[RElias21]

My e92 335 is 6MT and is currently FBO and protuned for 93Oct with PTF. I also have the CDV mod done.

Now that the car is much faster, I notice a "significant" shift bog when I am pushing it and try to shift very quickly. I usually feel it the most between 2-3 and 3-4. (Obviously "significant" is subjective to me)

Though possible, I don't think it's my clutch slipping because I feel like the rpm's grab right after I shift. It just feels like the car is delayed in throttle response right after I shift.

I've been searching this issue, and can't seem to find an answer that I really understand. I feel that if I was able to solve this issue, it would be equivalent to a major power upgrade, because I definitely lose ground when shifting.

Any thoughts on how to address this?

[2jzn54]

post a few logs so we can see

[335NJ]

This may relate back to the post shift timing drops we have. I have a similar issue as well, where at WOT, if I'm hammering through gears, it does lag noticeably, but if I got WOT, and shift gently into the next gear it seems to not lag so much when I get back on the gas.

No-lift shifting has been kicked around as a plausible helper in this scenario. Post some Datazap links if you can.

[RElias21]

Originally Posted by Daily Three

post a few logs so we can see

Originally Posted by 335NJ

T Post some Datazap links if you can.

How about we start with:
(1) What measurements should I have my AP set to read
(2) I should log through the shifting, correct?
(3) How do I post logs here?

[2jzn54]

idr what the values show up as in the cobb.. but essentially we want to see target and actual boost, afr, ignition advance, fuel trims, rpm, throttle/load.

attach a csv, graph, or use datazap

[Myrder]

There is no perfect fix so far other than doing a protune with someone I hear. Even they the post-shift timing drop can still happen... problem with the DME...

[335NJ]

Originally Posted by Ragi Elias

How about we start with:
(1) What measurements should I have my AP set to read
(2) I should log through the shifting, correct?
(3) How do I post logs here?

I don't know much about the accessport. But, you want to get a full rpm range of 3rd and try to get the first couple thousand of 4th.

If you can't do that safely because of how fast you'll likely be going then, do 2nd to 3rd at WOT.

Goto Datazap.me (website) and create an account, then upload the log file from your computer after transferring it from the AP.

[Kennybar112]

I am having the same issue with my e92. When I change gear quickly in lower rpms there seems to be a lag. I thought it might be the xdrive or turbo lag. Higher rpms no so much.

[NA55]

What rpm are you shifting at?

[jeffblue]

Shift no higher than like 62/6300. Turn traction control completely off. Problem solved.

Even on 335xi the traction control makes the car bog without any 'slip' light coming on. Shifting at high rpm like near 7k u will always bog on fast shifts. No real reason to shift that High anyway on a Stock turbo car. Our cars fall off up top anyway

[blisstik]

Originally Posted by jeffblue

Shift no higher than like 62/6300. Turn traction control completely off. Problem solved.

Even on 335xi the traction control makes the car bog without any 'slip' light coming on. Shifting at high rpm like near 7k u will always bog on fast shifts. No real reason to shift that High anyway on a Stock turbo car. Our cars fall off up top anyway

Yes even on stock car this happens, that lag feeling. But it all goes away after holding the magical DTC button.

[DuDai]

Power shift and keep your foot planted while shifting. It solves it no lie. Lol. Only do that if you don't care about your clutch though.

I find shifting around 6000 and just shifting slightly slower helps as well.

[RElias21]

Originally Posted by jeffblue

Shift no higher than like 62/6300. Turn traction control completely off. Problem solved.

Even on 335xi the traction control makes the car bog without any 'slip' light coming on. Shifting at high rpm like near 7k u will always bog on fast shifts. No real reason to shift that High anyway on a Stock turbo car. Our cars fall off up top anyway

Originally Posted by blisstik

Yes even on stock car this happens, that lag feeling. But it all goes away after holding the magical DTC button.

I do have an Xdrive, so I never thought I needed to turn DTC off. The yellow light usually doesn't flash. I'll try it and see. I would be very pleasantly surprised if the post-shift bog decreased just by turning DTC off.

[jeffblue]

Originally Posted by Ragi Elias

I do have an Xdrive, so I never thought I needed to turn DTC off. The yellow light usually doesn't flash. I'll try it and see. I would be very pleasantly surprised if the post-shift bog decreased just by turning DTC off.

yea but you also want to shift at like 6k ish. this is with DCT completely off shifting at around 6k

https://www.youtube.com/watch?v=K50qvq072JE#t=16

[RElias21]

I just wanted to update that I finally got a chance to go WOT earlier today with DTC completely off, and I did notice a significant improvement in shifting. Clutch grabbed well and the car just kept going.

Thanks guys.

[Dmacc]

Originally Posted by Ragi Elias

I just wanted to update that I finally got a chance to go WOT earlier today with DTC completely off, and I did notice a significant improvement in shifting. Clutch grabbed well and the car just kept going.

Thanks guys.

Good to hear but sadly there is still an issue with post shift bog even with traction off for MT guys.

[Blaizon]

Originally Posted by Dmacc

Good to hear but sadly there is still an issue with post shift bog even with traction off for MT guys.

Most definitely!

[trinx335i]

ive had the same issue feels like the boost dies out and spools up again seconds later.