7 speed good it just can not believe this.

wstar

Since you slipped this into the end of a locked thread elsewhere, I'll pick it up here where it flows right into the conversation.

AT's aren't as efficient as MTs, you do have to just get over that basic fact. Solid gear engagement vs fluid drive, simple as that. Our AT's do have a lock-up mechanism, but it's not employed full time, it's conditional. The 7AT is known to be faster in the 1/4, that's true on most good cars really.

Shifting time has two factors to it: the reaction to the shift input, and the actual shift time. The actual shift time on the stock 7AT is reasonably good, but any half decent manual driver will beat it. Add in the reaction delay to the up/down-shift commands, and it's notably slower. Of course, you wouldn't realize any of this because, and I quote:

Those paddles are there for a reason, if you're not using them you're really not driving the car. D-mode doesn't ever downshift properly for corners (it can't, it's not psychic, regardless of your special tuning). If all you do is drag-race the car, frankly there are faster and cheaper options for drag-racing than a 370Z :P. Your opinion on the relative shifting speed and predictability are meaningless if you only ever drive in D.

I don't regret my choice on the 7AT, but you have to face up to the fact that it is an AT, and it does come with an AT's shortcomings.

Back to your special tuning, I wasn't even aware Osiris Tuner was capable of changing the line pressure, do you have more details on this? They're certainly not advertising the feature publicly. Did your tuner say anything about possibly reduced tranny life with the upgraded line pressure without valve body upgrades?

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7AT Track Car!
Journal thread / Car setup details

Blue370tt

I am not getting into an opinion debate here: "but you have to face up to the fact that it is an AT, and it does come with an AT's shortcomings".....yes you're right....its still 1962 and AT's have'nt changed at all.

As far as your awareness of Osiris tuning on the 7AT: Its a well known fact among any 7AT's considering FI (SC or TT) on this forum and is in many of the posts and threads about FI. The tuner does'nt really know about reduced tranny life due to increased line pressures, but its irrelevant because if you dont increase your line pressures with FI you might damage the tranny NOW because of increased HP/TRQ.

There are many mysteries with this car. Will it reduce tranny life, its a new tranny....no one knows....they can guess but dont really know. Unrelated to the thread but related to this post: VVEL hasnt even been figured out by FI and tuners yet......its very complicated......so is the ECU......NONE of the tranny, VVEL, or ECU technology is the same as the 350Z or any previous car. Its still being figured out from an aftermarket point of view.

wstar

I didn't say they hadn't changed. They've improved greatly since 1962. So have MT's for that matter (much better synchronization, and of course now the automatic blipping on our cars). But it's still a fluid-drive transmission.

Think about it: There's a real reason that higher end manufacturers are putting in expensive, heavy systems like PDK and DSG (the true semi-automatics which are basically sequential manuals with automated clutches), instead of just using ATs with paddle shifters. ATs are fluid drive (lossy/inefficient) and slow to shift. The one nice thing about the AT system is the fluid torque multiplication, which really can help in the low RPMs.

In truly aggressive/track driving situation, the 6MT has the edge in shifting speed by a mile. Your quoted numbers are just the physical shifting time (e.g. in D-mode drag racing), you have to add on top of that the input delay on the M-mode system, which you're going to have to use for any serious driving (downshifting). A good 6MT will beat that any day. I've gotten used to the 7AT's shift delay to where I can compensate by shifting "early", but it took a while to get my brain to do that reliably. There are other things you have to re-teach your brain about too, like not dropping off the gas pedal until after you upshift instead of while upshifting (or else the 7AT gets confused and shifts extremely slow and clunky).

I wasn't aware this had been discussed elsewhere, but it's interesting. I'll have to talk to some local Osiris tuners and see if I can get them to play with the line pressure on mine. I'd love quicker shifts and engagements even without FI. Something tells me it will have no effect on the lag between shift button input and the start of the shifting process in M-mode though.

I love the 7AT, it's a great transmission for a mixed-use car, I just think you're taking it a little too far in claiming it's superior in every way to the 6MT. It clearly isn't.

__________________
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Journal thread / Car setup details

Blue370tt

A few things:
1. Your car is not my car and I have no shift delay in M or D mode.
2. In stock form, with non pro drivers, the 7AT has proven to be faster.
(How can that be if....as you say.....ITS HEAVIER.....SHIFTS SLOWER....
and.....IS NOT AS EFFICIENT?????)
3. You cant imply/expect every 7AT car and driving experience to be the same as your car. I dont think I have the fastest 370....BUT....if you were to ride in MY CAR.....your opinion on the 7AT would change.
4. Z1 Motorsports has done several 370 GTM TT installs (including a Nismo). Mine was the first 370 they did and they EXPECTED the 6MT to be more stout when they finally TT'd one. To their surprise IT WASNT. According to John @ Z1: All things being = (boost, mods etc..) my car was faster/stronger. NOT MY WORDS....JOHNS.
5. You seem to only be able to see things from your cars point of view.....No where on this forum have I heard anyone else talk about a shift lag on their 7AT in M or D mode. Based on this, I think you need a tranny tune or that the issue is individual to your car.
6. If you need more information about the Osiris tranny tune you should call John @ Z1 motorsports for the details on how its done. He was the one who did my tranny tune.
7. This topic (tranny tuning) has been heavily discussed on this forum for many months/a year. Originally, it was passionately discussed because 1 person on this forum (Shumby) blew his tranny up when he added an SC to his 7AT 370. Because of this perceived possible issue, we were all (FI people) trying to do what we could to potentially prevent this. So again, while its new to you, this is about my 20th discussion on this.
8. Lastly, if you feel your tranny is inferior then go buy a 6MT. I dont and I am done with this conversation.

wstar

That's physically impossible. You have a measurable delay on the shifts themselves (time to complete), which is what you'd be measuring in D-mode, and there's an additional reaction-to-input time in M-mode.

It gets better times in the 1/4 mile in general, we've established that. It doesn't shift faster (* although I'll concede with tuning and upgrades, it might be faster than a slow-*** 6MT shifter in drag-race shift times in D), and it isn't capable of being as efficient at transmitting power in gear on average. Again, it's physics.

I have no doubt with your line pressure upgrades, your 7AT is snappier than mine, that's really not at issue here.

I'll let that stand on its own. Don't know what to make of that statement really.

Nope, mine's pretty normal. This was all hashed out a couple of years ago among the first 7AT owners. Most 7AT drivers aren't manual drivers, they really have nothing to compare to experience-wise.

I've been away for a while, but I did catch up on all the problem threads about FI + 7AT. It's one of the reasons I dropped FI off of any immediate plans of mine, I don't want to deal with the additional tranny hassle.

The 7AT is factually inferior for track driving, line pressure upgrades or not. It's still a great tradeoff for me, and I like mine, as I've stated several times already. Get a grip.

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7AT Track Car!
Journal thread / Car setup details

Blue370tt

Really: here is a quote from Zelim

"I data loged the the 7 AT in the 12.42 run.

Launched at 2500 rpm.
2nd engaged at 5237, shift time 0.3 seconds
3rd engaged at 5237 , shift time 0.31 seconds
4th engaged at 5525, shift time 0.39 seconds
5th engaged at 5587, shift time 0.68 seconds"

So, MT's can shift faster than an average of .35 seconds......really???REALLY????

theDreamer

Yes, they can.

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theDreamer's Z // Fast Intentions // Uprev // GTM // HKS // TEIN
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Houston Zs // Facebook // Twitter // Instagram

KaienZ34

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Blue370tt

No way....not most average drivers....guess thats why they call you "the dreamer".

theDreamer

Do you realize how long .3-.5 of a second is?
That is a lot of time, now you want to tell me the Z auto can shift at under 0.1 then yes you can beat a manual.

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theDreamer's Z // Fast Intentions // Uprev // GTM // HKS // TEIN
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Houston Zs // Facebook // Twitter // Instagram

b1adesofcha0s

How much time does it take you or any good manual driver to shift?

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Project: b1adeZmobile (2009 370Z) | Uprev Tune by AAM Competition | Berk Exhaust
Project: b1adeZmobile 2.0 (2014 C7 Z51) | Corsa Xtreme Exhaust

theDreamer

Well clearly it takes probably TWO seconds for a manual driver to shift because there is no way it could compare to a 370z 7AT.
I am probably around .3 as I am fairly quick but not the best, a solid driver who knows what he is doing and has more practice can be in the .2 range. Beyond that you are starting to get out of the limits of a manual transmission which is when supercars and now your 70k+ cars have moved onto.

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theDreamer's Z // Fast Intentions // Uprev // GTM // HKS // TEIN
theDreamer's Silvia // URAS // GREDDY
Houston Zs // Facebook // Twitter // Instagram

4r3s

I'm confused on why this person was hitting 5th gear in the 1/4 mile, I barely got into 4th before the 1/4mile was over...

KaienZ34

Faster car, faster through the gears.

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