Suspension, Brakes, Drivetrain discuss the wondrous effects of boost and your miata...
Sponsored by:
Sponsored by:

7speed getrag DCT transmission swap.

Thread Tools
 
Search this Thread
 
Old 03-25-2019, 09:46 AM
  #21  
Senior Member
 
LukeG's Avatar
 
Join Date: May 2017
Location: Austin, TX
Posts: 1,119
Total Cats: 166
Default

Originally Posted by hf-mx5t
A used DCT box from a M4 cost us 1000 euro, and the rest of the conversion parts are similar, but not the same as K miata manual swap parts.
Damn! Was expecting it to be way more than that.
LukeG is offline  
Old 03-25-2019, 10:26 AM
  #22  
Junior Member
iTrader: (1)
 
sometorque's Avatar
 
Join Date: Jul 2018
Location: Coral Springs, FL
Posts: 187
Total Cats: 57
Default

Originally Posted by LukeG
Damn! Was expecting it to be way more than that.
They're surprisingly cheap since they were/are used on a bunch of DCT-equipped BMW's for the last 8-10 years. I had bought one locally for $1600 about 2 years back that i ended up selling after i sold my old 135i. They're all over the place now for $1300-$1500.
sometorque is offline  
Old 03-25-2019, 11:05 AM
  #23  
Junior Member
Thread Starter
 
hf-mx5t's Avatar
 
Join Date: Jun 2005
Posts: 286
Total Cats: 235
Default

Originally Posted by sometorque
They're surprisingly cheap since they were/are used on a bunch of DCT-equipped BMW's for the last 8-10 years. I had bought one locally for $1600 about 2 years back that i ended up selling after i sold my old 135i. They're all over the place now for $1300-$1500.
Also helped by the fact that they are difficult to use in anything else than a BMW with the same gearbox. making the marked for used ones because of chrashed cars really small.
hf-mx5t is offline  
Old 03-25-2019, 04:33 PM
  #24  
Senior Member
 
HarryB's Avatar
 
Join Date: Jul 2015
Posts: 1,015
Total Cats: 140
Default

That's waaaay cheaper than anticipated! And progress looks great so far!
HarryB is offline  
Old 03-29-2019, 10:25 AM
  #25  
Newb
 
mattj's Avatar
 
Join Date: Mar 2019
Location: Washington State
Posts: 40
Total Cats: 37
Default

Holy ****. This is right up my wheelhouse. What trans controller are you using, if I may ask?

In for the engine height as well. My K24 probably can't go any higher.
mattj is offline  
Old 04-01-2019, 02:15 PM
  #26  
Junior Member
 
Morello's Avatar
 
Join Date: Jul 2009
Location: Orange County, CA
Posts: 419
Total Cats: 45
Default

Can you share more details on the trans controller? What does the trans use for inputs? Are they regular (12V) solenoids that engage particular gearsets/clutches?
Morello is offline  
Old 04-16-2019, 09:19 AM
  #27  
Newb
 
Slow_1.6's Avatar
 
Join Date: Jul 2017
Posts: 8
Total Cats: 0
Default

This is awesome. I'm surprised that there is little excitement about it here. A Miata with a DCT was in my head for a long time and I was waiting for someone to finally engineer this out.

Can we get more details? Is there another place where you describe your project in more details?

Do you plan on creating a kit once you are done so other people can use this awesome solution?

Please give us more updates.
Slow_1.6 is offline  
Old 04-16-2019, 02:59 PM
  #28  
Senior Member
iTrader: (2)
 
Der_Idiot's Avatar
 
Join Date: Nov 2007
Location: Saint Paul, MN
Posts: 1,489
Total Cats: 28
Default

Nice work man, thanks for taking the time to document it.
Der_Idiot is offline  
Old 04-18-2019, 10:24 AM
  #29  
Elite Member
iTrader: (9)
 
TurboTim's Avatar
 
Join Date: Jun 2006
Location: Chesterfield, NJ
Posts: 6,898
Total Cats: 399
Default

Pretty damn slick swap here. Congrats on taking this on.

I want one with the TCU solution please.
TurboTim is offline  
Old 04-18-2019, 12:10 PM
  #30  
Elite Member
 
z31maniac's Avatar
 
Join Date: Oct 2011
Location: OKC, OK
Posts: 3,693
Total Cats: 222
Default

Originally Posted by TurboTim
Pretty damn slick swap here. Congrats on taking this on.

I want one with the TCU solution please.
I am also curious. As someone who owns a BMW with this transmission, it's my understanding the TCU determines clamping pressure of the clutches by the "torque request" made from the pedal to the DME.
z31maniac is offline  
Old 04-18-2019, 10:13 PM
  #31  
Junior Member
 
engineered2win's Avatar
 
Join Date: Dec 2016
Location: Columbus, OH
Posts: 189
Total Cats: 48
Default

Originally Posted by z31maniac
I am also curious. As someone who owns a BMW with this transmission, it's my understanding the TCU determines clamping pressure of the clutches by the "torque request" made from the pedal to the DME.
Line pressure vs engine torque is half shift feel (shock vs response) and half durability. You don't want your luxury car slamming gears driving around a city. You also don't want slow lockup at WOT, because you will put a lot of heat into the clutches due to slippage.
It's pretty common to run bench engine dynos with automatic transmissions by actuating the solenoids with 12v power supplies. At work we literally don't even use a TCU sometimes and just have a row of power supplies we toggle to select gears. Assuming this is a race car, you can make this work with fairly crude methods. We've done it with the NSX 9DCT and a slew of 6/9/10 speed torque converter slushboxes.
engineered2win is offline  
Old 04-19-2019, 09:24 AM
  #32  
Elite Member
 
z31maniac's Avatar
 
Join Date: Oct 2011
Location: OKC, OK
Posts: 3,693
Total Cats: 222
Default

Originally Posted by engineered2win
Line pressure vs engine torque is half shift feel (shock vs response) and half durability. You don't want your luxury car slamming gears driving around a city. You also don't want slow lockup at WOT, because you will put a lot of heat into the clutches due to slippage.
It's pretty common to run bench engine dynos with automatic transmissions by actuating the solenoids with 12v power supplies. At work we literally don't even use a TCU sometimes and just have a row of power supplies we toggle to select gears. Assuming this is a race car, you can make this work with fairly crude methods. We've done it with the NSX 9DCT and a slew of 6/9/10 speed torque converter slushboxes.
I knew the first part, but thanks for the insider info on dynos and such!
z31maniac is offline  
Old 04-19-2019, 11:50 AM
  #33  
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 7,341
Total Cats: 2,379
Default

Have to say, I'm very interested in this. The trans height and need to raise the engine is a concern though. Would be interested to see if any measure could be taken to minimize block relocation.
I can see one of these in Vegas running ST2 at 2350# & 300 average whp with Sonny behind the wheel on 245 A7's. Even if we got our asses kicked, I would love to build it and see it run.

Thanks for sharing Harald.
__________________


www.facebook.com/SuperMiata

949RACING.COM Home of the 6UL wheel

.31 SNR
emilio700 is offline  
Old 04-26-2019, 04:21 PM
  #34  
Junior Member
Thread Starter
 
hf-mx5t's Avatar
 
Join Date: Jun 2005
Posts: 286
Total Cats: 235
Default

for a pure race car it might be the wrong transmission mainly because its a heavy bastard. and the ratios for most racecars would need a very tall rear end to keep the top speed down. but for a dual duty car that will see mostly street use and some trackdays i think its a great choice. low cruising RPM, quiet, and capable of handling any power a miata engine can make.

There really is no way of installing this without raising the engine Emilio. as the sump section of the gearbox actually sits a little lower than the BP sump. and that is with a gearbox sump of around 1/2" height.
you could probably make a new sump and save a few mm, but not more.

Here it is installed on the final transmission mount.





hf-mx5t is offline  
Reply
Leave a poscat 11 Leave a negcat
Old 04-26-2019, 09:57 PM
  #35  
Junior Member
 
tomrev's Avatar
 
Join Date: Oct 2016
Location: N. Mi.
Posts: 387
Total Cats: 41
Default

Beautiful fab work!
tomrev is offline  
Old 04-27-2019, 03:02 AM
  #36  
Junior Member
 
mx5psi's Avatar
 
Join Date: Mar 2013
Posts: 209
Total Cats: 35
Default

Very cool idea
mx5psi is offline  
Old 04-27-2019, 01:23 PM
  #37  
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 7,341
Total Cats: 2,379
Default

Sorry if I missed it, but how much did you have to raise the engine?
Any change to angle of engine?
__________________


www.facebook.com/SuperMiata

949RACING.COM Home of the 6UL wheel

.31 SNR
emilio700 is offline  
Reply
Leave a poscat -1 Leave a negcat
Old 04-27-2019, 05:00 PM
  #38  
Junior Member
Thread Starter
 
hf-mx5t's Avatar
 
Join Date: Jun 2005
Posts: 286
Total Cats: 235
Default

Originally Posted by emilio700
Sorry if I missed it, but how much did you have to raise the engine?
Any change to angle of engine?
I raised the engine 17mm. a DCT had never been tried in a mx5 so we didnt know anything about how it would fit until we tried the angle is still spot on.
hf-mx5t is offline  
Old 04-28-2019, 03:15 PM
  #39  
Junior Member
Thread Starter
 
hf-mx5t's Avatar
 
Join Date: Jun 2005
Posts: 286
Total Cats: 235
Default


Custom 3" driveshaft made by a friend of mine installed. Perfect fitment
hf-mx5t is offline  
Old 04-30-2019, 09:32 PM
  #40  
Newb
 
rnasequence's Avatar
 
Join Date: Nov 2014
Posts: 5
Total Cats: 4
Default Nice

Good to see you got this off the ground.

I have the dev firmware for MaxxECU and the DCT wiring harness releases soon, to use the stock mechatronics with clutch kick feature as well. Less expensive and don't have to replace the factory BMW TCU!
rnasequence is offline  


Quick Reply: 7speed getrag DCT transmission swap.



All times are GMT -4. The time now is 07:57 PM.