Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 07-17-2001, 09:12 AM
David C Klasse's Avatar
CheFrac is Back!
 
Join Date: Jan 2001
Location: Mission Hills in the City of San Diego
Posts: 2,352
When in my 1995 C280, and stopped, then if I floor it to the floor (before kickdown), the engine will only rev up to about 5600 RPM. But if I floor it and use kickdown, the engine will rev to redline @ 6400 RPM. Now I know that peak horsepower is at 5500 rpm for this car. Is there any benefit of keeping it floored past kickdown to get the max RPM out of the engine when accelerating? What is the point of it being like this?

Now I do notice that on all electronic transmission (722.6/ 1997 +), putting the pedal to kickdown makes not difference at all. You don't even have to floor it all the way to get it to get right near redline. I have experienced this on a 1999 S420, 2001 CLK320, and a 1999 E430, so I know this is consistent and the way it's supposed to be.

Also, does anyone know if MBUSA does their 0-60 with it in kickdown (prior to 97, I suppose)??
__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)
Reply With Quote
  #2  
Old 07-17-2001, 10:21 AM
Moderator
 
Join Date: Mar 1999
Location: Tucker, Ga USA
Posts: 12,153
IF you let the engine shift before redline the engine will slow down TOO much for the next gear & will take much longer to get the rev's up to the higher HP area. HAVING 5 gears(1997+ later) instead of 4 allows the engine to build revs quicker. Also the rear axle ratio can be changed due to the "overdrive" ratio in the 5-speed. Better mileage & acceleration!
__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator
Reply With Quote
  #3  
Old 07-17-2001, 11:59 AM
David C Klasse's Avatar
CheFrac is Back!
 
Join Date: Jan 2001
Location: Mission Hills in the City of San Diego
Posts: 2,352
Ok, I think I have it...
So in essence, I will get better acceleration if I floor it into kickdown because that will leave my revs at full RPM when shifting, thus retaining a higher RPM to the next shift to gain maximum horsepower again...
Why is it different on the electronic transmissions?
__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)
Reply With Quote
  #4  
Old 07-17-2001, 12:05 PM
Ali Al-Chalabi's Avatar
Senior Member
 
Join Date: Nov 2000
Location: Knoxville, TN
Posts: 1,837
With the electronic transmissions, when driving on the highway around 70 or so, if you push full throttle the tranny will downshift to fourth. If you push kickdown, it will shift down to third.
Reply With Quote
  #5  
Old 07-17-2001, 12:09 PM
David C Klasse's Avatar
CheFrac is Back!
 
Join Date: Jan 2001
Location: Mission Hills in the City of San Diego
Posts: 2,352
Ali Al,
Yes I know this... I am not talking about downshifting, but rather the upshifting upon full (kickdown and no kickdown) throttle for the non electronically controlled transmission.
THanks anyway.
__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)
Reply With Quote
  #6  
Old 07-17-2001, 04:51 PM
smalltime
Guest
 
Posts: n/a
What about torque? Higher torque means quicker acceleration, does your engine perhaps develop the maximum torque above maximum hp? It is not likely, but could explain this. Is the range between 5600 and 6400 dead?

Steve
Reply With Quote
  #7  
Old 07-17-2001, 05:49 PM
David C Klasse's Avatar
CheFrac is Back!
 
Join Date: Jan 2001
Location: Mission Hills in the City of San Diego
Posts: 2,352
I am not positive about torque, but I think max torque is at 5,000, I will have to check. But I'm pretty sure that max torque is not at 6400. I thought about this though.
__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)
Reply With Quote
  #8  
Old 07-18-2001, 12:14 AM
JEFF
Guest
 
Posts: n/a
What you want is for the engine to fall when shifting to the peak of the torque curve. What that means is when the car ****s it will probably drop about 1000 to 1500 rpm right to the top of the torque curve from 6400 rpm, giving you the best acceleration.
Reply With Quote
  #9  
Old 07-19-2001, 07:21 PM
David C Klasse's Avatar
CheFrac is Back!
 
Join Date: Jan 2001
Location: Mission Hills in the City of San Diego
Posts: 2,352
I'm not sure about when the torque curve spread is, but max torque is at 3,750 RPM (199 lb/ft). It will fall to just under 4,000 rpms after shifting out of first into second gear (without kickdown).
You know, I've never known this.. what exactly is torque?
__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)
Reply With Quote
  #10  
Old 07-19-2001, 08:57 PM
Clauser1
Guest
 
Posts: n/a
Torque is what you feel under your pants
when you stomp at the gas pedal.
Reply With Quote
  #11  
Old 07-19-2001, 09:37 PM
Registered User
 
Join Date: Jan 2000
Location: New Bedford, MA USA
Posts: 1,583
Dave, torque is a measurable "twisting force". This quite simply put is the amount of twist your engine can apply to the drivetrain. It is, all other things considered equal, what gets you and your car moving at a prodigious rate of speed. Longer piston stroke usually produces higher torque. Measured in foot pounds (US). I remember a chevy 454 large block we built (in my old or should I say my younger racing days.) With these engines, it was not necessary to do much with the displacement, bore and stroke (pretty big already). With a Holley 3 barrel, oversize valves, ported/polished heads, Edlebrock cross ram intake manifold, Crane high lift, long duration cam, Simpson roller lifters, etc, etc, we got an easy 735 hp@6500 rpm and 575 ft/lbs torque@5200 rpm. This was on a chassis dyno too!! This beast wouldn't idle below 1000 rpm. But I can tell you, it left nothing to the imagination when you dumped the clutch at 5000 rpm. It was that big torque number that got you down the track real quick. I hope this helps your understanding. You may get other responses which may be more scientific, but, when all is said and done, the torque your engine produces is what gives you that "seat of the pants" feeling previously described. The engines used in most MBZ's are long on rpm's, short on stroke (good for the upper limit of revs) and, depending on the engine, average to above for bore.

[Edited by jeffsr on 07-19-2001 at 08:40 PM]
__________________
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.
Reply With Quote
  #12  
Old 07-24-2001, 01:24 AM
crhenkel's Avatar
Registered User
 
Join Date: Mar 2001
Location: Decatur, Illinois, USA
Posts: 616
talk to me like I'm 4

SOmeone help...does my 1990 190E have this kickdown we are talking about? After reading all this I don't know what we are talking about any more...exacly what are we doing to " put it in kickdown" Is there something I am missing here?
I was under the assumption that we were talking about pushing the pedal down far enough to put pressure on the switch that reduces the tranny gearing to the next lower gear...help
__________________
Christopher Henkel
1990 190E 2.6 - Arctic white SOLD
1986 190E-16v - Blauswartze
1993 300CE - SOLD
2003 W208 CLK 320 Cabriolet - Magma Red
Reply With Quote
  #13  
Old 07-24-2001, 01:30 AM
David C Klasse's Avatar
CheFrac is Back!
 
Join Date: Jan 2001
Location: Mission Hills in the City of San Diego
Posts: 2,352
Your assumption about pushing the pedal to the floor is correct, there should be a resistance point at the end of it.
I replied to your other post about how this works. Check with the car off and notice the resistance point at the end of the pedal when floored.
If you do not feel anything, then your kickdown switch has probably broken (my worst fear..! J/K). Not sure what involves replacement.
__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
83 300CD tranny modulator question freesprung Tech Help 0 04-07-2004 11:10 PM
Trouble Codes Question talons40 Tech Help 2 08-22-2003 03:36 PM
Newbie Question josephcorderomd Diesel Discussion 1 07-07-2003 11:59 AM
Center Console Question hippie_elmo Vintage Mercedes 2 02-02-2002 12:47 AM



All times are GMT -4. The time now is 10:46 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page