Archngl

So, first off... my xb rules and I love it.
I got in an accident a lil' bit ago, and had a pt cruiser for a rental when my xb was in the shop.

(by the way I hate pt cuizers)

I did notice that when going over 40 or so, when I lifted off the gas pedal, it felt like the car was put into neutral... VERY smooth deceleration.

With my xb, it seems like it's trying too hard in the same scenario.
Is there an engine component that can be swapped out to make it smoother/lower rpms?

thanks in advance!

autopainter13

i think thats all in the gearing of the transmission

Archngl

really? nothing can be done? no lightweight aftermarket performance part?

autopainter13

im not 100% sure, but it might help (a little) to change the transmission fluid to a better synthetic brand. other than pulling the trans and having it regeared, i cant think of anything else. definitly no bolt on's for that.

vintage42

The rental PT Cruiser was most likely an automatic, and maybe your xB is manual? Manual transmissions are always directly connected to the engine, and lifting the gas pedal causes compression braking, where the engine slows the car. Automatic transmissions are not diretly connected to the engine and so the engine does not slow the car much unless you downshift them. Automatics allow the car to maintain speed for awhile after you lift off the gas pedal.

Archngl

both were automatic

autopainter13

did you notice what rpm the pt was at, compared to the rpm at the same speed in your xb?

hotbox05

you could change the torque converter , or maybe it's a clutch pack.

been awhile since i've dinked around with auto tranny's

Archngl

not specifically... I was just going by sound and feel.

autopainter13

this is just a guess, but your xb probably is at a higher rpm than the pt (at the same speed) which im guessing would give you a different sound and feel when lifting off the pedal. i have a pt as a daily driver and it dosent sound like im turning as many rpm's on the freeway. my xa is a manual though

TwistedScionxB

Lightened crank pulley makes a big difference in this department.

vintage42

I don't see how a lightened pulley could have any effect on how his automatic xB slows down when he lifts off the gas.

skoobus

It's the ECT function of the automatic transmission that drops it down a gear when coasting down hills. I noticed this myself a few weeks ago, and researched it. The car uses the tranny gears to decelerate the car, very annoying if you ask me.

TwistedScionxB

The lightened crank pulley allow the engine to turn the crank easier. When applied in an auto setup. Wich I have. The transmission slow down is no were near as dramatic as with the stock pulley. If I am understanding his question he is refering to how the car seems to almost "engine-brake" when letting of the gas. With the lightened pulley the car has a more of a coast versus the stock pulley. I personaly have the Agency Power pulley. Same size as stock but several pounds lighter.

Archngl

too bad there wasn't a switch to stop the car from decelerating itself
lol

vintage42

Seems like that downshifting would be a very significant factor in the slowing down of an xB, compared to a light pulley.

vintage42

A light pulley only has effect when engine rpms are changing rapidly, as in rapid acceleration, where it takes less power to increase the rpms of the light pulley.
I think it is a real stretch to say a light pulley prevents the engine from slowing down when you take your foot off the gas, as that is a gradual deceleration.
Now that automatic downshifting out of overdrive has been identified as the cause of this slowdown, I wonder how many people would be willing to undertake the expense and risk of a lightened pulley in the belief that it could affect the slowdown?
As for the reason for the xB's downshifting out of overdrive when decelerating, that is probably to anticipate that throttle might be applied below overdrive speed, at which time a forced downshift in response to the throttle might be an irritating delay.
If the PT Cruiser does not downshift out of overdrive on deceleration, it may be because the 2.4L 150 hp engine can pull its overdrive gearing at a lower speed than the xB.

TwistedScionxB

I wasn't emplying that it slows engine de-acceleration but in order for a transmission to slow down the car it uses the engine to slow down. The fly wheel is connected to the torque converter. If I am wrong then engine RPM's has nothing to do with this conversation. Also I have been running my pulley with no negative side effects. I noticed that at highway speeds when I let off the gas it no longer slows as it did stock. But what do I know.

ajayaitch

Downshifting when the pedal is relased? You guys are funny.

vintage42

It sounds funny, but could it be true?