6AT to DCT Converstion

doublespaces

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Oct 18, 2016
7,206
AZ
Now that we have the ten pin connector, we'll need socket contacts for it as well. The guide currently tells you to buy six contacts with leads #61130005197 however these are about $3 each, so I recommend that the individual contacts be purchased and crimp them with your own wire #12527510668 right now they are on sale for 70 cents each.

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doublespaces

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Oct 18, 2016
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So, I spent quite a bit of time on the wiring diagrams, mapping out the harnesses, both DCT and 6AT and comparing it to the diagrams that ncat10 has provided. I'm still learning how to navigate that newtis site, but I believe I can make the GWS harness without going through the firewall and into the ECU box at all. Out of the 10 pins for the GWS connector, 4 go to local sources under the shift plate. Three more can find their destinations by repinning the existing wiring which goes into the ECU box for the 6AT stuff, and three more wires I'm pretty sure can find their destinations on the Junction box.

I might be completely wrong here, but I'm hoping I'm right because it would actually simplify the process of making this harness quite a bit. This also does not work with all versions of the car, basically you need to be MSD81, I'm not sure of what other limitations there are but I wouldn't recommend attempting this unless your car came from the factory with an MSD81.

It is late, I'll do more actual checking later, before I attempt to do this so I don't fry my TCU, CAS, FRM and who knows what else.

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Rob09msport

Captain
Oct 28, 2017
1,163
Monroe CT
Overall if you were had a auto would the pd upgrade at 2500 euro trans install 1200 pd kit and 150 shipping each way cost more less or pretty close and if anyone has driven both what did you feel pros and cons of each were. I purchased the pd kit and have always wanted dct but when i purchased my car dct cars couldn't handle as much power without slipping now with tuning advancements it seems that dct handles more on stock clutches but once again now i think pd transmission can handle more and dct clutch kits seem to be very expensive so prob not best option.i am looking to hold 600 to 650 whp in the end which if xhp stage 3 can hold on its own with a healthy trans maybe i will just sell the pd kit but if the pd kit and tuning speeds up shifts and makes feel better on top of better reliability and room to go i will do that or if dct still blows away a pd trans ill do the conversion prob. I really just looking for any info or comparisons between upgrade options for auto guys
 

doublespaces

Administrator
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Oct 18, 2016
7,206
AZ
Overall if you were had a auto would the pd upgrade at 2500 euro trans install 1200 pd kit and 150 shipping each way cost more less or pretty close and if anyone has driven both what did you feel pros and cons of each were. I purchased the pd kit and have always wanted dct but when i purchased my car dct cars couldn't handle as much power without slipping now with tuning advancements it seems that dct handles more on stock clutches but once again now i think pd transmission can handle more and dct clutch kits seem to be very expensive so prob not best option.i am looking to hold 600 to 650 whp in the end which if xhp stage 3 can hold on its own with a healthy trans maybe i will just sell the pd kit but if the pd kit and tuning speeds up shifts and makes feel better on top of better reliability and room to go i will do that or if dct still blows away a pd trans ill do the conversion prob. I really just looking for any info or comparisons between upgrade options for auto guys
DCT is fantastic, if you already have it. The price to upgrade the clutches is relatively similar to upgrading the 6AT. This conversion is for those of us who love to do things just because, or we are already too deep in our vehicles to justify swapping a 335is. I've thought about doing this more than once, but I've already bought everything and at the end of the day, the end is almost in sight and I don't feel like doing the work again.

What I haven't seen is someone push the N54 DCT past 800 and beyond. That is probably the part I'm most curious about.
 

dyezak

Major
May 4, 2017
1,768
Plano TX
Overall if you were had a auto would the pd upgrade at 2500 euro trans install 1200 pd kit and 150 shipping each way cost more less or pretty close and if anyone has driven both what did you feel pros and cons of each were. I purchased the pd kit and have always wanted dct but when i purchased my car dct cars couldn't handle as much power without slipping now with tuning advancements it seems that dct handles more on stock clutches but once again now i think pd transmission can handle more and dct clutch kits seem to be very expensive so prob not best option.i am looking to hold 600 to 650 whp in the end which if xhp stage 3 can hold on its own with a healthy trans maybe i will just sell the pd kit but if the pd kit and tuning speeds up shifts and makes feel better on top of better reliability and room to go i will do that or if dct still blows away a pd trans ill do the conversion prob. I really just looking for any info or comparisons between upgrade options for auto guys
Something to think about is the PD upgrade holds more power, but it doesn't do anything to significantly improve shift times. Stock 6AT shift times hover around .500sec, xHP Stage3 is .400sec and that's as far as the trans can be pushed. Additional line pressure might shave off another .050sec but that's if you are lucky. So yea, a PD 6AT will hold more power, and shift harder, but not faster.

I have tons of DCT logs showing .010sec shift times. Complete shifts. In a single 1/4mi run you will have between 3-4 shifts depending on your rear gear ratio. That means you will save anywhere from 1.010sec to 1.910sec going down the track. (this is why the N54 record is held by a powerglide transmission...one shift to make it down the track)

Extrapolate that to a 1/2mi event.

Add that up for a road course where you'd experience 20-30 shifts per lap and 5-30 laps per race.

The DCT is an eye opening experience. Something people with lots of auto experience can't even comprehend. So many people think their B&M trans that chirps the tires between shifts is "fast". It's not. It is shifting "hard" due to high line pressure

The exception to this is the new Chevy/Ford co-designed 10sp automatic. It has dual gear sets inside it. And although it has a single torque converter, internally it behaves as a DCT does. So the next gear is already pre-selected and engaged and ready for use. But it still has a single input shaft and will never be as fast as dual input shafts. I think they are getting solid 0.100 shifts out of that tranny which is insane, but sill is 10x slower than our 15y old Getrag designed DCT.
 

Rob09msport

Captain
Oct 28, 2017
1,163
Monroe CT
Something to think about is the PD upgrade holds more power, but it doesn't do anything to significantly improve shift times. Stock 6AT shift times hover around .500sec, xHP Stage3 is .400sec and that's as far as the trans can be pushed. Additional line pressure might shave off another .050sec but that's if you are lucky. So yea, a PD 6AT will hold more power, and shift harder, but not faster.

I have tons of DCT logs showing .010sec shift times. Complete shifts. In a single 1/4mi run you will have between 3-4 shifts depending on your rear gear ratio. That means you will save anywhere from 1.010sec to 1.910sec going down the track. (this is why the N54 record is held by a powerglide transmission...one shift to make it down the track)

Extrapolate that to a 1/2mi event.

Add that up for a road course where you'd experience 20-30 shifts per lap and 5-30 laps per race.

The DCT is an eye opening experience. Something people with lots of auto experience can't even comprehend. So many people think their B&M trans that chirps the tires between shifts is "fast". It's not. It is shifting "hard" due to high line pressure

The exception to this is the new Chevy/Ford co-designed 10sp automatic. It has dual gear sets inside it. And although it has a single torque converter, internally it behaves as a DCT does. So the next gear is already pre-selected and engaged and ready for use. But it still has a single input shaft and will never be as fast as dual input shafts. I think they are getting solid 0.100 shifts out of that tranny which is insane, but sill is 10x slower than our 15y old Getrag designed DCT.
So dct should be able to get pretty good et if can hold power but stock dct wont really hold 650 right?
I know our shifts take time but don't they continue transferring power during shift cause of the sequential design . Like the 2nd gear clutch starts engaging while first gear is letting go .i remember reading that the 6hp has full power overlapping shifts its just that when we increase power levels we have to reduce torque on shift allot to allow the transmission to slow the engine but we should technically still be accelerating. Last i would think a 2nd gear launch and if pd allows less torque reduction should be able to cut some nice times if not does anyone want to buy a pd kit. Also i know what you mean every round of mods i look at used 335is s for sale and think damn i would done that if i hadnt spent that money ,i am deff at the point where i would have to convert , only way i would buy a 335is at this point is if i totaled my car and swapped all parts and i really hope that never happens
 

dyezak

Major
May 4, 2017
1,768
Plano TX
So dct should be able to get pretty good et if can hold power but stock dct wont really hold 650 right?
I know our shifts take time but don't they continue transferring power during shift cause of the sequential design . Like the 2nd gear clutch starts engaging while first gear is letting go .i remember reading that the 6hp has full power overlapping shifts its just that when we increase power levels we have to reduce torque on shift allot to allow the transmission to slow the engine but we should technically still be accelerating.

Last i would think a 2nd gear launch and if pd allows less torque reduction should be able to cut some nice times if not does anyone want to buy a pd kit. Also i know what you mean every round of mods i look at used 335is s for sale and think damn i would done that if i hadnt spent that money ,i am deff at the point where i would have to convert , only way i would buy a 335is at this point is if i totaled my car and swapped all parts and i really hope that never happens
The DCT is powering F80's at over 1000hp in the 9sec territory.

Stock the DCT clutch limit is somewhere around 600-650hp, SSP or Dodson clutch upgrade can get you clutches that can double that.

Totally incorrect, like not even remotely close to accurate. If you really did read that, it was likely from some idiot posting stupidity on a board somewhere.

2nd gear launch sucks 60ft times down. I've had 3 N54 6AT's, I can reliably cut 1.7sec 60ft times in any FBO 6AT you give me the keys to.

The DCT's downfall has been the launch control that the 335is has been crippled with. We have fixed that here at SpoolStreet by facilitating a retrofit of the M3 DCT control systems including launch control. I am pretty confident that regular 10sec time slips are close for DCT cars with the power to get there.
 

Rob09msport

Captain
Oct 28, 2017
1,163
Monroe CT
It was on e90 post their was thread with all these articles trying to say that the 6hp is better than the 8hp and that its the benchmark etc but i do remember actual articles i lookong for that had diagrams of the gearset and clutches and showed video of them engaging saying that shifts overlap and clutches engage sequential and closer to dct then traditional auto plus converter locks. The stuff trying to say was as good as dct was written by a zf engineer though
I haven't been on this board very long but i value knowledge greatly and try very hard to not spread mis info or bs to look cool on forum that why i made sure to say i read but i promise you ill never make anything up and have pretty good memory so usually am pretty accurate. I understand your being skeptical if i really read that but just wanted to clarify
 
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Rob09msport

Captain
Oct 28, 2017
1,163
Monroe CT
Does anyone have logs of g meter or acceleration as opposed to shift time so can see those values any high poll rate chart showing mph vs time would suffice i just don't think canbus shows enough detail again could be wrong.
 

dyezak

Major
May 4, 2017
1,768
Plano TX
Does anyone have logs of g meter or acceleration as opposed to shift time so can see those values any high poll rate chart showing mph vs time would suffice i just don't think canbus shows enough detail again could be wrong.
Yes, I posted tons of logs here and on other boards with some testing I was doing with xHP. If you want to see 6hp performance look in the xHP threads. Nobody has ever posted any log with a shift time faster than 0.400sec. The community has thousands of 6hp logs showing this, covering thousands of cars. If someone tells me the shifts are 350ms and we log 400ms then we can agree logging differences could account for that. When a claim is 2-400% different than actual results....well... we call that marketing
 

Rob09msport

Captain
Oct 28, 2017
1,163
Monroe CT
Yes, I posted tons of logs here and on other boards with some testing I was doing with xHP. If you want to see 6hp performance look in the xHP threads. Nobody has ever posted any log with a shift time faster than 0.400sec. The community has thousands of 6hp logs showing this, covering thousands of cars. If someone tells me the shifts are 350ms and we log 400ms then we can agree logging differences could account for that. When a claim is 2-400% different than actual results....well... we call that marketing
I agree with that deff, what i am asking is does all acceleration stop for 400ms cause i see the rpm drop showing the shift time and understand the time for the complete shift but i am curious as to how long power is not being transferred and also if pd improves that or if pd allows more power during shift with their calibration. I see conflicting info one says that xhp works to emulate pd calibration so works good but do they stack or would pd set values and then xhp sets it's values or is xhp adding to pd values. Basically does one negate the benefits of the other.
 

dyezak

Major
May 4, 2017
1,768
Plano TX
I agree with that deff, what i am asking is does all acceleration stop for 400ms cause i see the rpm drop showing the shift time and understand the time for the complete shift but i am curious as to how long power is not being transferred and also if pd improves that or if pd allows more power during shift with their calibration. I see conflicting info one says that xhp works to emulate pd calibration so works good but do they stack or would pd set values and then xhp sets it's values or is xhp adding to pd values. Basically does one negate the benefits of the other.
Acceleration doesn't "stop" between shifts for that .400sec. But then again even when viewing a log of a 6MT, acceleration doesn't stop between shifts there either. You have momentum that is accelerating the car forward, so even on a 6MT when that clutch is depressed and the engine is fully dis-engaged from the driveline you will still see the speed increase slightly at that point, it's the sling shot effect. But acceleration does reduce significantly.

I can pull up tons of marketing wank where the marketing team is, shall we say, extremely liberal with the truth. I won't call them liars, but they certainly choose what facts they present, what facts they hide, and how they color the story to paint the picture they want.

OK, they lie.

As for your other question, I don't know, and I'd be guessing with any answer I gave to that so I'll refrain from causing more confusion.
 

Rob09msport

Captain
Oct 28, 2017
1,163
Monroe CT
Acceleration doesn't "stop" between shifts for that .400sec. But then again even when viewing a log of a 6MT, acceleration doesn't stop between shifts there either. You have momentum that is accelerating the car forward, so even on a 6MT when that clutch is depressed and the engine is fully dis-engaged from the driveline you will still see the speed increase slightly at that point, it's the sling shot effect. But acceleration does reduce significantly.

I can pull up tons of marketing wank where the marketing team is, shall we say, extremely liberal with the truth. I won't call them liars, but they certainly choose what facts they present, what facts they hide, and how they color the story to paint the picture they want.

OK, they lie.

As for your other question, I don't know, and I'd be guessing with any answer I gave to that so I'll refrain from causing more confusion.
If you could post or pm me any log that shows speed vs time with wot shift and if have part throttle shift .i always felt that part throttle shifts like aggressive but not wot were lightning quick but i would like to try to see if i can figure out the percentage of acceleration due to sling shot effect and then figure out how long actual torque stops transferring . Thanks for helping me wrap my head sometimes i over think and take 7 lefts instead of 1 right
 

doublespaces

Administrator
Free Vendor
Oct 18, 2016
7,206
AZ
The 8HP xHP flash is coming by @RayBan and the 8HP is flat out a superior unit.

Also, the F80 DCT is the same overall transmission but it uses different gearing and software. That TCU uses FlexRays and is rumored to support more power than the BoardNet versions found on the E chassis.
 
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