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Unread 02-18-2014, 09:18 AM   #1
Tlacuache
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Can one convert a qt2 to a qd2?

(2014, GC Overland) Is it possible/feasible to convert a qt 2 system to a qd 2? If so, what is the expected cost?

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Unread 02-18-2014, 09:21 AM   #2
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If possible, you'd be replacing a substantial portion of the drive train and also entering into potential challenges with the vehicle electronics. And it would be major expensive. If you want/need QD, it may be less expensive to trade in what you have now for a vehicle that's equipped the way you want it. This is not a simple conversion; it's more of rebuilding the vehicle. Now if you win the PowerBall...
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Unread 02-18-2014, 09:41 AM   #3
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Originally Posted by Tlacuache View Post
(2014, GC Overland) Is it possible/feasible to convert a qt 2 system to a qd 2? If so, what is the expected cost?
Its been discussed here before, the consensus is it would be less money to trade the QT vehicle for one with QD, probably be more reliable to.

As a minimum the entire rear diff assembly would be replaced, a QD control module added, some wire harness work, the traction control computer updated, the ECU and ABS computers reprogramed with the new capability (and to turn rear brake traction control off)... if you can find a dealer that knows how to do that and is willing to.

If you are thinking about just replacing the diff from a donor vehicle and not integrating the diff control with traction control (e.g. a separate diff control switch), the ELSD diff uses a stepper motor and you need a more sophisticated controller than a simple switch to operate it. The OEM controller operates off the CAN bus. Someone clever may be able to hack something, but it won't be integrated.... and I dunno how you would disable just the rear brake traction control without throwing codes. That seems to be the one of the biggest hurdles with many of these mod attempts, getting rid of the fault codes.
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Unread 02-19-2014, 07:41 AM   #4
Tlacuache
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Thank you both very much. It appears that I would have a better shot winning the power ball than successfully converting over from a qt2 to the qd2 system. I also do appreciate the detailed technical explanation...
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Unread 02-20-2014, 07:20 AM   #5
loveracing1988
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Originally Posted by ColdCase View Post
Its been discussed here before, the consensus is it would be less money to trade the QT vehicle for one with QD, probably be more reliable to.

As a minimum the entire rear diff assembly would be replaced, a QD control module added, some wire harness work, the traction control computer updated, the ECU and ABS computers reprogramed with the new capability (and to turn rear brake traction control off)... if you can find a dealer that knows how to do that and is willing to.

If you are thinking about just replacing the diff from a donor vehicle and not integrating the diff control with traction control (e.g. a separate diff control switch), the ELSD diff uses a stepper motor and you need a more sophisticated controller than a simple switch to operate it. The OEM controller operates off the CAN bus. Someone clever may be able to hack something, but it won't be integrated.... and I dunno how you would disable just the rear brake traction control without throwing codes. That seems to be the one of the biggest hurdles with many of these mod attempts, getting rid of the fault codes.
Would you really need to disable the brake traction control for the rear? It needs a decent amount of wheel spin to operate so in theory the ELSD should kick in before the traction control has a chance to. That is just one of the problems anyways but just a question.
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Unread 02-20-2014, 09:43 AM   #6
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Originally Posted by loveracing1988 View Post
Would you really need to disable the brake traction control for the rear? It needs a decent amount of wheel spin to operate so in theory the ELSD should kick in before the traction control has a chance to. That is just one of the problems anyways but just a question.
I dunno, may work. They do go to a lot of effort to disable the LSDs when ABS is activated, so there may be some unwelcome vehicle dynamics. Axles locked together while ABS is trying to stop one or both wheels.... you have the engine trying to spin the drive shaft but can't because the ELSD is locked and brakes are applied... something is gonna give maybe.. although the torque converter may prevent damage... it could get ugly.

I suppose for off road slow speeds it may not be a problem.

Oh, by the way I played powerball yesterday and won $7..
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Unread 02-20-2014, 10:26 AM   #7
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Congrats ColdCase on your power ball winnings.

Although both systems can get you where you need to go, both off road and in slippery conditions, if qd 2 was rated a perfect 10 in the worst case scenario (meaning that the qd2 can bail you out without any additional assistance), were would qt 2 rate? 9 out of 10...8 out of 10...7 out of 10...?
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Unread 02-20-2014, 02:26 PM   #8
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Originally Posted by Tlacuache View Post
Congrats ColdCase on your power ball winnings.

Although both systems can get you where you need to go, both off road and in slippery conditions, if qd 2 was rated a perfect 10 in the worst case scenario (meaning that the qd2 can bail you out without any additional assistance), were would qt 2 rate? 9 out of 10...8 out of 10...7 out of 10...?
I don't think there is a simple answer. In my opinion there are bad situations where a good driver and QTI is better than QTII and QTII better than QD.

QD's advantage is preventing wheel spin before it happens, important when you are stoplight-stoplight racing (no rear wheel spin and without power robbing BTC), on rocks with several tires off the ground, or when starting from a stop in a slippery situation. QD just doesn't spin the tires as much. QTII and QTI is better where you don't want both rear tires spinning for stability. QTI can be smoother than the others, as QTII/QD clutch operation seems to be abrupt in many situations.

If you are in so deep that QTII is not going to bail you out, QD is probably not either. The low range in QTII and QD will probably make it easier to get out of a really tough situation than QTI, or make it easier to modulate the engine power to creep along at a slow rate. All in all there are probably many more likely situations where QD has just a bit of advantage over a QTII vehicle other things being equal.
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Unread 02-22-2014, 11:25 PM   #9
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I just scream america and stomp the gas on the SRT let SRT system do it's werk Basically a modified QT1. even in 6-8 of stuff .

Basically trade it in for a QD model.
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Unread 02-22-2014, 11:48 PM   #10
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That seems to be the con census...
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