[clivem2]

Originally Posted by corn18

It's not turbo lag, it's the computer dumbing things down. When I bought our X3 M40i, it was a rocket. Over time, it became a dog. Then I towed a 5,000 lbs trailer over 20 hours. When I dropped off the trailer, the first words out of my mouth were "holy shit!". The X3 was back! Now a month later it has become boring again. Not sure why BMW has installed an old lady algorithm, but when it is new, it is faaaaaaaast.

Can you be sure this isn't down to your loving the boost in performance with the trailer unhitched?

I remember when I had a 1.6 litre car with a turbo (1980's...). If I wanted to overtake I needed to drop couple of gears, hold the revs then whoosh. Lag was more like 2 seconds.

[corn18]

Originally Posted by clivem2

Can you be sure this isn't down to your loving the boost in performance with the trailer unhitched?

I remember when I had a 1.6 litre car with a turbo (1980's...). If I wanted to overtake I needed to drop couple of gears, hold the revs then whoosh. Lag was more like 2 seconds.

Who knows. Qualitative observations can be flawed and vary drastically by observer. All I know is the car changes over time and not for the better. This has been discussed myriad times here on BP.

[scotthilly]

Originally Posted by BMWGuySweden

I don't think it's turbo lag. I think it's the gear box. Everyone is praising the ZF gearbox but I actually am not thrilled with it. I think it's bmw that was forced to program it to be in the highest gear possible for emission purposes. When you want immediate power then it needs to shift down one or two gears and then you get the push. I find the car much more punchy if you use the paddle shifters or have the gear lever in sport mode. Then there is no lag at all.

It's actually just the BMW tuning of the ZF8. I switched from a 340i to an Alfa Romeo Stelvio and it's so much better I can't even begin to describe. We've got an X1, too (Aisin, not ZF) but it seems to alwasy be wrong for me - BMW's are too comfort oritented, tranny wise, in comfort, and overly sporty in sport. There needs to be an in between.

[satz]

Originally Posted by corn18

It's not turbo lag, it's the computer dumbing things down. When I bought our X3 M40i, it was a rocket. Over time, it became a dog. Then I towed a 5,000 lbs trailer over 20 hours. When I dropped off the trailer, the first words out of my mouth were "holy shit!". The X3 was back! Now a month later it has become boring again. Not sure why BMW has installed an old lady algorithm, but when it is new, it is faaaaaaaast.

Agree...apparently the BMWs with electronic throttle have this 'learning' inbuilt that supposedly learns the driving patterns. Probably to smooth out the acceleration/improve economy/reduce emissions, etc

Trouble is, if you're on a longish drive and suddenly need a quick burst of speed (and honestly...who doesn't just for fun at least....), the ECU has learned the 'long cruise/steady speed' mode, and so delays the response to throttle.

It could also be some turbo lag in there to compound the delay.

Okay..in all honesty it's not that long a delay in real terms, but when you want/expect a quick response, even 0.5 - 1 second seems like an eternity.

On my 335i that delay often meant almost getting hit by a car when I merged and couldn't get up to speed quickly enough.

(And to be honest, I never felt the stock N54 engine was as powerful as people seemed to make out).

[Douggie]

Originally Posted by corn18

It's not turbo lag, it's the computer dumbing things down. When I bought our X3 M40i, it was a rocket. Over time, it became a dog. Then I towed a 5,000 lbs trailer over 20 hours. When I dropped off the trailer, the first words out of my mouth were "holy shit!". The X3 was back! Now a month later it has become boring again. Not sure why BMW has installed an old lady algorithm, but when it is new, it is faaaaaaaast.

Yep, it's definitely not turbo lag. The modern turbos push pressures at below 2K RPMs. It's the throttle/transmission adaptation logic that they use that adds another "brain" between the gas pedal and the engine.

There are ways to force reset the adaptations. The other way is to drive it aggressively once in a while, forcing lots of downshifts.

[Alias1431]

Originally Posted by corn18

It's not turbo lag, it's the computer dumbing things down. Not sure why BMW has installed an old lady algorithm, but when it is new, it is faaaaaaaast.

How do I kill it?

[Alias1431]

Originally Posted by Douggie

Yep, it's definitely not turbo lag. The modern turbos push pressures at below 2K RPMs. It's the throttle/transmission adaptation logic that they use that adds another "brain" between the gas pedal and the engine.

There are ways to force reset the adaptations. The other way is to drive it aggressively once in a while, forcing lots of downshifts.

Can you code a "brain" wipe every startup?

[Alias1431]

Originally Posted by scotthilly

It's actually just the BMW tuning of the ZF8. I switched from a 340i to an Alfa Romeo Stelvio and it's so much better I can't even begin to describe. We've got an X1, too (Aisin, not ZF) but it seems to alwasy be wrong for me - BMW's are too comfort oritented, tranny wise, in comfort, and overly sporty in sport. There needs to be an in between.

Will xHP trans tune fix this? Or BM3 tune? I read somewhere recently that BM3 also tunes your tranny, but perhaps not as much as an xHP tune. Is this true?

[Douggie]

Originally Posted by Alias1431

Can you code a "brain" wipe every startup?

I doubt you can do it to the car, but you can always "code" your own brain to do the reset sequence everytime before going off

[tonyb15re]

you can also consider getting your gearbox coded with the Alpina Software by your local coding specialist.

This post is old but gives you an idea

https://f30.bimmerpost.com/forums/sh....php?t=1422733

[satz]

Originally Posted by Alias1431

Will xHP trans tune fix this? Or BM3 tune? I read somewhere recently that BM3 also tunes your tranny, but perhaps not as much as an xHP tune. Is this true?

I tried the xhp tune on my 6-spd 335i. Wasn't impressed.
The only tangible benefit I found was being able to see the gear number displayed on the instrument panel.

I know this is a totally different car, so xhp might work better?

[strohw]

My F-pace S would do this. If you're driving along and gave it the beans it would take a second and rev way up and then go. The delay was so annoying. If you put the transmission into sport mode it was better but it would still do it. The X3M I have now just goes. You hit the gas on the expressway to pass and there is 0 delay. It's one of the most obvious differences outside of the extra power.

[clivem2]

For satz who said the revs jumped immediately too 5k but there was no push this must have been turbo lag not trani lag.

For a lagging trani does using the kickdown switch help?

[satz]

Originally Posted by clivem2

For satz who said the revs jumped immediately too 5k but there was no push this must have been turbo lag not trani lag.

For a lagging trani does using the kickdown switch help?

Hi Clive, i tried that as well. I guess the delay is about the same using the kickdown.

I still wonder whether it's really turbo lag as it's a fairly large engine, smallish turbo and modern technology. And not an exorbitant power output. Also, it's like a switch when the power does come on, rather than a soft-ish build up of power.

I'm curious that the X3M doesn't do that according to strohw

[strohw]

My main point was that my F-pace did the same thing and that has a supercharged 3.0L engine but it also used a ZF8. If you fed in a lot of throttle while you were moving it would just rev up and not doing enough and then it would take off. I just believe the transmission was sitting in too high of a gear most of the time to make that kind of throttle input work. Instead of feeding in power and shifting it would rev up, then shift down a few gears and then go. If you manually controlled the engine it would never do it.

It doesn't help that I believe the Jag tuning of the ZF8 in their SUVs isn't as good as BMW. It's very obvious it isn't as good as the setup in the X3M. I only test drove a 40i for like 10 minutes so I don't have good experience with that one to compare.

[Tubes23]

Its likely to be Throttle Adaption that impacts almost all auto BMW's.

Procedure is a bit hit and miss with regards to success but the procedure goes like this:

- Put the power on but do not start the engine.
- Floor the throttle for 30-60 seconds
- Keep the throttle to the floor and put the power OFF
- Release the throttle and wait 2 minutes.

During the 2 minutes you should feel or hear some kind of mechanical sound. That should tell you the reset is complete.

[Alias1431]

Does tuning get rid of throttle adaptation?

[satz]

Originally Posted by Tubes23

Its likely to be Throttle Adaption that impacts almost all auto BMW's.

Procedure is a bit hit and miss with regards to success but the procedure goes like this:

- Put the power on but do not start the engine.
- Floor the throttle for 30-60 seconds
- Keep the throttle to the floor and put the power OFF
- Release the throttle and wait 2 minutes.

During the 2 minutes you should feel or hear some kind of mechanical sound. That should tell you the reset is complete.

I used to use this procedure on my E90 335i automatic, but would these same steps be okay on a G01 X3?

I don't know why exactly, but I think there's something different in the Start/Stop button press sequences on this car? I think it's one press to 'ignition', and then next press to start?

[titomi]

Originally Posted by satz

I used to use this procedure on my E90 335i automatic, but would these same steps be okay on a G01 X3?

I don't know why exactly, but I think there's something different in the Start/Stop button press sequences on this car? I think it's one press to 'ignition', and then next press to start?

If I remember correctly, the procedure here should be:
1. pres start button (engine is off)
2. push gas pedal all the way down past the kickdown point for 30 seconds
3. release the pedal
4. use your car normal way

[Tubes23]

Originally Posted by titomi

If I remember correctly, the procedure here should be:
1. pres start button (engine is off)
2. push gas pedal all the way down past the kickdown point for 30 seconds
3. release the pedal
4. use your car normal way

Could well be, i imagine it varies between cars but that's how it was done on my M240 & M2.

[freshxdough]

Originally Posted by Tubes23

Its likely to be Throttle Adaption that impacts almost all auto BMW's.

Procedure is a bit hit and miss with regards to success but the procedure goes like this:

- Put the power on but do not start the engine.
- Floor the throttle for 30-60 seconds
- Keep the throttle to the floor and put the power OFF
- Release the throttle and wait 2 minutes.

During the 2 minutes you should feel or hear some kind of mechanical sound. That should tell you the reset is complete.

Fyi I know people say that this "throttle adaption clearing procedure" works but I can say with 100% certainty that there is no documentation provided from BMW that states this is a way to clear throttle adaptations. I honestly don't know where people got this from.

The only way to clear adaptations is to use the service function in the DME.

[msg617]

We're lucky to have expertise from @freshxdough; otherwise we'd be stuck with anecdote.