It's possible to have a car go faster from 1-4 than using all the gears... unlikely, but possible. Remember more gear shifts adds more time off the gas, so if the gear ratios were just insanely, stupidly tight, you could slow the 0-60 down... not really sure why a car would be like that, especially a vette though, so I don't see how a Vette would be faster going 1-4.

 

If I'm cruising at 45 MPH on a straight flat road, I'm in 6th gear.

This engine doesn't seem to get lugged on flat roads unless you're taching beneath 1300 or so RPM's or going up an incline.

 

Rev-matching isnt NECESSARY, its just a more aggressive and sportier way to drive. You can brake if you want to and then put it into lower gear, its all upto your own way of driving.

 

Sure.. you don't have to Rev match to downshift, but it's a good idea to save wear and tear on the synchros and it helps prevent your car from lurching as you let the clutch out as well(saves wear and tear on the entire drivetrain).

Many experienced manual transmission drivers don't realize that in order to actually save the wear and tear on your synchros though through rev matching... you have to rev match before you put the car into gear. By that, I mean that you have to push the clutch in, then rev match the RPM's before you shift into the lower gear and then you can let the clutch out(so that the RPM's are rev matched to the transmission speed as you're putting it into the desired gear). The synchros work as you're going into gear, not as your letting the clutch out.

 

The 5AT G35 tranny shifts to top gear at about 30mph when you are just cruising. Of course if you go to accelerate it will immediately downshift. So if my 5AT puts itself in top gear at 30mph, your 6MT should be able to be in top gear around 35mph too shouldn't it? (assuming you are cruising, not accelerating.)

 

Also, the 5AT's gearing is actually ever-so-slightly higher than the 6-speed when in top gear.... just to accentuate the point that this car is capable of being in top gear at speeds lower than 50 MPH without lugging the motor.

Those of us with the NAV system are privy to the benefit of real-time fuel economy monitoring which is actually one of the best indicators of whether you are lugging your engine. From what I have seen on mine, you start losing fuel economy when you drop below 1300 RPM's while cruising on a flat road. Optimal fuel economy is between 1400 and 1700 RPM's and preferably with the cruise-control engaged.

I've noticed that my car gets better economy when I drive at a constant speed with the cruise-control enabled, rather than manually actuating the accelerator pedal with my foot. I'm guessing this has something to do with the intelligence behind drive-by-wire technology and the car optimizing fuel delivery in a more predicatable "Cruise-Control" environment.

 

does anyone know the perfect shift point for the car?

 

For WOT, All out acceleration = Redline
For good amount of power + Gas saver = 3.5K - 4K
For all out gas saving = below 2.5K

 

lately ive been craving some speed, until i get another ticket (been a year, **knocks on wood**):

1 to 40mph
2nd to 60mph
3rd to 83mph
4th to 120mph...........

dont really do that much, gas is too expensive o_O, but when you wanna WOT it thats how i ussually do it (redline right on 7k), but now that we are on the topic, to give a little background on my stickshift, ive been driving stick for almost 2 years now - and id like to say ive mastered it.....at least it seems like that when i see some others driving.

Anyway's, lets give a scenerio: cruising about 45mph in 5th gear, and lets say you'd like to punch it....personally i would simply clutch, put it in second, and while releasing the clutch, i floor the pedal (this all happens simultaniously in abut .8 seconds flat....you know, quick =D)..... the car feels like an auto that just downshifted and guned it.


Is that hurting the car in any way? is that the corect way to do it, or would this beat up the car in some way....how does an auto do it?......also, does the smaller gear, in the same scenerio have the same effect, for better or worse? (ie: 30mph cruise in ....3rd, and gunning it down to 1st to redline at 40mph)

I dont do that alot, if at all in the past 3-6 months, but as everyone, ive got some questions . Especially since i dont know what the difference between auto and manual car's are internally.

 

nyway's, lets give a scenerio: cruising about 45mph in 5th gear, and lets say you'd like to punch it....personally i would simply clutch, put it in second, and while releasing the clutch, i floor the pedal (this all happens simultaniously in abut .8 seconds flat....you know, quick =D)..... the car feels like an auto that just downshifted and guned it.


Is that hurting the car in any way?

No. If you are smooth, it definately won't hurt the transmission or rear end.

is that the corect way to do it, or would this beat up the car in some way....how does an auto do it?......

There are many ways of shifting and your way is fine. An auto has a completely different setup than a manual tranny. An auto uses a torque converter to execute shifts.

also, does the smaller gear, in the same scenerio have the same effect, for better or worse? (ie: 30mph cruise in ....3rd, and gunning it down to 1st to redline at 40mph)

The lower the gear, the lower the gear ratio, so you have to get your rpms up quite a bit so as to not have the tranny act as a brake when downshifting. It's generally not a good idea to downshift into 1st; 2nd gear should do the trick.

 

Wow, I think there's quite a bit of hyperbole in this thread. Rev matching on a downshift, while a good thing to do on paper, won't result in a blown up tranny if you don't -- especially in most daily driving situations.

I think I know what you mean, but when downshifting you still have to be careful. For example if you are going down the expressway at 70 MPH in 6th gear, you can't downshift to 3rd without hitting the gas pedal to increase your rpm. Otherwise, you'll be putting a lot of stress on your transmission and rear end. Moreover, if you downshift into 2nd at 70MPH, it will result in a blown engine.

 

Yeah, but that's common sense and has nothing to do with the merits of rev matching -- if someone tries to downshift into 2nd at 70 on the highway, they deserve to blow up their car because they obviously don't know what they're doing.

Neither likely nor possible. Show me one writen reference -- anywhere -- to support this. You can't because it simply isn't true.

 

I cruise in 4th at that speed...

 

I said that you don't have to double clutch because today's cars have synchros to do that for you.

The problem is that some people think rev-matching is the same as double clutching, but it's not. The synchros are matching the input shaft speed to the wheel speed. With the clutch in, the input shaft is disconnected from the engine so rev-matching the engine does not spinup the input shaft, the synchro does this when you put car into gear. That's why even if you rev-match but downshift too quickly, you'll still grind gears (if your synchros are on their way out)

My friend actually saved our converstaion and uses it to teach other people about double clutching beacuse I asked a lot of good questions. Now you guys can check it out too: http://www.boo-yah.org/synchros.txt. I'm Dan

 

Sounds to me like "rev-matching" is just revving your engine in neutral before you downshift. Lol. I know it's better on the track. Didn't know it was more better for efficiency.