400E owners acceleration question: - PeachParts Mercedes-Benz Forum

Lebenz · #1 07-30-2004, 04:48 PM

So when you put your foot into the gas pedal, what is the acceleration like below 3000 RPM vs. above?

TIA

400E · #2 07-31-2004, 09:53 AM

I'm not aware of a distinct change in acceleration at 3000 RPM in my car, but will pay more attention to it now and see.

#3 07-31-2004, 09:21 PM

I think it downshifts and upshifts again around 4K rpm.

y2kimmel · #4 08-02-2004, 10:36 AM

My 1995 E420 definitely "comes alive" after 3000 rpm. Below 3000 rpm, it is good, but not great acceleration. Has something to do with the intake runners or variable cams, I believe.

Troy
1995 E420 83k

Lebenz · #5 08-03-2004, 10:56 AM

Thanks for the feedback. Mine behaves similarly to y2kimmel's in that it is slow below 3000 and takes off with a vengence at and above that point. Any additional recommendations before i have a shop look at it?

Holson Adi · #6 08-03-2004, 11:17 AM

The tall 2.24 rear end ratio is responsible for its out of the hole performance.

Lebenz · #7 08-04-2004, 07:20 PM

Quote:

Originally posted by Holson Adi
The tall 2.24 rear end ratio is responsible for its out of the hole performance.

I'm not sure if that is true, at least in the case of mine. If i remember, the M119 is supposed to achieve 90% of it's torque at about 1500 rpm, If true, it should pull almost as hard at 1500 as it does at 3000.

carman850 · #8 08-06-2004, 12:09 AM

My previous 400E definitely slept when rpm under 2000, man, that was frustrating!

Tall gear is the major reason, a lower gear would allow engine rev with higher rpm at the same speed therefore more power would be unleashed.

Also if you hit the point when variable valve timing is engaged, there is a power jump, for this reason, I like the continuous Vanos valve timing on BMWs, you really feel a smooth and consistent pulling.

czwbkx · #9 08-06-2004, 01:36 AM

There is a noticeable jump at about 3000 rpm. The torque and hp curves are notchy at this point. I'm looking for the dyno graph to illustrate - will post if I can remember where it is.

Best cure is the kick-down switch. It pushes mine to 3500 rpm quick enough to squawk the tires. I pulled the carpet up to check out the switch and to make sure the switch was engaging properly and didn't have any interference with carpet or padding. I'm tempted to shim it up a bit to reduce the extra travel and pressure required to engage it.