Re: alfa-digest V8 #1262 Autocross launch

["George Schweikle" <schweikg@domain.elided>]

Glenn,

Here's my response: My wife and I have autocrossed Alfas extensively since
1968, and have never experienced a driveline failure related to launch. This
while always using the stickiest tires available. The experience I can offer
is our use of a G-Analyst several years ago. This was an accelerometer with
an in-car screen to play back the forces in an autocross run. This screen
lacked resolution,  but the scan could be downloaded to a PC with graphics
accurate to .01 G. My launch style then was pretty aggressive with lots of
RPM and wheelspin. Dee would merely rev to 3000 RPM and release the clutch
smartly. The G-Analyst gave a clear trace of acceleration, and guess which
was steeper?. Not mine.

My current method is a part throttle launch with some clutch slip, then full
throttle after approxamitely 10-15 feet, wherupon the tires break loose
again, then grab. This with an SCCA Street-Prepared '76 Spider, Hoosier
Radial autocross tires on 9 x 15 in. rims, and a Tilton aluminum flywheel.
So, the launch for best time is a compromise depending on your level of car
preparation, while I am convinced the drivetrain can take almost anything.

Have fun,

George Schweikle
Lexington, KY

> Date: Mon, 28 Oct 2002 17:52:26 -0800
> From: "Glenn Wasserman" <glennwa@domain.elided>
> Subject: RE: Autocross launch - is it abusing the car?
>
> Resending due to only one response - anyone else care to weigh in?
> What's the "best" way to launch for lap times? How about the
> "friendliest" launch for the drivetrain?
>
> Thanks
> - -Glenn
>
> - -----Original Message-----
> From: Glenn Wasserman [mailto:glennwa@domain.elided]
> Sent: Thursday, October 24, 2002 1:17 PM
> To: alfa@domain.elided
> Subject: Autocross launch - is it abusing the car?
>
> I have a question regarding launching the car from a stop at autocross
> events. It's been said many times the fastest way to launch the car is
> to rev to a critical level of RPMs (say, 3000) and release the clutch
> quickly - i.e., slide the foot sideways off the pedal, suddenly.
>
> I believe the idea is that the best launch will involve a hint of
> wheelspin, and then a "hooking up" as the car slingshots away. After the
> launch the throttle is applied to accelerate accordingly.

> Assuming the above is the quickest launch (and I believe it is), I'm
> wondering how hard this is on the car - including the clutch,
> driveshaft, etc. (What autocrossing does to the tires is obvious!)
>
> I had always thought this was a bad thing for the clutch, but then
> again, there's no slipping of the clutch involved - and therefore should
> be minimal wear, right?
>
> Wouldn't the engine mounts, trans mount, driveshaft support, and other
> components take the brunt of wear on a launch?
>
> If I thought I were doing serious damage, I would tend to launch more
> gently, sacrificing a few tenths.
>
> Thanks
>
> - -Glenn
> '93 Spider Veloce
> '94 164Q
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