[alexg212]

Originally Posted by Christian87n

Hello all!

I acquired a beautiful 2012 BSM 335is with DCT about a month ago. I've enjoyed the car so far. I have a few questions though. I've noticed on two different occasions that the rpm indication will drop to almost zero while braking to a stop. The car doesn't feel like it's about to stall or doesn't shake. It just drops to almost zero and comes back to the usual idle RPM. The other thing I noticed today was while on manual mode (can't remember if I had sport activated or not, I think I did) was the RPM would bump up maybe 100-200 rpm or so while up shifting. I had about 50% throttle, shifting at 2000rpm. Didn't feel any lurch or power loss, just noticed the slight jump in RPM. Has anyone else seen this? Going out of town tomorrow, otherwise I'd make an appointment with the dealership.

The other issue, but I blame the cold weather, is the increased battery discharge message. It only occurs during cold temps. These last few days, the temp has been above 50F, and it hasn't appeared.

Is it really almost zero? Rpms dropping when braking is normal, but not that low. Since its dct, it's acting like someone is slipping the clutches. And sport mode keeps the rpms high, as it is much more aggressive throttle and shift mapping. See if the rpms drop when in sport mode.

And the battery, the lifespan when coded/registered correctly is usually 5+ years. Assuming it's being driven. Unless it's super cold, like 0 degrees, I don't think it should cause issues. Especially since our batteries are enclosed and not open.

[Christian87n]

Originally Posted by alexg212

Is it really almost zero? Rpms dropping when braking is normal, but not that low. Since its dct, it's acting like someone is slipping the clutches. And sport mode keeps the rpms high, as it is much more aggressive throttle and shift mapping. See if the rpms drop when in sport mode.

And the battery, the lifespan when coded/registered correctly is usually 5+ years. Assuming it's being driven. Unless it's super cold, like 0 degrees, I don't think it should cause issues. Especially since our batteries are enclosed and not open.

Both times I had the rpm issue, it dropped below 500rpm, according to the needle. The needle itself was almost at zero, and then quickly back to idle, almost as if it was playing catch up. No pre-stall shudder or anything. I wondered if it was slippage like you said, but wasn't sure. Thinking back on when it happened today, I was on manual mode with sport activated.

Edit:both times that this has happened, I quickly braked to a stop. Both times for a yellow turning to a red quicker than anticipated.

[boostE92d]

Originally Posted by Christian87n

Both times I had the rpm issue, it dropped below 500rpm, according to the needle. The needle itself was almost at zero, and then quickly back to idle, almost as if it was playing catch up. No pre-stall shudder or anything. I wondered if it was slippage like you said, but wasn't sure. Thinking back on when it happened today, I was on manual mode with sport activated.

Edit:both times that this has happened, I quickly braked to a stop. Both times for a yellow turning to a red quicker than anticipated.

There is a considerable difference between 500 and 0. You watched this happen as you were coming to a stop as you were stopping instead of running a yellow/red light?

[Christian87n]

Correct, since the lights are in an area by casinos, it's best to stop since people like to jaywalk instead of wait their turn. Both times, I was already at a stop. As soon as the car fully stopped, I caught the rpm dropping. May have happened more times than two, but those are the ones that I saw. I may go and burn some gas in a bit, see if I can get it to replicate on video.


Update: burned some gas last night. Shifting from 5th to 6th, I'll see the rpm bounce around a little, about 200rpm. Very minor. I couldn't replicate the other issue. Slippage?

http://youtu.be/GvzAEMz2Sfo

http://youtu.be/pyWeBcRtJlo

[Barefoot-335is]

So I joined the IS Club....Traded in my 08 335i for a 2012 335is!!!

Space Gray over Oyster, DCT loved the ride home!!!

Car has 45k miles on it, one owner, every option, taking it to BMW Monday have them go through it before the 50k is up. Car definitely handles better than my sedan.

I'm Still figuring out the DCT but it has been raining the last day so no real time to play.

Anyway, had it less than 24 hours and already a fan

[JunkyardDogg]

Originally Posted by alexg212

I think stock looks better. Gloss black carbon fiber version looks good if you want to change it up. Maybe you could even just wrap the stock diffuser.

Yeah f it, just gonna leave it stock.

On another note, I got all my stuff for my first MHD tune

Actually still need a battery charger. Will a 15 amp one be ok?
http://www.amazon.com/gp/product/B00...=ATVPDKIKX0DER

[FoShizzle]

Originally Posted by Barefoot335i

So I joined the IS Club....Traded in my 08 335i for a 2012 335is!!!

Welcome! Now you know what you've been missing.

Originally Posted by JunkyardDogg

On another note, I got all my stuff for my first MHD tune

I just did the backend flash tonight on mine with the jb4 and its WELL worth it. Since tuning the 335is I've always felt that the DCT couldn't keep up with the tune. The backend flash totally brought the DCT back to life. The power is amazing and the shifts are incredible!
Currently running ina0s pump backend flash with jb4 on map 6 and 5 gallons of E85. You will not be dissapointed.

[SUHleen]

Originally Posted by FoShizzle

Welcome! Now you know what you've been missing.



I just did the backend flash tonight on mine with the jb4 and its WELL worth it. Since tuning the 335is I've always felt that the DCT couldn't keep up with the tune. The backend flash totally brought the DCT back to life. The power is amazing and the shifts are incredible!
Currently running ina0s pump backend flash with jb4 on map 6 and 5 gallons of E85. You will not be dissapointed.

So you are running an MHD tune through JB4? I thought MHD has to be done through a tablet or android device?

[STIHLBOLTS]

^ You have the special IS rear spoiler? You want to replace that one?

[LMB335IS]

Originally Posted by SUHleen

So you are running an MHD tune through JB4? I thought MHD has to be done through a tablet or android device?

MHD has backend flashes that are supported by the JB4. Same concept as the flash only MHD but leaves the JB4 as a boost controller. You still use a android device and the flashing module, etc. to accomplish this.

[JunkyardDogg]

Originally Posted by FoShizzle

Welcome! Now you know what you've been missing.



I just did the backend flash tonight on mine with the jb4 and its WELL worth it. Since tuning the 335is I've always felt that the DCT couldn't keep up with the tune. The backend flash totally brought the DCT back to life. The power is amazing and the shifts are incredible!
Currently running ina0s pump backend flash with jb4 on map 6 and 5 gallons of E85. You will not be dissapointed.

Nice! I'm doing the standalone flash on stock 93 for now and will gradually add in mods.

[JunkyardDogg]

My current plan for mods is as follows:

VRSF FMIC 7"
VRSF charge pipe with Tial BOV

But i'm torn about which DP to go with. I know some IS guys have complained about rasp and drone which I do not want. I already love the sound of the IS exhaust but definitely do not want to make my car sound like a rice rocket. Is everyone with a catless disappointed in the sound? Is it that bad? Which should I go with?

Catless
Catted
Catless with resonator

[SUHleen]

Originally Posted by JunkyardDogg

My current plan for mods is as follows:

VRSF FMIC 7"
VRSF charge pipe with Tial BOV

But i'm torn about which DP to go with. I know some IS guys have complained about rasp and drone which I do not want. I already love the sound of the IS exhaust but definitely do not want to make my car sound like a rice rocket. Is everyone with a catless disappointed in the sound? Is it that bad? Which should I go with?

Catless
Catted
Catless with resonator

I have cat less. First I had the stock IS exhaust, then active auto exhaust, now hpf. I never was disappointed. It was a tad raspy with the stock exhaust but still loved the sound. Cat less with the AA exhaust I think would be loved by most on this forum though

[335is-dct]

So I finally said screw it and installed my vrsf cat less downpipes. Instsll was a pita...


Anyways, I have absolutely no idea where the rasp is some of you guys complained about. It sounds like any other turbo car with downpipes. With the stock exhaust valves closed, its very quiet too. I was really expecting the worst with the way some of you made it sound. I guess it's all relative, but coming from someone whose driven modified cars for 12+ years, there is no rasp and it sounds fine.


Turbos seem to spool more violently now. Good mod.

[335is-dct]

Originally Posted by FoShizzle

Welcome! Now you know what you've been missing.



I just did the backend flash tonight on mine with the jb4 and its WELL worth it. Since tuning the 335is I've always felt that the DCT couldn't keep up with the tune. The backend flash totally brought the DCT back to life. The power is amazing and the shifts are incredible!
Currently running ina0s pump backend flash with jb4 on map 6 and 5 gallons of E85. You will not be dissapointed.

Running jb4 alone on a dct car is a horrible idea. Trans will not see accurate torque figures and may start to slip depending on mods.

[JunkyardDogg]

I guess I could handle a bit of rasp.

Is this what it typically sounds like?

[FoShizzle]

Originally Posted by 335is-dct

Running jb4 alone on a dct car is a horrible idea. Trans will not see accurate torque figures and may start to slip depending on mods.

It's worked for the last 4 years for me. Albeit, not ideal, but never had slippage. A few years back guys were talking about upgrading clutch packs as the only solution. We've come a long way.

[LMB335IS]

Originally Posted by FoShizzle

It's worked for the last 4 years for me. Albeit, not ideal, but never had slippage. A few years back guys were talking about upgrading clutch packs as the only solution. We've come a long way.

No back end flash? Are you running E85 at all or just 91/93?

[FoShizzle]

Originally Posted by LMB335IS

No back end flash? Are you running E85 at all or just 91/93?

Not until a few days ago. I run about 5 gallons of e85 every other fillup.

[LMB335IS]

Originally Posted by FoShizzle

Not until a few days ago. I run about 5 gallons of e85 every other fillup.

My DCT started to slip when I got to the point I was running the E85 backend flash on Map 7. I've heard the new backend flashes have been reworked to correct that. My custom MHD maps have my car shifting harder than it every did on a JB4. I'm at 460/530 with zero slip and about to bump it close to 490-500 shortly so we'll see what happens.

[335is-dct]

Originally Posted by LMB335IS

My DCT started to slip when I got to the point I was running the E85 backend flash on Map 7. I've heard the new backend flashes have been reworked to correct that. My custom MHD maps have my car shifting harder than it every did on a JB4. I'm at 460/530 with zero slip and about to bump it close to 490-500 shortly so we'll see what happens.

Is that trap in your sig on your current power levels? Seems a little low for 460

Edit: also what are your mods for 460? That's a strong n54

[LMB335IS]

Originally Posted by 335is-dct

Is that trap in your sig on your current power levels? Seems a little low for 460

Edit: also what are your mods for 460? That's a strong n54

That's my trap. I don't have much to compare it to as to whether it's high or low. I've only been to a couple 1/2 mile events and the first had a couple 335i's that I was as fast or faster than and the last one had none, but there was a new F80 M3 with a JB4, intake, and exhaust there and we were running the same traps.

I have the usual bolt ons, no inlets or outlets yet. I run E60 on a custom tune by BuraQ. The car is strong.