Ah yes I remember now...looks like I shared some comments back then. I hope your new 600 gives you many miles of pleasurable motoring...you deserve it

 

I’ve now put close to 400 miles on the SL600 and although I think it’s a great car overall, the sluggishness at low speeds is becoming more and more annoying, particularly given how well it performs at high speeds. My new theory is that the main problem is that the transmission’s torque converter is very lazy about lock-up. I’ve noticed that when I am coasting down a city street at 10 or 15 MPH the tach reads about 1000 RPM. Tap the accelerator and the needle jumps to nearly 2000 RPM, taking up the slack in the torque converter before the car goes any faster. This is in stark contrast to my old 55, where the torque converter did lock up at low speeds in the low gears, just as advertised in the marketing literature for the car. I’m praying that the aftermarket transmission computer will ultimately fix this. Otherwise I’ll be stuck with a car that’s a rocket at high speeds but an Oldsmobile with a hydramatic transmission at low speeds.

 

Take into consideration the MB's driver adaptive transmission. When I drive around town even in my RennTech modified 600 it can have the same feeling. When I push the car and/or use the manual shifting option in both M and S modes, the car comes alive in the situation you describe. When I drive mellow/normal, the car acts mellow and normal. When I drive aggressive and sporty, the car becomes just that. Keep the revs up and the car will be more than most can handle.

My friends who have SL55's are absolutely floored with the performance and response of my car after driving aggressively for a while. One of their minor complaints is that they get very little engine/car feed back from my 600 compared to their 55's.

 

The tranny in the SL600 was the main reason I passed on the car. So it seems that AMG really knows its stuff on making the 5 speed come alive.

However, the new Mercedes 7 Speed is not like the 5 speed at all. It is very lively at low speeds. Actually, it kind of has the opposite problem since if you are loafing along in 7th gear, you need to get down to at least fourth to see any real acceleration (at least in the SL500). I find myself banging the gearshift repeatedly before anything happens. Downshifting to sixth or fifth has little effect.

Would be interesting to see how the new 7 speed behaves in the SL600 or how AMG modifies it.

 

I’m up to 800 miles and am liking the car more as I drive it harder near the end of the break-in period: the Oldsmobile hydramatic thing is receding into the background. The other day I finally tried the kickdown from third to second and could feel the back end squirm from lack of traction in a straight line on a dry road. A good feeling actually. I even had the traction control going in a straight line in third gear during this morning’s commute. There may have been a little condensation on the road surface, but my old 55 didn’t have the thrust to lose grip in third gear under similar conditions. I’ve got to agree: the car is definitely a rocket when driven hard (and elegantly smooth when driven gently). I also exercised my wife’s C4S during the stretch of great weather we had over the weekend. The SL600 feels heavier but to its credit it doesn’t feel 1300 pounds heavier. I’m set to do the mods later in March.

 

For what it's worth, here are some SL600 pictures another member was kind anough to host for me.

 

Of all the pictures I've seen, this has to be some of the most beautiful ever in snow!

 

Sillydriver, your car looks great in the snow. But be careful of driving on roads that have been "salted". I don't have that problem in Houston. My Mars Red SL600 has the same interior color as yours. I had 2 silver Mercedes before this one (2001 SLK320 and 2002 SLK32 AMG), so I decided on something different. I don't notice a sluggish feeling during acceleration. Even though I am still conservative with my driving (only 650 miles since delivery on Feb. 28) I can tell this car is quicker than my SLK32 AMG. The SLK32 AMG was very fast (Car & Driver test said 4.5 sec. for 0 to 60mph and 13 sec. in the 1/4) but I can feel that the SL600 is faster. I'll try to post some pics of my car later.

 

A geogious car! The detailing of the leather around the guage surounds and the wood steering wheel really look sharp.

The discription of smooth and quiet handeling at low speeds and abundant tourque when driven more aggressively ... has me thinking it is R230 SL600 for me.

Must start saving right away!

 

Speaking of the detailing and stitching, I’m not entirely sure whether that level of detail is stock to the SL600 or only there because I bought the designo silver package. In general, designo packages are the way to get 600-level workmanship and leather quality on a 500-engined car. My S500 has a similar package and the interior is absolutely gorgeous. In the case of this SL600 I chose the designo package so I could have the champagne-silver exterior paint and maple trim; however I suspect that the stone leather and stitching in the designo package are exactly the same as in the stock stone color interior for the 600. Since the price of the designo package is the same for both the 500 and 600, I may have effectively ended up paying for the nice leather twice. I suspect Mercedes prices it that way to see whether they could fleece spendthrift idiots with no sense of value. Of course I am just that sort of idiot.

 

Nice write up and pictures.

I remember seeing a SL600 (the same color as yours, might be you) couple weeks ago, it looks gorgeous!

 

That colour really looks great in the snow, its so easy on the eyes. It also appeard that inbetween the speedo and dash it is alcantara or the like instead of plastic with poor fit and finish, which really makes it look nice. Just one question, can you ever get all the power of the SL600 down in those conditions!

 

Thank you all for your kind comments.

It might have been me, particularly if you saw me in the financial district, Back Bay, the Chestnut Hill area or (most commonly) north of the city on Route 1, 1A, 95 or 128. The dealer (Flagship) tells me mine is the first designo silver SL of any kind (not just 600) at the Herb Chambers dealerships. However, that color was used (with a different interior and without the pano roof) on the 03 launch edition SL500 so there are similar cars in the area.

The weather conditions in those pictures are a little deceptive. They were taken mid-February just after I took delivery of the car. That part of my property is shaded so the snow takes a long time to melt. The roads themselves were clear and dry that day. I’ve been very careful not to drive that car in the snow or when snow is forecast.

 

Hope you to your car more around Boston, it's lovely. The weather should get better next week. Bring it out more, plsss.

 

I’m taking advantage of the bad weather (up to four inches of rain expected during the next several days) to send the ECU and TCU off to be reprogrammed. While the instructions were as clear as they could be, removing those boxes was roughly equivalent to changing out a PC motherboard, so doing it at home is not for everyone. Hope this operation works!

 

You'll have some fun now with your new mods!

 

Trimmer2 : Did you dyno your car to get the real reading?
I suggest you do(same mods in my S resulted in 524.4 hp at the wheels,torque 656 lbs at the wheels)

 

looks great sillydriver! I only have seen 1 SL600 and it was in a dealer showroom, green @ MB of westwood. Looking forward to seeing ur SL downtown sometime, or better yet u should send it my way for a detailing like my friend's BRABUS SL55..

 

AlBoston, Does that Brabus have their interior package? I was looking into getting one for my SL500. If so, what are your impressions of it and do you have any pics.

Thanks,

Paul

 

I believe that SL has the standard AMG interior. Noticed the seats have the AMG tag on it.

 

The reprogrammed computers arrived this morning. Now I have the car I was hoping for! The mushy throttle thing is history, the manual mode is fun to play with, and the car is definitely quicker at full power in third gear (I couldn’t floor it in second or first because the roads here are wet). It’s noticeably quicker in third than the old 55. Trimmer’s descriptions of the performance of the car are quite accurate.

Concerning some details, the manual mode seems to be programmed a little differently than the 2003 SL55. The car wants to hold higher revs and will downshift from third to second below 2000 RPM or 40 MPH. The 55 (at least last year’s model) downshifts only at a much lower speed. I actually like this set-up because driving the 55 I would tend to downshift right as the computer was doing so too, landing me one gear too low. This way I just let the car downshift in slow traffic or going around a corner. Finally, the automatic S mode seems more natural and sporty, holding the low gears longer.

I hope some Mercedes product planners are reading this: I can’t believe Mercedes didn’t set the thing up this way in the first place! Some may still prefer the 55’s Detroit muscle car engine noise and AMG styling cues, but given my taste I can finally recommend the 600 over the 55 without hesitation.

 

sillydriver,

I know this may seem like a wacky question given your ebullience, but are there any negatives associated with the modifications, such as the loss of a smooth launch, etc? Also what did you have done exactly and how much did the modifications cost?

 

Physically removing and reinstalling the transmission computer was tricky because of its location behind a panel on the right side of the passenger footwell. The engine computer was easy.

Theoretically there are warranty issues, although Mercedes service people have told me that the modifications aren’t very visible to them so it shouldn’t affect warranty service. I doubt whether it decreases the longevity of the drivetrain, particularly if installed after the break-in period. Remember that the identical Maybach engine is tuned to produce about 550HP, is designed to run full speed down the autobahn for lengthy periods and is stressed by the fact that it’s moving a 6000 pound car.

My experience with the modified car is limited so far (I left it at home today because there’s snow in the air) but the kick-down from third to second overpowers the traction control for an instant so I wouldn’t want to floor it on a curve in the wet, but I wouldn’t want to do that with the stock car either.

The launch is actually smoother than before. The gas pedal seems stiffer and the response much more linear. I use to run in “3” or “4” rather than “D” in order to keep the revs up to 2000+ where the throttle was more responsive and less mushy. Now the car feels great in “D.” It responds more quickly, even when it’s in a higher gear at lower revs.

I suppose the increased horsepower marginally raises the odds of a high-speed crash or reckless driving arrest.

The actual product is the Renntech Stage 3 engine and transmission software. The cost is $6,400, which may seem steep for a software download. They definitely price to value, although I am very satisfied with the value delivered. Their turnaround time was excellent: just one day.

Other than that I think it was all upside.

I’d love to hear whether any of the others who have modified their 600s have experienced any problems.

 

No problems so far,throttle response dramatically improved,car pulls much harder esp at speeds over 100mph.
Transmission is marginally less smooth then before.

 

I just used the modified car in my normal early morning commute for the first time, making for an easy comparison.

Holy @$@!% that car is fast !!!!

The back end squirms for lack of traction even is a straight line in third gear. In fairness, the higher density of sub-freezing air at sea level adds some more HP but even so, it's a rocket sled.

Got to cool it from now on before I’m arrested or killed.