Swankins

Is shifting gears during driving bad for your automatic transmission? I have an Acura TL 2.5 and when I shift from 1 -> 2 -> D3 -> D4, it increases the start off speed dramatically and pushes me back into my seat. But is doing all this bad for your transmission or just wear it down more?

Also, is shiftng from D4 to D3 during driving to go up hill bad for your transmission, or is that normal?

Haha, I'm only 16, so I don't know much about cars.

wackjum

It is a little rough on the tranny. You can get the same results more or less by putting the car in D3 and just stepping harder (this would be safer too). Manually shifting an auto makes the auto shift slower.

Swankins

But flooring the pedal is also going hard on the automatic transmission too right? I don't want to do anything to my transmission because my part-time job will definately not be able to pay for the repairs. Haha.

Go90go

Ricer race: 1 shift to 2 shift to D3 shift to D4... shift to ROCKET!!!

~Cheers~

KaMLuNg

iTrader: (5)

that is called gate shifting.. and if done correctly right at the exact shift points you can keep the engine within its power band... i wouldn't do it everyday... but you are basically holding the gear until you allow the computer to take over and shift to the next gear...

Swankins

Oh, so I guess it wouldn't be bad to do it once or twice every month. Thanks for the heads up.

wackjum

While the principle sounds good, it doesn't really work like that in practice. The auto Prelude and TL boys will tell you to just not bother and let the tranny shift itself. And they have sport shift.

Shifting to keep the engine in the powerband is an option for manual drivers, not for automatics. And certainly not for automatics without sport shift.

The best you can hope for is the ECU will hold the gear until the car redlines. Take your TL, keep it in D4 and mash the gas. If you're at a stop, you'll spin your tires merrilly before they finally grab and you go. If you stay on the gas hard (pedal to the metal), it'll redline (6,250) in first before jumping to second. Fun.

Now drop the gear select into L. You're at a stop. Mash the gas full. You'll spin your tires before they finally grab and you go. Let's say for the sake of argument that the optimum TQ point is 5,500 RPM and the TL (the 3.2 at least) has a redline of 6,250. So you see the needle get to 5,500 (probably blow by it because 1st is pretty aggressive on our cars). You move your gear selector to 2 while keeping hard gas. When does the car shift?

You might be surprised but it'll shift at.... 6,250.

Why? Because you didn't let off the gas and selecting 2 only tells the tranny "Oh I want you to shift to 2 when you can." It doesn't tell the tranny "Shift to 2 now damn it!" That's what sport shift is for.

So what's the diff between manually shifting and leaving it in auto? Well for one thing, the shift is a lot harder and slower. That translates to: 1) harder on your tranny, 2) slower acceleraton.

But now imagine for a moment instead of spinning your tires wastefully at the beginning, you ease into wide open throttle. Instead of just mashing the gas, you do a slower controlled press. This is good for traction, good for launching.

In D4, the ECU is going to want to shift to 2nd as soon as possible in the interest of comfort and fuel economy. You can tell it to redline by doing hard stomps, but we don't want to spin the tires. So what to do?

Pop the tranny into D3. On most autos, they have a "sport" mode. Typically its marked S or D3. Now, the ECU shifts into a more aggressive standard. You don't have to hold the gas all the way for the tranny to redline. More controlled launches, quicker times.

Try it yourself.

Swankins

That's probably why I always burn my tires. I will have to practice that more myself, but I can't seem to get D3 to shift gear fast enough. <Really wished I bought a manual>

wackjum

Automatics have their uses. As a daily driver, I prefer automatics myself.

The tranny in D4 or D3 is going to shift about as fast as its going to shift. Most automatics are pretty slow. You have to go to the SMGs to get any really fast shifting done.

But then again, its not that easy to quick shift a manual either.

slownlow32tl

Also if you read in any automags (the good ones, automobile road and track etc....not the turbo or hot import mags) they descride how they got the fastest times to 60 on the review sections in automatics. Most apply the brake and rev up the engine to like 2 or 3 and then let off the brake and either floor it or moderately floor like wackjum was talking about if you get alot of wheel spin. This is like the auto equivelent to reving a manual and poping the clutch. Although this isnt very good for your brakes so theres the trade off. But brakes are cheaper than a new tranny.

wackjum

What you're explaining is brake torquing. And its absolutely useless in a Honda.

The engine retards the timing so you get nothing out of it. As soon as you release the brakes to launch, it takes a bit for the engine to start back up to full.

As the CL and TL guys have figured out, its better in a Honda to just start normally.

Haikoo

Incorrect. Forget the brakes cause what you're actualy doing is burning the torque converter which is located inside the bell housing of the transmission.

Ken1997TL

Start off with half throttle for the first half second and then apply full throttle and keep the pedal down. Dont bother gate shifting or brake torquing. Turn off your A/C and traction control (if you have it)

vishnus11

wackjum is incorrect. I understand the theory, but its flawed. I've owned four auto Honda's so I speak from experience

When you manually put the shifter in 1, it uses only 1st gear. Self-Evident. However, putting the shifter in "2" uses ONLY second gear. And thus irrelevant of throttle position the car WILL shift to second gear. The ONLY scenario where it won't shift to 2nd when you put it in "2" would be when you shift into "2" at say 80mph, which would cause an overrev.

Thus, the fastest way would be to stick it in "1", launch in the manner Ken suggest (btw, Ken, the AC compressor should automatically disengage when you floor the gas). Holding it in "1" allows you to go PAST redline until the 6600rpm fuel cutoff. Knock the shifter into "2" just before the cutoff and if you time if right the needle should just kiss the fuel cutoff rpm. Do the same in 2nd, (and in 3rd and 4th, if you feelin lucky ). This will produce faster times than just sticking the tranny in D4 and letting it do the shifting.

Go90go

And don't forget, for an extra speed boost, put it in Rocket after D4!! You'll see alot of sparks when the Rocket drops out from under your car!

~Cheers~

wackjum

Vishnu is right in that you can go past the redline to the fuel cutoff if you gate shift.

But I don't see the value in this. A car accelerates hardest at its peak torque point and less hard anywhere else. If you're building revs, then you have no choice. But if you have gone past the peak, its in your best interest to shift back to a usable portion of the curve.

The extra wear associated with taking a car past red is not worth it in my opinion. There's almost no usable torque past 5900.

desired_speeds

Aren't you supposed to keep it in "1" then when you want to shift into 2nd, drop it into D3 and the tranny will automatically downshift into 2nd gear, then it will shift into 3rd , then if you're gonna keep going, push it into D4. Its a bit easier on your tranny actually.

98_2.5_TL

we have slow cars without sport shift. everyone is wasting their time.

98_2.5_TL

hey, you can see the GATED shifter in my avatar. haha

juman231

sorry for bringing an old thread up, but as I was looking for the answer to the similar question as OP, I came upon an answer that said that putting the car in "2" means the car will use the first two gears, and D3 the first 3, and D4 all four gears.

Is this true? I knew that putting the car in D4 lets the car to shift up to 4th automatically, but does this mean that if I put the car on "2," I can just keep my foot on the gas and the car will automatically shift up to 2nd gear? Then what happens in D3?

Another question is,

Let's say I accelerated using D3, and now I wanted to use the 4th gear to save gas and etc. Would I just simply push the gear into D4 with my foot on the pedal? Or would it be safer on the car to let go of the gas, put some brake? down, and then put it to D4?

Thanks in advance! It's a lot of questions!

philipsajerk

Just put it into gear, you can leave your gas on the pedal. And D2 means you're only allowing the tranny to shit to 2nd gear( used in high mountain climbs or steep slopes like SF) D3 means 3rd gear will be the maximum gear.

4x4_mafia_jon

if y ou only have a part time job and no other income... just drive it to work and back... on thing i learned the hard way with my cars and trucks.. daily drivers need to stay that way untill you either have a good cash flow or have an extra car.. i vote truck so you can trailer it out to the track.. caus you are racing on a track right?????

Go90go

2 will only use 2, D3 will use the first three. You can push it into D4 from D3 without worry.

~Cheers~