pokerFACE

I've never dared try, but for those with Touchshift here.. if you're in any gear other than D, will the transmission upshift automatically when you hit redline? (Question 2 would be: Will Touchshift let you downshift if you're too fast? The probable answer would be no.)
I'm just curious, as I've been trying to find the best way to accelerate on the hwy (as in, chase somebody ). Like if I am cruising at 100km/h and I need to accelerate quickly, I'd tap to 4, then to 3.. and then WHOA: engine roars and I start pulling. But with 3rd gear @ 100kmh I'd have like 1000rpm before redline, which I find somewhat risky. What if I'm actually doing 125, misjudge my speed, shift down to 3rd gear, and only have 300rpm left to use?

BTW, I find that holding the shifter to the left until the transmission selects teh lowest possible gear takes too long.

Same questions go for those with gated shifters. But I would assume the answer for Q1 would be that the rev limiter would just kick in, since the shifter is "mechanical" compared to the Touchshift.

TimmyC230boy

Even if you are doing highway speeds the most that you can downshift will be controled by the engines computer. If you have the touch-shift in first gear and redline it you will automatically go to 2nd. The automatic transmission will not let you over-rev the engine. Nor can you downshift and over-rev it. If you are wanting to chase somebody on the interstate just mash the gas and go. I like the touchshift as it lets you hold it in gear especially in turns and twisty backroads, but its not a true manual. If you have touchshift and want max acceleration just mash the gas.

MB-BOB

I agree with Tim, pokerFACE. The mental gyrations you have to go through to decide to go for the lever, downshift, worry about overrevving, etc. take more time than simply mashing the GO button and letting the tranny pick its own gear. Give it enough boot and the tranny reacts quickly enough.

c240x

I wonder myself sometimes what are the true benefits of touchshift or manumatics in general from an acceleration point of view. If the computer decides when the optimal shift point is from first gear, how can one be faster than the computers reaction? Has anyone demonstrated that manumatics offer faster acceleration from a standstill when done manually vs. automatic?

As for engine braking, it would be less wear on the engine to use the brakes. So, I guess the benefit of manumatics is for hills and such where automatics cannot anticipate a gear change (except for the new manumatics which incorporate grade sensors) or to keep you busy when you're bored

young

i think its more of a control issue. some like to change gears at higher revs.

one of my italian relatives thought he was Mario Andretti in some tiny euro car (i forget what it exactly was but it was like a vw golf but much smaller). he was constantly flooring it and would shift just before it would hit redline and it was annoying (and a bit scary on those teeny roads). i didn't ride w/ him again...

Drew

The easiest and most productive way (i've found ... IMHO) to use Touch-Shift ... if your going to use it at all is:

When cruising in D and you want to downshift for fast acceleration... just push-and-hold the shift-lever to the left. The trani. will drop down to the lowest gear allowed by the computer (which seems to be whatever gear is at the speed your going ... which is around 3K rpm).

In other words, you don't have to tap the lever ... just push and hold to the left.

The same holds true when your accelerating through the gears ... and you decide to take it easy on the souped-up Honda Civic you just blew-away: Don't have to tap the lever a couple of times to the right to get to D ... just push-and-hold the shift-lever to the right ... and shazam, your in D.

I use both techniques almost exclusively, every day, for going-fast and slowing down. IMO: engine's under warranty ... but wear and tear like brake-pads, are on my dime. (just being honest ... and cheap too!).

Hope that helps.

[shout-out to 'E' for showing me the "hold-technique" last year]

young

drew, are you holding it down while it accelerates and the rpms get to redline? and while your holding it down, does it upshift at that point?

or do you hold it down until it gets down to the appropriate level (say 2) and then release it as you gas it?

Bux

it doesn't matter if you have the gas mashed or not

young

do you hold it to the left while accelerating or do you release it at some point? basically, by holding it to the left, are you forcing it to shift right at redline? and just keep holding it. if i were to release it, it would probably upshift at a lower rpm.

also, i wonder if this technique works w/ all manumatics in general (eg bmw's shift?tronic)

Drew

Yeah Young, Roozy's right (and even if he wasn't ... he'd just raise his rear-sunshade and that would pretty much end the conversation! ).

Even with 'my' technique ... when you push shift lever to one side or the other and hold it there ... under acceleration ... the 'trani' hardly even hesitates before shifting: but it will never let you go over redline ... only into a 'safe' gear (one that will not over-rev the engine).

At almost any speed, I've found that you get at least a one-gear downshift by pressing and holding to the left ... and at any speed, you'll go from the gear your in ... to D .... by pressing and holding to the right ... but under hard acceleration ... there is, at times, a brief, momentary hesitation ... allowing you to use-up the power band in the gear your in ... before jumping to D.

MB-BOB

Now that's good information... As Ted Nugent would say, "A pocket knife, an hanky, and a pistol... you know, stuff a guy can use."

I think I might leave work a few minutes early...

young

SWEET! i have a passenger today (carpooling) so i won't try it today but i am going to test this very soon

young

ok, tested this and it does work as advertised. that is hold it to the left and it will downshift to the lowest gear (w/out going to a gear that would be bad like 1). keep holding it an as you accelerate it will upshift at the redline. lets just say that i almost hit a curb at a curve b/c i didn't expect such acceleration...

but this does not seem different from just tapping down to say 2, and just accelerating. it seemed like it would shift up by itself at the redline. so i feel that there is no advantage (is it different at all?) from tapping vs holding. am i missing something?

Bux

run this test.....put your car in drive....tap it too the left until it says 1 then don't touch the shifter...and mash the gas it will shift for you all the way up to D a little passed redline ( i always do this)

Drew

Not sure if its an 'advantage' ... just a different technique. No technique is going to override the computer however, so to each his own.

When I come to a stoplight in D and want to wind through the gears, or smoke another car off the line, instead of tapping FOUR times to get to 1, I just push to the left and hold ... i'm in 1.

And when I do smoke that car off the line, and I'm now in second gear, four car lengths away from the kill and I see him backing off ... instead of tapping THREE times to the right to get to D ... I'll push and hold the lever to the right ... and I'm in D.

And when I'm cruising in D, at lets say 40 mph ... and I want to get up and go ... I just push and hold the lever to the left ... and the car determines in which gear I'll land (and again, its almost always whatever lower-gear that will leave me at close to 3k rpm's ... a strong launching point for my engine and its torque curve).

No real 'advantage' ... just a different technique ... instead of tapping your way around town, if you should so desire.

young

ah, i understand. btw, i smoked several cars as i was testing this. of course, they didn't know what the heck i was doing so... :p

pokerFACE

thanks for the info guys!

I only brought up this question because I was wondering if it was useful to downshift to 3 at highway speeds to accelerate.. since holding it left seems to take too long. Or maybe since the computer doesn't think it would help, so it just doesn't downshift to 3.

If Drew hadn't said so, I would have completely forgotten that it's not about the trans downshifting and landing at 5000 rpm.. it's about landing at 3500ish where the torque is.

And if I understand correctly now (bear with me), Touchshift will not let you select a gear that will overrev the engine (and will also upshift automatically at redline). What about the traditional gated shifter (my dad's 97 E320)?

Drew

In my experience ... there is no difference: either holding it to the left or tapping ... the computer will not let you into a gear that will over-rev the engine:

That having been said ... I wanted to test the above theory out before I mentioned it, so I went for a little drive:

Driving at 40 mph (on an empty side-street) I tried to downshift from D into FIRST GEAR via quick-tapping. Got to first, but the transmission lagged and kicked in (with a jolt) a second or two after I saw '1' in the display. It was almost like the computer held the car in '2' until it felt I was ready for '1st.'.

Now, the same test (going the other way down the same deserted street) I tried to 'push and hold' into '1st.'. No can do ... the best the computer allowed me was '2nd'.

So, by tapping, I got to the gear I wanted, but the computer didn't let me have it at the exact moment I wanted it.

There you go ... for whatever its worth.

pokerFACE

... are you a lawyer?

Drew

That a nicer way of putting it ... I've been called worse (like landshark for instance ... see my Avatar ... lots of emails telling me it's perfect for me).

Experimented again regarding Touch-Shift ... see below in quote/reply to 'roozy'.

Drew

Almost blew my engine today trying this one!!!

No kidding.

Stopped at a stoplight, tapped all the way into '1'. Floored it ... 4K rpm, 5k - no upshift yet - 6K - hitting redline now- still in '1' with no upshift yet - 6500 - well into redline - no shifting yet ... screw this ... and I tapped it into '2' ... manually.

What gives?

Vic55

Drew, two different trannies with two different computers. Ours will not shift automatically to the next gear. Ours will hit the redline and then the fuel pump shutoff will engage which will cause the RPM's to drop. Ro0zy has a C32 I believe which has a different touch shifter.

Drew

Now you tell me!

Well, it was fun anyway! Never taken my Beast to the redline before ... well only while in D and flooring it from a standing-stop did it approach redline.

I was really surprised/impressed at how much 'punch' there seemed to be left to use at 6000 rpm's.

MarkL

Guys, I've got a C240 6-spd, so I don't have experience w/ the Touchshift. But, I've got a question. Drew, you said when you're at about 40mph and want to "get up and go", you manually shift down by holding the lever to the left. How is this different from just hitting the gas and letting the trans downshift automatically? I mean, if you floor it at 40, any auto trans will downshift to the appropriate gear, right? Also, if you floor it from a dead stop in "D" and let the trans do its job, how far below the redline will it shift as opposed to doing it manually? I thought that the main "advantage" of the manumatic was to let you select and hold a gear, say around a turn, for improved acceleration after the turn instead of letting the trans upshift.

Drew

Mark, I don't know that there any real difference. However, I feel there is a slight hesitation when just "hitting the gas and letting the trans downshift automatically". I feel NO hestation when I push and hold to the left or tap-left to find a lower gear.

As I found out today, with Vic55's acknowledgement, the computer/transmission in our E55's will do just what your saying: hold the gear we select manually (until just past redline, when fuel pump will cut off). I usually have my eyes on the road, scanning the street for Blue-hairs in my path, so I don't keep an eye on my tachometer frequently ... but it 'feels' like when I'm in 'D' and want to accelerate, the gears shift prior to redline.

Ffor all but pedal-to-the-metal acceleration (and this I know for a fact ... because I do it often when showing off the automatic transmission to friends with manuals) that when you absolutely stomp on and flatten the gas pedal to the floorboard ... the E55 will wind through all gears to the redline before shifting into the next highest gear ... using all the power it has to give.

It seems like there's no real difference in performance when going *****-out in either automatic or manual modes with the E-AMG.