Dct vs 6mt turbo lag?

[1Hokie]

So.. I have a 2010 z4 35i dct and my gf has a 2011 35i 6mt.

In sport mode on my car I put it in manual mode. If I go hard on the gas there's a distinct turbo lag. Like it takes almost 2s to feel it pull.

Her car doesn't show any lag at all. Can go from no throttle to nearly full throttle in the same gear I tried on my dct

It's my first dct. Is this normal or should I get it serviced?

I have a jb4 but disabled or map 1/5 is the same. I also put on a cp and bov but I thought that would help the lag.

If I watch my boost gauge on my jb4 app. It spikes hard

If i feed it some gas to spool up the turbo then gun it. It's fine. But it's nothing like the 6mt

Halps!

[SpikeMilligan]

That may not be turbo lag you're experiencing.

It may be that the throttle body needs to be reset - the car "learns" your driving style an adjusts to it. I notice that I often drive the DCT more gently than I would a manual transmission, so the car begins to expect that.

Instructions for resetting the throttle body here: https://video.search.yahoo.com/yhs/s...7c&action=view

[1Hokie]

Originally Posted by SpikeMilligan

That may not be turbo lag you're experiencing.

It may be that the throttle body needs to be reset - the car "learns" your driving style an adjusts to it. I notice that I often drive the DCT more gently than I would a manual transmission, so the car begins to expect that.

isn't sport mode supposed to alleviate this? i thought that was its purpose..

also i noticed if i floor it, sometimes itll take the 2s to get full boost, then pull, but then spike down and up again like it lost boost

[jparnes1]

Originally Posted by 1Hokie

isn't sport mode supposed to alleviate this? i thought that was its purpose..

also i noticed if i floor it, sometimes itll take the 2s to get full boost, then pull, but then spike down and up again like it lost boost

Are you talking about turbo lag or throttle response? The best throttle response is going to be either with a 6MT or DCT shifted manually (not just throwing the shift lever to the left into sport mode, but actually shifting manually). You can't get away from the minimal turbo lag in the N54 or 55 but the throttle response can be greatly improved in any car with an automatic tranny by shifting manually.

[1Hokie]

Originally Posted by jparnes1

Are you talking about turbo lag or throttle response? The best throttle response is going to be either with a 6MT or DCT shifted manually (not just throwing the shift lever to the left into sport mode, but actually shifting manually). You can't get away from the minimal turbo lag in the N54 or 55 but the throttle response can be greatly improved in any car with an automatic tranny by shifting manually.

So even in sport and manual mode. If I'm in 3rd about to floor it. I floor it, it slowly accelerates for two secs then I see the boost gauge fill up then pull. I can do the exact same thing at the same speed with my gfs 6mt and it pulls right away. So both at a rollin start. About 35-40mph. Both let off the gas completely before flooring it. Completely different results. The car accelerates on dct but doesn't pull for 2s and my jb4 is showing no boost until then

[jparnes1]

Originally Posted by 1Hokie

So even in sport and manual mode. If I'm in 3rd about to floor it. I floor it, it slowly accelerates for two secs then I see the boost gauge fill up then pull. I can do the exact same thing at the same speed with my gfs 6mt and it pulls right away. So both at a rollin start. About 35-40mph. Both let off the gas completely before flooring it. Completely different results. The car accelerates on dct but doesn't pull for 2s and my jb4 is showing no boost until then

Well I can't speak relative to your tune. Maybe your jb4 is messing up. But you have to compare apples to apples. Your car is tuned and your gf's isnt. When I had a DCT I didn't notice the degree of lag you're describing when driving in manual. If you're flooring it and going past the detent with the pedal, it's going to take the ECU a little time to figure out what you're trying to do and adjust the car's response. For all the reasons we're talking about, I'm happier with my 6MT.

[1Hokie]

Originally Posted by jparnes1

Well I can't speak relative to your tune. Maybe your jb4 is messing up. But you have to compare apples to apples. Your car is tuned and your gf's isnt. When I had a DCT I didn't notice the degree of lag you're describing when driving in manual. If you're flooring it and going past the detent with the pedal, it's going to take the ECU a little time to figure out what you're trying to do and adjust the car's response. For all the reasons we're talking about, I'm happier with my 6MT.

It aws happening before my jb4. I installed jb4 hoping it would help

[hooolala]

I have the same problem. If I drive 70mph (6th gear in sport mode) and floor it, the transmission drop to 3rd gear and the RPM goes up to about 5000RPM (if I remember correctly). The car accelerates, but full boost comes 2~3 secs after the gear change. Not sure if that turbo lag or something else.

[1Hokie]

Originally Posted by hooolala

I have the same problem. If I drive 70mph (6th gear in sport mode) and floor it, the transmission drop to 3rd gear and the RPM goes up to about 5000RPM (if I remember correctly). The car accelerates, but full boost comes 2~3 secs after the gear change. Not sure if that turbo lag or something else.

are you running jb4 as well? i been playing with it and did a throttle body reset, which seemed to fix it if i turn of the jb4 in map0, but map 1 or 5, its completely wonky if it has to force downshift after it clicks on full throttle... if i go hard on the throttle without clicking, it is somewhat okay

[hooolala]

I had jb4 Before, now running MHD. Same problem on both setup.

[jts1981]

Are you guys hitting the kick down switch by flooring it all the way?

I think it's the dct trying to Rev match in the best gear. I also suspect that if you are in comfort, or sport + the dsc maybe kicking in to eliminate wheel spin. Try with the dsc fully off.

[hooolala]

Here is a video I just record, you can see after I floor it, the RPM stay at 5000 for like 1~2 seconds before the boost kick in.