[lconn]

I have owned my 08 335i E92 for a couple of years now and one thing that has always bothered me is the huge lag it has from a stop. I read another thread on it from 2010 and everyone was giving him $#%^ about traction loss, turbo lag, heavier car, etc.

As far as I can tell it seems to be more related to the dtc system. In drive from a stop, you might have a 1/2-1 sec of delay from the time you hit the throttle till the car starts moving. Holding the brakes with a little throttle/rpm to spin the turbos up doesn't seem to help either so it's not turbo lag.

Dropping it into sport or M1 doesn't help but turning DTC off seems to shorten it some. It is very frustrating but it has always been this way.

I'm putting a JB4 on it next week but I don't expect that to make a difference. Have read about the known lag problem here but not sure if it is related.

Any intelligent suggestions? TIA

[Beemw335]

In drive the car never uses 1rst gear. From a stop its in 2nd.
Use ds (sport) and you should notice a difference.

[MrRetep]

Originally Posted by Beemw335

In drive the car never uses 1rst gear. From a stop its in 2nd.
Use ds (sport) and you should notice a difference.

"Dropping it into sport or M1 doesn't help"

To OP, the lag you are experiencing might be the Drive By Wire/Electronic Throttle control. I'm not sure but that's my best guess. I think the COBB has a way to adjust it to make it more responsive.

[Beemw335]

Originally Posted by MrRetep

"Dropping it into sport or M1 doesn't help"

To OP, the lag you are experiencing might be the Drive By Wire/Electronic Throttle control. I'm not sure but that's my best guess. I think the COBB has a way to adjust it to make it more responsive.

I did read the thread, and I explained to him that from d to ds IS AN IMPROVEMENT.
I could care less how op feels lag, te truth is starting off in 2nd gear opposed to 1rst is much slower to get moving and more "lag" per say.
Op at the end of the day the n54 is a turbocharged engine, no way to get around spooling up turbos, ds is as good as its gonna get.

[CitrusE92]

Originally Posted by Beemw335

I did read the thread, and I explained to him that from d to ds IS AN IMPROVEMENT.
I could care less how op feels lag, te truth is starting off in 2nd gear opposed to 1rst is much slower to get moving and more "lag" per say.
Op at the end of the day the n54 is a turbocharged engine, no way to get around spooling up turbos, ds is as good as its gonna get.

That's interesting info. 335 takes off like a monster in D... and it's second gear? I'm not doubting you, just kind of amazed.

I also notice that little bid of lag/delay/hesitation from normal standing start. I keep wanting to compensate with more pedal and end up with a not very smooth take-off.

[Beemw335]

Originally Posted by CitrusE92

That's interesting info. 335 takes off like a monster in D... and it's second gear? I'm not doubting you, just kind of amazed.

I also notice that little bid of lag/delay/hesitation from normal standing start. I keep wanting to compensate with more pedal and end up with a not very smooth take-off.

Obviously if you completely floor it, you hit the kickdown button and it down shifts to first.
But yes from d it starts in 2nd gear.

[AK 335i]

i never noticed this issue much but i tuned the car within a few weeks of buying it..
With the jb4 and my current setup, DS mode second gear launch on street tires, launching around 3K or so i hit 60 mph in 3.2-3.4 seconds based on the 1/8 mile time/mph calculators. I think once you tune it and launch in 2nd gear in DS mode with traction control fully off, youll be pleased

[Beemw335]

Originally Posted by smi1gj

i never noticed this issue much but i tuned the car within a few weeks of buying it..
With the jb4 and my current setup, DS mode second gear launch on street tires, launching around 3K or so i hit 60 mph in 3.2-3.4 seconds based on the 1/8 mile time/mph calculators. I think once you tune it and launch in 2nd gear in DS mode with traction control fully off, youll be pleased

Are you full bolt on+ meth with drag radials?
If not 3.2 seconds to 60 is impossible.

[AK 335i]

Originally Posted by Beemw335

Are you full bolt on+ meth with drag radials?
If not 3.2 seconds to 60 is impossible.

FBO street tires and No meth
don't say impossible

and i said "i hit 60 mph in 3.2-3.4 seconds based on the 1/8 mile time/mph calculators."
none of that shit is bombproof, but its damn fast


do the math first.

1/8th Mile Time: 7.65 in seconds
1/8th Mile Speed: 92.38 in MPH
Your 0 to 60 time is: 3.23

http://www.wallaceracing.com/0-60_equation.php

[lconn]

Going to DS helps a little but it is still there, my SL600 also started in 2nd so this is one of the first things I tried. Double push on DTC helps the most. Just installed a JB4, once I update the firmware I'll go over it again.

You notice something kinda similar when you floor the car while moving. The whole car spends about a second winding up before it does anything, then finally lets loose.

I'll play around with the tune and see if it helps any. Could be a boost issue but it happens even at low throttle settings where boost shouldn't be playing a part anyway. Since I can now see boost via JB4, we'll see. Its like all the squirrels have to run from the front of the car to the back before it'll go anywhere ;-)

Len

[lconn]

Well the JB4, even on old software, improves the problem quite a bit so it is probably related to throttle tip-in as the previous poster indicated. Much smoother to the point that if it had come this way, I probably wouldn't have noticed.

[shadow191]

Sorry to drag this back. But I'm having a similar issue with my '07. It's not turbo lag, it's just as if there's a delay between stepping on the throttle and movement. Like 1/2 second or so. Nothing to do with turbo spool or anything. Literally for that half second, nothing happens then the car gets going. Not a huge deal, but it's annoying when trying to get into traffic. I have a JB4 and that doesn't really help in my case.

Sometimes I end up giving it too much throttle and it takes off. Makes it hard to drive the car smoothly. Is there an issue w/ the electronics? My other car is an Infiniti FX and that car has 0 delay. Even though it's a much slower car overall, it could probably take the 335 up to about 20mph. However, on the newer versions of that car, there was an issue w/ the throttle delay and they recalled them and reprogrammed things, fixed it right away. Didn't know if there was something similar for the BMW.

[eyim1988]

hmm, are you turning traction off completely?
by holding the dtc button for 5 seconds?

[DuDai]

Pretty sure the lag these posters are referring to is just the DriveBYWire system. They're known for having a lag. Although i find it tends to make for extremely smooth take off if you don't romp on the gas. I've driven several Drive By Wire systems, a bunch of BMW's, Cadillac CTS, and my work truck 2010 GMC 2500HD, and they all experience this slight lag upon take off. It goes away if you really step on it, but if you just do a normal take off its a noticeable lag but makes for extremely smooth and gentle take off.

Call me crazy, but i thought i once read that was the purpose of this lag, for a smooth gradual take off. The computer for some reason puts the throttle on gradual. I know that some tunes remove this "feature" so its back to the normal way.

[ksalih]

Originally Posted by DuDai

Pretty sure the lag these posters are referring to is just the DriveBYWire system. They're known for having a lag. Although i find it tends to make for extremely smooth take off if you don't romp on the gas. I've driven several Drive By Wire systems, a bunch of BMW's, Cadillac CTS, and my work truck 2010 GMC 2500HD, and they all experience this slight lag upon take off. It goes away if you really step on it, but if you just do a normal take off its a noticeable lag but makes for extremely smooth and gentle take off.

Call me crazy, but i thought i once read that was the purpose of this lag, for a smooth gradual take off. The computer for some reason puts the throttle on gradual. I know that some tunes remove this "feature" so its back to the normal way.

+1111 this. My head was hurting reading all the "its Turbo lag" posts.

[shadow191]

I've tried turning DTC off, but it's still there. Plus it's a little irritating that you have to turn off traction control just to try and take off normally. I've owned several "drive by wire" cars and this is the only one I've had with this issue. Former IS350 had it at first, but after ECU adapted it went away. Only came back after resets, then it would go away. Current Infiniti FX, no issues with it. Didn't know if this issue would go away like it did on my Lexus.

Maybe I'm not describing it correctly, but it's not like throttle modulation for a smooth takeoff. It's more like for 1/2 a second, nothing happens then the car goes. It makes for a very jerky takeoff sometimes if you try to give it more gas to compensate. If I floor it, there is no delay.

[Spyjunior]

I know exactly what you're talking about! I describe it as a bit of a 'dead zone' in the throttle, right at the beginning of travel, and when it gets to the end of that dead zone, it's like a switch comes on, and the throttle kicks in too hard. It's almost like an on/off switch. It's definitely not turbo lag, because the turbos aren't involved at the low rpm off a stop. F'n annoying! And frankly, unacceptable. I'm looking for a fix too. Sounds like the Sprintbooster or tune. Ridiculous that we should have to even deal with this.

[deathbunny]

Mine does this too. I press the pedal and then a second later the car will respond to the pedal press and start moving. Its like it takes a second for the software to respond to the pedal press or for the transmission to do what ever it has to do to start you off and then it starts moving. It is a little better in DS but still there and it is annoying.

[KMEninety335]

from the looks of it, sprintbooster would be your best bet for that lag. Tunes might help a little

[E90Company]

Nature of the motor. The S65 will have much better throttle response than this car period. (Individual throttle bodies)

[shadow191]

What is the nature of the motor that causes this? The throttle body is electronic, not cable so they could program it just about any way they want. As I posted before, my other car is an Infiniti FX. N/A 3.5L V6 w/ electronic throttle body as well (no ITB's either). Incredibly responsive and linear throttle response. Tap on the pedal a little, car moves a little. You know exactly what is going on. On the 335, it's dip into the throttle...nothing happens...step on it harder, car jerkily takes off. There's almost no relation between your foot and the throttle response. It's most annoying when you slow down for a light and then get back on the gas before coming to a full stop. Then you have to deal with the transmission lag and throttle lag.

Originally Posted by E90Company

Nature of the motor. The S65 will have much better throttle response than this car period. (Individual throttle bodies)

[E90Company]

Originally Posted by shadow191

What is the nature of the motor that causes this? The throttle body is electronic, not cable so they could program it just about any way they want. As I posted before, my other car is an Infiniti FX. N/A 3.5L V6 w/ electronic throttle body as well (no ITB's either). Incredibly responsive and linear throttle response. Tap on the pedal a little, car moves a little. You know exactly what is going on. On the 335, it's dip into the throttle...nothing happens...step on it harder, car jerkily takes off. There's almost no relation between your foot and the throttle response. It's most annoying when you slow down for a light and then get back on the gas before coming to a full stop. Then you have to deal with the transmission lag and throttle lag.

Numerous factors. Bigggest factor of your specific comparison would be turbo vs NA. Taking turbo lag out of the equation for a moment, on the N54 air needs to get sucked in through small inlet tubes (2), pass through the compressor wheel, join the seperate air channels in through an intercooler biggest restriction right here), then up through a charge pipe that have diverter valves open at idle/until the TB opens and creates pressure in the intake manifold for the DV's to close. All of this signifigantly reduces throttle response as you would be used to in your comparo. All the NA motor has to do is open the TB and air goes straight into the combustion chamber. Adding turbo lag back into the equation, it makes it even worse.

Also, head design (N54's head flows very poor in comparison to say the E46 M3's S54), intake manifold design, and obviously electronic throttle tuning plays an important roll in throttle response.

This car is a DI motor (I don't think that Infinity motor is) so carbon caked on top of the intake valves will add to the delay you feel, among gearing differences as you mentioned (That's more how fast power can be put to the ground however)