z06girl

Hi HEK,
If you have ever ridden a motorcycle, you would know how the manual transmission in bikes shifts different from a regular gearbox of a Manual Transmission car. It requires you to shift gears by clicking a lever up or down with your foot or toe. In other words, it allows you to shift in a much faster way than old fashion MT shift. This kind of shifting is called a sequential gearbox or a sequential manual transmission. A sequential gearbox gives the driver several important advantages Although it's quite different from a regular manual transmission setup, there is still a set of gear selector forks that move collars that engage gears. The only difference is the way the control rods are manipulated. The "H" pattern is eliminated and replaced with a different motion.
this motion, instead of a "H" patern, it becomes a "push forward" to up-shift or "pull backward" to downshift. If you are in a gear and you want to go to a higher gear (e.g. from 2nd to 3rd), you push the shift lever forward. To go from 3rd to 4th, you push the lever forward again. But to drop back down a gear, say from 3th to 2nd, you pull the lever downward.
What these motions are doing is rotating a ratcheting drum, each of the grooves can do one of two things: If the drum is located away from the transmission's gears, the grooves control standard control rods. If the drum is located next to the gears, the grooves directly move the gear selector fork, and no control rods are needed. This seems to be the more common technique because it has fewer parts and is more compact. So, when you move the lever, it rotates the drum one increment (for example, 50 degrees). This rotation causes the rods or forks to move according to the grooves in the drum, changing the gears
Because of the drum, you have to shift in sequence. There is no skipping, for example, from first gear to third. You must always go through second gear to get to third gear. It is the same when downshifting. The advantage of this system is that shifting mistakes are impossible. You always go to the next gear.
So the advantages of a sequential gearbox allows you to shift quicker, consistent. You do not have to think, "which gear I am in now, or will I shift into the wrong gear, letting go the clutch too soon, etc,." and the hand location is consistent. With the "H" pattern, the location of the shift lever changes, so you have to think about where to put your hand depending on which gear you are in. With a sequential gearbox, the shift lever is always in the same place for the next shift. The sequential shift has no surprises. If you mis-shift with the "H" pattern in a race (for example, down-shifting to 2nd when you meant to go to 4th), it is possible to blow up the engine. That can never happen with a sequential gearbox.
So the sequential gearbox is very similar to tiptronic transmission, except the tiptronic transmission is nothing but a slush box.

have a good day

geminisdc

THis are the kind of things you check before buying the car . Have you heard of this thing call TEST DRIVE ??? stop the whinnig pussy

theslik1

I wouldn't put it as strongly, but that's basically correct. I test drove the G35 sedan before I bought my TL and the G's SS is markedly better. But the TL is my wife's car...it simply had to be auto and the SS wasn't make or break. If I had bought the TL for me it would've been 6MT A-Spec...end of discussion.

The car I'm most annoyed with right now is the new IS350 and its bullshit paddle shifters tied to a regular AT. Who's falling for THAT? The 306 hp (new SAE) is nice but a true SMG would've really set it apart. The paddle setup for a run-of-the-mill AT is just lame. Lexus really missed an opportunity here.

By the way, if there are any Mitsubishi EVO fans here, the EVO engineering team is hinting that the next generation EVO X (Concept X right now) may have a true SMG. Expect Subaru to follow suit if they do.

Actuary

I don't think nothing higher gear ever drops into second. only 1-2 are controleld by computer even in SS mode.

Atrain

Two things, if you want total control over the transmission, you should have gotten the 6MT, not the 5AT. Yes...it's rude...but true. Deal with it.

Next, my 5AT 2003 RSX will hold 1st gear as long as I want it to. If I forget to upshift she'll peg the rev limiter. If I forget to downshift when coming to a stop, she'll do it for me.

So the fact that the TL's 5AT automatically upshifts into 2nd gear tells you something.

A-Train

Pure Adrenaline

iTrader: (2)

Just in case HEK is confused --

z06girl is explaining how an electro-hydraulically actuated transmission works. In other words, a manual transmission with a computer-controlled clutch. It eliminates the H-pattern, which allows the engineers to put the lower gears in the center of the structure, which is the strongest part. Because the gears are placed based on optimal locations, not based on the conventional H-pattern, it would create a shift pattern that is way too awkward for a human being to pull off, or live with on a daily basis. Hence the computer controlled clutch and shifting.

But this is TOTALLY different from the transmission in our cars. Our cars are conventional automatics with clutchpacks and a torque converter. The SportShift is merely an override control of the TCM to send simple commands of shifting, limited to its functions of an automatic transmission.

In other words, when you shift on an SMG, here's what happens -- computer disengages the clutch, disengages gear from its current position, shift it into the desired gear (depending on upshift or downshift; if downshift, most SMG's are capable of blipping the throttle and rev-matching), then engage the clutch.

When you shift on our SportShift, it's nothing more than any other automatic transmission without SportShift. Honestly, it's no different than holding it in D1, D2, D3, etc. like you mentioned.

TL Crystal Lake

Thanks to Mr_Superlove -

Your sugestion does work, it does take a bit of practice. As easy as it sounds to do, when you try to do it during an agressive acceleration it becomes a bit more challenging. It doesn't take long to get good at it. Hint - practice it doing semi-agressive accelerations to get the hang of it first.

BTW - we are not trying to drive it like a Manual, if I wanted to get a tired left leg I would have bought a manual. Not to mention this is 2005 where one does not just drive down the road. We drive while we are - fidgeting with the Lame Stereo (No mp3, DVD Audio?, no display of tracks, artist, etc...) in the TL, - talking on the cell phone (sometimes yelling), - trying to pay attention to the Navi instructions while drinking or eating something. Did I forget to mention we are late on top of all of this. So shifting is a task I did not want to commit to every time I am trying to get from point A to point B.

I bought the TL because I liked the styling of the exterior, there were trade-offs, I did test drive the car and knew the limitations of the stereo when I made the purchase decision. I will admit the shifting problem was a surprise.

Bottomline is, if you aren't going to give control of 1st and 2nd gear to the driver then they shouldn't have even offer the option.

Thanks to all that posted!

HEK

I had totally forgot to look back at this topic, Z06girl thanks for the detailed "class" in motorcycle shifting vs car shiting H pattern, but I have to agree with Pureadrenaline that there is little diffrence in shifting an automatic w/out SS and one with..thanks both very educating..

Actuary

I noticed using "L" is so much fun when you want to do a little show off from around 10MPH. Just shift to L while giving little gas(to avoid shift shock). Then push it to D around 5K RPM(by this time everyone around road is probably hearing exhaust note)