Jim Brady

After being jumped by a 6Z06 from a 60 mph roll (later found out he was modded), I thought I'd do some testing with my Racelogic data logger and see if Luke is correct about M mode being faster. This is dangerous so don't try this on public roads (not advocating breaking the law even for the sake of science). Keep in mind this is for straight line racing not on a circuit.

If the transmission is in S mode and it has to down shift for the proper gear you're going to loose at LEAST a 1/10 of a second or more. The transmission software will get the right gear... eventually. While it may seem by seat of the pants it's faster, my testing didn't confrim this.

My test was from 60-120 mph. Starting in S mode the best I could record was 8.2 seconds starting from 55mph. Remember at 55 the transmission is in 6th or 7th much like when I encounter the hated Z.

In manual mode 3rd gear start it was 7.9 seconds 60-120 mph.
Whatever I did in S mode, I could not break the 8 second barrier unless I manually shifted down to third gear which defeats the purpose of the test.

My conclusion: Being in the right rpm range is the key to the best results, but your transmission may not want you in that gear and may up or down shift depending if it thinks your Michael Schumacher or my 88 year old mother in law.

Now, if I happen to see ANY P cars, BMW, Z, Shelbys, Cameros acting even half way aggressive, I make sure I'm in M mode, ESP off and in 3rd gear.

This has been a public service announcement by Jimmy
BTW, for the teenager with a keyboard in your basement who wants to refute the numbers the test was done at an elevation of 1250 ft and the Z had headers and exhaust a killer B intake, tune and needed a detail.

bobus63

Thanks for the valuable info. I've just been doin' what the manual sez "pulling back on the downshift paddle or to the left on the shifter will auto' select the best gear"

Are you runnin' stock exhaust? I've been very tempted to do the full Evosport exhaust system but not so sure I want to go that far plus warranty issues.

Please update us when you get around that z

alexander stemer

Jim,
Thanks for the breakdown, but I don't think it addresses my observation.
For the street, if you are in traffic and suddenly recognize the need to accelerate, you won't be cruising the highway in 3rd gear. You will be in a higher gear, and will need to manually shift down, which will be slower than just stomping on the gas.
For the track, I did not find that the M mode could reliably and predictably give red line upshifts, nor did it yield consistent, timely, and immediate downshifts. On the other hand, S does shift properly at wide open throttle, and the downshifts under braking are consistent and timely.
I think the track question could only be answered by consecutive hot laps.
I don't differ with your data from this specific circumstance, but I don't think it can be assumed to apply in other dissimilar circumstances. AS

Jim Brady

AS,
The test was to determine the optium acceleration in a STRAIGHT LINE from a given speed. If you change the test varible (as you have) you can get a different result. Granted it maybe easier to drive in S mode and down shift when one wants to pick up the pace.
The downshift time from hitting the gas peddle, and the drive by wire is at least 1-2 tenths slower. I had several instances when the transmission up shifted rather than downshift, so the idea that the transmission knows the right gear isn't necessiarly true, but you've just lost two car lengths to the hated Z.

Jim Brady

stock exhaust. Calif is a little to green on the full modified exhaust and will not pass smog.

alexander stemer

Point accepted. I love this car in C, M, or S. Now have 30,000 miles, and look forward to each new one. AS

shuttie

We need the program or update for the electronics for the paddles, at Wakefield track I use M though I only need 3 gears and after having a drive at Albert Park in March on the F1 track with AMG in their C63 and E63 also had a sit in the SLS no offers of a drive ,funny that!! (I was one of 120 who got in first with their Offer) and the downshift blip was the first thing that impressed me (just the sound) We couldnt turn off the ESP though we could use M if we wanted I left it in S and for most of the time it was ok. At wakefield I find that having the esp off it is much sharper though because the track is tight and has sharp edge drops of the track I mostly leave it on. I wish Benz had offered a upgrade ( I would have paid) to make it similiar to other AMG models though I think it was wishful thinking.

LZH

Interesting results, Jimmy. While I agree that the car is easier to drive in S mode, I think you have proved me right and M mode yields faster times. As we all know, this is a pretty smart transmission as it learns and adapts to your driving style and alters shift parameters based on driver input. I think that is why so many people report that while on the track, they feel that S mode always has them in the right gear and upshifts and downshifts perfectly. Sure, because it learns the track...but, I still contend that M mode, while more difficult to operate, is a faster, firmer shifting program that yields quicker lap times. And as far as being able to accelerate quickly at a moments notice, no one can say that S mode is faster as it requires more time to grab the lowest gear..but in M mode, you are already in it and all you have to do is mash the throttle and away you go. The only drawback is that you burn ALOT more fuel.
Thanks for posting your results. I guess the only way to put this to bed once and for all is for us to meet at Willow again for a little wheel to wheel action

SMP

Jimmy, thanks for posting your results! I would love to go to Willow with you and Luke...... Now that would be fun

Jim Brady

Let's do it, Big Willow and maybe we can get Evosport to pop for a track day.
It's been too long!

Jim Brady

Bring your M6 so we can video it and post on the Bimmer forums.

SMP

Mmm, that could backfire......been practicing in the M6 on some midnight runs ......there is no substitute for a sequential gearbox

LZH

Agreed!! We could do the next El Toro event but I'd prefer Willow...

C'mon Sacha - bring BOTH !!!

I've got a buddy who wants to hit the track as well - he's gonna bring this

forhamilton

^^wow. very impressive.

Jim Brady

[. I guess the only way to put this to bed once and for all is for us to meet at Willow again for a little wheel to wheel action [/QUOTE]

June 17th Big Willow www.drivingconcepts.com
I will be there.

PyroLume

Please don't kill me but I usually leave it in C unless I'm actually looking for trouble. If I'm looking for trouble on the highway I put the car in S / auto especially after learning that the trans will happily bang out a 7 -> 3 downshift. I wish there was some way of forcing a 2 or 3 gear drop with the paddles but there doesn't seem to be one!

alexander stemer

I tend to use "S" f or everyday, but I think if you keep your finger on the downshift paddle, it will drop as may gears as the computer allows. That;s what I used to do on the track- namely let the trans upshift for itself without using paddles, but just keep the left paddle pulled back while braking for each corner. In the end, it wound up being just as fast to leave it in S. AS

LB63

If you have the car in S mode and manually downshift to third then let it do all the shifting to 120 what was your time?

We know the kick-down loses precious time. Also, if you manually up-shift in M mode the transmission doesn't always shift immediately or at the intended RPM leaving the possibility that you may lose a little more time. However leaving it in S does give consistent upshifts at the same RPM. The problem with S is getting around the kick-down.

That is why I am asking if you did a comparison using that method (S mode, manually downshift to 3rd, floor it, and let the transmission do the rest) because it sounds like at least it will be upshifting at the proper RPM and you don't have to wait for the kick-down to 3rd.

This "hybrid" may get better times than just M mode.

johno530

"Now, if I happen to see ANY P cars, BMW, Z, Shelbys, Cameros acting even half way aggressive, I make sure I'm in M mode, ESP off and in 3rd gear."

Excellent formula. I also turn the AC off in such situations. Wouldn't it be great if we had a single "get ready" button that did all of that?

Jim Brady

Didn't time the down shift. BTW it did occure to me, if the down shift is instantanious you'd have a point, it's not. As for the upshift you won't miss a shift in S but if your a bozo and don't watch the tach you could hit the rev limiter in M

A one car length lost off the mark is much more difficult to make up ergo the M start.

My car is in for a little tune up a Evospot when I get it back I'll time your hybrid.

LB63

That's what I'm talking about. If you keep it in S, manually downshift to 3rd and then floor it there is no waiting for the kickdown. If you were in S around 60 mph the tranny was at probably in 4th and when you floor it you have to wait that half second for it to downshift to 3rd.

Jim Brady

LB63,
OK, ran 3 runs with your method, two were good and they seemed about as fast as the manual mode, but on one the transmission actually dropped to second and then up shifted to third. I would consider this a potential fail. ( may have been too low of speed but that could happen at any speed in S).

Best time in S was 8.2 seconds 60-120 mph. This was slower than the manual modes best of 7.9. I know there are different conditions on different days. Ran a back up in manual and got a 8.1 on an average run. Law enforcment caused a early shutdown of our testing even though it was done in Mexico so I couldn't do a back up manual run. I do believe my best run was with the ESP off. I ran today with the Esp on in both manual and S modes.

MB_Forever

I'm not sure I'd call it a potential failure because I think he meant to say to downshift to the lowest possible gear in S mode (just as you would in Manual mode) before starting the run. Using this hybrid method would isolate the comparison to up-shifts only. Mercedes claims that manual mode shifts 20% faster than S mode (MCT tranny) and it would be nice to see if that is the case with our trannies and actually see live data from different cars.

Thanks for the tests and all the data by the way, your posts are very thorough

Jim Brady

Fail means one would have lost the race with the inadverertant downshift in S as the transmission is thinking for you. Wouldn't have happended in M..but may hit rev limiter in M.
I'll be doing some testing next week and see what data on shift time in M vs S.

jrcart

Very interesting data, thanks. FWIW at the strip from 0-130 or so S mode is consistantly .200-.250 seconds quicker and 2-3 mph faster than with me shifing the car in M mode. Ive got dozens of passes with VBox data to back up these claims. I'm not at all doubting your results from 60-130 because the transmission is prone to that pesky downshift in non optimum RPM range.