| cinergi |
I've never done this before, but was curious when a friend of mine informed me about standing brake starts .. but it appears the murano won't do it? Presumably because it would be a bad idea with the CVT and the computer's programmed not to allow it ...
I'm also sad that the torque converter doesn't allow higher RPMS in general at low speeds.. there's a lot of lost low-speed power there :-( |
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| Snow MO |
| Your Murano is being smart by not allowing you to do this. It's not good for your transmission and even if it did allow this I wouldnt recommend it. |
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| Eric L. |
| I believe in one of the car mags (the one that got a Murano going from 0-60 in 7.5s), it was noted that the Murano could be brake torqued, although I imagine it would be killer on the CVT and tiny torque converter. |
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| wchandler |
| When my son was 16, with a hot new driver's license in his pocket, he tried this on my Plymouth Valiant. Took out the transmission AND the differential! |
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| Edward98 |
| I don't get all the fuss. Yes the Murano can be brake torqued. Doing so will spin the wheels on a FWD model. I did this on our test drive. What's going to get "killed?" I don't know what the stall speed of the TC is; but I'd put it around 2.2k. If you hold the brakes and bring the engine up to that, then release the brakes with a gas pedal stab, what's the harm? It's less of a shock to the entire driveline because the driveline is now preloaded. Simply mashing the go pedal is more stress since it's a shock to the whole driveline. The only thing that torque braking does is raise the temp of the tranny fluid. Now simply holding down the gas to the floor while holding the brakes is not proper brake torquing and IS bad. |
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| Eric L. |
| My understanding is that brake torquing loads up the transmission, which means it generates excess heat. Heat is the major cause of transmission failures, and with the $5000 piece of technology in the Murano, I would not take a risk for slightly faster acceleration. |
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| senza |
| Edward98 - there is a concern that the CVT is a weak link in the drive train...this is reinforced by the fact the engine is programed to not provide full power at launch when "floored"...I don't think a short "brake stand" would be harmfull...the CVT is programed to shut down if overheated... |
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| GMTURBO43 |
I wonder about the validity about the strength of the Murano's transmission. How many people have actually experienced a failure?
It's probably less than a conventional trans as there aren't and bands or clutches to break.
Doing a brake torque does generate a bit more heat - a lot more heat. There are SOME vehicles that the acceleration will improve by doing this. I don't know if the Murano will or not. But really, what are you trying to accomplish? It wasn't designed as a drag car. Doing this isn't going to make enough of a difference that you're gonna beat a Mustang (or whatever other car you have a personal vendetta against :) ).
Now, I have done a bit of a brake torque in the Murano. It does make a difference - but really isn't something that should be done with any sort of frequency.
The transmission does have a load when you are in drive. Now revving it neutral - you have NO load going to a whole lotta load. That maneuver will certainly cause problems. |
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| Eric L. |
| Reading about how people have no reservations with brake torquing their cars or driving at velocities which bump the speed limiter, it makes me question whether I would ever want to buy a used car, ever. |
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| Kris |
quote:
Originally posted by Eric L.
Reading about how people have no reservations with brake torquing their cars or driving at velocities which bump the speed limiter, it makes me question whether I would ever want to buy a used car, ever.
Had 3 "preowned" and 7 new cars. I cannot say the preowned caused me more problems...........but as you said, reading some of the horror stories make me wonder, should my next car be "preowned"............ |
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| cinergi |
woah look at what I stirred up :-)
I just brought it up as a discussion point really.. I'm not into racing the murano :-) but I am disappointed at the slow low-end startup.. it could do a lot better.
The belt can handle more, but with the obvious lifetime tradeoff.. Search for "350" on this page:
http://www.lasercannon.com/cvt.htm |
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| Edward98 |
quote:
Originally posted by Eric L.
My understanding is that brake torquing loads up the transmission, which means it generates excess heat. Heat is the major cause of transmission failures, and with the $5000 piece of technology in the Murano, I would not take a risk for slightly faster acceleration.
Yes the tranmission is loaded. No there is nothing moving in the tranny. Any heat generated during brake torquing is ONLY due to the TC. There is absolutely no slip in a CVT, or conventional transmissions (except during gear changes), to generate heat while brake torquing. Only the friction between the pump, fluid and turbine generate heat. |
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| Kris |
quote:
Originally posted by cinergi
woah look at what I stirred up :-)
I just brought it up as a discussion point really.. I'm not into racing the murano :-) but I am disappointed at the slow low-end startup.. it could do a lot better.
The belt can handle more, but with the obvious lifetime tradeoff.. Search for "350" on this page:
http://www.lasercannon.com/cvt.htm
You started a good discussion. I am too dissapointed with slow start, 0 to 40 is really sluggish. Could have been better. But this is the nature of the Murano. We have to live with it..........or get a different car...;) |
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| wynand32 |
Is it my imagination, or does the Mo accelerate more crisply if one taps the accelerator, waits a millisecond while the vehicle begins to accelerate, and THEN presses alot more firmly on the accelerator? I was intrigued by the comment that the Mo is computer-limited against too-harsh acceleration; this makes sense to me, as I've noted that flooring the thing doesn't have the expected results (e.g., high revs).
It's an oddity, but I do seem to get MUCH better acceleration with this technique... |
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| SIM |
| The best acceleration I got until now was always when I stepped on it in Ds and sligthly lifted the right foot after a couple of secs. |
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