[MATT32AMG]

Here’s a quick quiz and only out of curiosity, (and probably dumb question for today but hey it is April fools day after all)

Anyone know why it costs extra to de-restrict the slk32amg (or any vehicle for that matter) at the factory by adding the "Sport Pack"??? And err what exactly does the sport pack consist of???

In simpleton terms, surely this is just about flashing the EMC chip with new software, or is this an entirely different Chip?

What other areas would need tweaking to the handling characteristics to accommodate the increased top end speed??. Though I would’ve thought the AMG car was pretty well sorted in the usual areas such as brakes suspension, or are we talking further modifications such as beefing up the anti roll bars??

 

[16falcon]

I think I read recently that one of the main things added is Y rated tires, I'm not sure of what else. Z rated tires are what come standard on the 32. Info from The Tire Rack:

When Z-speed rated tires were first introduced, they were thought to reflect the highest tire speed rating that would ever be required, in excess of 240 km/h or 149 mph. While Z-speed rated tires are capable of speeds in excess of 149 mph, how far above 149 mph was not identified. That ultimately caused the automotive industry to add W- and Y-speed ratings to identify the tires that meet the needs of new vehicles that have extremely high top-speed capabilities.

W 168 mph 270 km/h Exotic Sports Cars
Y 186 mph 300 km/h Exotic Sports Cars


While a Z-speed rating still often appears in the tire size designation of these tires, such as 225/50ZR16 91W, the Z in the size signifies a maximum speed capability in excess of 149 mph, 240 km/h; the W in the service description indicates the tire's 168 mph, 270 km/h maximum speed.

225/50ZR16 in excess of 149 mph, 240 km/h
205/45ZR17 88W 168 mph, 270 km/h
285/35ZR19 99Y 186 mph, 300 km/h


Most recently, when the Y-speed rating indicated in a service description is enclosed in parentheses, such as 285/35ZR19 (99Y), the top speed of the tire has been tested in excess of 186 mph, 300 km/h indicated by the service description as shown below:

285/35ZR19 99Y 186 mph, 300 km/h
285/35ZR19 (99Y) in excess of 186 mph, 300 km/h


As vehicles have increased their top speeds into Autobahn-only ranges, the tire speed ratings have evolved to better identify the tires capability, allowing drivers to match the speed of their tires with the top speed of their vehicle.

 

[ch7ckc]

MATT,I would think someone at AMG would have that info but sharing it with you is another matter(liabilty and such).One of the top tuners,like Brabus,may help you out.

As far as 155+mph...it's more the tires I would think.I saw a TV clip once of a guy driving a modified Porsche at something over 180-190 and,as you might guess,a tire could not hold on.It was a bad scene to watch and the driver did live through the horrific wreck.I like speed as much as the next guy but the tires always give me the willies at any thing over 100 or so.After all,it just takes one to fail and you are in big time trouble.

later,chuck

 

[MATT32AMG]

I think I read recently that one of the main things added is Y rated tires, I'm not sure of what else. Z rated tires are what come standard on the 32. Info from The Tire Rack:

W 168 mph 270 km/h Exotic Sports Cars
Y 186 mph 300 km/h Exotic Sports Cars

While a Z-speed rating still often appears in the tire size designation of these tires, such as 225/50ZR16 91W, the Z in the size signifies a maximum speed capability in excess of 149 mph, 240 km/h; the W in the service description indicates the tire's 168 mph, 270 km/h maximum speed.

225/50ZR16 in excess of 149 mph, 240 km/h
205/45ZR17 88W 168 mph, 270 km/h
285/35ZR19 99Y 186 mph, 300 km/h

Most recently, when the Y-speed rating indicated in a service description is enclosed in parentheses, such as 285/35ZR19 (99Y), the top speed of the tire has been tested in excess of 186 mph, 300 km/h indicated by the service description as shown below:

285/35ZR19 99Y 186 mph, 300 km/h
285/35ZR19 (99Y) in excess of 186 mph, 300 km/h

As vehicles have increased their top speeds into Autobahn-only ranges, the tire speed ratings have evolved to better identify the tires capability, allowing drivers to match the speed of their tires with the top speed of their vehicle.[/I]

Right, interesting stuf...
Currently I'm running Perelli P ZEROS ROSSO 245/50ZR17 91Y on the rear and
similar spec on the front only Perelli P ZERO ROSSO 225/50ZR17 91Y

So if I'm understanding you correctly the above tyres have been rated at 186mph as indicated by the '91Y' demark already, or am I mis reading that??

Anyone have any thoughts on Tyres as we're on the subject??

Perelli afford good levels of grip I find, but are subject to wear perhaps a tad quicker than other makes but nice and even.

 

[MATT32AMG]

MATT,I would think someone at AMG would have that info but sharing it with you is another matter(liabilty and such).One of the top tuners,like Brabus,may help you out.

As far as 155+mph...it's more the tires I would think.I saw a TV clip once of a guy driving a modified Porsche at something over 180-190 and,as you might guess,a tire could not hold on.It was a bad scene to watch and the driver did live through the horrific wreck.I like speed as much as the next guy but the tires always give me the willies at any thing over 100 or so.After all,it just takes one to fail and you are in big time trouble.

later,chuck

Yup I agree that's a bad scene running excessive speed on the wrong tyres. Like you say, if they go pop you can easily become a passenger to the scene of the accident and there is absolutely nothing you can do about it. Though much would depend on circumstance, such as car position, or if you were cornering braking hard etc…

Yup I agree that's a bad scene running excessive speed on the wrong tyres. Like you say, if they go pop you can easily become a passenger to the scene of the accident and there is absolutely nothing you can do about it. Though much would depend on circumstance, such as car position, or if you were cornering braking hard etc…

As regard to other aspects such as EMC chip software, yeah you are probably right they'd be a bit reluctant to share that info. That said de restricted cars are available here in the UK as an option, certainly the SLK55 AMG. I was offered that last year when I was considering changing my car, the trouble was that the price was getting very naughty £62,000K or a Whopping $122,012 US Dollars

 

[16falcon]

So if I'm understanding you correctly the above tyres have been rated at 186mph as indicated by the '91Y' demark already, or am I mis reading that??

That's the way I read it too. I just checked the Michelin Pilot Sport PS2's on my car, rear's are 245/40ZR17 91Y, so I guess they are rated to 186MPH also, cool. I thought the ZR17 ment Z speed rating and radius 17", but apparently we have to go to the 91Y, which is load rating of 91 and speed rating of Y. Here are a couple of other sites I found that discuss tire speed ratings:

TIRE RATINGS

Yokohama - Understanding Your Tires

This is an interesting article on the history of performance tires: The Truth About Performance Tires by Frank Ranelli

 

[MATT32AMG]

That's the way I read it too. I just checked the Michelin Pilot Sport PS2's on my car, rear's are 245/40ZR17 91Y, so I guess they are rated to 186MPH also, cool. I thought the ZR17 ment Z speed rating and radius 17", but apparently we have to go to the 91Y, which is load rating of 91 and speed rating of Y. Here are a couple of other sites I found that discuss tire speed ratings:

TIRE RATINGS

Yokohama - Understanding Your Tires

This is an interesting article on the history of performance tires: The Truth About Performance Tires by Frank Ranelli

Interesting reading, particularly the article regarding performance tyres.
At the risk of stating the obvious, it underpins the common train of thought that tyres play a very critical part in overall car performance. Tyre properties are factored into the cars overall performance specification throughout the design process in terms of how the chassis influences tyre ware. In the case of the Bugatti Veron they had to design a completely new tyre to cope with the massive loads being subjected to it.

The message here is (IMHO), when next at the tyre bar looking at fitting new boots; don’t fit anything under recommended performance specification for that of the car, (not that I do), in order to save maybe £100 ($200) on a set.

Anyway this neatly brings me back to the original point which is: What then is contained in the AMG sports pack that they want to charge extra for?

Having established that the tyres fitted to both our respective cars are rated to 186mph and are within the performance envelope, it’s looking more like a software tweak to remove the line of code that limits the car to 155mph.

What a great business model that is if you can get away with it :thumbsup:

 

[Bruce R.]

I think something you fellows are missing is the "Gentleman's Agreement" that Mercedes, BMW, and Porsche made a number of years ago. They agreed to the 155 mph speed limit, because they thought that most driver's couldn't handle anything over that. In most cases they were probably right. Hey, around this area most people can't handle anything over 30 mph.........
Anyway Porsche broke with that agreement some time ago, and both Mercedes and BMW have been toying with it for some length of time. I believe it was just a safety issue that they no longer feel is worth persueing...........
The SLK and other classes of ///AMG cars can easily handle the speeds, it's the drivers that have and always will be the limiting factor.

 

[Jeff Kushner]

I think something you fellows are missing is the "Gentleman's Agreement" that Mercedes, BMW, and Porsche made a number of years ago. They agreed to the 155 mph speed limit, because they thought that most driver's couldn't handle anything over that. In most cases they were probably right. Hey, around this area most people can't handle anything over 30 mph.........
Anyway Porsche broke with that agreement some time ago, and both Mercedes and BMW have been toying with it for some length of time. I believe it was just a safety issue that they no longer feel is worth persueing...........
The SLK and other classes of ///AMG cars can easily handle the speeds, it's the drivers that have and always will be the limiting factor.

I had never heard about that agreement before but it doesn't surprise me...a lot of industries have unwritten agreements.

Bruce, I have to agree and disagree with you at the same time....but for different reasons. You know that I used to roadrace motorcycles so I'm used to speed...lots of speed. I'm quite aware that cars and bikes are worlds apart with cars being infinitely safer IMHO...so in regards to drivers..yes, most people couldn't handle keeping a clear mind at speed (140 and above). It's downright terrifying for a lot of people. They tend to freeze at the controls and have horrific accidents at the result.

On the other hand, I've had my baby silver bullet up to 152 and I FELT, that I was at the outer limits of the chassis's ability. The car had about 18K on it and was tight all the way around. tire pressures checked before and even with the back 2 lbs higher. I'm sure that your 32 has a better chassis and with your track experience my guess is that you could explore the upper reaches of your engines ability without incident. It just felt to me that things were beginning to "get squirrelly"....yes, that's a technical term<LOL> and I didn't feel confident to push it any higher although the engine was still pulling. It seemed to be tracking fine, just not really liking any input from the driver at that point. I may have been, as you said, the limiting factor but it really felt that the chassis had also reached it's limits.

I doubt that I'll go there again even when I do get my new tires.....just like with bikes, nothing wears tires as fast as high speed runs!

Jeff

 

[Bruce R.]

Jeff, the early SLK's were never envisioned to run at those speeds. The 230 ungoverned could reach about 150 on a good day with a slight tailwind, the 320 was a little better and could go 150+ but again, only with a long straight and that wasn't always available. The 32 was a different story, and both Mercedes and ///AMG did some aerodynamic work on the body.
You might notice that the trunk lid has a small upturn on it, more like a slight dent just in front of a subtle uplift on the back. That was just enough to keep the car stable at the speeds that it could run. The 32 has a “spoiler” on the lid as an addition to the aero package that develops 50% more down force on the back of the car. It actually works quite well. My car has been out on the VIR straights at 150+ and is very stable, there have been others here that have been “modified” to remove the governor, and been up to 180+ mph and reported the car as quite stable. If you like the higher speeds you might want to look into adding that spoiler to see if it feels better to you………………… :thumbsup:

 

[Jeff Kushner]

Jeff, the early SLK's were never envisioned to run at those speeds. The 230 ungoverned could reach about 150 on a good day with a slight tailwind, the 320 was a little better and could go 150+ but again, only with a long straight and that wasn't always available. The 32 was a different story, and both Mercedes and ///AMG did some aerodynamic work on the body.
You might notice that the trunk lid has a small upturn on it, more like a slight dent just in front of a subtle uplift on the back. That was just enough to keep the car stable at the speeds that it could run. The 32 has a “spoiler” on the lid as an addition to the aero package that develops 50% more down force on the back of the car. It actually works quite well. My car has been out on the VIR straights at 150+ and is very stable, there have been others here that have been “modified” to remove the governor, and been up to 180+ mph and reported the car as quite stable. If you like the higher speeds you might want to look into adding that spoiler to see if it feels better to you………………… :thumbsup:

You're probably right...From what I've read on spoilers, it doesn't take much of a lip to force the rear down and down hard....the spoiler can be HUGE which is why they are so regulated in NASCAR and INDY cars......but I think that I've had my fun or least most of it.....I was hoping to one day find the top end of my car but I think that I can be ok without knowing what it is. Evidently, getting the chip remapped last summer got rid of any limiters. Thanks Bruce.........

 

[papa]

Ive had mine up over 150 a number of times, Feels very stable and planted, if anything it was better at 150 then 130, seemed to go quiet, dont know how to explain it other then that, just felt better.


The car I had before the slk, Had the the opional Aero kit fitted

Here it is with some lush welsh grass
http://img259.imageshack.us/img259/2053/porkynoplatexn5.jpg

 

[16falcon]

Anyway this neatly brings me back to the original point which is: What then is contained in the AMG sports pack that they want to charge extra for?

I think I found the answer on the MBUSA site, it's for a 2007 SLK55:

2007 Packages
P30 AMG Performance Package
The Performance Package begins with a 12 percent increase in top track speed to 174 mph (see note 1 below).

18-inch AMG twin-spoke multipiece wheels are finished in sterling silver and equipped with high-performance tires (see note 2 below) — the largest available factory wheel and tire combination mounted on AMG lightweight two-piece alloy wheels.

The AMG track-calibrated suspension system is 20 percent stiffer and is exclusively calibrated for use in high-speed driving conditions.

1. Electronically limited. Obey speed laws.

2. Lower aspect ratio tires and accompanying wheels provide substantially increased treadwear, tire noise and reduced ride comfort. Serious wheel and tire damage may occur if the vehicle is operated on rough or damaged surfaces or upon encountering road debris or obstacles. These tires are not designed for use on snow and ice. Winter tires mounted on appropriately sized and approved wheels are recommended for driving in those conditions.

 

[MATT32AMG]

Jeff, the early SLK's were never envisioned to run at those speeds. The 230 ungoverned could reach about 150 on a good day with a slight tailwind, the 320 was a little better and could go 150+ but again, only with a long straight and that wasn't always available. The 32 was a different story, and both Mercedes and ///AMG did some aerodynamic work on the body.
You might notice that the trunk lid has a small upturn on it, more like a slight dent just in front of a subtle uplift on the back. That was just enough to keep the car stable at the speeds that it could run. The 32 has a “spoiler” on the lid as an addition to the aero package that develops 50% more down force on the back of the car. It actually works quite well. My car has been out on the VIR straights at 150+ and is very stable, there have been others here that have been “modified” to remove the governor, and been up to 180+ mph and reported the car as quite stable. If you like the higher speeds you might want to look into adding that spoiler to see if it feels better to you………………… :thumbsup:

I would concur with what you are suggesting there Bruce. The chassis, or rather the combination of the wider track, stiffer and lower suspension ride height, and aero package, are quite different from that of the 230, and therefore make the whole driving experience very different from the 230 at most speeds, in fact I might say all speeds. That said try adding the boot lip spoiler, as Bruce rightly states it adds as much as 50% down force which should help car stability at high speed.

As regards the gentlemen’s agreement to limit speeds to 155mph, yes I was aware of it, purely because the German public who enjoyed thrashing down the autobahns weren’t too chuffed when it was introduced as it spoiled their fun. It’s probably not too many on this forum that have experienced this, (I used to live and work out in Germany so I can speak from experience), but to be going down the motorway at 120 mph or so in say your BMW, and to then have a Porsche 911 Turbo, or Ferrari come past you like you were parked was just something else. It is a completely different style of driving out there, you had to become very spatially aware, I mean everyone is doing at least 100mph even the Trabants !! (Well in spirit)

That said they didn’t have any more accidents than say here in the UK , it was just that when accidents did happen it was pretty much always HUGE, involving it seems just about everyone within a 10miles and sadly fatal.

 

[MATT32AMG]

I think I found the answer on the MBUSA site, it's for a 2007 SLK55:

2007 Packages
P30 AMG Performance Package
The Performance Package begins with a 12 percent increase in top track speed to 174 mph (see note 1 below).

18-inch AMG twin-spoke multipiece wheels are finished in sterling silver and equipped with high-performance tires (see note 2 below) — the largest available factory wheel and tire combination mounted on AMG lightweight two-piece alloy wheels.

The AMG track-calibrated suspension system is 20 percent stiffer and is exclusively calibrated for use in high-speed driving conditions.

1. Electronically limited. Obey speed laws.

2. Lower aspect ratio tires and accompanying wheels provide substantially increased treadwear, tire noise and reduced ride comfort. Serious wheel and tire damage may occur if the vehicle is operated on rough or damaged surfaces or upon encountering road debris or obstacles. These tires are not designed for use on snow and ice. Winter tires mounted on appropriately sized and approved wheels are recommended for driving in those conditions.

Ahh now we're making progress, however one notes the limitations of use that you point out. This seems to suggest that unless you are on a track then don't bother. One also wonders who on earth in their right mind would want to use the car to its full potential in that trim in snow or ice??? (Those jockeys would surely be found residing in the local asylum me thinks!! )

20% stiffer ride than it is already, I wonder what that entails aside from the larger rims, bigger antri-roll bars, springs and dampers perhaps. I wonder if the similar factory tweaks were ever applied to the 32?

 

[Robbie]

On a few late evenings, looking well ahead, I took my old 32 well above 150 mph on a few occasions on the road with standard tyres fitted, no problems at all, the car felt smooth, stable and safe. Had I needed to brake quickly it may have been a different matter I guess.

 

[Bruce R.]

On a few late evenings, looking well ahead, I took my old 32 well above 150 mph on a few occasions on the road with standard tyres fitted, no problems at all, the car felt smooth, stable and safe. Had I needed to brake quickly it may have been a different matter I guess.

I would suggest that if you needed brakes, you would not have had any problems. As I mentioned before, my car which is in stock trim went from 150+ to probably 30 or 40 mph with MAXIMUM braking repeatedly with no problems or surprises twice a lap with additional braking in between for twenty minutes straight. I was not alone, there was another SLK 32 out there with me, and he was harder on the brakes then I was. Theses cars are well engineered and solid at all speeds, the weakest link, as always is the driver.......

 

[MATT32AMG]

I would suggest that if you needed brakes, you would not have had any problems. As I mentioned before, my car which is in stock trim went from 150+ to probably 30 or 40 mph with MAXIMUM braking repeatedly with no problems or surprises twice a lap with additional braking in between for twenty minutes straight. I was not alone, there was another SLK 32 out there with me, and he was harder on the brakes then I was. Theses cars are well engineered and solid at all speeds, the weakest link, as always is the driver.......

Do you do a lot of track days Bruce?? I ask this as you say your 32 is stock, and by that I'm taking it that you drive it to the circuit, do the checks and off you go...
Ever been tempted to mildly tweak it, aside from brake pads and discs maybe? The other question is tyres, what do you run??

 

[16falcon]

I've had my 32 to the track a couple of times, I'm certainly no authority on the subject. I run it pretty much stock too. I put the porterfield brake pads on it but that was to reduce the brake dust not because I thought they were that much better than the OEMs. I still have the stock rotors. I did put on the Goodridge Stainless Steel brake lines mostly because I was looking for easy projects I could handle. I have the stock rims and I use the Michelin Pilot Sport PS2 tires, rear 245/40ZR17 91Y and front 225/45ZR17 91Y. For the track I bump up the tire pressure by about 2 psi. The track I have been to has a couple of longer straights where I hit close to 100mph, the track is really all about braking and cornering. The first couple of times I ran with the ESP on since I really didn't know what I was doing. The last run I did I ran with the switch off and had a much better experience without the engine bogging down when it thought I needed help, my understanding is that you still get the traction control at the rear wheels even with the switch off.

 

[Bruce R.]

Do you do a lot of track days Bruce?? I ask this as you say your 32 is stock, and by that I'm taking it that you drive it to the circuit, do the checks and off you go...
Ever been tempted to mildly tweak it, aside from brake pads and discs maybe? The other question is tyres, what do you run??

For the track I have a set of Toyo Proxes RA-1's, and frankly I don't like them. When they wear out I plan on getting a set of Kumho V710's. I liked the Kumho V700's, and the 710's are supposed to be better yet.....
Yes, I drive to the close by track (Summit Point) on my slicks, and then to the track itself, just check and adjust tire pressure to suit.
I haven't felt the need to tweek the car, because it's already one of the fastest out there, and I doubt that I can handle much more.......... I'm not getting any younger you know.....
At Virginia International Raceway, I changed from street to track tires and that's about it. The car is bone stock, and still can hit 150+ on the straights.