What's the perfect way to downshift in a manumatic mode? Sometimes when i downshift the car jerks a bit, so I am assuming that I am downshifting too early. I HATE this jerky motion, it feels like the car is getting abused - I hope I am not ruining the tranny. And if you wait too long, the car will downshift for you. If I wait a bit long, and the car downshifts for me right before i downshift, I am quickly down two gears, instead of one, and i get a nasty jerk.
So I wanted to know what speed is best for each gear, for downshifting a manumatic. Upshifting is not as sensitive.
Thanks for your help!

 

Im assuming you when you are downshifting you are doingit to slow the car down and the best speed that i have found for that is around 20mph to go into first, but if you dont want your transmision to slow the car down, make sure when you come to a stop you are in 3rd gear, and let the car down shift for you it will down shift nice and smoth with no jerking, hope that helps ya

 

Only shifts you ought to be making are 5th to 4th and 4th to 3rd. Both of these are clean and smooth across a broad range of speeds. The tranny is indignant to taking two gears (double-clicking I heard someone say??? -5th to 3rd, for example) in quick succession. If you really feel the need, you can shift to 2nd below 25mph (40 km/h) (20 is better- at or below 20, the engine will kick in a puff of throttle to rpm match, so be sure not to find your way into the back end of the car in front of you when it does. There's just no good reason to grab 1st before you're stopped- that's one I leave to the box. Too much engine braking/ mechanical advantage in 1st- hard on the drivetrain- big difference between a lock-up torque converter and a regular converter.
Something else to experiment with- 3 basic throttle positions while downshifting: 1. engine braking only, or coasting- hardest for the tranny to cope with for smoothness. 2. Braking- assisted by downshifts. smoother than coasting but still some unsettling of the chassis unless you let the speed come off. 3. Throttle on. Smoothest alternative, but a little tricky to master. equivalent to rpm matching on a 6MT.

DB

 

You should not need to downshift to 1st gear at all while moving above 10mph. Let the car do that for you, the lowest gear you should be downshifting to is 2nd, then the tranny will automatically be downshifted to 1st gear. You do not need to drive very much in first gear.

I use this technique: say I'm in 4th gear doing 40mph and I see a light turn red up ahead. I let go of gas, start pressing the brake pedal, as I see the RPM's drop to say 1500, I shift to 3rd gear, the RPM's rise then when they go down to 1000rpms, i shift to 2nd, by this time I should be going no faster than 15mph. Then as I come to almost a complete stop, the tranny is shifted to first automatically by the TCU.
If anyone has a better idea, please share, I could be off on my MPH and RPM's by a little bit, but you should get the general idea.

Keep practicing, and you'll find your own best technique. I learned my way by watching the tranny and RPM's while in automatic mode. I watched when the transmission would downshift and how fast, same with upshifts, and I do the same. Even if this technique is not the coolest way to downshift (collest is with your motor blaring in high rpm's and your exhaust droning) I at least know that this is the safest way to do it.


CB 5AT - SAC, CA

 

I use a technique similar to what derek and mozy describe. When coming to a complete stop, shift to 2nd below 25 mph and let the TCU shift to 1st - after stopping-. You don't want the deceleration in 2nd to be too slow because the tranny may try to go to 1st resulting in drivetrain jerk. If you have adequate stopping distance or are not coming to a complete stop then you can blip the throttle to shift into 2nd above 25 mph. For accelerating, such as coming out of a corner, jab the throttle harder and try to match the rpm before the downshift.

Also, have to keep brain fully engaged. The other day, accelerating hard, I hit the rev limiter twice before I realized I was unconsciously trying to use an H pattern (down for 1st to 2nd) instead of manumatic up.

It would be nice if when in full auto mode or D the display would also show the gear such as D3 or 3 inside the D.


Dave

03 G35 Coupe, Black/Graphite, 5AT

 

Thanks everyone for your advise - it helps a lot.

I have a couple of questions:
1) What's RPM matching (please don't laugh)
2) Does it hurt the car (tranny) if I change to automatic mode from manumatic, while driving (i.e. accelerating or slowing down)?
2) When you are in city traffic going at constant speed, do you upshift to 5th gear above 40MPH (say going 42 miles per hour)?

You guys are a great help. Thanks again!

5AT, DG/G, Loaded - No Nav.

 

RPM matching is the smoothest results.Say your in 4th gear at 4000 rpm's,you want to drop to 3rd and enter it at the same rpm by adding gas.For my coupe it seems to not like shifting from 2nd to 1st by itself,it seems to always slam into gear.so for 2nd I'd say stick to this method.I don't know about you guys but, I drop into first all the time around corners(Only when the coast is clear,cause those tires WILL spin).If you don't feel like balding your tires all the time,drop to 3rd when you see a red light(saving some brake pad)and let the trany do the rest.Anybody else have that 2nd to 1st gear slamming problem?Anyways,drive it hard,you have a killer warranty!

 

> Anybody else have that 2nd to 1st gear slamming problem?

I had this problem intially at about 300-500 miles mark. While coming to a stop in the 2nd gear in manumatic, I would hear a "thunk" sound when it automatically dropped to 1st. If it dropped from 3rd to 1st, the shift would be smooth. I am at about 3100 miles now and have no such problems. 2nd to 1st shifts are smooth now. I guess the ECU learned something :-).

 

2) Does it hurt the car (tranny) if I change to automatic mode from manumatic, while driving (i.e. accelerating or slowing down)?

No, it's no big deal. But why would you do that if you are accelarating hard? You should have made that choice before hand. Also it might not be a good idea because you'll get caught off hand by the sudden jump in RPM's if you are holding the gas pedal and switch to manumatic.

2) When you are in city traffic going at constant speed, do you upshift to 5th gear above 40MPH (say going 42 miles per hour)?

From my experience, cruising between 40 and 50mph, the tranny likes to be in 4th gear. I use 5th gear above 60mph, but have not personally seen the tranny use 5th gear in automatic mode.


CB 5AT - SAC, CA

 

Thanks for your reply.
I wouldn't change it from manumatic to automatic while accelerating fast. Sometime I switch it back to automatic, and let the car downshift for me, especially when I am coming to a stop light/sign.
Sometimes I switch back to automatic when I get up to a constant speed. If I switch to automatic going around 45MPH and in 4th gear in manumatic, I notice that the car's RPMs go down, which means that it shifts to 5th gear. So, I assume it likes to be in 5th. I guess I have to play around more to come up with a good range for each gear...

 

Maybe a stupid question, but why?

If you're driving an automatic, unless it is up or down hills or other extraordinary situations, why are you shifting at all.

Asked by someone who has always driven an automatic.

 

Why shift? Why not?

For fun, and to keep the car in one gear as long as you want (reasonably long). This manumatic thingy is in no way comparable to a real 6spd, but it's still fun sometimes. It has not been proven to be any faster than the automatic mode, but then again if you wanted to be really fast you would have gotten the 6spd,

Why you ask? To each his own, if you're perfectly happy with leaving it in D, more power to you. 80% of the time I leave it in D also, but sometimes, I just want to do the shifting. If it's there, why not use it? And it makes me feel like Richard Burns in his rally car....sequential shifting baby!! Except the gear changing technique on our cars is made for stupid people because it goes against inertia (in rally cars you shift up by pulling back instead of forward....when you're pinned against your seat it's easier to pull back). But seriously, if you don't want to shift, don't!


CB 5AT - SAC, CA

 

Yes, I have the 2-1 thunking issue. It seems to happen when you are slowly decelerating in 2nd to a creep, like when you are slowing up to go over a speed bump or driveway entrance.

Why shift? Well, shifting down and up at the right times will give you the max peformance and max control over your car. It takes a bit of driving to get used to, but the manumatic mode in the G coupe is very nice, especially considering its based on a torque converter auto. The only better one I have driven is the SMG system in the M3 which does not have a torque converter.

 

Hey, guys, quick questions...

Is there a really obvious permormance advantage do going into the manumatic mode??? Also, if you go through the powerband, will the tranny shift for you, or will it just run to redline and the fuel cutoff? The reason I ask is the G35 is not fully broken in, so it hasnt been taken over 4000 rpms.

Oh yea, and do you guys leave your foot in the gas when you shift the manumatic, or breath the engine a bit? I forget what the manual says, but at any rate just trying to see what the rest of you all are doing.

Since when does hitting a pothole cost $322? Thanks a bunch Michelin...

 

I feel that there is an obvious peformance advantage, because of the added control. You hold a gear when you need to, you upshift right at the redline, and you downshift when you need to, not when the computer thinks you should. The computer just keeps you from screwing up.

In the coupe, the tranny will never upshift for you. If you don't shift it will bounce off of the limiter.

You can do either and I do both depending on the situation. For an acceleration run, I leave my foot planted and just hit my shift points. If I am goofing off around town, I like to breathe the throttle when I shift. If you do it right, it gives the effect of matching revs. If you don't it just bogs the motor a bit.