RE: alfa-digest V8 #1262 Autocross launch

["Glenn Wasserman" <glennwa@domain.elided>]

Thanks for your response, and thanks to the others who responded. I
think next time I'll try slipping the clutch a little and then getting
aggressive after the tires grab.

And George, looks like you married well!!!

Thanks
-Glenn

-----Original Message-----
From: George Schweikle [mailto:schweikg@domain.elided]
Sent: Tuesday, October 29, 2002 8:51 PM
To: alfa@domain.elided; alfa-digest@domain.elided
Subject: Re: alfa-digest V8 #1262 Autocross launch

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
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided