hesitation on rapid acceleration

I think what happened is that the ICE didn't kick in immediately, but the MG's are already moving the car.

 

i agree, the engine takes a second for the electric motor to spin it up before the engine gets gas and is able to put out power. also while the motor spins up the engine, that motor's output does not go into acceleration.

 

Grrr. Jonbeck, you stole my idea for an avatar photo. :angry: Is that a great spot for a pic or what?!? Well, Colorado has plenty to offer in the way of photo ops.

 

happened to me, once. i'd say if you're worried, bring it in. it is still under warranty.

 

there is a bit of lag not a lot but noticable in certian situations like your in. As a suggestion if it happens at the same spot every time what you should/can do is, as you approach the spot where you merge put the car in "B" mode that way the ICE won't stop running and when you step on it as it's already running your going to eliminate the lag. Just a thought.

 

I've has this happen, and it seems repeatable from about maybe 15-20mph. There is an onramp with a right turn just before entering it. I take the turn at that speed, and when I stomp it (the ramp is steep), there is a noticable lag in throttle response. It seems to be the nature of the drivetrain to do this.

It will change depending on the loading just prior to stomping. I'm off the pedal during the turn, so I'm stomping from zero throttle at 15-20 mph. If I'm already accelerating mildly (foot on gas) when I stomp, the lag is much less noticeable. Experiment and you may be able to "preload" the car before you stomp, and avoid the lag.

 

for getting into the HOV, I leave a few car lengths between me and the car in front of me, so that I can accelerate a little in my lane (just to get rolling) then jam on it as i hop over into the HOV. Again, this is basically "preloading" as the other posters have mentioned.

You can also set the AC no MAX (Heat or cold, depending on outside) to keep the engine running. (Like B, but uses a little more fuel.)

 

if you have VSC, it could have kicked in if the tires slipped upon sudden acceleration, causing that "hesitation" or pause.

 

The PSD could be absorbing some of the hard acceleration initially first as it revs up the engine even if you have the MGs pushing hard.

Make sure you have it floored so the MGs don't conservatively wait for the ICE to spin up. If you can manage it, give yourself some space too...

The Honda CVT lags, and I believe Toyota PSD lags in a similiar way so you need to 'preload'.

I also expect people to slow down if I'm cutting in like that since what else could they do?

 

Wow, nine responses and not a single mention of what I believe is the most likely culprit: TRAC (NOT VSC) kicking in. When it it senses the slightest amount of wheel slip it behaves exactly as you describe. Did you get the car with squiggles under it lighting up on your dash?

 

Although that is reasonable too, I have YET to see TRAC kicking in under dry weather on dry ground when accelerating in a semi-straight manner, or from stop, on the Integrities.

In fact, TRAC will not kick in also if one of the driving wheels is mostly flat (20lbs), and the tire will squeal freely as I made a right turn from stop before.

If TRAC was kicking in without lights, then the dyno tests by Brian would be affected too.

 

i have seen it a lot and its repeatable anytime you are in EV mode and punch it.

to make it less of a jolt you could just go on the throttle a little at first then punch it. that works...but if you have that much time, then punching is probably not necessary

 

The Prius will hesitate for a second when floored in that situation. This is normal. It will also hesitate due to wheel spin in wet pavement because of traction control. Normal too. Keep as far away from the dealer as possible.

 

I've also used this method when passing other vehicles on a two lane road. Rather than just jamming on the gas pedal and putting it to the floor, I rapidly but smoothly ease the pedal to the floor. This way, I can feel the car responding more accurately to the movement of the gas pedal. It seems to get me up to speed a bit faster than just stomping on the gas like one would in a regular car. This is true when the ICE is running or not.

 

I agree- flooring the accelerator always results in a delay before anything happens whereas a controlled ramp-up in pedal pressure seems to get the car going much more quickly and without the delay..

 

The hesitation or lag is certainly not TC or VSC; I get no indication, and I know how both feel--this is different. It seems to be a characteristic of the transition from zero-throttle/ICE-off to full ICE at low effective gear ratio. Pre-loading (not the right term, but I don't have a better one) seems to be the solution, and once you know of this, you can use it for most situations where you need a spurt. Lane changing, onramps... these are known before you make the move, so the two-step works. I just go half throttle for 1 sec (which does nothing because of the lag, but preloads it), then mash it when I make my move.

I wish it weren't programmed this way, but I am guessing it is due to the inertia of the drivetrain components (the motors must move or change direction to change the ratio) and/or programming to not make the car hypersensitive to throttle input.

 

hey cant be all bad... i had a chevy with a vacuum leak, messed up carb and it hesistated frequently too that is if it didnt stall on me...

wonderful POS other than that though...oh wait...

it also got 17 mpg...ah!! those were the days!!

hopefully to never return