[Proctor750]

Originally Posted by 3tekcorps

Feels like there's a lot of flex in the drivetrain to me. My 1st -> 2nd shifts are not very smooth when getting back into power like there's some excessive flex somewhere.

Anyone else have slopping 1st/2nd shifts? I've rowed a lot of gears in my life and don't recall this before.

I think the weak links are the front tension arm bushing (there are OE monoball replacements), the rear upper control arms (also rubber, also have monoball replacements) and the diff having not only 1 rubber mount for the rear but also the 4 in the front.

With everything else being balljoint and the subframe solid mounted that's where you will get slop. I also believe removing the inline clutch delay valve will help as well.

No evidence until I can swap everything out. I will update anything we find as time goes on. I'm currently having an existential crisis with the brakes..

[doughboy]

I think the 1st/2nd issue is because it has a pretty stiff drive train.

When i put stiffer box and rear subframe mounts on my 335i the 1st/2nd shift became tricky like this.

Yes m2c is not a race car but it's more rigid than 99% cars on the road.

I've driven manuals for 30 years too. Make the drive train more rigid will make it even harder to drive smoothly.

That's another reason i think auto rev match is always on because its quote hard to shift smoorhly without it unless you pay attention. Again due to relatively stiff drive train.

[M Fifty]

Originally Posted by Proctor750

I think the weak links are the front tension arm bushing (there are OE monoball replacements), the rear upper control arms (also rubber, also have monoball replacements) and the diff having not only 1 rubber mount for the rear but also the 4 in the front.

With everything else being balljoint and the subframe solid mounted that's where you will get slop. I also believe removing the inline clutch delay valve will help as well.

No evidence until I can swap everything out. I will update anything we find as time goes on. I'm currently having an existential crisis with the brakes..

And again with the M4 GT4 using exactly the same rear differential mounting - it also has ball-jointed rear suspension though.

https://www.realoem.com/bmw/enUS/sho...diagId=33_2148

If you're looking to minimise the effect off the line, some higher sidewall tyres may help, albeit at the expense of cornering grip.

[jeff4598]

I find running 36-38 PSI vs 33-35 strongly counters wheel hop tendency. Must be a resonance frequency effect.

[aerokubectl]

Originally Posted by M Fifty

If you're looking to minimise the effect off the line, some higher sidewall tyres may help, albeit at the expense of cornering grip.

Not that simple but if your going with that mindset might as wel start with non RFT

[M Fifty]

It doesn't have RFT anyway?

No it isn't, but more give in the sidewalls will still help.

[3tekcorps]

Originally Posted by doughboy

I think the 1st/2nd issue is because it has a pretty stiff drive train.

When i put stiffer box and rear subframe mounts on my 335i the 1st/2nd shift became tricky like this.

Yes m2c is not a race car but it's more rigid than 99% cars on the road.

I've driven manuals for 30 years too. Make the drive train more rigid will make it even harder to drive smoothly.

That's another reason i think auto rev match is always on because its quote hard to shift smoorhly without it unless you pay attention. Again due to relatively stiff drive train.

Are you having trouble with clean 1st/2nd shifts as well?

[CSBM5]

We've had no issue with smooth 1-2 shifts.

The only issue I'm not fond of is the torque management the DME does on a WOT hard acceleration to 7k in 1st and then upshift to 2nd sharply...instead of needing to manage the potential wheelspin in 2nd like every other high HP car I've driven the past 44 years, the S55 is tuned to have a huge decrease in torque output on that 2nd gear engagement. This is with DSC fully disabled of course, but it feels just like what would happen if DSC wasn't disabled in other cars except in those DSC would be very slow to return power whereas the S55 gets right back with the game. Nonetheless it feels awful. I suppose it protects 99% of the population nowadays who don't have a clue what happens in a high HP RWD car under such conditions... This isn't unique to the M2C as the M3/M4 apparently have similar tuning.

I'd prefer to be able to drive the real car and be responsible for managing the engine's output and tire's grip levels myself on that DSC off WOT acceleration quick 1-2 upshift, but it is what it is.

As and aside, in my now sold E39 M5 you'd better be ready to handle 2nd gear when you snap off a WOT run and the 1-2 upshift. A good friend of mine bought a wrecked E39 M5 from an insurance company and parted it. It was from a friend of his, and the owner had never turned off DSC. The first time he tried it, he hammered 2nd gear like he always did, immediately spun and hit a tree...so *that* is obviously the reason for such turning nowadays. So many drivers actually have no clue how to control a real car and have only experienced DSC inhibited responses.

My E90 M3 will bark the tires hard and lay down a good bit of rubber on a WOT 1-2 upshift run (DSC off of course), so I imagine there have been people wrecking these cars too by not understanding how to drive.

[M Fifty]

Reluctant 1st/2nd shifts - particularly when cold - are something I experience. Oddly, they get better if I make a point of spending time in 5th/6th when road and traffic conditions allow.

Reverse remains a great way of checking whether I did enough Core exercises...

[doughboy]

Yeah I'm not talking about nailing it WOT 1st to 2nd.

Just regular driving, 1st to 2nd is tricky, worse when cold. And you have to be quite precise with clutch release and throttle to avoid a jolting oscillation in the transmission, with passenger's heads nodding back and forth!

This is actually very similar to my e90 330i and e91 335i 6MTs, only more so.

I don't mind it all at all, I enjoy mastering it!

[Proctor750]

Originally Posted by doughboy

Yeah I'm not talking about nailing it WOT 1st to 2nd.

Just regular driving, 1st to 2nd is tricky, worse when cold. And you have to be quite precise with clutch release and throttle to avoid a jolting oscillation in the transmission, with passenger's heads nodding back and forth!

This is actually very similar to my e90 330i and e91 335i 6MTs, only more so.

I don't mind it all at all, I enjoy mastering it!

Could just be cold.

Once it's warm out i bet your issue is reduced significantly. Have you thought of removing the clutch delay valve?
It takes awhile to get used to another car's clutch and shifting until it's muscle memory. The cold compounds the issue.

[BlkSVT]

Originally Posted by M Fifty

Reluctant 1st/2nd shifts - particularly when cold - are something I experience. Oddly, they get better if I make a point of spending time in 5th/6th when road and traffic conditions allow.

Reverse remains a great way of checking whether I did enough Core exercises...

For reverse, sounds stupid, but just give it a good slap and should pop right past the "block". Getrag seems to use this in several of its MTs that I've driven rather than any other number of more common R lockouts

[3tekcorps]

Originally Posted by doughboy

Yeah I'm not talking about nailing it WOT 1st to 2nd.

Just regular driving, 1st to 2nd is tricky, worse when cold. And you have to be quite precise with clutch release and throttle to avoid a jolting oscillation in the transmission, with passenger's heads nodding back and forth!

This is actually very similar to my e90 330i and e91 335i 6MTs, only more so.

I don't mind it all at all, I enjoy mastering it!

That's exactly what I'm talking about. Maybe i'm not used to the torque or the bimmer rhythm, but it seems much tricker than it should to get a smooth upshift.

[doughboy]

Originally Posted by Proctor750

Could just be cold.

Once it's warm out i bet your issue is reduced significantly. Have you thought of removing the clutch delay valve?
It takes awhile to get used to another car's clutch and shifting until it's muscle memory. The cold compounds the issue.

It is much better when warm and it's only done 1000miles. Gearbox takes longer than the engine to warm up, cold weather doesn't help this time of year either. It's as if the synchro on 2nd is tight and it's takes a little longer to slot into second so you have to manage the rpm in the meantime and if you're not spot on it let's you know!

My wife's mK7.5 GOLF GTI 6MT is so forgiving it absorbs even the most ham fisted shifts without so much as a wobble, I much prefer the more demanding M2 though.

I removed the CDV on my 335i and that made things a lot better for smooth quick shifts, I might look into it again.

[doughboy]

Originally Posted by BlkSVT

For reverse, sounds stupid, but just give it a good slap and should pop right past the "block". Getrag seems to use this in several of its MTs that I've driven rather than any other number of more common R lockouts

Yep be positive with the shove, or I can't get it past the indent. Being RHD UK we have to push it away to our left, I think makes it more tricky than pulling it towards you on a LHD car. I had to use both hands for the first few days...

Maybe a muscle / movement expert can advise?

[M Fifty]

Leave the left hand on the wheel and use it to brace while pushing the gear lever with the right.

[Commanderwiggin]

Can the CDV be removed from the M2 Comp? I thought the M3/M4 had the CDV internal to the transmission.

In regards to shifting have you considered an Autosolutions SSK? They're made to order and on my E46 it was one of the best upgrades. Miles better than UUC/Rogue Offerings imo.

[doughboy]

https://www.realoem.com/bmw/enUS/sho...diagId=21_0271

Yup, looks like there is no discrete delay valve in the hydraulic line anymore like there used to be.

But really it's ok. The sticky 1-2 is in the box not the shifter. It's fine when warm.

[chris719]

CDV on my Z4M didn’t affect shifts really. It affected your ability to modulate it finely starting from a stop and in reverse. It was as recalcitrant as ever going into 2nd gear after it was removed.

[Proctor750]

Originally Posted by doughboy

https://www.realoem.com/bmw/enUS/sho...diagId=21_0271

Yup, looks like there is no discrete delay valve in the hydraulic line anymore like there used to be.

But really it's ok. The sticky 1-2 is in the box not the shifter. It's fine when warm.

I believe it's actually still present based on the list of vehicles which share the same slave cylinder. It's buried inside of the line itself.

Here is a thread of F30 guys with the same P/N slave cylinder removing theirs:
https://f30.bimmerpost.com/forums/sh....php?t=1486773

As for those with a sticky 1-2 shift when it's cold - have you tried just double clutching until the gearbox is warmed up?


Also from a previous post elsewhere:

[yahweh]

Probably M50 Swap, a diffsonline mechanical LSD diff, and you got a slam dunk.

[Proctor750]

Originally Posted by yahweh

Probably M50 Swap, a diffsonline mechanical LSD diff, and you got a slam dunk.

THERE HE IS. Post up that adapter you found