Faluzure

Ok, this is kind of long post, but I value your opinions & expertese. Months ago, I knew I was getting 350Z and as I approached the feasibility of it, I practiced driving a manual transmission at work using these old clunker Mazda trucks. The Z is actually my first manual transmission car, but because I practiced in those work trucks, I was able to drive it comfortably off the lot. I have several questions on driving a manual and I've read all sorts of forum posts as well as web links on "how to drive a manual". I guess I'll break it up in different categories...

Casual Driving: The Z is my primary and only means of transportation, so it is very important that I do not mess it up. I don't always wind up the car and I actually drive it "like an old person" (one way my friend put it) a majority of the time. That means I don't have speedy takeoffs, I don't accelerate fast unnecessarily, etc. Now when I drive, I have smooth takeoff in 1st gear with no problems. I haven't stalled it in a while, so that should tell you about where my "skill" level is. When I shift from 3->4+, my shift is very smooth (like an automatic). I feel no jerks, pulls, etc whatsoever. However, when I shift from 1->2->3, the car doesn't but its slightly jerky. It happens about 50% of the time. I notice that if I don't rev the engine too high, then it doesn't happen.

My friend tells me I need to match the RPM of the drivetrain to the speed in which the wheels are spinning. I'm thinking this is Revmatching? How do you do that? How do you "know"? So here is an example of my driving.

1) Start slowly from a stop in 1st gear, get to 2500-3000 RPM, shift to 2nd. (Sometimes its jerky, sometimes it smooth).
2) In second, shift to 3rd at around 3000-3500 RPM (sometimes jerky, sometimes smooth).

Should I be revving higher to keep from jerking? My friend says that I won't jerk if I shift driving slowly, but it sometimes happens. He says I only jerk if I'm trying to go fast. Since we all drive 350Zs here, when do you shift when you are casually driving? Here's mine: 1st->2nd (2500-3000RPM) / 2nd->3rd (3000-3200RPM) / 3rd->4th (3500-3600RPM) / 4th->5th (3500-3600RPM).

Moderately-Racey Driving: This is where I want to have a decently fast takeoff & decently fast acceleration (like trying to pass cars while at a stoplight, or trying to turn onto a road with traffic and getting to the speed of the rest of the cars ASAP). I notice when I try to do this (whether at a stop) or trying to speed up fast (but not putting the pedal to the floor), the car jerks a bit when shifting from gear to gear (only 1->3). Is this natural? My other friend says I should rev the engine while shifting from gear to gear to prevent this, but I think it is kind of hard to rev and shift at the same time when the shifting of gears is less than a 2nd.

Time Trial/Fast Takeoff: Having a Z, I knew I was going to at least test out the speediness of the car, so I went with a friend to a long stretch of road in my city. From a rolling start in 1st gear, he told me to gun it (I shifted from gear to gear at around 6000RPM). I got to 6th gear (100MPH) pretty quick, but as I shifted from gear to gear, it would jerk a lot. Another thing to note is while I'm shifting between gears, my car's RPM shot up high once I let go of the clutch and shifted to a higher gear. I know when you engage the clutch, the RPM in the car drops. Is it natural for my RPM to shoot up when driving like this? Am I doing this correctly? Is there anything to prevent this? More importantly, am I hurting my car? My friend says that if I do that, no matter what car I drive its going to do this. I'm wondering if I should give it a little gas while engaging the clutch.

Thanks for listening.

Faluzure

Is there a glossary for all these terms? I have a few I'm a little unsure about.

Feathering the Clutch - Example: "I would feather the clutch a little to allow the engine to spool up a bit slower. How do you feather a clutch?

Blip: Is this just tapping the gas? I know the goal is to make the RPMs increase, but how hard do you press?

julian

this will take too long to explain everything. quick note on your rpms rising on upshifts. get off the throttle faster and push in the clutch faster. your foot should be moving off the throttle just as you push in the clutch fast. the engine rpm's then drop (which is what you want) as you shift gears. during this drop if the engine rpms match your wheel speed in the next gear there won't be any jerking when you let the clutch out. you're jerking right now because the engine rpm's aren't where they're supposed to be for your next gear.

do a forum search. it's been explained before.

also just looks like you need more seat time. don't worry. it'll come once you understand the basic theory.

ttsupra94

iTrader: (1)

Feathering the clutch just means kinda holding it in and letting it out very slowly, usually when you are downshifting, it makes things a little smoother if you are downshifting at higher rpms.

I noticed you said you drive it like an older person, but where you are shifting in the rpm range doesn't seem like it. For normal driving, i usually shift at 2k rpms in every gear, in 6th by 40mph. 1, 2 and 3 gear i also find harder to be as smooth as 4, 5 and 6. Just keep doing it and you will get smoother.

mr2fasterthanyo

you might be letting up on the clutch too fast.
but when you drive hard, you do have a tendency to shift harder and jerk a little more as the clutch grabs.

i am not sure of the optimum shift points of the z, but typically, you do not want to shift at redline. my mr2 has a 7500 RPM redline (stock, i changed it to 8500), but i would shift at about 600-6500 (again stock) depending on the gear. usually after a certain point, power drops off.

feathering the clutch isn't agood thing. it is basically riding the clutch so it only partially engages a little a time, and will wear it out pretty fast. (I can't feather really at all, ACT 6 puck extreme pressure plate clutch- it just grabs).

blipping the throttle/heal toe-ing/ rev matching are all techniques that are useful when racing, i do it around town even, but basically what it is, is this:

you drive your car enough to know what RPMS you will be in when you shift up or down to the next gear, at what speed you are at. the goal is to match the rpms to this point with your heel, while your toe is on the brake. now i say as well shift up, because some people do it while drag racing so that the engine doesn't have to climb back up the rpm band in the new gear. this is especially usefull in a FI car. My turbo spools at about 2600 RPM to full boost, now if i shift and my rpms drop down below that, it takes a second for them to climb again. by keeping the rpms in the powerband, you can eliminate that rebuild of engine speed while it is under load.

both of these take lots of practice, and should be mastered only on the course. it is pretty easy to rev the car up to high while downshifting, let the clutch out to fast and spin the car around.

but it is especially helpful on small tracks where you dont have a lot of time to build up speed, and carrying a little extra speed, and putting down the power earlier is a big advantage (and a great part of owning a mid engine car is you can put power down a lot earlier coming out of a corner than most front engine cars)

hope this helps...... it is kind of hard to expain. much easier to show. go to an autocross or track day, and i am sure someone there can explain it better to you

ANXIOUZ

iTrader: (13)

Just keep driving your car....you'll get better at shifting without even noticing that you've changed how you drive. Around town I usually shift between 2500-3000rpms. The only exception is 1st gear which I stay in longer....for me it helps to give a more smooth shift into 2nd.

And you might be letting out your clutch too quickly which is causing some jerkiness. As a test, drive normal from stop-1st-2nd-3rd. Then go from stop-1st-2nd-3rd but *ease* off the clutch purposefully slow (be sure to give it more gas to compensate). That might help smooth things out. From there try to find the happy medium.

Faluzure

Thanks again everyone! I know it takes practice & I want to get better. It just bothered me that I drove it for a 2 weeks now and I still cause it to jerk every now and then. I drove around for lunch today and I paid attention to how I was driving. I didn't get much jerkiness at all by easing off the clutch slower. Will this wear my clutch out quicker by doing this method?

To ttsupra94: You said you shift at 2K RPMs in every gear. Is there a reason why you shift so early? Also, does the car shift smoothly at those RPMs?

mr2fasterthanyo

he was just telling you to "short shift" usually at lower rpm's it is easier to learn how to get your car to shift smoother. i never go above 4000 in normal driving typically. just taking it easy on the car. no reason to run it hard if i dont have to

Faluzure

Oh I see. Thanks mr2fasterthanyo. I agree, no need to wind it up if I don't have to.

bixby

iTrader: (2)

Feathering = "riding" which = clutch replacement sooner than normal. Just release and go. Keep your foot away from the pedal when you don't need the clutch. This is the biggest mistake most new MT drivers make.

HOMiEZ

iTrader: (1)

I think you should at least be in 40mph in 3rd gear in the Z. If not than at least by mid 4th gear anything slower than that should not be driven on public roads.

I don't believe you would want to be shifting at 2k RPMs throughout every gear not just because of the slow acceleration, but also because of car just isn't designed to be moving at that speed.

mr2fasterthanyo

yea, 2000 is rather low. i am not familiar with the torque curve of a z, but most cars will bog at that low of an rpm

ttsupra94

iTrader: (1)

There is still power to drive and shift at those levels. It might be a bit above 2k. If i'm just driving normal then i shift early for 2 reasons, its easier to shift smooth at that low of rpms and also you get better gas mileage from shifting earlier. If i'm gunning it, it is a different story. I take my time usually, like a van will beat me off of a light cause i dont accelerate that fast all the time.

I'm not sure of the rpms but i shift like this:
into second about 8-10mph
into third about 15mph
into 4th about 22mph
into 5th about 30mph
into 6th about 40mph

I mean, if i'm getting on the interstate or something, i obviously dont shift this early, but for just cruising around town, it works and i get very good gas mileage, about 29 or 30

kewlii

I dont know about that TTsupra, that's some serious shifting there lol. I just can't allow any manual car to be in 4th gear at 22ish mph. but that's just me. Can some expert shine some light into this??

ANXIOUZ

iTrader: (13)

Anyone read the manual where they recommend you to shift? It's similar to the above but a little absurd IMO.

Gear - MPH

1-2: 8
2-3: 16
3-4: 25
4-5: 28
5-6: 33

6th gear while going 33mph? Come on, this is a sports car.

Faluzure

I saw that in the manual! I was like, "wth??"

Faluzure

Again, thanks for all your responses. Here's another question. I've been reading all sorts of threads on racing, etc. I think I can handle myself starting from a complete stop (like at a stoplight). However, I notice a lot of races are done with a rolling start (like on the highway). When doing these types of races, I see a lot of you guys downshift to a lower gear. This is to have better acceleration (I think).

If I were to do this, I would perform what you guys call revmatching and downshifting correct? I already notice that if I downshift without revmatching, my car jerks a hell of a lot. I've already been practicing it a bit (trying to do the heel-to-toe method too). I notice my car doesn't jerk at all when I blip the gas and then shift to a lower gear. However, I'm pretty slow at it. It takes me a while to think about it & do it at the same time.

So say I'm driving and I want to downshift. I do the following:
1) Engage the clutch.
2) Shift car in neutral.
3) Release the clutch.
4) Blip the gas to the correct RPM for the gear I'm going to.
5) Engage the clutch.
6) Put it in the lower gear.
7) Press throttle.

Also, does it hurt the car at all if I do it this way (I've tried both and it works the same):
1) Engage the clutch.
2) Shift to the lower gear.
3) Blip the engine while clutch is still engaged.
4) Release clutch.
5) Press throttle.

Am I doing this right? Which way is the correct way?

mr2fasterthanyo

you down shift to get the car in the power band (depends on the speed and the gear). in the two, gears 1, 2, 3 pull like a raped ape, while 4th and 5th don't pull as hard.

and its not racing if you go from a roll. only biotches that don't know how to drive or launch a car go from a roll. yes, there are times that you may across someone that screws with you while you are driving ont he highway, and i will show him my tailights. but i never call it a "win" hell, i never even call it a race.

uberfaybk

faluzure, as long as the clutch is fully engaged, it won't wear out the clutch. but hey, if you're downshifting to race, i think smoothness would be way down there on your list of priorities.

just for reference, from a stop i usually run each gear to 2500 rpm or so and then upshift (normal driving). if i want a little zip, i run 1st and 2nd to about 3500. Then i wind 3rd to 4500 and shift straight into 6th to cruise at a comfortable 45 mph @ 1800 rpm. (police around my town are really ****)

taurran

iTrader: (18)

My Z generally is prone to less than flawless starts because the low idle RPMs require a bit higher rev. I don't want to take off like a bat out of hell or feather the clutch every time. So, I'm looking into taking it in and getting the idle RPMs adjusted +100.