PTF / BM3 is GAME for 6MT flat foot shifting ... do you want it?

[TouringM3]

Hey buddies –

I reached out to the ProTuningFreaks team about software features to enable (Power Shifting) / (Flat Foot Shifting) with 6MT S55 cars.


If you're unfamiliar, here's the gist:
Right now, if you're shifting traditionally (being kind to your clutch & gearbox) - you disengage the throttle, which shuts the throttle body, which results in the bypass / blowoff valve discharging boost so you don't choke the turbo.

Then, when you're in the next gear, you experience an acceleration bog because your engine has to re-pressurize the charge system (build boost) before all your ponies wake up and kick.


The benefit of Powahshifting / flat foot shifting is:

You get to keep your foot on the throttle
The throttlebody doesn't shut, so boost stays on
The software adjust timing and/or redline so you're not over-revving your engine while not in gear.
You shift into the next gear, drop the clutch and you're at full torque and power in gear
The software does this by recognizing the clutch has been released, and instantly advances timing to the norm / releases low redline and you're flying.

Screen shot of the email from PTF here. Let's let them know we want this!!!!




Lastly, don't take it from me, here's an "Engineering Explained" video on modern tech w/ manual transmission cars - using the brand new Cadillac as a demo vehicle:

~David

[MJ6]

No-Lift shifting is something I've had on other cars and it worked great. It does come with the risk of greater transmission wear and tear, but the benefits of staying in boost and avoiding that shift bog is a phenomenal feeling.

[Kilabyte]

In.

[Sahbatage]

I would use that! But it'd be better if you could turn it on/off on the fly, I wouldn't use it as my daily setting

[TouringM3]

Originally Posted by Sahbatage

I would use that! But it'd be better if you could turn it on/off on the fly, I wouldn't use it as my daily setting

I think that's another main benefit ... if you don't have the throttle pushed while the clutch engages, the timing / redline don't get impacted.

NOW - i don't know how well this would play with DIY rev-matching or auto-blip rev matching ... so now that i type this, you would probably want to be able to deactivate it.

[RElias21]

Currently the boost delay between fast shifts on a 6MT with BM3 is horrrrrrrible.

Would love if BM3 could adjust that.

[TractionControlDelete]

Originally Posted by TouringM3

Hey buddies –

I reached out to the ProTuningFreaks team about software features to enable (Power Shifting) / (Flat Foot Shifting) with 6MT S55 cars.


If you're unfamiliar, here's the gist:
Right now, if you're shifting traditionally (being kind to your clutch & gearbox) - you disengage the throttle, which shuts the throttle body, which results in the bypass / blowoff valve discharging boost so you don't choke the turbo.

Then, when you're in the next gear, you experience an acceleration bog because your engine has to re-pressurize the charge system (build boost) before all your ponies wake up and kick.


The benefit of Powahshifting / flat foot shifting is:

You get to keep your foot on the throttle
The throttlebody doesn't shut, so boost stays on
The software adjust timing and/or redline so you're not over-revving your engine while not in gear.
You shift into the next gear, drop the clutch and you're at full torque and power in gear
The software does this by recognizing the clutch has been released, and instantly advances timing to the norm / releases low redline and you're flying.

Screen shot of the email from PTF here. Let's let them know we want this!!!!




Lastly, don't take it from me, here's an "Engineering Explained" video on modern tech w/ manual transmission cars - using the brand new Cadillac as a demo vehicle:

~David

"The throttlebody doesn't shut, so boost stays on"

The valvetronic does this in Sport+ already

https://f80.bimmerpost.com/forums/sh...d.php?t=893216

"The S55 uses BMW's Valvetronic variable valve timing and Double-VANOS variable camshaft timing system… In "Sport" and "Sport Plus" settings, the turbochargers are "pre-tensioned," which means that they keep spinning at a high rate of speed even after you have taken your foot off the throttle. This trick ensures ultra-quick response times fully comparable to those of a naturally aspirated engine. To bring engine revs down, cylinders are deactivated. The system doesn't work for extended time, but it operates under racetrack conditions and whenever the car senses quick bursts of acceleration and deceleration."

[Trevorstein]

Sub'd.

[TouringM3]

Originally Posted by F82KPowers

"The throttlebody doesn't shut, so boost stays on"

The valvetronic does this in Sport+ already

https://f80.bimmerpost.com/forums/sh...d.php?t=893216

"The S55 uses BMW's Valvetronic variable valve timing and Double-VANOS variable camshaft timing system… In "Sport" and "Sport Plus" settings, the turbochargers are "pre-tensioned," which means that they keep spinning at a high rate of speed even after you have taken your foot off the throttle. This trick ensures ultra-quick response times fully comparable to those of a naturally aspirated engine. To bring engine revs down, cylinders are deactivated. The system doesn't work for extended time, but it operates under racetrack conditions and whenever the car senses quick bursts of acceleration and deceleration."

OK this is really cool. I have to admit that i have yet to notice this working, and I know for sure i've had it in "Sport".

I do think that an actual, dedicated powershift implementation would really take things up another notch or two.

[Kilabyte]

Originally Posted by TouringM3

OK this is really cool. I have to admit that i have yet to notice this working, and I know for sure i've had it in "Sport".

I do think that an actual, dedicated powershift implementation would really take things up another notch or two.

It's the tuning, BMW didn't want us slamming gears and breaking stuff that they have to cover under warranty

Our IMHO closest competitor, the ATS-V has that feature stock, but they run a stronger tranny/ diff it seems

[TopJimmy]

I daily the MT6 and drag race it too. Our cars have so much power I only see this working on a prepped track with drag tires, otherwise you'll have wheelspin. The trick to launching these cars is modulating the pedal pressure in SP+.

[TouringM3]

Originally Posted by TopJimmy

I daily the MT6 and drag race it too. Our cars have so much power I only see this working on a prepped track with drag tires, otherwise you'll have wheelspin. The trick to launching these cars is modulating the pedal pressure in SP+.

So do you notice far reduced turbo spool "bog" in Sport+?

If so, i'm stoked, just looking to learn where people are finding the greatest success with this setup and various tune(s).

[heitzke]

Super in for this. Would I use it a lot? Probably not, but I still want it.

[TouringM3]

You mean you wouldn't just epoxy a brick on your throttle and call it good?

[TopJimmy]

Originally Posted by TouringM3

So do you notice far reduced turbo spool "bog" in Sport+?

If so, i'm stoked, just looking to learn where people are finding the greatest success with this setup and various tune(s).

I have very fast spool with my Paul E85 tune.

[Rjpacman]

I'm definitely interested

[mike@x-ph.com]

from PTF response this is not something that will be available any time soon

[c4ss]

Originally Posted by mike@x-ph.com

from PTF response this is not something that will be available any time soon

This. Knowing PTF, they will R&D it for a year, add it/tease it...release it 1+ year later (a la Flexfuel/Antilag)

[Soul Coughing]

I remember when a buddy in his turbo s2000 had his tuner set up flat foot shifting and he was able to break into the 9's with the same power! His transmission stayed together for 4 passes before the output shaft casing blew apart. I know the Getrag transmission is a lot tougher, but I'd be curious to see how these 6 speeds stay together with the added abuse!

[1000hp]

Originally Posted by TouringM3

The benefit of Powahshifting / flat foot shifting is:

You get to keep your foot on the throttle
The throttlebody doesn't shut, so boost stays on
The software adjust timing and/or redline so you're not over-revving your engine while not in gear.
You shift into the next gear, drop the clutch and you're at full torque and power in gear

You forgot "fill your transmission with shrapnel"

[TractionControlDelete]

Originally Posted by 1000hp

You forgot "fill your transmission with shrapnel"

: Literal LOL

I'll keep an eye out if they do release it though to give it a shot I guess. I'm a car enthusiast so I'm not going to start making smart decisions now

[M2Blu]

Anyone know if there has been any new updates on this?