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Defeating the torque limit request on the Volvo 850 Turbo

How to go faster, stop quicker, and turn harder. Chips, exhaust, larger turbos, bigger/slotted/drilled rotors, high performance brake pads, manual boost controllers, performance shocks/struts/springs, airbox mods and more! Also discussion on HID and Xenon lights, aftermarket foglights and other exterior lighting.
RyanT5
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Re: Defeating the torque limit request on the Volvo 850 Turb

Post by RyanT5 » Tue Feb 05, 2013 12:30 pm

Youre probably right :/


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ARD-Lucky
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Re: Defeating the torque limit request on the Volvo 850 Turb

Post by ARD-Lucky » Wed Feb 06, 2013 10:47 am

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!



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

Post by cleven » Sat Feb 09, 2013 12:23 am

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



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

Post by RyanT5 » Fri Feb 22, 2013 9:04 am

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 :D


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

Post by matthew1 » Fri Feb 22, 2013 8:29 pm

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. :D


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

Post by RyanT5 » Sat Feb 23, 2013 9:38 am

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. :D
Hey lets all make fun of the volvo newb and his stupid questions! haha thanks matt 8)


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

Post by jacobharding » Sat Feb 23, 2013 7:30 pm

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.


I am not an expert mechanic, but I will attempt any repair. Worst case scenario is I screw it up worse than it was.

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94 850 Turbo wagon waiting for tranny
2 94 855's gone
They're all gone now....

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

Post by mercuric » Mon Feb 25, 2013 10:43 pm

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! :mrgreen:

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

Post by Reys » Sat Aug 10, 2013 1:00 pm

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



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

Post by matthew1 » Sun Aug 11, 2013 2:03 pm

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


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1997 850 T5, MSD ignition coil, Hallman manual boost controller, injectors, R bumper, OMP strut brace [gone]
2004 V70 R [gone]

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