UltraYellow350z

iTrader: (6)

Hey guys, I'm not sure if this has been covered but I got a question about trying to get smooth shifts on the Z. I've got 2 basic questions and I've been asking people but I can't really find an answer. Most people say they just drive it and are not sure exactly what they do.

1) I understand that when upshifting you must rev-match to get a perfect shift. Today I was driving around the block watching the tach and it takes about 2 seconds for the tach to drop (1000rpm) to the correct rpm when shifting from 1-2. Is this really the only way to get a smooth shift? Waiting 2 seconds between shifts seems like a long time.

When I shift faster to 2nd, the car jolts because the rpms only drop 500rpm when it supposed to drop 1000rpm.

2) My other question is when I have a passenger in the car, I can't drive where their head won't bob. It seems like as soon as I let go of the gas, their head will bob. Is there a fix to this? I've been told that holding the gas while shifting will help fix it, but it doesn't, it just makes the rpms not match and jolts the car. My question is basically based on the fact that the car will stop accelerating on the shift so there will be a change in tempo. Shifting faster, I thought should fix it since its leaving less time where the car is not accelerating. But by shifting faster I run into problem #1.

Im stuck on how im supposed to figure this out. If anyone could provide some insite, I would be very thankful.

NewJerZ

iTrader: (1)

If the passenger's head is bobbing that much...it may be a seatbelt-related issue

davidv

iTrader: (2)

1) I understand that when upshifting you must rev-match to get a perfect shift.

Not exactly sure what you are talking about. If you shift from, say, 3rd to 4th at 5,000rpm, just go easy on the clutch and gas. The transition should be barely noticeable to a passenger.

2) My other question is when I have a passenger in the car, I can't drive where their head won't bob.

You can expect a bit of decrease in forward momentum, but it should not be abrupt. Consider that the OEM flywheel is heavy: it keeps the rpm up when shifting. What you may be doing is allowing the rpm to drop too far, then coming in hard on the gas.

I have more than 500,000 miles driving a manual transmission. After awhile it becomes natural. Just drive and you will be fine.

06Firebase

That's right. I've also driven manual trans all my life.

Like anything else, driving a manual takes practice!

Just start out slow, and shift into the next higher gear around 2500-3000rpm to get started. As far as "rev-matching", you may be thinking of downshifting.

kPaNdA350

iTrader: (9)

+1 When I shift gears, I treat every gear as first gear. So i left off the clutch slowly while giving it gas. I usually dont see my passenger's head bobble, but there are sometimes when I forget and give it to much gas while releasing the clutch quickly.

Manu

You have to cancel out the jolting by using the clutch and the engine.

I apologize in advance if this sounds confusing. It is very difficult to explain it in writing, here's my shot at it.

When you are shifting up, right before you move the shifter into the next gear, do not take your foot of the gas pedal before you depress the clutch pedal. Otherwise you'll be braking with the engine and that will cause a jolt. Instead, you want to have the engine reving unloaded for a fraction of a second after you've depressed the clutch pedal. Clutch first, take foot off gas pedal second.

Use the shifter and select next gear

Now again, you don't want to release the clutch on an engine which is not being accelerated at all. Try to accelerate the engine a bit right before you release the clutch pedal. The idea is to slip the clutch ever so gently as to ease in the car in the next gear, matching the very very small blip of throttle you've applied.

I hope that makes sense.

Zmazing03

iTrader: (9)

I don't revmatch on upshift. It just use the gas and clutch to make the shifting transition smooth, when not pushing her. Passengers would never notice I shifted if they couldn't see me doing it, because its smooth enough where their head doesn't move. There is a fine line between slipping the clutch away and shifting smoothly without the "head-bob". How long have you had the Z? Just comes with practice and once you get a better feel for it.

UltraYellow350z

iTrader: (6)

Thats the exact same thing my GF's dad tried to explain except you explained it better. I understand now why he told me to keep my foot on the gas a little.

To all others, thanks for all the input!! I got a good understanding of it now. I give it a go and try to work with it. I need to learn to slip the clutch a little, which is what im not doing. I was too afraid of hurting the clutch and that seems to be my problem.

Thanks!

Manu

You're most welcome brother, glad I could help and that my post made sense.

Over time you will master those little throttle inputs on upshifts. The next step will be to master downshifting, and eventually heel-and-toeing.

Don't worry about your clutch. Overtime your throttle inputs will be so small and so short in duration, that they will become neglible. I've been driving this way all my life, and I've never had a clutch fail prematurely.

Miko

iTrader: (2)

Yeah, this car + MT is tough, especially if its your first car. Really hard to make it smooth all the way through. I try to be so careful, that when I shift I notice the RPMs come back up like 100-200 RPMs after letting the clutch out. I think it's related to watching the RPM during the shifts.
Do you guys ever watch the RPM besides when revmatching (or are you sooo good at downshifting you don't even glance at the RPMs lol).

plumpzz

iTrader: (10)

If the passangers head is bobbing you're not giving enough gas when you release the clutch. It should be seemless. Its harder for 1-2 shifts but the rest especialy 3-4 4-5 and 5-6 shouldn't even be noticeable

sry110

iTrader: (17)

I have actually noticed that my passengers' heads bob more when I depress the clutch / release the gas at the beginning of the shift than when I release the clutch / depress the gas at the end of the shift. This is especially noticeable when I am driving fast and trying to execute a quick shift. I think it is because I want to allow the revs to drop enough to engage the next gear at the proper speed but I also want the shift duration to be minimized, so I don't want to give it gas too much after I disengage the clutch. If I kept on the gas a little longer after depressing the clutch pedal I'm sure the first jolt would be decreased, but then the engine would be revving to high when I engage the next gear so a bigger jolt would probably occur then. Maybe a lighter-weight flywheel would help this situation?

To get back closer to the topic, I just recently installed a new cat-back exhaust (jic y-pipe and fujitsubo legalis-R) which have larger than stock piping diameter, and while I have not necessarily noticed increased power/torque I have noticed improved throttle response. It may be placebo effect, but somehow magically my shifting has improved dramatically. Maybe it is because now I can hear the engine more? At any rate, I can personally vouch for the idea that a freer flowing exhaust has improved the car's throttle response and helped me to better judge engine speed vs. clutch engagement point, resulting in smoother and more precise shifts. Maybe it is something for you to look into, if you have some disposable income laying around.

But I think everyone's advise here is very helpful, and would definitely agree that you should start out driving slow and shifting around 2500-3000 RPM when it's not too loaded up to get the feel of it, then start going faster once you get those engagements smooth.

priscilla ls1

iTrader: (15)

shift at a lower rpm! head bobing problem fixed!! Also what manu said.

roast

iTrader: (2)

You do revmatch upshifts. It's different than rev-matching a downshift, but it's still the same basic thing. All rev-matching is, is getting the RPM in the right place before you engage the clutch. That can be applied to both upshifting and downshifting.

One thing that can help speed up the 1>2 shift (and all your other shifts) is not taking the RPM up so high. RPM falls by a percentage. The lower the RPM when you shift, the less RPM it has to fall and the less time it takes. If you are daily driving (just tooting around town-not trying to show out) there is no real reason to take the RPM very high anyway.

I'm not sure if I'm reading that right, but keeping the gas pedal held down between shifts is a waste of gas, not the 'proper' way to shift, and could potentially cause excessive clutch slipping.

I agree more with kpanda in that he treats every gear like first gear. Upshifting = off-throttle/clutch-in(simultaneous) -> select gear -> on-throttle/clutch-out.

350zroadster

iTrader: (1)

Before you're shifting from 1-2, give it a little more gas/rev, then let off gas/change gear so that the needle will drop faster. I usually shift gear when it's 3k-4k, when do you shift gear?

I think you'll find that this would solve both your problems

roast

iTrader: (2)

Sorry bro, but giving gas and the needle dropping are two OPPOSITE things. Not sure what you're trying to say. You should read my above post it's explained perfectly.

350zroadster

iTrader: (1)

You're right, I wasn't clear, I mean give it gas/rev while it's in 1st gear, then let off gas, shift to 2nd.

UltraYellow350z

iTrader: (6)

Wouldn't giving it more gas in 1st give it more a jerk once you release for the shift to 2nd?

350zroadster

iTrader: (1)

It's easier just to try it out.

I had the same problem.

UltraYellow350z

iTrader: (6)

Well I got pretty smooth today by easing off the gas before shifting then adding more gas while releasing the clutch (slipping clutch). It just seems like you have to ease on the gas when you start and before your going to shift. I wish there was a way to drive faster (accelerate) while keeping it smooth.