[3002 tii]

Just wondering how trackable the Xi is with 6MT? What’s your experience been on road courses?

[martinm0]

Originally Posted by 3002 tii

Just wondering how trackable the Xi is with 6MT? What’s your experience been on road courses?

For me personally, I struggle with any level of consistent hard shifting with my 328xi. If I go slow and only get on the gas once I have fully disengaged the clutch, I can shift consistently. But if I hammer it and rev high and shift hard, I get all kinds of rubber band type of effect in the drive train that makes it impossible to keep momentum and control. I even feel like if I just drive in high RPMs the drivetrain gets all loaded up and jerky. The clutch also just doesn't bite hard enough I swear it feels like it slips if I come off the clutch and gas it at the same time. The clutch does not slip if I floor it in 4th gear or so.

Note that I have replaced the CDV with the M3 version and I have Koni Yellows with the Monroe upper shock mount kit.

The drivetrain is the single most distracting issue for me in my car. I would love to figure out if this is something I can fix (SMF conversion, subframe bushings, TC mount, etc). If anyone has experienced this and corrected it, please help me understand what I should be checking. Car is 2008 328xi 6MT with 50k miles.

[atmosphericM]

Martin, I have similar experiences regarding the clutch with my RWD, however my clutch might just be on the worn side (shouldn't be, but who knows). It's the original clutch, 30,000 miles, so should be good, but I have zero knowledge regarding the MT driving competence of the previous owner. Whenever I 'test' the clutch it seems to grab well enough, well.. I guess it performs as I'd expect for a soft OE clutch coupled with a DMF, however if I go out and do some hard driving for a little while, the clutch really FEELS like it's slipping just a little at times when 'softly launching' from stops.

FTR, my method of testing for a super-worn clutch (my method may very well only find problems when a clutch is REALLY on it's way out) is by slightly engaging the clutch pedal while also giving heavy throttle so that I *force* it to slip, all while traveling at around 50 MPH. If I let off the clutch pedal and it seems to quickly grab, all while I'm giving it a lot of throttle, I deem the clutch to be 'ok'. If the clutch is on its way out, at least in my experience, it won't want to grab and the throttle will either hang or keep climbing. even after fully letting off the clutch pedal. This method does seem to predict total clutch failure before one can tell from normal driving conditions (such as it slipping when normally accelerating from a stop).

[hassmaschine]

you can also try starting from a higher gear, like 3rd gear - a good clutch will bog and/or stall, a bad clutch will slip.

[martinm0]

Originally Posted by hassmaschine

you can also try starting from a higher gear, like 3rd gear - a good clutch will bog and/or stall, a bad clutch will slip.

This has been my test to see in the clutch is going bad. It definitely bogs down for me and doesn't slip during the test.

But let's keep this discussion going as it is something that makes me want to sell my car and get something else since it is so frustrating and ruins the driving experience for me.

My issues are that the car just doesn't rev freely. I know, I know - it's not an M3. The DMF is heavy and is not meant for fast revving. I have to give the car quite a bit of throttle (I feel), and when the revs are above 3k rpms, I swear things just don't feel right and get a lot of lash in the drive train. My gut tells me to swap out the DMF for a SMF as when I come off the clutch the car almost loses revs for a second and the whole car loses momentum, like a pendulum swinging back. Sometimes when I come to stop at a light the revs dip ever so slightly as if the flywheel got out of balance/rotation. The car will also rock side to side a little too at startup here and there (maybe motor mounts, but they seemed in fair condition).

atmosphericM - does any of this happen to you? I actually have not driven as RWD BMW outside of my E36 M3, so I can't really compare. I assume having to send power to a front diff adds some complexity to the comparisons.

Let's keep this going! Thanks in advance!

[atmosphericM]

Hmm. I'm not sure if I understand all you are saying.

My car does seem to 'rev up' pretty quickly (while in neutral) compared to other, more "normal" cars. But of course, the electronic throttle requires a good press of the pedal. I don't see any reason as to why your car would behave differently, because this action only involves the engine and flywheel. Sure, a SMF would probably let it rev a bit more freely, but I doubt the difference would be noticeable, tbh.

Now if you are talking about it revving freely while driving.. sure, you have more drive-train than I do, and I bet yours does feel different, at least slightly, even if all was functioning properly (as new). Perhaps there are some bushings, etc. in the drivetrain that can be replaced (like the GUIBO)? Not sure of your mileage..

My guess is that the nature of AWD is what you're experiencing. No offense meant at all, but an AWD BMW was never something for me. I'm not saying it isn't a great car, or a great AWD system (I really have no idea), but I'm not in an area that merits AWD, and even if I was, personally I'd go Quattro or Subaru (if not a truck), most likely. That said, I'm sure the car is a great car, and I'm sorry to hear about your troubles/annoyances. Hopefully they can be mitigated at least to some extent.

My drivetrain in the upper RPM's is very smooth actually. There is some slight lash at times, such as when letting off throttle after heavy accelerating to 6,000+ RPMs, for example, but that's completely normal in my book.

Sometimes when I come to stop at a light the revs dip ever so slightly as if the flywheel got out of balance/rotation.

This is completely normal, I believe. I think it's just the weight of the flywheel dragging down the revs below redline a bit.

[dwashy]

Originally Posted by martinm0

My issues are that the car just doesn't rev freely

Things that will help and you probably already know:

• headers
• tune
• diff with higher gearing (see here for xi)
• 3 stage intake

Easiest and cheapest out of these all will likely be the diff

EDIT: Oh, and MILVs help with power/torque everywhere once they are installed and you have the tune