i was reading a lot about how people start off on the "1" position on an auto. is this a good way to race? will starting off on 1 and then shifting to 2 and the D ruin you tranny? i'm not sure about this. can anyone provide any extra explanations/details? thanks

 

There have been many posts on this topic. Search for it.

 

i searched but there was no clear detail on upshifting and downshifting. which is worse? and i want to try upshifting. can anyone provide precise information on this subject? thanks

 

Basically when you are stopped and you put the auto in 1st....you are basically acting as a manual. However, when you start to accelerate from the stop and you need to shift into 2nd, the car takes about a second to actually shift into 2nd gear. This lag is what kills us against 5 spds. This is the same for shifting from 2nd to Drive. Upshifting on the Maxima is fine if you do it at the right times. However, DO NOT DOWNSHIFT. When you are coming to a stop, do not downshift. This is SO bad for the transmission it isn't even funny. Many people have done this and have had to replace their transmission. What it basically does is it "eats" up the transmission's gears. Hope this can help. Post back if you need more info.

Erik
Southeast Maxima Group

 

Shift it about 400rpms too soon and then it will shift at the rpm that you want.

 

Isn't downshifting ok if you gun it right when you down shift it? (using it to accelerate, not to slow down) Do you understand? Like say you are on the road going 65, as long as you stomp on it right when you shift down to 2nd, wouldn't that be fine? I understand that if you just downshift and let the rpm's soar by theirselves its terrible b/c you can feel it... but i had assumed that if you are accelling and you ds it would be ok... any ideas?

 

Don't do it. People that eat up their auto tranny usually manually shift.

 

Yeah my friend with an altima downshifted into 1 from 50mph and he totally killed his car.

 

Shifting manually in the 1/4 made my car quite a bit faster. But yeah, don't down shift. I used to do that with my camry and over time it developed a cluncking noise in the transmission.

 

one word....DUH!

 

downshift. it's the worst thing you can do for your auto...right? and upshifting...is ok?

 

I have a seriously hard time believing that you guys run faster 1/4 times while auto shifting the tranny. Doesn't the car shift close to redline anyway when you're WOT??

Please tell me you're not like my friend with his 93 Accord who puts it in 1st to take off fast...know what he says? It launches faster with the tranny in 1st. Dear God...how can we educate these people?

 

Depends on if you want to shift at redline or not.

 

Does not shift at redline if I leave it in drive. I believe most maximas, and for that matter, most cars shift prior to redline. I have used the manual shifting technique now for awhile, and can tell you that it is quicker than leaving the car in D. Oh...if your going up thru the gears manually, keep the overdrive off, that way you'll be in 3rd and will stay in third. I have shifted into lower gears at speed, but not at too high a speed in the gear your going into...argggg..bad. I never put it into 1st from 2nd though...I do think this is bad for the tranny, unless your at a real slow speed already....real slow! But if your at say 35 or so, you can put it into 2nd and be in a decent powerband. The advantage to this type of method is that you don't have to wait for your tranny to downshift when you do a roll on...If you ease up to say 40 or 50, you'll be right in the mea of your power. When you hit it, no wait....

Also this can be done in 3rd at certain speeds. As a roll on from slower speeds, start out in 1st, then ease up to the meat of the powerband still in first, when you hit it, instant reaction...no downshift...then take 1st to 6200 or so and shift to 2nd, by the time the tranny responds you'll be at redline(or close). this will mean that when you start out in 2nd, you'll be at a higher RPM than if you leave it in D...again at the meat of the powerband....SEE...it's easy.

Be careful not to be abusive going down in gears and don't hit your rev limiter while accelerating. Also the auto tranny is designed to handle going into a lower gear manually. This is found in some owners manuals as a way to help slow the vehicle down going down hills and in certain road conditions. An example would be: A combination of brake torqueing and using the brakes on a 30 minute descent of a mountain. The engine can help(I mean just a little) you slow down too. In this example, I don't mean using high revs.

I know that this may sound rough, but if you want the quickest times you can get out of your auto in acceleration...there you go.

 

From what I've been reading, it seems like people feel like manually shifting the auto yields the best time. However, from a lot of my reading and a direct email to Motor Trend, it doesn't appear so. FEELING fast and GOING fast are two different things. For today's automatics, their engine/transmission computers maximize torque, horsepower, and optimize shift points for best performance. In automatics, there's different sets of "clutches" if I may use that term, depending on how hard you're pushing the throttle, and your car will shift at different points depending again, on how hard you've got your right foot down.

kevm14 has got a point, and I'm leaning towards his end. Why don't we give credit to those automatic engineers at Nissan? I don't think they just randomly made some shift points on the transmission computers, and since the car's electronics end up causing the shifts, why should be limiting the computers? We can't ever make a manual out of an automatic, and a computer knows the car better than well ever be able to, let alone shift at PRECISE points everytime that a lightning fast computer can do. Yes, in the past, when there were the older mechanical automatics, the cars shifted at certain shift points with low adaptive characteristics and it limited your performance. However, with today's computerized automatics, limited shift points are a moot point, and they will continuously adapt to your drivig style--passive or aggressive. Thus, in the end, to maximize the best times, put it in D, and floor the gas (with some brake-torqueing, if you prefer), let the car autoshift at redline (and yes, the auto Maxima will definitely redline or pretty damn close (my RPMs will peak around 6400-6500 at shifting)).

To help settle this point, I'd like for those out there w/ an auto transmission to post some time slips: 1) Put the car in D, and gas it and 2) Start in "1", then shift your way up. Whatever you do, if you employ brake-torqueing, employ for both tests, and if you don't use brake-torqueing, make sure the same is applied for the other to ensure a fair test. If you guys are having meets, have some auto transmission Maximas do this, and get some time slips as proof to settle this issue. However, for the time being, I'll put my money on the Nissan auto engineers and leaving it in "D" for the best times.

[Edited by Maxima95GLE on 01-05-2001 at 03:39 AM]

 

Ok, here's the bottom line. When not dealing with an auto-manual transmission, where the driving can force a downshift OR and upshift, manually shifting the auto to aid acceleration can't do anything.
The only thing it can do is hold the gear longer. Does the Maxima need to hold the gear longer? Is it shifting at 6 grand and it you want it to shift at 6500? Firstly, it was my understanding that they shifted close to redline anyway. Secondly, at least for the 5-speeds, the optimum shift point is ~6200-6300rpm, not redline.

 

What about the fact that the higher the rpm is in one gear before shifting, then the higher the rpm is starting out in the next gear. this equals more time spent in the powerband, and less time before having to shift to the next gear. Actually, I believe this is where the true benefits are gained in manually shifting. Along with the fact that you'll benefit from the rpm range a little more with a modded car(usable power for the gearing available).

I guess my tranny is shifting a little early then as far as leaving it in D.

I would have thought the engineers would have set the shift points in a Sport sedan Auto, for comfort/durability/and some performance as well. Not all out performance shift points. Although I do agree that the time it takes a auto to actually make the gear change is going to be the same manually or left to do it itself. The control is primarilly shift points not shift speed. Shift speed would be in relation more so to a shift kit, or modified VB.

Honestly though....I'm not going to dispute with you guys about this subject because everybody has their personal tastes and to each his own...

So try whatever there is out there and decide for yourself what you feel is best for you.

 

Shifting manually with an automatic does improve launches for all you disbelievers out there. Go ahead and try it for yourself. You'll definitely feel and SEE the difference. I'm definitely no car expert but I have experimented with this technique and have come to the conclusion that it works. However, this is indeed bad for the tranny as many have mentioned before so I don't do it too often.

 

The problem with the argument about leaving it in D or shifting it manually is that shifting manually "feel" faster. Until we get some kind of actual timeslip, we won't really know for sure. I have an auto, and have tried out shifting it manually. Sure, it felt faster, but I wasn't sure if it's just a mental thing. However though, when leaving it in D, my Maxima doesn't shift at redline. It shifts kind of close to redline, but not exactly at redline. If I have a G-Tech thing, I will go test it out and prove/disprove it. Oh well, guess it's just a unsure thing right now.

 

Well, obviously the car would feel faster if it was indeed going faster. The car launches quiker at D1 because of the extra torque. When leaving it on D and then flooring, there is a greater lag time.

 

My '97 SE auto tags the redline in 1st, and comes within a hair in 2nd. I don't think I couled get any more accurate than that with shifing the auto by hand.

I have a question, since this got me to thinking: if the Max's gear selector is electrical, not cable operated, then how would it be harmful to upshift when driving? Isn't it just telling the computer that it's free to use the selected gear whenever its time comes? I always thought that for example, 2 meant the tranny is prohibited from using anything higher than 2nd gear, no matter what. It's still able to use first gear as it sees fit.

 

Good Point!

 

that is a really good point! when you tell the computer to do something..it'll do it if it's safe. the misconception is...people think that manually shifting gears on an auto means FORCING the gears into the desired #. but yeah, can anyone back up Klamath's comment?

 

Adding to the theory that the computer is actually telling the transmission to shift once you have changed gears (and I'm pretty sure this is how it works)...

How can down shifting be that harmful to the car. Let's have a moment:

Your cruising down the highway doing 55 (why?) in overdrive. Suddenly you get one of the male urges that we all tend to get and you floor the gas. What does the car do? At 55 it will down shift all the way to 2nd. Off you go.

And now a slightly different version...
Your cruising down the highway doing 55 (again why?) in overdrive. Ditto the urge. EXCEPT! You hit the OD button and throw the car into 2. Off you go again.

How are either of these situations different since the computer/transmission combo is what actually did the shifting? Now I totally agree that you don't need to shift into 2 when going 85 (trust me on this one, that rev limiter hurts). But when you know that it's okay to shift, how could it hurt the car? Oh...going below 2 is crazy...if they car can make into 1 w/out any problems, it will when you floor it. Otherwise there is no need to be in 1 (until you stop). Why use the engin/transmission to slow you down? Got brakes? Use 'em.

Just my input. Feel free to comment or correct!

 

little farther to get the od to shift down or manually clicking the button is any diffrent

 

Just to clear a little detail, The shifter is a cable operated unit. When you move it, it moves a lever in the tranny directly.

 

Daniel B. Martin is being summoned for assistance....hehe


So it is different doing it manually than letting the signal from throttle position to tell the tranny to downshift....correct?

What we need to understand is the actual mechanism that engages the tranny to make the shifts. So the signal to this mechanism can come form the throttle positioning, or the actual gear selector. Does it then hurt the mechanism to be activated by the gear selector instead of throttle position? I believe its ok as long as the mechanism is not activated by the gear selector at too high a rpm in that certain gear you are selecting(ie:65 on the highway and then putting the tranny into 2nd). I'll put the gear selector in 2nd at around 35 or 40, but usually no higher than that. Your starting to get into the power band of second at that point, and if you bring up your speed to say 45 or 50, then your ready for instant power delivery in the gear(2nd). I don't think this method really hurts the tranny much at all. Same method can be used in other gears as well.

 

Most cars at this speed going into first would ruin it.

 

--I doubt the Haynes manual touches on this subject.


The transmission is designed to shift at the optimum RPM at wide open throttle. This may not necessarily mean redline. When is peak power created? 190hp@5600 rpm. The power curve flattens out then heads south after that.

What's the big deal - a slushbox will never be as fast as a stick.

 

1. You cannot force an upshift in a conventional auto tranny. This was said already (also by me) and it needs to be reinforced.
2. When "manually" shifting, the car's acceleration in that gear can NOT be any stronger than it would be while another gear is selected. For example, with the gear selector in 1, you CAN'T get any stronger acceleration when the 1st gear clutches are engaged when compared to accelerating with the selector in 2, or D. If 1st gear goes from 0-49mph, and 2nd gear engages at 49.5mph, then your 0-49mph CANNOT be any quicker regardless of the gear selector position.

The only thing shifting manually can possibly affect is shifting speed, i.e. how fast the clutch packs engage. It has been claimed that for the common GM transmission, the TH700R4, that keeping the gear selector in a lower gear increases the tranny fluid pressure, which results in firmer/quicker shifts (like if you shifted from 1 to 2 when the time comes vs keeping the selector in OD, the 1-2 would be faster, thus, your 1/4 mile time would be lower). However, I have not been able to read anything official on this, and I also do not know if this applies to any other automatic transmission.

So - let me reiterate. Keeping the gear selector in 1 won't make the car take off any faster (or accelerate all the way through 1st, for that matter) than with the selector in any other position. It's just not possible. The gear selector does not affect the torque converter.

 

[QUOTE

So - let me reiterate. Keeping the gear selector in 1 won't make the car take off any faster (or accelerate all the way through 1st, for that matter) than with the selector in any other position. It's just not possible. The gear selector does not affect the torque converter. [/I][/QUOTE]

You know what.. ? Just go out there and try it for yourself. You constantly make claims that this will not work based on what you think you know. But like I said earlier, go out there and try it. The differences can be seen.

 

[QUOTE]Originally posted by Botnik

Quote:

You know what.. ? Just go out there and try it for yourself. You constantly make claims that this will not work based on what you think you know. But like I said earlier, go out there and try it. The differences can be seen.

Ok, listen. Instead of shifting manually, why don't you try holding the brakes and giving it some gas (aka brake torquing). That should yield far more of a speed increase than shifting manually.

Also, I'd like for all the manual auto shifters to explain something to me. What, precisely, do you think shifting manually helps, with regard to the car's acceleration? Launch? Acceleration? Shift speed/firmness?
Those are the only 3 things I can think of.

I want you to compare the following between lauching with the shifter in 1 and upshifting manually (which only tells the transmission "ok, you can shift whenever you want now") and launching in OD:
1. Launch strength (try this while brake torquing to a pre-chosen RPM as well as just punching the gas off the line. Note wheelspin, if any, and the overall seat-of-the-pants strength of the launch...however, if you tell me that "wheelspin was the same both times, but I swear it launched harder while in 1...", I'm just not going to believe that)
2. Acceleration (how hard the car pulls...this should be the same with the gear selector in any position...it simply can't affect the car's acceleration, post-launch)
3. The 1-2 shift (how fast it is, how hard it is, if the tires chirp or not - this is the only thing that could possibly be different while manually shifting, but I don't think it will be)

I guess you could also tell me at what RPM the auto performs the 1-2 shift while in OD...should be above 6000.

 

[QUOTE]Originally posted by kevm14

Quote:

Originally posted by Botnik

Quote:

You know what.. ? Just go out there and try it for yourself. You constantly make claims that this will not work based on what you think you know. But like I said earlier, go out there and try it. The differences can be seen.

Ok, listen. Instead of shifting manually, why don't you try holding the brakes and giving it some gas (aka brake torquing). That should yield far more of a speed increase than shifting manually.

Also, I'd like for all the manual auto shifters to explain something to me. What, precisely, do you think shifting manually helps, with regard to the car's acceleration? Launch? Acceleration? Shift speed/firmness?
Those are the only 3 things I can think of.

I want you to compare the following between lauching with the shifter in 1 and upshifting manually (which only tells the transmission "ok, you can shift whenever you want now") and launching in OD:
1. Launch strength (try this while brake torquing to a pre-chosen RPM as well as just punching the gas off the line. Note wheelspin, if any, and the overall seat-of-the-pants strength of the launch...however, if you tell me that "wheelspin was the same both times, but I swear it launched harder while in 1...", I'm just not going to believe that)
2. Acceleration (how hard the car pulls...this should be the same with the gear selector in any position...it simply can't affect the car's acceleration, post-launch)
3. The 1-2 shift (how fast it is, how hard it is, if the tires chirp or not - this is the only thing that could possibly be different while manually shifting, but I don't think it will be)

I guess you could also tell me at what RPM the auto performs the 1-2 shift while in OD...should be above 6000.

I can tell you 2 things for sure that occur when manually shifting...and this can not be disputed. More control of being able to get to redline before shifting into another gear. The fact that you take a gear to redline, means that the next gear is engaged at a higher rpm, meaning that you'll already be at the top of that next gear sooner than if you start at a lower rpm. This is better as well as also being more so in the powerband after a gear change. EXAMPLE: 6550 in first then switching to second it drops to(let's say) 3900 rpm. You start out at 3900 rpm and accelerate until 6550 again. Let's use your reasoning as an example: shift thru the auto at 6200 or 6300, then getting into second at 3750 rpm, and accelerating to 6200 or 6300 then doing the same. I can attest that a modified max will be able to utilize the power above peak hp rating. This method I described also means you will carry more speed in each gear engaged. I'll go over 80 easy in second, and over 120 easy in third. Do you think this would occur if left in drive...not.

Some cars can't utilize power above peak hp in the rpm scale, but with a well opened up exhaust and other mods, I think a max does. If your theory were true, why not everybody shift at the factory rating of 5600...hmmmm.

Being that we have auto's, we need to utilize everything we can if we are looking for extra.

Everything I just went into didn't even tap into the fact that you can do a roll-on with manually shifting. Lets say you had a stick and wanted to do a roll on with me using an auto that I have. Lets say you wanted to do the roll on at 40 to 120. I would drop into second and keep my revs where I was right at 40 ready to throttle it. I would waste time if i had to floor it to make it drop out of drive(OD on or off), the tranny would need to shift down into second first then deliver power. you would be sitting in second waiting to romp on the throttle. Thats a major disadvantage for me, I'm already at a disadvantage with the gearing. We could also demonstrate with a roll-on at 20mph as well in first, I would much rather be in first manually than waiting it to downshift. I wish I could show you what I mean...

 

I cant believe how drawn out this has become!! The only reason I manually shift first into second is that if left in drive my 99SE will shift itself at 6200. If I leave it in 1 and slide shift lever into second at 6200 it shifts at 6600. This is quicker!!! Thats 400 rpm further into second gear and I know i go from 6200 to 6600 in first faster that 3800 to 4200 in second!!!!Launching is identical as 1st gear is 1st gear no matter where the shifter is.....GET IT!!!!

 

Like I said before, I'm no genius when it comes to the technical stuff but I have experimented with this several times by racing against my friend's car and regardless of what you guys say you think you know how Maxima's and the way the gears work in the Maxima, the truth is that starting out at D1 gives a quicker launch. Go out there and test it out. Perhaps against a friends car or something. And about brake torquing, I would never do that because it's making your tranny work against something that won't move(the brakes) which makes it very damaging to the transmission.

 

Very true, brake torqueing and neutral drops are horrendous

 

Oh and about wheelspin. There is a lot less wheelspin in D1, which is definitely better when it comes down to a race.

 

[/I]

[QUOTE]

I completely understand what you mean. I guess I didn't clarify - I was referring to manually UPshifting while drag racing only. Not general manual selection of the gears.



EXACTLY.



The truth? What do you mean, quicker? Are the wheels getting more torque? If you dyno'd the car in 1st gear, would the graph show more torque by launching in D1 vs a higher gear? I don't think so. The only thing that can affect the quickness of a launch with an auto is the torque converter stall speed. And let me tell you - not only can you not change the stall speed of a torque converter on the fly, but the gear selector would not be the way to do it, if you could.



It's not THAT bad for the tranny. It strains the torque converter, and can heat it up (causing burnt fluid), but a quick brake torque before launching won't hurt anything. A neutral drop, on the other hand, is AWFUL for the transmission. With a brake torque, every drivetrain item has been pre-stressed, so the launch is smooth. A neutral drop not only stresses the tranny, but other components. Try a mild brake torque next time you drag race - maybe up to 1500rpm. Figure out the RPM where the front wheels are at threshold for acceleration. I think a little wheelspin is desirable. If the maxima can peel out from a standing start without brake torquing, then this is all moot (but I don't think it can).



What?! Now there is less wheelspin? So....you're saying that it actually launches less powerfully, but with less wheelspin so the 1/4 would be faster? I find that incredibly hard to believe.

Something else I wanted to touch on since this is already pretty long - downshifting manually in an auto. This is definately not something you want to do. If you want to hang at, say, 60mph in 2nd for a roll-on drag race, then put the tranny in 2nd gear and accelerate to 60, letting it upshift normally into 2nd. Downshifting to 2nd at 60 after it was sitting in OD is, debatably, worse than brake torquing. Brake torquing is no different than, say, accelerating up a hill from a standing start, or towing a boat. The main problem is overheating of the tranny. To really hurt it, you'd have to sit there, gas to the floor, standing on the brakes for a few minutes.
Someone brought this up before - downshifting manually to 2nd at 60mph is different than flooring it at 60 and automatically downshifting to 2nd. So the safest way to get to 2nd gear if you're already at 60 would be to floor it, wait until it downshifts, then stick the gear selector in the 2nd position and let off the gas to get back to 60mph...

 

I ran mine at the Seguin track day last Fri. I got in seven runs. 2in "D", and 5 shifting manually 6200rpms (thats when I moved the shifter)
My average of the two times in "D": 15.86 sec in qtr.mi.
My average of the five runs shifting manually: 15.84 sec.15.82 being the best.
My conclusion is that it doesen't make much of a difference and leaves more room for driver error. In a race I don't think it would make a difference. I used to drive a modded Mustang Gt and the difference in shifting was .4 sec in favor of leaving it in "D".
The torque curve issue makes sense, but after shifts my tach never falls below 4000rpms.

Just my experience.

 

haha well all i wanted to know is if it harmed your transmission? anyone have concrete proof it will?

anyway, with all of this table about which it's faster...remmeber, it's more fun! that's the main point i do it.