4 speeds for 55-56 chevrolet superstockers

bill dedman · 12-22-2007, 03:19 PM

Ken,
You don't "feel" the gear changes in a Turbogglide, but they are there.

That Wikipedia site explains it a lot better than I can, but the explanation that I have heard that makes the most sense is that the first, second and third (1:1) geared elements in the converter are ALL pulling as you leave from a dead stop. But, the one that's really MOVING the vehicle is the one with the "longest lever," the 1st gear element with its 2.5:1 gearng. When the vehicle speed reaches the point where it can no longer contribute (because of the rpm) the 2nd-gear (1.5:1) element, which has been pulling all along, continues to accelerate the vehicle more rapidly than the high gear (1:1) element can, but at some point, it, too, runs out of rpm and it "overruns" on its sprag, and is just along for the ride, and the 1:1 high gear element continues to pull, but with no gear reduction... you're in high gear, now.

The rpms stay pretty constant until the 2nd gear element starts to overrun; then, you're in "high gear" and as the vehicle accelerates, rpms will increase in a linear manner, since it's a 1:1 ratio, now.

Clear as mud??? Like I said, the Wikipedia explanation is much better than mine...

http://en.wikipedia.org/wiki/Turboglide

12-22-2007, 03:19 PM	#22
bill dedman VIP Member Join Date: Feb 2002 Location: Conway, AR Posts: 1,739 Likes: 0 Liked 6 Times in 4 Posts	Re: 4 speeds for 55-56 chevrolet superstockers Ken, You don't "feel" the gear changes in a Turbogglide, but they are there. That Wikipedia site explains it a lot better than I can, but the explanation that I have heard that makes the most sense is that the first, second and third (1:1) geared elements in the converter are ALL pulling as you leave from a dead stop. But, the one that's really MOVING the vehicle is the one with the "longest lever," the 1st gear element with its 2.5:1 gearng. When the vehicle speed reaches the point where it can no longer contribute (because of the rpm) the 2nd-gear (1.5:1) element, which has been pulling all along, continues to accelerate the vehicle more rapidly than the high gear (1:1) element can, but at some point, it, too, runs out of rpm and it "overruns" on its sprag, and is just along for the ride, and the 1:1 high gear element continues to pull, but with no gear reduction... you're in high gear, now. The rpms stay pretty constant until the 2nd gear element starts to overrun; then, you're in "high gear" and as the vehicle accelerates, rpms will increase in a linear manner, since it's a 1:1 ratio, now. Clear as mud??? Like I said, the Wikipedia explanation is much better than mine... http://en.wikipedia.org/wiki/Turboglide __________________ Bill Last edited by bill dedman; 12-22-2007 at 03:45 PM.