accelerating hard and shift shock, is it unavoidable?

[BlahBlahYouToo]

when WOT to redline and then upshifting, you're met with a nice jolt when transitioning gears.
seems like it doesn't matter what car you're driving, what wheels are propelling the car. every car i've driven exhibits this, but i'll admit i haven't driven that many cars.

do these go hand in hand?

 

[EightySix Four]

No, you need to let the RPMs drop down to match the speed you're going for the next gear, though this is less efficient than power shifting through.

 

[Zenmervolt]

Unless you're slipping the clutch to smooth out the gear change, yes, there will be a definite surge every time you grab a gear in a manual transmission vehicle. Most automatics will also shift noticeably harder at WOT.

For more sedate, "normal" driving, you can shift slower and feather the throttle a bit more to smooth out the gear changes, but when you're hard on the throttle as soon as the clutch engages, it's going to be a firm shift.

ZV

 

[Pantoot]

With an SMG it feels like I got rear ended when shifting with WOT.

 

[MJinZ]

when WOT to redline and then upshifting, you're met with a nice jolt when transitioning gears.
seems like it doesn't matter what car you're driving, what wheels are propelling the car. every car i've driven exhibits this, but i'll admit i haven't driven that many cars.

do these go hand in hand?

No, the cars you drove just suck/and or have the transmission suckage.

 

[Arkaign]

No, the cars you drove just suck/and or have the transmission suckage.

???? lol.

Shifting fast at redline at WOT is going to be a jolting experience in any car. I just rode in an '09 STI last weekend, with the excellent 6-speed, and the 1-2 and 2-3 shifts were like sledgehammers.

 

[PricklyPete]

???? lol.

Shifting fast at redline at WOT is going to be a jolting experience in any car. I just rode in an '09 STI last weekend, with the excellent 6-speed, and the 1-2 and 2-3 shifts were like sledgehammers.

But it doesn't do that on his Camry slushbox...hence all other cars have "transmission suckage".

 

[punjabiplaya]

DCTs (if made and programmed correctly) can provide seamless shifts.

 

[ayabe]

DCTs (if made and programmed correctly) can provide seamless shifts.

Not in high powered applications, GT-R or Evo X shifts are brutal in Sport mode.

 

[BlahBlahYouToo]

No, the cars you drove just suck/and or have the transmission suckage.

obviously you have no idea what the grown ups are talking about.
go troll elsewhere in your automatic corolla.

excuse my attitude- mjinz has a history of trolling my threads.

 

[MJinZ]

But it doesn't do that on his Camry slushbox...hence all other cars have "transmission suckage".

Yup, my slushbox does not do this. Neither does any good Automatic. As slushy as it is, it still slushes to 60 in 5.8 seconds, over a WRX at the quarter mile in 14.3 seconds. Mmmm slushy.

 

[ayabe]

???? lol.

Shifting fast at redline at WOT is going to be a jolting experience in any car. I just rode in an '09 STI last weekend, with the excellent 6-speed, and the 1-2 and 2-3 shifts were like sledgehammers.

It takes a lot of effort to shift Subaru's smoothly, especially on the 1-2, the clutch uptake is rather abrupt and the engagement point is sort of high on the travel path.

Plus the whole rear flabby subframe bushings which leading to some not nice noises on a hard 1-2.

But I digress, this is true of most cars in WOT unless you're burning some serious clutch and/or going pure granny on your shifts.

 

[EightySix Four]

obviously you have no idea what the grown ups are talking about.
go troll elsewhere in your automatic corolla.

excuse my attitude- mjinz has a history of trolling my threads.

He has a history of trolling every thread, including his own.

Like I said before though, you can lessen shift shock if you let off the throttle, drop to the right RPM, get off the clutch, and then hammer it again. You're going to lose time, but it's nicer on the drivetrain. My car has a NLS system in it, so when I shift without letting go of the throttle it opens up the cams and burns a little fuel to keep the turbo spinning mid shift. I can usually let the rear end go shifting into 3rd pretty easy and on the rare occasion it hooks, it feels like you've been rear ended by a freight train.

 

[Arkaign]

Yup, my slushbox does not do this. Neither does any good Automatic. As slushy as it is, it still slushes to 60 in 5.8 seconds, over a WRX at the quarter mile in 14.3 seconds. Mmmm slushy.

It would have been faster still with a decent MT. The slushbox times you mention are really due to using a big V6 rather than an overall good 'sport' powertrain.

The shift shock comes from the clutch grabbing hard as the next gear comes online at full power. With an old-school automatic, the torque converter insulates you from most of the shock of the gear change, but it also has more power loss and isn't as fast. The DCTs and SMGs that are so fast use actual clutches as they're designed for high performance use.

 

[MJinZ]

It would have been faster still with a decent MT. The slushbox times you mention are really due to using a big V6 rather than an overall good 'sport' powertrain.

The shift shock comes from the clutch grabbing hard as the next gear comes online at full power. With an old-school automatic, the torque converter insulates you from most of the shock of the gear change, but it also has more power loss and isn't as fast. The DCTs and SMGs that are so fast use actual clutches as they're designed for high performance use.

Well true, but the OP asked a simple question and I answered him - good automatics simply do not do this. I mean, redline it from 0 in an Slushbox M3 and or C63 AMG and tell me it does this and I will .

And also, to expound, the best Dual-clutch Autos will shift faster and better than the best human can with the best manual. It's just the way it is. Slush > Manual at the high end.

 

[radioouman]

I like that shift!! I installed a shift kit in my Dakota to make shifts sharper!

 

[EightySix Four]

Well true, but the OP asked a simple question and I answered him - good automatics simply do not do this. I mean, redline it from 0 in an Slushbox M3 and or C63 AMG and tell me it does this and I will .

And also, to expound, the best Dual-clutch Autos will shift faster and better than the best human can with the best manual. It's just the way it is. Slush > Manual at the high end.

Have you ever driven am SMG M3? It hammers you on every shift. They aren't slushboxes.

 

[Arkaign]

Well true, but the OP asked a simple question and I answered him - good automatics simply do not do this. I mean, redline it from 0 in an Slushbox M3 and or C63 AMG and tell me it does this and I will .

And also, to expound, the best Dual-clutch Autos will shift faster and better than the best human can with the best manual. It's just the way it is. Slush > Manual at the high end.

Doh.

The conventional torque-converter auto in your Camry has nothing to do with DCT/SMG, which are computer-controlled manual gearboxes with clutches (dual in the case of the DCT, obviously).

There is no slushbox M3, ditto the M5. The C63 does use something of a slushbox, but typical of Mercedes, it's engineered exceptionally well.

Just remember : slushbox =! DCT/SMG

EDIT : I was incorrect, the new Mercedes 7-speed autos are in fact DCTs from Getrag, they've done away with the slushbox (they were the lone holdouts when BMW and Audi went to SMG/DCT style autos for the high end).

 

[Arkaign]

Have you ever driven am SMG M3? It hammers you on every shift. They aren't slushboxes.

I was about to say that, the thing disengages and re-engages the clutch with such severity that it's VERY visceral and noticable.

 

[MJinZ]

Have you ever driven am SMG M3? It hammers you on every shift. They aren't slushboxes.

Nope, I've only experienced M- Double clutches.

 

[MJinZ]

Doh.

The conventional torque-converter auto in your Camry has nothing to do with DCT/SMG, which are computer-controlled manual gearboxes with clutches (dual in the case of the DCT, obviously).

There is no slushbox M3, ditto the M5. The C63 does use something of a slushbox, but typical of Mercedes, it's engineered exceptionally well.

Just remember : slushbox =! DCT/SMG

EDIT : I was incorrect, the new Mercedes 7-speed autos are in fact DCTs from Getrag, they've done away with the slushbox (they were the lone holdouts when BMW and Audi went to SMG/DCT style autos for the high end).

I thought people called all Automatics slush boxes?

 

[punjabiplaya]

that's why they have 156 settings, so you can control how hard it shifts. Nothing can prevent the change in acceleration as the driveline is disengaged from the wheels (through the transmission) and then re-engaged. It's just variable depending on how hard you (or the computer) re-engages the clutch. Newton's laws once again save the day.

 

[amdhunter]

Not in high powered applications, GT-R or Evo X shifts are brutal in Sport mode.

I dunno. My brother guns his Evo X from time to time and it actually shifts quite smoothly at WOT. He never really takes it out of sport mode though, and the gearbox thumps way too much for my tastes. I can see he kind of hates the gearbox.

As for the person who said the SMG felt like he was being rear ended -- I totally agree. I thought the M3 my friend test drove had a busted gearbox or something from how hard it hit -- turns out that it was normal. D: Scary ass car.

As for my GLi, I was able to chirp the tires through 3rd gear at WOT, and I could manage how hard it would hit between shifts. I haven't tried beating my 8 really bad yet -- but I love the way the car goes from 2nd - 3rd - 4th at decently high acceleration. It just feels so perfect...lol

 

[Arkaign]

I thought people called all Automatics slush boxes?

I can see why some people do, but you'll never catch a serious gearhead make that error.

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

http://auto.howstuffworks.com/automatic-transmission.htm

^^ You can see where the term 'slushbox' came from when you look at how conventional auto transmissions work.

 

[Pantoot]

As for the person who said the SMG felt like he was being rear ended -- I totally agree. I thought the M3 my friend test drove had a busted gearbox or something from how hard it hit -- turns out that it was normal. D: Scary ass car.

Yup, if I put it in S6 and shift with WOT it really does scare people with how hard it hits.