6MT vs 7AT and the Track/Auto X
 

FLAME SUIT ON!!!

I know the 7AT is faster in a straight line and all... But, which do you think would be better/faster for the track or AutoX??

The CaymanS PDK best the MT on the track, but what about the Z's 7AT? Will it best the 6MT on the tracks??

I would really like to hear from those who may have tracked a 7AT.

Sorry for another thread like this. PLEASE let's keep this mild and civil as I really would like this input versus having the thread locked! If I looked over another thread discussing this point, just point me in the right direction.

THX ALL!!

7AT would best a manual in that situation for a few reasons.

1) More gears = more ratios to keep it in the best range for delivering the most torque/hp.

2) It shifts faster than a manual.

Not sure what others do but when I auto-x I keep it in second the whole way and never change gears because there is no need. With me I know that auto or manual it wouldn't make a difference as it would be in 2nd gear in both cases. For longer track use such as road courses I can't say as I don't have any experience with it.

280z/300zx is right, I also read a review about the auto in a auto x event and they felt neither 2nd or 3rd really felt like the perfect gear where with the manual they could slap it in 2nd and be happy.

I guess it depends largely on the course and your driving habits.

Couldn't this be due to (or be resolved by) changing the FD ratio?

(reference to the FD Ratio for the 7AT is different than that of the 6MT)

It could be, but I have not done much research yet on changing the FD ratio yet.

also gentlemen, keep in mind, the auto tranny's temp will skyrocket during prolonged track use, you'd need an expensive transmission cooler. Not needed for the 6MT. And I agree, depending on the track, you can pretty much stay in 2nd the whole time. Also keep in mind that the auto isnt a twin clutch setup like the Evo's.

Who said anything about twin clutch?

As for an "expensive transmission cooler" - either the auto has one, or, it's not that bad...considering.

I made a reference to the twin clutch for the simple fact that the twin clutch doesnt overheat like an auto tranny will. During auto x events, the transmission is under constant load, and overheating and inefficiency will occur. Its ok to defend your car, but the OP wanted honest opinions, and I gave mine.

There is nothing special to the Z's auto. Don't let the paddles fool you...it is nothing like the more advanced clutch-[pedal]-less manuals which just recently surpassed their equivalent standard-manual counterparts on a track driven by a professional. It still has a torque-converter, and while it's better than your average auto found in most passenger-cars...it's still an auto.

Regardless, even if the 370Z had an optional transmission on the same level as a DSG or Ferrari's F1...I'd still take the standard.

Good honest thoughts guys...

Keep them coming!!

Sorry, but I drove a Golf R32 with DSG, and it shifts slower than my 370Z 7AT. My 2002 BMW M3 with SMG also shifted at the same speed or slower than my 370Z (to/from gears 1-5).

JMO

Gimme a stick and a clutch pedal.

Yeah...no. Sources show VW's DSG to have a shift-time of only 8 milliseconds, while BMW's SMG supposedly shifts in 80 milliseconds. A conventional automatic like the one in the Z will come anywhere near that.

Besides...too much importance is placed on shift-time. A competent driver operating a clutch and gear-lever can shift quick enough to where it doesn't matter, even when not trying to shift mad qu1ck. 400 milliseconds, or 100, or 50, or 3...who cares. At this point, you are marginally effecting straight-line acceleration. What matters is control over gear-selection, where in that case there is no comparison between a manual and conventional auto.

As mentioned above...gimme a stick and a clutch-pedal. There is no replacement for it when talking about sports-cars. I will always opt for it whenever it's available for a given model.

This is the first time I've seen a conventional automatic be defended to this level in a sports-car. Had the auto been a dual-clutch or sequential-style setup, and then we'll have an argument. :icon14:

I think auto slushboxes are greatly improved now, but i'll stick to my manual 6 spd for the challenge and fun of driving a sports car. I love rowing through the gears.

ahh, I see this getting into another 6mt vs. 7at flame war, im backing out while I still can. :)

Hey guys... remember we are looking for track related comparisions, not just the typical MT vs AT.....

Thanks for the input thus far!

Since there is no evidence to support one argument over the other, you would have to look into examples from other cars. I can't think of any sports-car offered with both a manual and conventional automatic where the automatic proved to be faster around a road-course.

I can't see why the Z would be any different. Based off conventional wisdom, this holds true until proven otherwise.

I completely agree... No question about it.

... Dont want to go there... but although 1 might be semi-accurate. 2 certainly is not... maybe its faster than your grandma w/ the 6mt but I doubt it :p

It (7AT) shifts faster than the 6MT, when viewing the entire process...ie, let off gas, drop clutch, shift, enguage clutch + gas...

The whole process is faster.

I can see the AT edging out the MT in a 1/4 mile race, but not around an actual course/track. There's just not enough control with the AT for it to beat even a semi-competent MT driver. Not a knock on the AT, but that's just how it is.

I guess it'd depend on the track.

Even then the margins would be pretty small, I'd imagine.

The AT shifts at about 500 milliseconds...

Thats a LOT ... compared to a competent MT driver... And lift off... kick in... gear change... engage is all done in ONE motion...

From what I've read, the best manage around 300 milliseconds but most aren't going to match that.

Point is - you CAN... and its something you perfect from driving your car... not to mention... you can knock off more time on the shift if you were to do some clutch / flywheel upgrades...

While Autos have come a long way from what they used to be... its still not good enough for me to replace my driving habits...

Professional drivers do something called a clutch-kick shift, its a quick stomp of the clutch, pull gear through neutral, release and gas simultaneously, this can be done in a fraction of a second, so the "Auto is faster" debate is unfounded. Hell even I can do it, and im not exactly a professional, a little bit of practice and it can be done.

btw, here is a simple example, the music is kinda gay, but you get the point...
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right around 4-500 milliseconds..

Theres a big diff on the track between a 7AT and a dual clutch box.....you can't compare a nissan 7at with a porsche pdk.

Thanks for that, Red. I also read, in Car & Driver I think, that they had issues with the 7AT not wanting to drop down 2 gears when requested. I can't see how the 7AT could best a manual on the track with a competent driver.

Who are you referring to?

If it's me, I'm not comparing the 7AT to a dual-clutch setup, or even saying anything about them.

I'm just saying that that the 7AT shifts faster than a manual.


I'm also curious what will happen when boost is involved, specifically turbo's where it's more noticable that boost would be lost due to having to let off the gas to hit the clutch, shift and go back in.

I can shift my truck fast. My Z still shifts faster.

Seems to work fine for me, but, then again, I've yet to hit a "track" with it.


The manual's only advantage on downshifting is that you can skip gears easier.

Ha ha ... comparing your Zs AT to your trucks MT is not at all accurate man...

You're right, I should compare my trucks 5MT to every other MT vehicle I've driven...oh, wait, I have, and my statement still holds true. My trucks 5MT is just as fast between gears as any other MT transmission...I can bang from one gear to the next just as fast as anyone on here, and just as fast as that video posted above, if not a shade faster. Granted, my truck is a POS 4-cyl that can't accelerate worth a crap, and when I do shift like that, I can feel the engine being dragged DOWN to the new RPM, but, I can easily shift that fast...

So, better explanation 5 steps in a manual...

1) Let of the gas
2) Push in the clutch (can be done at the same time as step 1, goal is to not let the engine "spin free", or drag)
3) Shift gears (not a lot can be done here to speed things up - physics!)
4) Let out the clutch
5) Give it gas (this can be done with step 4 if you don't mind burning your clutch)

Now, if you skip step 1, you're power shifting, and I bet you'd STILL be slower than the 7AT in shifting. You could save even more time if you don't care about getting a new transmission, and just slam it from gear to gear, if you're good with your throttle. I've done it with my bike when I got in a wreck and rode it home with a broken left wrist...can't work a clutch that way!

There's not much that you can do to make a shift between gears happen faster with a manual..you have a stick that you have move to get to the next gear, and synchonizers that DO slow the process down a bit.

7AT does what - release a band or a clutch pack? The difference with the 7AT in this car and most autos is that it's not trying to be smooth, it's getting the job done the way a sports car should. Snappy...

I believe he meant that your comparing your truck clunk box to a true sports car manual transmission, completely different gear ratios, shift throws, etc. If you cant shift faster than your 7AT, then my friend, you just arent that great of a shifter. Its ok to defend the car you drive, thats all fine and dandy, but the car will not be a solid track performer in stock form, the 6MT will always have the advantage on an auto X track. If its racing you want to do, leave it to the drags.

Have you driven a 7AT Z...in manual mode?

I'm also not defending what I drive...I'm stating what seems to be contrary to what a lot of people think regarding the 7AT.


You realize that the average person's reaction time at a drag strip is around 500ms - right?

At least, those who don't try and anticipate the light.

It still has a torque converter. "Manual mode" means squat as there is nothing special about the transmission. It's akin to "manually" shifting a Honda Accord between 1-2-3-D and thinking it makes a difference in performance.

Again, have you driven it?

And, yes it is different. Once you put a honda in D, it'll downshift if you mash the gas, and shift early...

Not so with the Z's 7AT. You put it in manual mode, it'll stay in that gear come hell or high water....with the ONLY exception being that the RPM drops low enough that the engine could stall.

And, regarding the torque converter - it locks early and it locks hard. You can engine brake with it. When is the last time you could do that with an automatic...seriously engine brake...I'm not talking about dropping it in a lower gear and having it wind up a little. I mean 10-20 seconds of straight engine braking from highway speeds on down without touching the brakes, downshifting from 7th, to 5th, to 4th, to 3rd, to 2nd and watching your RPM guage go smoothly from 6K on down, with no "drop" due to the TC going limp...and know that you can hit that throttle and bust the ***-end loose at any time from 3rd or lower?

I test drove one before mine, felt like an automatic.:tup:

^ Likewise... but I never would have gotten any non clutch short of a DSG

Honestly Kannibul, my wife's CX7 acts just like the Z's AT. The Z's AT does shift however.