"We've compared the M class with the G-Wagen... - Page 3 - PeachParts Mercedes-Benz Forum

G-Man · #31 01-29-2002, 10:18 PM

I don't think it is a matter of dissapating the energy. I think it is a clever use of electronics to somehow calculate torque output and limit power production with electronic throttles. This is a little OT but does apply to the Merc vehicles too so here goes. I learned a lot from an Allison Transmission tech today. We looked at percent throttle opening, trans input and output speeds etc. The engine control computer also knows when you set the cruise control, it knows when you ask for power via throttle opening, it knows what gear you are in, 4wd or not, it knows how fast you are going it knows the tempand humidity outside, lots of stuff, in addition to various sensor monitoring. It is amazing what we could look at real time on the road with a laptop. Point is, with all of these parameters being monitored it shouldn't be too hard to limit power. On the G500 for example, the computer will see you select low range, it will see you select diff locks, it can then monitor the throttle opening and calculate availible torque based on rpm, road speed, throttle postion etc. and could easily reduce the throttle opening to remain within programmed parameters. Unlocking the front diff kicks it out of the limiting program and away you go unaware that anything happened. That is my understanding of how the systems work. One key advance that makes this all possible is the death of mechanical throttle linkages. Kind of scary really, but it allows cool features like the torque limiting.

I haven't followed the Rally scene much. THAT is some wild racing, I am really glad it seems to be having a comeback in the US. I should get out and watch but, you know the story, just not enough days in the week to do all of the stuff I want to do.

Gilly · #32 01-30-2002, 06:59 AM

The amount of power the engine is capable of producing isn't altered, but the engine control module does control the throttle itself. This has been the case ever since the demise of CIS-E injection back in the early to mid 90's, depending on the engine.
"4WD" is not a possility on an ETS-4 vehicle, as ETS-4 is an AWD system. I don't believe the engine controller on an ETS-4 even knows when it's put into low range.
Mainly, the engine control unit will alter the throttle setting based on info from the ETS-4 control unit, which is only acting upon info from the 4 wheel speed sensors. It also of course alters the throttle opening to control idle, to accelerate/decelerate in response to drivers commands, and also cruise control inputs, there is no seperate cruise control module anymore.
Gilly

Kuan · #33 01-30-2002, 08:32 AM

G,

Speaking of rallying, they're gonna be running in Garrison on Lake Mille Lacs on 2/2-3, 2/9/10 and 3/2-3, at Thunder Bay on
2/23-24. I guess word is that they have to hit the track because of lack of snow and ice. Anyone here know what it takes to get like a Novice license? Man, be nice to go run with the dogs

Kuan

G-Man · #34 01-30-2002, 10:09 AM

I might try for the one in March. I am going to be gone next week to sunny So. Cal. so I would miss the first couple dates. Thunder Bay is too far and too cold for me.

I am not sure what is required for a license. The SCCA sets up a booth at the Mpls auto show every year though. I am sure they could tell you. I am going for a competition license starting with Porsche Club Racing. Since I have already started, most of time having one type of racing license helps you to get one with a different sanctioning body.

I have seen some of the cars being trailered. Looks like you could do it on a pretty low budget. The cars I saw were old RX-7s and a Dodge Omni. I still think tearing around in the woods would be really intense. With a cheap car and good safety equip. I bet it would be a blast.

Gilly, What I meant is, that by modulating the throttle, the computer reduces the amount of power produced. I did not mean to imply that the computer in any way changes the potential output of the engine.

Lebenz · #35 01-30-2002, 01:20 PM

Hi guys. Skiing Friday saw 2’ (feet) of freshies on top of another 4 feet of snow in the last 5 days. I was lucky enough to be one of the first down a little breath-taker called Powder Bowl. Got stomach-deep snow on a steeeeeep grade. Ohhhhh baby. Anyone wants, I have a nice early season pix of this spectacular hill. The drive to the resort and back was a delight with complete snow & ice covered roadway for about 60 of the 80 miles. Brent if you aren’t doing anything we currently have the best snow of the far west.

If you root around long enough you can find from what linage the ML evolved, so to speak. As pointed out before the ML was designed in the mid ‘90s as an AAV and intended to be the next generation of the G wagon. The MB “family” had and still does have the G and I think engineering and/or marketing were looking to entice some new meat, so to speak. Mercedes being Mercedes (even in Alabama) wanted to advance the state of the art in SUV engineering and utilize modern approaches along with innovative combinations of equipment and manage the hardware with technological advances (read that, computers). They did and are continuing to do a nice job. Really it’s odd that a vehicle this feature rich in off-road abilities is mostly hidden. While in it’s inception the ML was more styled for off road use.
(http://www.4x4abc.com/aav/ ), during its development and marketing, upscale soccer moms (and the occasional ski bum) are the targets. In true Mercedes form, they’ve appealed to both. In its off-road prowess the only real shortcomings are the tradeoffs made for lower step in height and wheel travel to reduce body lean. Notice that on the new MLs they have made the front and aft bumpers considerably shorter, to increase the approach and departure angles (and no doubt due to people *****ing about the bumpers being scraped off).

For the moment, since the 4ets system is under current discussion, I’ll attempt to pick up there. Gilly well covered the system, except that it has continued to evolve in MY 02 to 4ETS+ I don’t think it’s been mentioned but 4ETS+ refers to 4 wheel Electronic Traction System +. The 4ETS uses the ABS sensors as data collection sensors and it also employs microcomputers to sample the data collected by the ABS sensors. The computers use a series of algorithms to quickly apply differing amounts of braking force for differing circumstances. 4ETS also uses the brakes to effect change in the rotational speed of any one or multiple wheels as necessary. 4ETS is extremely responsive and is designed to do a multitude of tasks. As Gilly pointed, out the system employs open transfer cases which provide a great deal of adaptability for quickly directing torque. In addition to this combination of systems, the ML also employs another system called ESP. ESP provides directional stability. It too works by quick and selective activation of the brakes to counter the effects of yaw. These systems all work together and concurrently.

I mentioned above that with the ’02 there is a “+” added to 4ETS. This is a brake load booster that empowers even quicker response times (rated at 500 ms.) In the case of 4ETS the system manipulates the drive system of everything from the ML 320 to the up to the ///AMG ML 55. And it can do it in about 1/100 of the amount of time it would take you or me to do it!

“This allows 4ETS to apply the brakes to spinning wheels even sooner and to make optimum use of the drive power. The system releases brake pressure in response to the driving speed, wheel acceleration and accelerator pedal position.” (see http://www.whnet.com/4x4/4etsplus.html for a nice discussion of 4ETS and 4ETS+ and MB themselves mention ETS almost in passing at http://www.mercedes-benz.com/e/innovation/glossary/lex_begriff21.htm and for a brief but detailed history of traction control see http://www.whnet.com/4x4/abs.html#ETS )

In addition to the previous paragraph, the 4ETS+ offers a so-called “Two foot mode.” Here is an excerpt: a benefit when it comes to moving off on steep gradients. In "low-range" mode the system also works if the driver pushes down the accelerator and brake pedals simultaneously to ensure that the M-class does not roll back when moving off slowly. The previous 4ETS system was not activated in such conditions.”

Further there are a couple of other goodies integrated into the system used for other eventualities: “On the MBUSI off road course during my factory delivery, the driver demonstrated the anti-rollback feature of 4ETS+. With the transfer case in LO range, and the Touchshift in first gear, he drove nearly to the top of a steep hill, then took his foot off the accelerator. The truck actually rolled backward all the way down the hill and then the engine shut down automatically. He explained that as a safety feature. Next, he made the same maneuver in 2nd gear and the truck would use the brakes to hold any position on the hill. He said there was a special circuit in 4ETS+ for anti-rollback and hill decent that only works in 2nd gear.”

Pretty cool! In summary, 4ets+ is fast, and all but replaces the capabilities previously found in locking differentials. As an aside, that the G for MY 02 also uses the 4ETS system but not the + version. However the G also gets locking differentials or “lockers….”

That’s all for the moment. Will cover ground clearance and performance specs next

BTW did someone say Moab?

http://communities.msn.com/MLAdventures/moabwhiterimtrail.msnw

G-Man · #36 01-30-2002, 04:17 PM

Tracy, I am openly envious of your ski situation. I was a ski bum for a year at Colorados A-Basin. I skied everyday from Nov 15 until June 23 when they closed that year. Now I am stuck in the flatlands, at least temporarily.

Glad to have you back. Now to continue on. I agree that the ETS is a good system. Sounds like the new version is even better. I still do not consider it as good as a reliable mechanical locker system. Even if the ETS can mimic the lockers function the ML still has some strikes against it. Ground clearance is a big issue. Even up sizing the tires will not be enough for most situations. I wonder how large you can go? Would a 265/75-16 fit? That is the size on my G right now. I would like to fit 285/75-16s next time. The 285 is 33"s tall. This is generally accepted as the minimum size for serious wheeling. The G's supernatural capabilities exempt it from that requirement in most cases. How about the fuel tank issue? Is there a skid plate that can be fitted? The pics I have seen show it to be very vulnerable. One more point here. A solid axle is like a big lever. When one side lifts the low side is pressed into the ground as the spring on that side compresses. The ML does not have this feature with its independant suspensions. I may not be real clear on this but, there is an advantage traction wise just because of the axle configuration. I will find the link and post it.

Now to settle my end I will offer the following challenge. See my web page. The movie is about 2.5MB so if you have a dial up it will take a few minutes to load. Kuan, get your buddies together! If you guys can find an ML to take the challenge and succeed, not only will I pay off on the wager but I will publicly concede on this forum. http://homepage.mac.com/brentholm

#37 01-30-2002, 05:12 PM

Wellllll. If there is going to be a ML vs G showdown, count me in!

For those interested, this picture was when my G was BONE STOCK except the tires. I just tossed on some 265/85/16's and went out and ran some of the hardest trails in Colorado. I had some clearance and suspension issues (which I'm fixing) but I was still able to complete every challenge. I would like to see an ML even approach this ledge, but the G scampered right up. I can think of very few vehicles that could have done this without modifications, I know my old LR Defender 90 couldn't!

Frank X. Morris · #38 01-31-2002, 01:02 AM

Howdy GollyGwagen,
Welcome to the Forum. I noticed in your sig. line "Q" is that what you want us to call you?¿
Lets not call it a "showdown" but a "fact finding mission". On another thread we got a little overly enthusiastic about the difference in vehicles so we are trying to keep from becoming tooooo "in the face". Since we are spread all over the place it's a little tough to get together but a couple of the guys live within reasonable distance so they are going to do some fact finding and report back the results.And then we can inflict flesh wounds to the heart

Oh by the way nice pics.

#39 01-31-2002, 09:23 AM

I am new here, and certainly don't want to start on the wrong foot, but there are 4 basic elements that decide whether or not you will make it over an obstacal. Power, clearance, approach/departure, and traction. While I believe the ML probably has plenty of power and (with the right tires) grip, I would have to say that there is an issue with clearance and angles. Those bumpers are huge!

I tell you what, I do a lot of wheeling in Colorado, and would love to take an ML out wheeling. I mean it, not a 'drag them to a place where they will do damage' kind of thing. I have a bunch of trails near the house that range from really easy to moderately challenging. We could run through all of those to get our feet wet, and keep moving on to more difficult trails. It would be interesting to do a comparison and I would love to have other MB's on the trail. If anyone would like to go wheeling, but don't know how or where in Colorado, drop me a line and we'll go out and have a great time. Mettberry gulch would be a fantastic starting trail, and a stock Explorer can make it through. Then there is Longwater gulch (some deep water), and Hackett (the one real challenge... Hackett Rock)

After those we can move out to Chinaman's Gulch, then Wheeler Lake, Iron Chest, Holy Cross, and finally the Independance Trail bypass, Freedom.

I think that is a fantasic listing of trails that rance from 4 to 9 (on a 1-10 scale) and nothing is a quantum leap in dificulty. I've done them all and know them well. I even saw an ML in the area of the Gulches, but I couldn't convince him to join our group and run the trails.

I would guess if we laid out the pro's and con's of each vehicle, we would find that each vehicle has it's stong areas. Rally racing is to me a place where I would be no match for the ML, in any flavor. But rock crawling is an area where my G excels, and I have out perofmed many vehciles who area well suited to it. I would really love to go wheeling with ML owners, so please let me know if you live in the area and would like to try the addictive sport or wheeling. You'll love it!

G-Man · #40 01-31-2002, 09:48 AM

I think Q made another good point. While you may be able to make the ML perform OK off-road it will require some modification. That is part of the beauty of the G, in totally stock form it will embarrass anything else stock. It will also leave behind most modified, purpose built off-roaders. In addition to these skills it is also a quiet luxurious cruiser. I have comfortably run mine, for hours, across desert highways at 90mph. If you so choose the G can be lifted a couple inches and fitted with larger tires. Now it is a match for anything out there. As an added bonus it is designed to withstand many years of this type of use. In any other vehicle it would be considered abuse, well except maybe its siblings the Pinzgauer and Unimog.

The ML is certainly a fine machine. It was designed with serious durability and longevity in mind. What is being missed here is how seriously overbuilt the Gwagen is. We have one G club member that owns a 1980 280GE with over 250k miles on the clock. I also met the previous owner who used it off-road for over a decade. It still sees plenty of use, daily and for play. The truck is in spectacular condidtion and is functionally perfect with little more than routine service. Do you honestly believe that the ML was designed and built to this standard? Remember that the G has been hand built in Austria, in the same factory, by many of the same people, for over twenty years now. This truck is built the old fashioned way. Brake lines are hand bent over a jig. Frames are welded by hand by experienced artisans. I am sure that computer controlled robots are capable of repeatable quality manufacture. I still prefer a competant human brain controlling the work directly.

Out on the highway technology can be a wonderful thing. When you are miles from anything on a boulder strewn trail I will take mechanical simplicity anyday. I view things like ETS as a liability. I think a large issue here is the needs and intended use by the owner. If rock crawling is not on your agenda, the premium for the G is not justifiable. You will pay a penalty in ride comfort, handling, and acceleration. If you do intend to USE the G, there is no finer choice.

G-Man · #41 01-31-2002, 02:41 PM

Check this link for a description of the MLs capabilities. The pic at the bottom made me laugh, sorry but that is really pathetic. http://www.4x4abc.com/DV/01/report3.html

Frank X. Morris · #42 01-31-2002, 10:54 PM

Howdy All
It makes me think that maybe that would be something you might want to have some momentum and hit it. But you should be able to just roll right over it. We have seen some pics of the ML in action and the more I see and read the less inclined I am to believe what anyone says. Just let me drive one to see if it fits my style of driving. I am still going after a Gwagen.

blau · #43 02-01-2002, 12:05 PM

I'm with frank on this. That rock in the picture. You could drive over it even with a regular car even if the ML has no off road ability it should have not difficulty.

I bet I could drive over it with my 87 xr4ti or the honda accord. I know because before my ML. I use my honda accord to go camping and sometimes there are trails that has bigger obstical than that.

blau

ML Dude · #44 02-01-2002, 05:14 PM

Fella's,

I have to say I'm very impressed with the tone of this thread, we have all just got along...

G-Man, I'm the proud receipient of a California Offroad Commission 4x4 certification. A one day course with several hours of lecture on trail navigation. This was followed by an afternoon on the course with instructors/spotters helping each of us through each hazard; mud pit, water crossing, hillside navigation, sand, and boulders.

The best part of all this was that it was all a group of ten ML owners and a couple with an ML55. Needless to say we all bonded during the day putting our trucks through their paces.
The instructor has seen most "SUV's" try his course and he was impressed with the ML's capabilities!

While I might not compare the offroad prowess of my ML with a Hummer, or GWagen for that matter. I ran out and got brush guards for the front and tail lights just in case

Remember guys, these are just sibling rivalries, we're still driving the safeset most capable vehicles in their class!

Frank X. Morris · #45 02-01-2002, 11:41 PM

Howdy ML Dude,
Glad you got out and tested your ML. You live right down the road from me (less than 2 hours away) I am about to get off the weekend work ordeal and ready to invite people to come up to El Mirage to the OHV park for some off-roading fun. We have trails for most any taste. So if you or anyone else don't mind 4 wheeling with someone who has a Jeep lets get together sometime.I hope to have a Gwagen by May and my Unimog done by October. So I might need one of you ML people along to pull me out of a sticky situation

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