What's all this double-clutching stuff, anyhow?

Bob Pease writes the Pease Porridge column in Electronic Design magazine, one of those freebies they send to dork engineers. It's actually pretty good, and Pease is a colorful curmudgeon who writes about whatever the hell he wants. Since we have a truck driver in our midst who's taken double clutching on as his tagline, here's Pease's What's all this double-clutching stuff, anyhow? article. I've read him for years. This guy drives a volkswagen bug around silicon valley to get to work at national semiconductor, but he usually knows what he's talking about even if it's not electronics. Correct me if I'm wrong, Mikey D.

Here's the crux of the matter:
First, you take your foot off the gas and kick in the clutch. You shift into neutral, AND let the clutch out. You wait perhaps 0.3 to 1.0 seconds for the engine to slow down from its high revs, depending on how fast you were revving when you started to shift and how much inertia the engine has to slow down. THEN you kick in the clutch and shift into third, and let the clutch out quickly, feeding the gas appropriately. If you have judged it right, when you let the clutch out, there isn't any JERK. And when you shove the lever into third, the gears and engine are at a synchronized speed, so there's minimum wear on the synchronizers, which are the tiny clutches that bring the clutch plate and the gears into smooth synchrony. There's also usually less wear on the clutch plates.

But there's much more, including naturalists playing tricks on condors.


Anonymous said...


Anonymous said...

jesus the fuckity fuck fuck, what the fuck is this? Myth Busters? get the fuck out!

Anonymous said...

First off, you don'ever have to double clutch a car, unless it has an UN-synchronized trans, which they haven't made since like the 50's (unless you drive a medium duty or larger truck)

Second, if you are driving an old un-synchronized trans, you will still need to "blip" the throttle while the clutch is out in neutrual to spin up the transmission internals to get them to match their speeds. That's the whole idea. Since these transmissions are not synchronized, the driver must synchronize the speeds of the moving parts, or you'll get a grind. It's not about smooth engagement, but no gear clash.

Anonymous said...

alchbactually I only use the clutch when I'm stopped or when I start moving, It's easier on the 12 speed trans, the clutch's and my leg. mikeD ,oh and if you dont like the topic go fuckity fuck fuck yourself,or better yet dont respond