superstuddc27

iTrader: (1)

So... i never actually drove the e shift type stuff like on the Z until tonight. My dad got a prelude. yes.. don't ask. but anyways, is there anything special i gotta know about using that?

Like when i downshift, do i have to revmatch and all that?

When i go from 5 to 3 or something, or 4 to 2, etc. can i just downshift down 2 gears without having to do anything?

Can i still blow the engine if i redline on 3rd and then downshift to 2nd... or is there a safety measure on the autos that don't allow you to do that. This can be a deadly mistake, playing Initial D or something cause Initial D, up means down, and down means up. yeah, go figure.
THanks

Speeddemon69

The tranny is computer controlled, so if your in 4th and try to downshift to 2nd it won't let you.

Aggro_Al

Uhh, OK.

The 5AT will let you doubled shift down. You can do the 5-3 or the 4-2 just by quickly tapping the shift lever down twice in manual mode or you can do the 5-3 in auto mode by quickly depressing the throttle. If your action bumps you up against the rev limiter it might delay the next shift by a bit but if you only do a single shift in manual mode you can bounce up against the rev limiter until you shift.

Speeddemon69

What I meant to say is if your redlining in 4th It won't let you shift down to a lower gear. You have control of the shifter but if you make a mistake the computer will take over. That's what he means.

Aggro_Al

It will let you shift and you might spike over the rev limiter for a short period but the rev limiter will eventually cut your throttle so that you are again below the limit. The manual transmission will do the same thing.

Aggro_Al

The most common mistake people make when using the 5AT in manual mode is lifting off the throttle when shifting. When shifting in manual mode keep your foot in the throtttle or accelerate. Lifting off the throttle will cause a lag or real slow shift.

superstuddc27

iTrader: (1)

oh okay.. yeah i noticed that too. but even when i foot is on the gas, it seems to come after like 1 or 2 seconds... just like how long a real manual would take with the motions and all that.

dkny_boi

iTrader: (2)

The ones in the prelude are pretty slow... when i drove it and nearing redline then up-shift, it's slow enough that i always thought i'd run into the rev limiter b4 it finished the shift so if that's what your gonna drive all the time you'll learn to leave room for that.
But as for downshifting when you're not supposed to the car won't let you screw the engine up. If you're already redlining and accidently go down the engine's not gonna keep revving past the limiter.

superstuddc27

iTrader: (1)

oh wow.. good to hear. now... another question comes to mind. I know when i downshift, the engine makes the revving noise and it seems like it's "straining" when i downshift at high speeds. Is it bad for my engine, unless i really need to downshift.

I.E Lets say im going 40mph and im in 4th manumode, and then i go down to 3rd, it goes "revvvvvv" and slows down a bit, and then after it slows at around 30mph, i downshift to 2nd and it kind makes the "downshift noise"... is that bad for the engine if i always drive like that? I mean there's no clutch to burn, so ...im thinking maybe something else might be getting screwed up. Thanks

superstuddc27

iTrader: (1)

^ i guess it's the same thing as, like when your're driving a real manual and you downshift to slow down instead of hitting the brakes.

Aggro_Al

What you are doing is engine braking. It's the same thing when you do it in a manual.

It is possible to spike over the rev limiter for a short time with the 5AT but the rev limiter will cut your throttle and bring you back down.

The 5AT is an adaptive transmission. It continually learns and adapts to your driving style. If you're aggressive, it will shift almost as fast as F1 type transmissions. It will shift in a fraction of a second. Drive it like a pansy and you will get shifts that match your style.

havabooz

at the speeds you mentioned, you will do nothing wrong by downshifting...i downshifted from 4-2 and yes it makes that sound but its perfectly normal

cbduece

So you are saying that my tranny learns over time how I drive and will adapt to my driving style. How does that work?

wildone_106

I noticed that too its pretty sweet the way it adapts, it'll not shift till way up on the tach if I leave it on auto sometimes

Aggro_Al

Yes, it does learn your driving style if you have the 5AT. The 6MT is not adaptive.

Here's a link with a quick description.

http://www.carlist.com/autoglossary/...ossary_31.html

Here's a press release from back in 2002 from Siemens VDO Automotive AG. I think the Nissan version is more advanced.

http://www.siemensvdo.com/com/pressa...ticleID=06006e

cbduece

Holy crap, I didn't know our cars had that! How often does the chip adjust? If I drive the car light for say, the first 1000 mi, will the chip permanently alter the shift point on the tranny? How often does it update driving styles?

Aggro_Al

The system is continuously adjusting and updating. I'm not sure how long or how much info is stored before the old info is dropped. If another driver started using your car (yeah, like that will happen) it would eventually adapt to the new driver. The dealer can also reset the system to the factory defaults. The transmission uses several different shift profiles and the system will adjust the appropriate profile. Casusal or easy driving will probably have no or little effect on the more performance oriented profiles. It will affect the conservative profiles more.

Sequential shifters have a similar system. In this system the driver pre-selects a fixed shift algorithm (ie Sport mode, etc), which won't change unless the driver changes it. The driver then uses another setting to adjust the quality of the shifts (ie BMW Drivelogic). Depending on the driving environment the driver may not be able to react fast enough to change the profiles when necessary. In the Z, the 5AT uses sensors to choose the shift algorithm. There is no need to guess if you are using the right algorithm and the changes are fast. The 5AT uses fuzzy logic from the info it gained from the sensors to adapt to the driver. Unlike the fixed profiles in a sequential shifter, the 5AT dynamically tweaks the base profiles to improve performance, comfort and/or efficiency based on the driver and his environment.

superstuddc27

iTrader: (1)

wow thats crazy.. so is that only for the Z's and other 30 grand cars?

im talking about a 1998 prelude.

Aggro_Al

Sorry, 98 Prelude won't have it.

Some similar systems to the Z that have Adaptive Transmission Control are:

BMW Steptronic
Porsche Tiptronic S
Mercedes-Benz AMG SpeedShift
Aston Martin Touchtronic 2

Not bad company if you ask me.

There are several torque-converter based transmissions with some sort of manual mode but as far as I know there aren't many with ATC.

SteveZ33

Aggro_Al,
This is very cool and interesting information. Where can I find the offical Nissan description of the 5AT that states that the tranny indeed uses an algorithm to adapt shift programs? I looked in the sellers brochure and there is no mention of it. Did Nissan publish it on the web somewhere? In no way I'm saying that this info is untrue, because I want it t be ;0) I just would like to see Nissans explanation. Thanks for the interesting reading.