CA_E55

If that line of reasoning were correct, the Veyron with 50% more torque than the 65 would do with a 3 speed? For a sedan, the 5 speed slushbox makes a lot of sense, for a high performance GT, its clearly not ideal, albeit in case of MB dictated by what they have already on the shelf. I would take a 7 speed in a heart beat...

sound 8

I agree, the 7 speed box is a sign of technology and is needed in cars like the
SL63, the auto box is ancient, but is ok with a car with lots of torque.
For instance I had a XKR with 380 bhp and a newer XKR with 410 bhp both
with auto boxes but the 380 had 5 speed and the 410 6 speed. The 380 5 speed was better, I guess they got the gearing better, the 6 speed never seemed to be in the right gear. A very big improvement on the mct box over
auto box is it's ability to recognize throttle input and put you in exactly the right gear to get the best from your engine, the auto box is a bit of a lottery
when you kick down as to what gear it will select, and also it doesn't brake the car on change down like the mct box, it's quite exceptional!

TMC M5

What your comparison fails to take into account is the Veyron's ability to go 250+mph. That top speed capability necessitates more than 5 (let alone 3) gears if you want robust acceleration all the way along. A stock SL65 will top out at 155mph due to its speed governor. An AMG "delimited" SL65 will be allowed to run to 186mph. A tuned SL65 may be completely delimited and may hit the wall at somewhere around 209mph. Maybe a 6th gear would help with acceleration above 155mph. However, I will stand by my previous statement (and reasoning), that I have never felt the need for additional gears, but maybe that is because I haven't exceeded 155mph. A 7 speed would have been "nice", but not really necessary.

Tom

Cylinder Head

iTrader: (1)

To the people knocking the MB 5 speed: You only need more gears (and gearing) if you have little torque to speak of. I know, I drive an M5.

jcpca356

the torque difference between my stock SL65 and stage 1 modded 996 turbo is pretty huge for rolling starts. just different cars. i wouldn't take the 65 to the track but that's not what it was made for either. on the highways, i'd take the 65 over the 996TT, even in the modded form currently (400rwhp)

sound 8

Very nicely put: y
My 1989 V12 Jaguar has a 3 speed box. It will pull away it top and go to
a terrorizing 150 mph.
Although not necessary it would surely improve the performance of a SL65
by it's faster change and ability to select gears better.
If it could take the torque of course.

TMC M5

I am not sold on a 7spd for the 65 engine. I think a 6 spd would be more than enough. You have to remember the characteristics of the engine. You are comparing a high reving V8 in your SL63 (7,200RPM redline) to the 65 engine which has a redline of only 5,950RPM.

Look at this website where I plugged in the relative ratios of the SL63 and SL65.

http://www.fatboyraceworks.com/gears...raph&Compare=1

You will notice that they don't have a slot for the .73 7th gear ratio. To me if the 6th gear has a theoretical top speed of 229mph (obviously assuming no friction)...then the 7th gear is purely an over drive gear for fuel economy. Then again, the SL63's 6th gear looks like an over drive gear as well. I just don't see the utility in two over drive gears..

Tom

sound 8

Your absolutely right, I couldn't give a toss that I have 7 gears. The thing
I like about the mct gearbox is it's proper manual mode, fast gear change and
the way it responds to throttle input, do you not think these attributes would
improve a SL65, even if it was still 5 or 6 speed?

TMC M5

In a perfect world...yeah sure...who wouldn't want lightning fast shifts. The problem is that with the torque produced by these engines, it doesn't make it easy on transmissions. Even our 5 speed speedshifts autos are hand cuffed by the TCU software. It basically cuts power before and after the shift to help save the tranny. Tuned 65s experience the most lag time because it senses the huge rush of torque... Marko's car has the most pronounced "lag".

MB has had the G-tronic 7 speed for at least 4 years...and have developed the MCT. I am sure they have been testing with the V12TT. They obviously don't feel comfortable sending it out to market. This probably isn't because they can't make the transmission stout enough...but more likely the process to get the transmission strong enough to handle every day use is cost prohibitive. The 65 models are already over priced coming from the factory. Why incur additional costs in manufacturing when the car is still going to be discounted at the MB dealer to get it off the lot?

Tom

sound 8

It would seem having ludicrous amounts of torque is on the down side.
Instead of trying to produce a box to take the torque, would it not be better
to reduce the torque ( blasphemy ) to a level where a mct type gearbox
could be used. Bear in mind how much torque you are loosing to traction/wheelspin. By reducing it ( not to 63 level ) and introducing a new
box surely that would make up for the reduction of torque. The one thing
I hate about the auto box in my 600 is when you want to change down quite
often it doesn't, this is maybe because changing down would bring the revs to near the red line, yet the 63 box will change down where there's only 500 revs before the red line. This must have happen to you unless you always overide it with buttons, however the same will apply if your too near the red line. I love the feeling of torque, but I also love the feel of the gearbox, I still
think it's a triumph of technology.

BI-TURBO-LOVER

LOOK guys im just saying the sl63 is a great GT, The SL65 may have more power 0-60 ,1/4th mile, and top speed. But the price is 200k, i know the sl63 is alot as well but for 600hp in a 4500 pound car jus doesnt make sense. I do love turbos on any car period no one can f-ck with them and they make much more power then N/A but the car is outdated quartermile in 11.9 at 120 for a 4500 pound car is great but it could be much much better with all that torque right? And the sl63 runs 12.4 at 116 i know msot mags test it as a 13.0 12.9 car but with a good driver it can do much better. with a few mods on the sl63 u got 600hp crank horsepower with a wonderful super fast shifting trans and the lil torque it has is enuf for a decent reving V8 engine with no lag lol. Now put that tranny in the sl65 give it less torque and watch it run 11.7 at mabye 122 But they wont do that, Also lets face it the handling is not good and yes i drove it. And as for somone saying the SL63 is not mod friendly, C63 stock 451hp to the crank right, POWERCHIP and evosport teamed together and gave it 532hp to crank and 435rhwp. thats almost 100hp for 1999.00. So imagine the tunning u can do to the sl63 and it has 518hp add 79hp to it and u got a 11.8-11.9 car doing 118-119 with better handling and new technolgy, everyone wants the new shiit plain in simple.http://www.6speedonline.com/forums/m...velopment.html

sound 8

I have had my SL63 re mapped, and drive with a/c off, you can feel the extra
believe me. I have had 12.5 116mph.
But it's not just about speed or torque, the 63 as a whole it's fantastic, looks,
g/box,roadholding, and that fantastic exhaust which you never seem to get tired of, apart from slightly more power what else is going for the SL65.

TMC M5

Not exactly...if you are going to quote magazine tests why not quote actual #'s from those tests:

http://www.roadandtrack.com/article....rticle_id=7449

11.8 @ 121.6mph for a stock SL65

As for real drag strip times...a member here (Camdon) got 11.27 @ 123.5mph in an SL65 with the only modification being drag radials.

And then you have Lou Fishgold's RENNtech tuned SL65 that ran a 130+mph trap speed and also ran a 10.853s 1/4 mile.

I really don't think the 5 spd auto itself is holding those cars back. In fact in the 1/4 mile, both the SL65 and SL63 are in 4th gear crossing the traps. Yes the new MCT is faster shifter...but will it be as "bullet-proof" as the old reliable 5 speed???

Also, you really are displaying some questionable knowledge on the 63 engine. The C63 is DETUNED from the factory by 50hp. So of course the software upgrades unlock an enormous amount of power on the C63. The tuning on the SL/S/E/CLS will not see those type of gains because they have been already improved right from the factory. You may see a 10hp-15hp increase in those other platforms but nothing close to the C63 gains.

Tom

jcpca356

you can pick up a sub 30k mile / 06 SL65, still under warranty for about 60k...that's a lot of hp for the money~

sound 8

I am sorry Tom but all you keep referring to is drag times.
I merely qouted some figures from another member and my own experiences.
For normal every day driving the new mct gearbox is far superior to the auto box. First it has a far faster change, secondly manual is proper manual, not just buttons which get overridden by the box, it's pointless having them.
Then there is the the way it reacts from throttle input, and lastly it's the way
it brakes the car. It seems that you and most other members are only interested in drag times when we are talking about a car that most members will never take to the track. Also the way the auto box memorises the way you drive and can have adverse effect, does not seem to be a problem in the mct box. It's time to hold up your hands and say the auto box is ancient, and
praise the mct box.

CA_E55

While I am not a fan of the 5 speed slush box, I don't think the MB 7 speed slush box sans TQ is much of an improvement - and that is what the MCT is.

If you want an efficient gear box - you have to go DSG or SMG or F1 whatever the moniker de jour is: friction losses are around 35 to 50% lower compared to a slush box - thats more power to the wheels, they also have better gear ratios; the M5 and M6 are excellent examples of how well that concept works.

Or why do you think AMG is using a DSG on the brand new SLS?

sound 8

They are using the DSG because the auto is ancient.
As you said the MCT is an improvement over the auto, that's my point,
so well said.

TMC M5

Was I talking to you??? You might want to take the time and see who I was quoting in my post....

Tom

sound 8

I thought that you posted threads so every one can read, I don't understand
your quote " was I talking to you" you replied to Bi-Turbo, I was responding
to what you said to him.
This forum should not get personal, when you post you are talking to everyone that cares to read, you can reply about the content of that post,
that's what I done.

TMC M5

Spare me the lecture...if you re-read your post and stop acting like a martyr for free speech on the internet you will see how YOU are making it sound as if my post was in some way a response to you.

Now...re-read Bi-Turbo's posts. Why not lecture Bi-Turbo for bringing up 1/4 mile drag times and trap speeds??? I was merely responding to him and his flawed logic...not you and your flawed logic.

Tom

sound 8

I get the feeling that you are always waiting for me to make a mistake, so you can jump on it. I on the other hand realize that you are a walking
encyclopedia and bow to your superior knowledge about cars, you are the teacher and we are at school, however you don't seem to be such a genius
when it comes to personalities. I often praise your comments, but I guess I am wasting my time trying to be nice. I love cars, and talking about them, I
don't sit in an ivory tower waiting to put members right about there inaccurate posts.

TMC M5

Now the persecution complex....

I try to be patient....when my patience wears thin my "flawed personality" takes over....and get it straight...I sit on an ivory tower...and flush when I am done...

Tom

AMGfan

sound 8

Does that mean you talk crap!!

TMC M5

It does indeed...

Tom