Throttle % while accelerating?

[comptiger5000]

Just don't go too far with that adjustment. Setting it to shift sooner tends to lead to lower line pressure in the tranny (in some cars), which can cause soft shifts and/or slippage, leading to shorter tranny life.

[AeroModder]

I'll need to look at that now. I'm wondering about the kickdown rod, though, and if pulling that off can help it not force downshifts when I don't want it to.

[dcb]

I've been trying to figure out how to get some feedback to the driver on acceleration efficiency for a while. With a stickshift and a bsfc map it is pretty easy to make a guess. But if you have an auto it will have varying degrees of slippage, and if you have no bsfc map then what?

I think a reasonable approach is to use something mpguinoish that reports the change in speed over the fuel used as an instant value, and as something that displays an interval, say until the rpm drops indicating another shift, then perhaps a third accumulator that reset at 0mph so that you can relatively easily:

hunt for a peak value while accelerating with pedal position.
hunt for a peak average within a gear with different strategies.
hunt for a peak average from zero to whatever speed you want.

Of course hills and wind will throw off any hope of absolute readings, but might be useful enough with relative readings.

I've asked a few times about this, hope it isn't beating a dead horse. But does it make sense? Sound like a useful tool? Any serious suggestions?

[user removed]

Originally Posted by AeroModder

I'll need to look at that now. I'm wondering about the kickdown rod, though, and if pulling that off can help it not force downshifts when I don't want it to.

Can you adjust the kick down rod to bring on up shifts earlier?

Pull rod=lengthen
Push rod=shorten

ATs that have kick down cables, rods, or vacuum servos, in most cases will shift very early if those components are not adjusted properly. At least it was that way some years ago.

regards
Mech

[ShadeTreeMech]

I've had a car (and worked on a car) where the kickdown cable was inoperative, ie it always wanted to start in 3rd (both 3 speed autos) and you had to manually downshift to function correctly. I wonder if a old school tranny couldn't be adjusted with higher line pressure and disable the kickdown to make for a manual shift auto? My cars have electronic controlled trannys so I'm sure that's a whole new ball of wax, but older trans seem to be a bit simpler.

My TPS adjustment I mentioned earlier was to the extreme allowed, I didn't force it to go further than engineered. And if power is needed, sometimes a manual downshift is in order. But I can now cruise at 35 in locked 4th without the trans trying to downshift constantly.

[comptiger5000]

Some will start in 3rd, others will still start in 1st and shift very early with the cable disconnected.

For most non-electronic autos (such as the 46RE in my Jeep), you can get a modified valve body that can make them full manual shift.

[Turbo Dan-O]

Has anyone done any testing with heavy acceleration vs. light? I can see good and bad points either way.

Dan-o

[Lokalazeros]

Originally Posted by Fr3AkAzOiD

Between 70% to 100% throttle and shift between 1,800 - 2,500 rpm.(...)

I was under the impression that the slowest you accelerated, the less you used gas. (SGII is on the way, so I used my butt-o-meter on this one). Maybe that's why I can get past 31MPG, even tho I drive slower than anyone in town.

thanks for the head-up !

[AeroModder]

I've done all jackrabbit starts on this tank, so we'll see how it goes. Though there are multiple variables at work, so I'll have to compare it to a few tanks with similar weather and no changes to the car.

[Turbo Dan-O]

But accelerating faster gets you up to cruise speed sooner. Like I said, I would like to see/do some ABA tests on this.

Dan-o