What makes a shift "sporty"?
What makes a shift "sporty"?
(OP)
I'm trying to define "Sporty" as a target for AT shift feeling. What, in your opinion, are the characteristics of a "sporty" feeling shift?
Thanks
Thanks
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
What makes a shift "sporty"?
|
RE: What makes a shift "sporty"?
RE: What makes a shift "sporty"?
With modern controls it is entirely possible to have a very fast firm change at full throttle but an imperceptible change at say half power or less, possibly controlled by manifold pressure.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: What makes a shift "sporty"?
Harvey.
RE: What makes a shift "sporty"?
Personally, I find automated up/down shifting in such daily driving situations as highway onramp cornering/merging unsettling enough as it is, never mind if they were made still more intrusive.
Norm
RE: What makes a shift "sporty"?
?? what kind of vehicle produces such unsettling upshifts? Is this some kind of sporty beastie, or were you accustomed to early Dynaflows?
(well, it could be unsettling when my old Dodge Aspen would grab first gear on a rainy freeway cloverleaf, and the rear would slide out...)
cheers
Jay
Jay Maechtlen
http://home.covad.net/~jmaechtlen/
RE: What makes a shift "sporty"?
In my C4 with a shift kit mod, at low power loading the shifting is just precision but under heavey throttle the shifting becomes very firm and to the point the tires will break loose on a 1 to 2 shift as well as burn them from a dead stop.
On my AOD with valve body mods taylored to the use of a Kenne Bell supercharger, the shifting is set up to respond to throttle control for shifting under high power but will still auto shift in normal driving. The changes are still quite firm and will accentuate drive lins slop if there is any. In this type transmission there is no overdrive accumulator so the OD up shift is harsh unless the throttle is used as a buffer loading.
In my 4r70w (AODE)with valve body mods, the shift is just percieved as firm and quick by intent. The truck is in a weight class of about 5600 pounds and used for heavey towing. I run a program tuner that can also change the shift firmness but don't run anymore than what the valve body gives because it gets way to harsh running both methods. The AODE is an electric control where the 2 previous are hydraulic with two different methods of shift control. So I end up with three different transmission control systems but all respond to valve body modifications is about the same manner.
RE: What makes a shift "sporty"?
Mostly it unsettles me more than it does the car. But I probably notice it more than do most folks as I haven't owned an auto-tranny car since about 1972. So when a shift occurs that I did not specifically request, it comes as a mild surprise.
Some of the vehicles that I have been (un)fortunate enough to have driven have hunted between gears under certain conditions of load and road speed, and I never feel that I'm driving very smoothly when that happens.
There were a couple of 1960s Dodges with the 3-speed Torqueflite transmission that were firmish to slightly harsh on the upshift - that part being mostly OK. But they were matched to rather poor downshift logic that was overly abrupt when you finally did get it to happen, and it always did seem that the ensuing upshifts came too quickly if you lightened up on the throttle even a little.
Still earlier was a 1950s Pontiac with the 4-speed automatic that was nearly as unobtrusive in its shifting as such a thing could get without actually being a Dynaflow. I was not even aware of just how many discrete gears it had until I installed solid-core spark plug wires, after which I could clearly hear it all happen over the AM-only radio.
Norm