CVT General Question

[A_C_Fanatic]

So i was driving to connecticut 2dai and im on the I95 and i just decided to mess wit the Trip-Tronic is there any difference on driving on that rather driving in the regular automatic transmission? sorry if i worded it wrong.

[08altima35]

in my opinion the sport shifters on automatic cars really serve no purpose as they are electronic and the delay is rediculous. the sport shift is still automatically shifting, but your telling it when to shift. when you shift with a standard you (the driver) are actually changing the gears with your shifter and not sending an electronic signal thru the computer telling your car to shift a gear. you're better off just driving in automatic mode in my opinion.

[godsgift]

in my opinion the sport shifters on automatic cars really serve no purpose as they are electronic and the delay is rediculous. the sport shift is still automatically shifting, but your telling it when to shift. when you shift with a standard you (the driver) are actually changing the gears with your shifter and not sending an electronic signal thru the computer telling your car to shift a gear. you're better off just driving in automatic mode in my opinion.

the delay electonically is probably faster then when you do it with youre hand an foot

[Mr. Music]

The only use I see for the manual mode is for getting your rpm's up quickly. If you are already moving, and floor the gas (while in "D") the rpm's will rather slowly rise, as when you tell it to down shift, the rpms will jump up much quicker. There isnt much of a delay, and it most likely is quicker than a stock 6spd and a "normal" driver... Anyway, its kind of fun to play with and zoom around every once in a while. Overall, it's probably best to leave it in "Drive" for every day driving...

[08altima35]

the delay electonically is probably faster then when you do it with youre hand an foot

negative dude. if that was the case the cvt in sport shift mode would beat the 6speed from a standing idle which is not the case or even close being the cars have the same hp. maybe there's work for nissan to be done in improving their sport shift on there CVT, but it's not there yet. i test drove both the cvt and the 6speed vq's before buying the 6 speed because for one, i love to drive standards, and two, the power when needed is always a gear or two away.

[adidas2go]

Thats a lie. They have made SMG transmission for years that shift faster than Andretti himself. SMG M3 beats 6 speed M3 all day. I used to have a Sportronic 330i myself and this CVT beats it with shifting quality and speed hands down. It doesnt matter that the 6 speed is faster than the CVT in 0-60 claims. Thats not the "shifting's" fault. Its the loss of power due to transfer between the engine and the ground. Alot more moving parts in the CVT than the Manual. The CVT is faster at shifting i guarentee it.

[08altima35]

well if that's a lie maybe you should study up some on bmw's and SMG's. Because FACTUALLY the M3 6 speed will win every time unless driver error is a factor.And that's fact and has been proved.if you need more info on this search for it, it's not hard to find.

[08altima35]

also, you can't equate the loss of power due to moving parts make up for the faster speed between shifts? you would think it would be more equal if that wer the case. the 0 - 60 times aren't really claims either. if you floor the cvt it will get the same 0-60 every single time without fail so long as the road is dry. in a man trans the 0-60 times will change depending on driver skills and know how, but this also is more than claim and has been proven too in favor of the manual trans in Nissan's

[Jeff7181]

well if that's a lie maybe you should study up some on bmw's and SMG's. Because FACTUALLY the M3 6 speed will win every time unless driver error is a factor.And that's fact and has been proved.if you need more info on this search for it, it's not hard to find.

You don't understand. The CVT transmission has more parasitic power loss than a manual transmission. It still has a pump that uses engine power to create fluid pressure to operate the CVT.

The fact that a car with a manual transmission can run the 1/4 mile faster than the same car with an automatic transmissioin is not due to the speed at which each can change "gears." The manual is faster because there's slightly more power available to move the car.

[adidas2go]

also, you can't equate the loss of power due to moving parts make up for the faster speed between shifts? you would think it would be more equal if that wer the case.

do you read what you write? make it in real sentences like the big boys and maybe i can understand. CVT has more power robing parts. Thats why its slower. You cannot shift faster than the CVT. Period.

[08Coupe]

The days when a stick was quicker are about gone, there is a reason exotic cars, "drag only" cars are going Paddle shift,SMG, auto(w/linelock) ect...A computer can shift faster then a human. The stick has its benifits on a road course due to downshifting but thats about it anymore.. My last car 2004 GTO the A4 auto was faster in the 1/4 mile due to traction concerns on the launch and also easier on the driveline. So far the CVT is a far better transmission for everyday needs (my only concern is what power levels will it handle) if I throw a 100 shot at it

[Hussain]

BMW's SMG wasn't that great and stick shift WAS FASTER. that's why they no longer use SMG. the new M3 is DSG. plus that's completely different. that has 2 clutches and something about 1 clutch is already holding the next gear so when you hit the paddle it shifts really fast. they got it to shift in .2 seconds and DSG is quicker then stick, NOT SMG. but as for CVT shifting slow, OMG enormous lag!!!! my mom had a 2005 Nissan altima 5speed (traded it for a maxima when i got my A/C) and i'd shift way quicker with that. i don't get it tho, CVT doesn't even have gears, they said something about you're not really shifting gears, you're shifting gear ratios or something (forgot the exact details) but if it's not shifting gears, it should be able to "shift" quicker. can't wait for a performance tune to come out for it

[Mr. Music]

i don't get it tho, CVT doesn't even have gears, they said something about you're not really shifting gears, you're shifting gear ratios or something (forgot the exact details) but if it's not shifting gears, it should be able to "shift" quicker.

From my understanding, it doesn't shift gears either; it just changes the gear ratios in set increments upon driver command.

[cliffy21]

Since no one appears to know the real difference between SMG and DSG, i thought i'd add some info. An SMG is a clutchless manual. It is usually shifted using steering wheel paddles. The BMW version was not very good, so yes, it's true that the 6sp was faster, in that case. But SMG's are all about programming, and the one's that are implemented properly, they should be faster than a good manual driver. Ferrari put a SMG in the Enzo. The only downside to SMG's is that the gas does have to be interrupted while the shifting takes place.

DSG's are a dual clutch system (like mentioned by the rich kid Hussain ). It's almost like having 2 3-speed gearboxes. The clutch is engaged for the current gear, and the 2nd clutch is engaged for the next gear already. This allows a seamless shift.

Some numbers i found. Aud's DSG can shift in 8 milliseconds. Ferrari's SMG, 150 milliseconds. Pretty substantial difference. Oh, and any human that things he can shift gears faster than 150 milliseconds is on drugs.

Hope some of this helps people understand the difference.

[cuzzbubba420]

Pop your altima into manual mode and just go wot and then you will see the difference. To me the acceleration is much slower in manual mode when you punch it than in "D"! The manual mode also shifts at like 5800 rpm's and I agree that there is serious lag in running through the next "gear". I find a much better burst when just punching it in drive where as trying to run through the cvt manual mode.. Besides, when your in "D" the rpm's will sit in the sweet spot where as in CVT your just running through electronic gears.. Just seems like your not getting the most out of the CVT in manual mode!!

[08altima35]

the standard shifts faster than the cvt in manual mode is all i was trying to say and everyone here seems to agree as well. i think you thought i was talking about shifting faster than the cvt in regular automatic mode which i was not being the cvt in drive does not shift. anyway, nothin' but love for ya adidas

[adidas2go]

na dude since in auto it doesn't shift i didnt think you were saying that. I have owned manuals in the past. And from shifting a manual and hitting the up switch in the CVT. Doesn't seem like any person is gonna shift fast thats all im saying. The milliseconds it takes to shift in cvt mode i dont think can be matched by a human. Just seems impossible to me. When i put my pedal to the floor and shift myself its shifts rediculously fast.

[Vhernandez919]

[Jeff7181]

From my understanding, it doesn't shift gears either; it just changes the gear ratios in set increments upon driver command.

Nissan uses a Jatco CVT which uses a pully and belt system. There are two pulleys, each is made up of two cones with the "points" facing eachother. The belt is a fixed width, so as you slide the cones together or apart, it changes the effective diameter of the spot where the belt is riding between the cones. For a better idea of what I'm talking about, check out this video.

Contrary to what some people think, the cones are not moved with electronic solenoids. The ratios are controlled with an electronic solenoid, but the solenoid controls fluid flow by moving a valve, just like in a normal automatic transmission. I found an animated diagram somewhere before but I can't find it again. Basically there's a pump in the transmission that's driven off the input shaft just like a regular automatic transmission... that builds fluid pressure (60-100 psi in a traditional automatic, not sure about the Jatco CVT). Then you have a spool valve (also, just like in the valve body of a traditional automatic transmission) that controls fluid flow. When fluid is directed in one path, it moves one pair of cones together and the other pair apart to adjust the ratio. Direct it in another direction and it does the opposite.

And for the record, I have a hard time believing anybody who says CVT's shift slow have driven a car with Nissan's Xtronic CVT. I think people are confusing shifting hard with shifting fast. Slamming a manual into gear and dropping the clutch doesn't necessarily mean you're shifting fast.

[adidas2go]

[adidas2go]

exactly. i think the people saying they can shift faster than the CVT havent driven it

[cuzzbubba420]

I concur wise oh wise one!!

[A_C_Fanatic]

so i was on my way to my house one night in the summer. So my friend goes yo lets race from one light to the other im like ight w.e. im thinkin he was gonna beat me since he has a Dodge Charger. So im waiting at the red light kept my car in regular nd when it turned green floored it so good that my tires didnt skid on the floor nd 2 seconds later switched it to trip-tronic and downshifted nd blew him outta the water....later he goes yo run it on the highway cuz some dude cut me off...personnaly i rather do it from light to light than on a highway cuz more chances of getting into an accident....even tho our breaks are really nice as hell...but thats just me highway doesnt prove nething but cutting nd switching lanes...thats bout it...but thats just me....but seriously i kinda felt power when i downshifted..sorry long story but i had to share it with my fellow coupe'rs haha

[Jeff7181]

Street racing is not cool. Take it to the track.

[cuzzbubba420]

Sounds sweet man!! I never tried that method of shifting so I'll give it a run next time I'm out driving!!

[XxXSnake23XxX]

Street racing is not cool. Take it to the track.

+1 yeah man

[Hussain]

i own a 3.5se Altima Coupe with CVT and drive it everyday (just came home from a drive actually) and i'm comparing it to the 2005 2.5S altima stick shift i used to drive. i could shift faster with the manual then CVT shifts. personally if i race from a roll, i put it in manual mode to get the RPMs up, floor it and hit it back into "D" and just stay at redline the whole time. manual mode does shift slow and in "D" your RPMs are at the full 270 horsepower the whole time, VS building up to that RPM and then shifting SLOWLY. plus i'm not sure if this is true or not (haven't raced manual mode in a while since it's slower) but doesn't "D" get the RPMs up higher? in manual mode it automatically shifts right BEFORE it hits the RPM you want it to. meaning the RPMs dont get high enough and does not give you the full power. doesn't "D" let the RPMs go a little higher?

[shift_mikey]

If it shifts in manual mode before redline, make sure your foot is smashed all the way to the floor to the kickdown switch. if your just resting on the kickdown switch it will shift about 300 RPM earlier

[cuzzbubba420]

Yeah for sure. On the 2.5 s it shifts at around 5800 rpm in manual mode. If your going from a dead stop or rolling both way's sound pretty good to get the rpm's up but I like starting in manual and going to "d" cus like you said the rpm's sit in the sweet spot and your getting the maximum power you can get! I'm going to post a vid once I get my stillen installed next week.. I've been hunting a civic si around town.. muahahaha

[cuzzbubba420]

I'm going to give that another try but I swear when I floor it in manual mode it just always seems to shift no matter what around 5800 and I mash the pedal to the floor! I read that online also there is the option of the "kick down" so you can red line but I have yet to rev that high!