 WRX from a stand still.

So your got well and trully beaten by the WRX. Did you do any other runs ... and if so, how did you go then?

but if you've enabled launch control, it'll permit wheelspin from the standing start.

I think it does even moe than that. All that driver needs to do is keep the it florred, and just push a button to launch it. The software will feed the right amount of launch revs, right amount of clutch-slip and then even the right amount of power to moderate the wheel-spin.

ps.
I remember reading something a long time ago where it stated that the quickest launch is with 20% (or something like that) wheel-spin. They had some data (or caclucations) to back that up.

On the other hand something like a proper top-fuel dragsters slip the clutch through the first 3 gears (ie. 1/2 way down the 400m strip) ... though again, it's all done through software.

 

[zuffy]

I've managed very good launches with my MT zed, you need to slip the clutch a tad to not spin. Don't drop the clutch it will either spin or wheel trample if u have that problem.

Unlike most cars I feel like I need to know i'm going to race to do it effectively.

 

[mr rizk]

DavidM

No more runs. I wanted to go to the twisties to see a comparison but he back out.

 

[mchapman]

RIZK,

Is this before or after?

 

[ky350]

Spinning in the first 3 gears is definately after!

 

[mchapman]

Hey, maybe he had space savers on the rear.