Defeating the torque limit request on the Volvo 850 Turbo

RyanT5 · Post by **RyanT5** » 05 Feb 2013, 12:30

Youre probably right :/

ARD-Lucky · Post by **ARD-Lucky** » 06 Feb 2013, 10:47

You could use an Arduino, Pi, or PIC to comm back and forth to the ECU or you could simply reduce limiter in the ECU for first/second without fully removing it... I'm a bit slammed now but I can do some further research on how the physical switch interrupt could be implemented if there is interest.

Few other projects to finish up first but I'm open to input!

cleven · Post by **cleven** » 09 Feb 2013, 00:23

What if someone where to put a resistor in line of the wire?

RyanT5 · Post by **RyanT5** » 22 Feb 2013, 09:04

Hmm it appears i paid no attention to the basic of this thread and failed to realize this is for 850 turbos and not 70 series. Ordered my green tune yesterday and in the notes on the buildsheet requested the low gear torque limits to be reduced a bit. i wonder now if i just asked for the impossible and looked stupid? lol regardless im excited, says it shipped yesterday at 3:00pm

Post by **matthew1** » 22 Feb 2013, 20:29

Ryan, the torque limit request signal is sent on '98s, also. See Jimmy's post regarding cutting the wire in his '98 S70 company car. So, no, Lucky won't think you're uninformed. Until he reads this.

RyanT5 · Post by **RyanT5** » 23 Feb 2013, 09:38

matthew1 wrote:Ryan, the torque limit request signal is sent on '98s, also. See Jimmy's post regarding cutting the wire in his '98 S70 company car. So, no, Lucky won't think you're uninformed. Until he reads this.

Hey lets all make fun of the volvo newb and his stupid questions! haha thanks matt

jacobharding · Post by **jacobharding** » 23 Feb 2013, 19:30

Very interesting topic. I just read it through for the first time. I did not know about the ECU limiting boost on take off. It has been my experience, on rare occasion, that I can smash it from a stoplight and get amazing torque and wheel spin from a dead stop. This is rare and I am pretty sure road surface is not to blame. I can't help but wonder, after reading this thread, if a fault in the ECU or it's wiring could be to blame.
Also if you want more power on takeoff I have found just a little bit of power braking goes a long way. I have laid many 50+ foot black stripes from the light right through second gear.

Post by **mercuric** » 25 Feb 2013, 22:43

Was cruising around VIDA and happened upon some information on the torque limiting... 437: Signal Description AW50-42 Connector B.

According to the information, B1 is at battery voltage with the ignition on, but goes to Ulow ("approx 0v") both on engine idle and torque limit.

B4, the limit request ACK, stays at battery voltage with the ignition on or idling, and goes Ulow on ACK.

Chart attached, PDF.

Interesting thread, y'all!

Not sure I'd want to do this, my T5 seems quite able to shred tires as it is, but I did like the suggestion of wiring it into the TRACS switch.

Also, in regards to the timing retard for gear shifts, that apparently only applies to ECON mode:

Shifting (cars with electronically controlled automatic transmission)
Just before shifting a signal comes from automatic transmission control module (TCM) (11). The engine control module (ECM) replies by retarding ignition for a short time. This gives a temporary reduction of engine torque and the shift is smoother. This function is normally only connected when the driving program selector for the automatic transmission is in economy position.

Reys · Post by **Reys** » 10 Aug 2013, 13:00

Matt, did you end up wiring a 12v source to that cut wire?

Post by **matthew1** » 11 Aug 2013, 14:03

No, not yet. Right now it's an "eventuality", unless I get brave sometime soon.

Defeating the torque limit request on the Volvo 850 Turbo

Re: Defeating the torque limit request on the Volvo 850 Turb