|
|
|
|
|
|
BMW Garage | BMW Meets | Register | Today's Posts | Search |
|
BMW 3-Series (E90 E92) Forum
>
Missed shifts - 6MT
|
|
05-10-2007, 12:36 PM | #1 |
Lieutenant Colonel
52
Rep 1,714
Posts |
Missed shifts - 6MT
Went to the drag strip for the first time yesterday. I'm normally a twisties guy so it was definitely a new experience to launch and just drive straight!
Out of the three runs I did, I blew my 1-2 shift in two of the runs! I somewhat forcefully move it into second at about 6000 rpms (didn't shortleg the clutch) and while the lever goes there, the gear doesn't engage. What gives? If I gingerly put it into second, it engages just fine. But when I'm trying to shift quickly, a ginger shift just doesn't seem effective. What causes missed shifts and more importantly, how do you avoid them? BTW - I'm in a 335i with 6MT and about 8000 miles. |
05-10-2007, 12:41 PM | #2 |
Private
9
Rep 85
Posts |
CDV
It's the clutch delay valve. It does not matter how fast you will try to shift, the CDV will only allow the fluid to move through it at it's rate.
Once you remove it, you will love your 6MT. |
Appreciate
0
|
05-10-2007, 12:44 PM | #4 |
Brigadier General
198
Rep 4,097
Posts
Drives: F30 328i
Join Date: Apr 2006
Location: Magic Mountain
|
ya do the cdv mod and youll be golden!!!!
shifting from 2 to 3 for me on teh drag strip is where i usually miss!!
__________________
|
Appreciate
0
|
05-10-2007, 01:10 PM | #7 |
Major
35
Rep 1,169
Posts
Drives: 67 GT500,69 Boss 429, 335i
Join Date: Sep 2006
Location: Houston,TX
|
Leftcoast - does it feel like your in gear pressing down the gas but the car isnt really going anywhere? Ive had this happen to me... gotta love shitty bmw clutches.
|
Appreciate
0
|
05-10-2007, 01:14 PM | #8 | |
Lieutenant Colonel
52
Rep 1,714
Posts |
Quote:
Presa - do the CDV delete. Never understood the bored out CDV. If your tranny blows, would you want to bank your warranty on BMW not peeking into the modified Zeckenhausen CDV? Or would you rather take 2 seconds and put the original CDV back in? |
|
Appreciate
0
|
05-10-2007, 01:21 PM | #9 |
Major
1014
Rep 1,268
Posts |
I have experience this too.
I have not been able to pin point exactly what causing this. Every once in a while, trying to hit second coming out of first it just does not engage it kind of sticks, something it misses totally other times it grines, and some times it partially engages and when you let the clutch you can feel the shifter fully engage. However, if you do not leave your hand on the shifter it will pop out. It happen going 2nd to 3rd some times too, but not as ofter, but never happens doing a down shift. I am thinking something is messed up with the synconizer. I never missed as many time as I have with this car, and I do believe the CDV has a little to do with it, but some times I really have to pull hard to get it into 2nd. |
Appreciate
0
|
05-11-2007, 11:09 AM | #10 |
Too many Alex's, from now on, call me Beaufort
342
Rep 6,188
Posts |
I firmly believe the syncros are off on the 1-2 shift. No matter how many people have the CDV, modded it, or deleted it, theres still a problem shifting fast. Going into any of the other gears 3-6 quickly isnt a problem. I still grind 2nd sometimes and I dont know why. The clutch is all the way down but its like it doesnt want to engage as quickly.
Id rather this than my fuel pump dying if theres a choice.
__________________
13 HD FatBob
17 A4 Glacier/Black 1st Edition/Pre+/Sport/EurocodeTMD/Racechip 16 S6 (gone),14 S6 (gone),14 S6 (gone),13 S6 (gone),10 S4 (gone) 07 335i(gone) |
Appreciate
0
|
05-11-2007, 11:20 AM | #11 |
Major
35
Rep 1,169
Posts
Drives: 67 GT500,69 Boss 429, 335i
Join Date: Sep 2006
Location: Houston,TX
|
Could a SSK help with this?
Mat |
Appreciate
0
|
05-11-2007, 11:29 AM | #12 |
Too many Alex's, from now on, call me Beaufort
342
Rep 6,188
Posts |
Maybe, but theres nothing officially made for our 6spd yet. From what I understand the B&M one has some fitment issues. Ill wait for Rogue or UUC to come out with theirs and then decide.
__________________
13 HD FatBob
17 A4 Glacier/Black 1st Edition/Pre+/Sport/EurocodeTMD/Racechip 16 S6 (gone),14 S6 (gone),14 S6 (gone),13 S6 (gone),10 S4 (gone) 07 335i(gone) |
Appreciate
0
|
05-11-2007, 11:40 AM | #13 |
Banned
330
Rep 1,134
Posts |
this is getting interesting. I have the CDV delete. But for some reason at higher revs, the car hates goign from 1st to 2nd, it almost forces me outta the gear, hell ill even put the lever in gear and sometimes you will hear grinding. So this is a comon issue?
|
Appreciate
0
|
05-11-2007, 11:45 AM | #14 |
Captain
72
Rep 613
Posts |
Get the steptronic....problem solved. j/k
You need to put some force/effort in changing your gears quickly...don't baby it...you won't break anything so don't worry. in my previous car (2003 M3), it supposedly had the CDV but I never had a problem doing very quick shifts. |
Appreciate
0
|
05-11-2007, 11:47 AM | #15 | |
Banned
330
Rep 1,134
Posts |
Quote:
|
|
Appreciate
0
|
05-11-2007, 11:49 AM | #16 | |
Too many Alex's, from now on, call me Beaufort
342
Rep 6,188
Posts |
Quote:
Yes.
__________________
13 HD FatBob
17 A4 Glacier/Black 1st Edition/Pre+/Sport/EurocodeTMD/Racechip 16 S6 (gone),14 S6 (gone),14 S6 (gone),13 S6 (gone),10 S4 (gone) 07 335i(gone) |
|
Appreciate
0
|
05-11-2007, 11:50 AM | #17 |
Lieutenant Colonel
50
Rep 1,600
Posts
Drives: e90 335i
Join Date: Aug 2006
Location: SoCal
|
|
Appreciate
0
|
05-11-2007, 11:54 AM | #18 | |
Captain
57
Rep 879
Posts |
Quote:
|
|
Appreciate
0
|
05-11-2007, 11:56 AM | #19 |
Colonel
76
Rep 2,104
Posts |
slip?
__________________
SaaS - The world of tomorrow is already here...www.saaschronicles.com |
Appreciate
0
|
05-11-2007, 12:02 PM | #20 |
Lieutenant Colonel
58
Rep 1,906
Posts
Drives: black 335i e90 PRE-LCI
Join Date: Apr 2006
Location: somewhere
|
i've had this problem before, but once i did the modified CDV, in my case.....my shifting has became not only smoother but quicker throughout all the gears...
__________________
|
Appreciate
0
|
05-11-2007, 12:18 PM | #21 | |
Lieutenant Colonel
52
Rep 1,714
Posts |
Quote:
I'm going back next week. Twas my first time at a drag strip. I'm thinking mid 13s with a proper launch. Hell I'd be super stoked to get 13.9x that here at 6,000 feet. Might even try starting in 2nd since the track is a bit slick. BTW - I have found that finger-shifting (gentle) is less likely to cause a missed shift than palm-shifting (forceful). To be honest, the challenge of properly launching a 6MT is appealing to me. No grandma-appropriate 6ATs here! Just kidding, fellas. |
|
Appreciate
0
|
05-11-2007, 02:03 PM | #22 | |
Lieutenant Colonel
50
Rep 1,600
Posts
Drives: e90 335i
Join Date: Aug 2006
Location: SoCal
|
Quote:
|
|
Appreciate
0
|
Bookmarks |
|
|