View Single Post
      11-13-2009, 04:22 PM   #165
sales@ESSTuning's Avatar

Drives: ESS M3 / M4
Join Date: May 2007
Location: AZ

iTrader: (6)

I guess some helpful information in this thread can help keep it open For those asking about DCT software I can help shed some light on it. We have been working with the DCT software for about 6 months. We have done lots of testing with several different software versions and have figured out the issues around DCT and high HP.

The factory DCT software was designed to keep drivers safe. This is done by delaying the downshifts by almost 2 seconds to the transmission and slightly slipping the cutch. This is done so that drivers in certain situations dont flip the rear end of the car out. This is also what customers experience as lag when the car begins its downshift cycle and you get on the gas, you sit there waiting. The problem this software will cause when you add high TQ and HP to the car is when you downshift under WOT the built in delay along with added TQ confuses the tranny and your 2 sec delay becomes a 3+ second delay until the clutch gets engaged. During this time if you do not let off the gas your RPM's will shoot up and when the clutch does finally try to engage it tries to engage as it would with 400 HP and it slips causing a transmission
overheat / malfunction. This happens in D mode when you floor it sometimes as the transmission tries to downshift and it happens in Manual mode also. There are no issues with upshifting when you run the stock DCT software on a supercharged car as the stock DCT software engages the clutch very quickly during upshifts.

There are a few solutions to this problem. One is to have a custom DCT file built that will slightly impove the clutch engagement during upshifts but will also remove the built in delay on downshifts. By having the software engage the clutch as soon as it is told to downshift and also slightly reducing power to the engine during this very quick period you can have the transmission perform flawlessly in all conditions. The second is to limit the power and torque in the car so that the transmission can handle the added power during downshifts. We have found that the limit for power on stock DCT software is about 575 chp and about 380 ft/lb tq. If you keep power at this level the DCT performs ok during downshifts under WOT with the factory software. Once you raise power to 600 + chp and 400 + ft/lb of tq the transmission begins to have issues with downshifts.

The other issue with DCT once you figure all of this out is being able to provide the customer with a custom DCT software file. The interface to access the DCT control unit is extreamly difficult to get. It is not a simple interface like the ones that can be purchased for loading engine software as the DCT ecu is in a difficult location to access and can only be flashed thru the OBD port. It also requires factory knowledge on how and where to load different version of software into the DCT ECU without erasing the current file and crippling the car. If you try to load a unauthorized file into the DCT ECU the ECU will lock you out and the transmission will be shut down. If you do this and fail to correct it you will need to buy a new $10k transmission. This is why we currently can only load DCT stage 2 software into cars that are brought to us for installation.

I hope this information helps.

Last edited by sales@ESSTuning; 11-13-2009 at 04:39 PM..