|
|
SUPPORT ZPOST BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER, THANKS! |
Post Reply |
|
Thread Tools | Search this Thread |
07-28-2020, 06:39 AM | #1 |
Private First Class
23
Rep 111
Posts |
2gear problem at the track?
I’m lucky enough to live 5 minutes from the bmw performance center in South Carolina and we had an autoX this past Saturday. It’s one full lap at the time format. My car didn’t want to downshift to second coming from third several times. It got better with heel and toe but still felt weird. It worked fine on my way home.
There was another Z4M roadster at the track and he also experienced the same. I’m using Redline with less than 4,000 miles on it considering swapping that to Motul. Any other suggestion/experiences with the second gear? |
07-28-2020, 12:04 PM | #2 |
Midlife Crises Racing Silent but Deadly Class
1827
Rep 5,337
Posts
Drives: 2006 MZ4C, 2021 Tesla Model 3
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day
|
This autocross course required a shift to third? Must be a long straight.
2nd gear synchro has always been wonky on this car, but I've never had an issue when heel-toe properly to get it down from 3rd into 2nd. The 1st to 2nd shift has always been the harder of the two shifts. I've had the OE fluid, Redline, and then Motul, and I can tell you the fluid doesn't make enough of a difference to justify IMO. In my experience, the 2nd gear synchros work better when engine speed is higher than output shaft speed, i.e. the RPM needs to be higher when clutched in to facilitate a smooth 3rd to 2nd downshift.
__________________
Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
|
Appreciate
0
|
07-28-2020, 12:41 PM | #3 |
dances with roads
5026
Rep 4,121
Posts |
I've had what I've heard called "2nd gear refusal" when downshifting under high stress situations. I've been shifting gears for over 50 years so I don't think it's me. I put a Autosolutions short shift kit in, and no more refusal.
|
Appreciate
0
|
07-29-2020, 01:13 PM | #4 | |
Major
368
Rep 1,379
Posts |
Quote:
__________________
07 Z4 M Coupe AW/IR |
|
Appreciate
1
3002 tii2387.00 |
08-05-2020, 08:30 PM | #6 | |
dances with roads
5026
Rep 4,121
Posts |
Quote:
I’ve seen instructions where they did not drop the exhaust. I was pulling the gearbox out anyway so I can’t comment on how that might go. |
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|