Funny Thing With The Od Button
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I was out driving the other day on the freeway doing about 70 mph and hit my OD button (so the O/D light came on) and floored it. Then while my rpms where around 4.5 K I pressed the OD button again to put it back into O/D mode and noticed the tach jump up by about 500 rpm and it felt as if my car began to pull harder. I repeated this several times with the same results. Its as if the car was getting a slight boost in power when engaging the O/D at high speeds (Yes I mean gaining power in the O/D mode vs. in the non O/D mode.) Would some of yall try this with your cars and see if you experience the same thing and get back to me. I just thought this was strange but at the same time kind of cool if in fact it is causing the car to get a little more juice at high speeds. Later
Diederik
Diederik
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I noticed this on my 2000 auto when I had it, I never said anything because thought it was all in the head. lol
Originally posted by DMan_2KMax
I was out driving the other day on the freeway doing about 70 mph and hit my OD button (so the O/D light came on) and floored it. Then while my rpms where around 4.5 K I pressed the OD button again to put it back into O/D mode and noticed the tach jump up by about 500 rpm and it felt as if my car began to pull harder. I repeated this several times with the same results. Its as if the car was getting a slight boost in power when engaging the O/D at high speeds (Yes I mean gaining power in the O/D mode vs. in the non O/D mode.) Would some of yall try this with your cars and see if you experience the same thing and get back to me. I just thought this was strange but at the same time kind of cool if in fact it is causing the car to get a little more juice at high speeds. Later
Diederik
I was out driving the other day on the freeway doing about 70 mph and hit my OD button (so the O/D light came on) and floored it. Then while my rpms where around 4.5 K I pressed the OD button again to put it back into O/D mode and noticed the tach jump up by about 500 rpm and it felt as if my car began to pull harder. I repeated this several times with the same results. Its as if the car was getting a slight boost in power when engaging the O/D at high speeds (Yes I mean gaining power in the O/D mode vs. in the non O/D mode.) Would some of yall try this with your cars and see if you experience the same thing and get back to me. I just thought this was strange but at the same time kind of cool if in fact it is causing the car to get a little more juice at high speeds. Later
Diederik
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Posts: 306
Originally posted by Russ2kSE
I noticed this on my 2000 auto when I had it, I never said anything because thought it was all in the head. lol
I noticed this on my 2000 auto when I had it, I never said anything because thought it was all in the head. lol
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Joined: Aug 2000
Posts: 437
Possibly the torque converter doesn't shut off if you do that so more torque (feel it in the seat of you pants) power gets applied in that rpm range when its not supposed to normally.
Reason:
Maybe nissan engineer never thought of that scenario? :P
Reason:
Maybe nissan engineer never thought of that scenario? :P
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Originally posted by DMan_2KMax
Hey Russ congrats on your new 2K1 5 speed maxima, I'm jealous only because yours is a 5 speed. Any plans to modify your new baby? Take care.
Hey Russ congrats on your new 2K1 5 speed maxima, I'm jealous only because yours is a 5 speed. Any plans to modify your new baby? Take care.
Yep, it has already begun... I orderered AXXIS Deluxe pads for the front, got my clear corners in today, and ordered my RSTB so far
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What's likely happening is that your torque converter is locked up when you're cruising, then when you turn off O/D, the tranny unlocks the torque converter.
This results in the torque converter "slipping". This isn't real slipping, but what a TC normally does: provides an RPM ratio between input and output shafts, and magnifying torque at the expense of higher revs.
Then, when you shift back into OD, the tranny hasn't decided to lock up the TC yet (since you're applying more throttle and trying to accellerate). Having the TC unlocked gives you a bit more torque at the wheels, and lets the engine rev a little higher.
You'll notice this when driving w/ cruise control on. For me, cruising at 60MPH, TC locked, the engine turns at 2K RPM. If I start going up a hill, where the engine can't pull at 2K RPMs, the tranny unlocks the TC, at which point the engine turns at about 2600 RPMs. This keeps the tranny from shifting down to 3rd, since there's enough torque from the engine at 2600 RPMs to pull up the hill.
I'm not sure when the TC gets locked (if it's only in OD or not). But in OD, it acts like another "gear", giving the wheels a little torque boost at the expense of a few engine RPMs, without having to shift out of OD.
Phew - wasn't that long winded?
This results in the torque converter "slipping". This isn't real slipping, but what a TC normally does: provides an RPM ratio between input and output shafts, and magnifying torque at the expense of higher revs.
Then, when you shift back into OD, the tranny hasn't decided to lock up the TC yet (since you're applying more throttle and trying to accellerate). Having the TC unlocked gives you a bit more torque at the wheels, and lets the engine rev a little higher.
You'll notice this when driving w/ cruise control on. For me, cruising at 60MPH, TC locked, the engine turns at 2K RPM. If I start going up a hill, where the engine can't pull at 2K RPMs, the tranny unlocks the TC, at which point the engine turns at about 2600 RPMs. This keeps the tranny from shifting down to 3rd, since there's enough torque from the engine at 2600 RPMs to pull up the hill.
I'm not sure when the TC gets locked (if it's only in OD or not). But in OD, it acts like another "gear", giving the wheels a little torque boost at the expense of a few engine RPMs, without having to shift out of OD.
Phew - wasn't that long winded?
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Originally posted by El Guapo
What's likely happening is that your torque converter is locked up when you're cruising, then when you turn off O/D, the tranny unlocks the torque converter.
This results in the torque converter "slipping". This isn't real slipping, but what a TC normally does: provides an RPM ratio between input and output shafts, and magnifying torque at the expense of higher revs.
What's likely happening is that your torque converter is locked up when you're cruising, then when you turn off O/D, the tranny unlocks the torque converter.
This results in the torque converter "slipping". This isn't real slipping, but what a TC normally does: provides an RPM ratio between input and output shafts, and magnifying torque at the expense of higher revs.
Well your REAL close. My VG AUTO does the same thing. If you notice in the original post....he is describing a JUMP of 500 rpm when he clicks into 4th gear. When you lock out 4th(O/D OFF) the car will hold 3rd BUT the TC WILL lock. When you click the button again to go into 4th the TC must unlock first....THEN shift into 4th. Thats why the rpms jump up 500....then the car shifts.
Good explanation on the TC though.
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Posts: 1,046
Originally posted by El Guapo
What's likely happening is that your torque converter is locked up when you're cruising, then when you turn off O/D, the tranny unlocks the torque converter.
This results in the torque converter "slipping". This isn't real slipping, but what a TC normally does: provides an RPM ratio between input and output shafts, and magnifying torque at the expense of higher revs.
What's likely happening is that your torque converter is locked up when you're cruising, then when you turn off O/D, the tranny unlocks the torque converter.
This results in the torque converter "slipping". This isn't real slipping, but what a TC normally does: provides an RPM ratio between input and output shafts, and magnifying torque at the expense of higher revs.
Well your REAL close. My VG AUTO does the same thing. If you notice in the original post....he is describing a JUMP of 500 rpm when he clicks into 4th gear. When you lock out 4th(O/D OFF) the car will hold 3rd BUT the TC WILL lock. When you click the button again to go into 4th the TC must unlock first....THEN shift into 4th. Thats why the rpms jump up 500....then the car shifts.
Also...having the TC unlocked would NOT give you more torque at the wheels. Sure the revs may be up a little but from 2k-5K the vq basically makes an even amount of torque(with a gentle rise throught 4K...then slowly falling, and a bump at 3200). Having the torque converter locked means the tranny is more efficent and gets more power to the wheels. Even if there is a tiny bit more power 500rpm up, its probably better to be slightly lower with the TC locked.
Last note. If you are going 75....nail it....the car will downshift to 3rd, BUT the TC WON'T lock up in 3rd. Thats because the car knows 4th is still available. When you click the O/D and force the downshift, YOU are the boss and the car knows you are preventing it from going to 4th....so she locks up in 3rd.
Good explanation on the TC though.
Make sense?
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Originally posted by Mike S.
Also...having the TC unlocked would NOT give you more torque at the wheels.
Make sense?
Also...having the TC unlocked would NOT give you more torque at the wheels.
Make sense?
from here:
http://www.howstuffworks.com/torque-converter3.htm
In addition to the very important job of allowing your car come to a complete stop without stalling the engine, the torque converter actually gives your car more torque when you accelerate out of a stop. Modern torque converters can multiply the torque of the engine by two to three times. This effect only happens when the engine is turning much faster than the transmission.
You gotta love fluid engineers!
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Re: question
Originally posted by MaxSEAE
i always keep my OD on cuz i don't want to go into the hassle of turnning it on and off....is it bad to do that? and if so, how bad?
i always keep my OD on cuz i don't want to go into the hassle of turnning it on and off....is it bad to do that? and if so, how bad?
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Posts: 160
Sounds about right. Try this to see how the unlocking of the converter feels.
Cruise around the highways around 60ish or so. Start feeding it extra gas and keep an eye on the tach. Don't trompt it - we don't want it dropping to third gear. Notice at some point, when enough gas is applied, the tach will jump (As we've established) about 500 rpm's and you'll feel what feels like a drop in gears - there's your unlock on the converter. NOW press the O/D button. THAT feeling is third kicking in.
When I originally did all of this, I thought, damn, did I read something incorrectly and these things come with 5sp autos? Unfort., no. It was just the converter doing it's job.
Cruise around the highways around 60ish or so. Start feeding it extra gas and keep an eye on the tach. Don't trompt it - we don't want it dropping to third gear. Notice at some point, when enough gas is applied, the tach will jump (As we've established) about 500 rpm's and you'll feel what feels like a drop in gears - there's your unlock on the converter. NOW press the O/D button. THAT feeling is third kicking in.
When I originally did all of this, I thought, damn, did I read something incorrectly and these things come with 5sp autos? Unfort., no. It was just the converter doing it's job.
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