megashift on a vw dsg gearbox?

A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
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Joes
Posts: 4
Joined: Sun Apr 15, 2012 8:52 am

megashift on a vw dsg gearbox?

Post by Joes »

hi there

was just wandering if anybody had tried running the megashift on the vw dsg gearbox or if not does anybody think this a plausable idea?

thanks Joe
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: megashift on a vw dsg gearbox?

Post by Bernard Fife »

Joe,

In general, MegaShift is designed to work on automatic transmissions, not manual transmissions. With dual clutch manual (spur gear based) the timing requirements can be quite strict, and the consequences on being in 2 gears at the same time are significantly destructive (unlike an automatic trans, where the trans is in two gears at the same time for a brief period on most shifts).

That doesn't mean MShift can't be used, but we would have to know a lot more about the control strategies needed by the trans (most likely available from OEM service documents), and would have to do a lot of testing beforehand. I couldn't tell much from this: http://en.wikipedia.org/wiki/Direct-Shift_Gearbox

For example, the clutch engagement might be handle by a single output (ON to engage clutch 1 and disengage clutch 2, and OFF to disengage clutch 1 and engage clutch 2) - in which case the trans essential handles the timing requirements.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Joes
Posts: 4
Joined: Sun Apr 15, 2012 8:52 am

Re: megashift on a vw dsg gearbox?

Post by Joes »

hi Lance
thanks for your reply
here is a vw self study guide http://www.cmdr-fire.co.uk/downloads/L- ... ox_02E.pdf

so this is plausable then?

thanks Joe
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: megashift on a vw dsg gearbox?

Post by Bernard Fife »

Joe,

Plausible with a lot of work, I would say. The trans appears to have 5 solenoids and 6 pressure control values. The MShift firmware allows for up to 8 solenoids, and there are 3 spare ports with PWM plus the dedicated pressure control output. But there are also the 4 LED outputs that could be 're-purposed' as necessary. Some hardware modifications and additions would be required - these could be done on a proto board, I suspect. I will have a closer look at the doc a bit later to see if I can find what the specific electrical requirements are.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Joes
Posts: 4
Joined: Sun Apr 15, 2012 8:52 am

Re: megashift on a vw dsg gearbox?

Post by Joes »

ok thanks let me know
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: megashift on a vw dsg gearbox?

Post by Bernard Fife »

Joes,

There is some interesting and useful control information in that doc. There isn't much in the way of electrical specifications, though (that I found).

These would be things like the various solenoid's resistance (Ohms), inductance (milliHenries) and pulse width modulation parameters (frequency and percent). Such things can often be gleaned from factory service manuals as part of specific troubleshooting procedures. Alternatively, things like resistance and inductance can be measured directly with a gearbox and the right tools.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Joes
Posts: 4
Joined: Sun Apr 15, 2012 8:52 am

Re: megashift on a vw dsg gearbox?

Post by Joes »

hi Lance thanks for taking the time and having a look

that is all the information i managed to find, as you said some of the information can be found out via testing the gearbox, i currently dont have one of these gearboxes but didnt want to splash the money out without knowing if this was do able.
just worried about how hard this could be to get working
thanks Joe
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