Manual upshift/downshift and smoothness

[JSUB]

Originally Posted by sierra

I find 3-4K rpm to be the worst rev range, it's the torque dip and I avoid it like the plague.
It's sweet up to 3000rpm and even sweeter after getting over 4000rpm and for me it's one or the other.
I also find it responsive below 3000rpm and more than enough to leave the traffic behind around town most of the time.

Was just generally speaking that cruising around town if in the right gear you should be + - in that RPM range...and when cruising you don't really feel the torque dip. All am saying is that 2K RPM is too low to cruise as it'll take forever to get back in the real power band without downshifting.

[titan_rw]

Originally Posted by sierra

Just don't hold the clutch down for long periods, say at traffic lights.
It has a release bearing that runs when it's pressed down and altough it's designed to be used, it's not designed to be used for more than short periods.
When it's knackered the gearbox has to come out to replace it.
Don't keep it in neutral at any time while you're on the move except as you are about to stop if you want to.
At the lights, if you just got stopped put it in neutral and let the clutch out. You'll learn to read the other traffic and lights to anticipate getting into gear ready to move off but if you don't it's no big deal. Just a couple of secs to slip it in and move off.

I have to disagree with you on this.

Yes, there's 'slight' wear on the release bearing while the clutch is in. However this wear is simply the bearing spinning. You normally don't have to remove the gearbox to replace the release bearing. The release bearing is part of the clutch assembly. A friend of mine is a mechanic who has done lots of clutch jobs. He's said you almost never have a release bearing fail before the pressure plate. Even though you normally replace the release bearing while doing a clutch job, it's not because it's worn out. It's just because it's not new, and it's a fairly cheap part, and you're there anyway.

Even if you reduce the wear on the release bearing by using neutral, with the clutch out, you actually increase the wear on the syncros when going back into gear on the green light. They have to slow down the idler shaft to 0 rpm for you to get into gear when you're stopped. Since syncros are much harder to replace than the clutch, and are replaced far less frequently, if at all, I'd rather just do the release bearing whenever the clutch needs doing, and not worry about it. (usually any kind of transmission work involves removing and reinstalling the clutch anyway, so if you wanted to rebuild the trans in order to replace syncros, you might as well do a clutch job too.)

All that being said, if you're 'parking', and waiting, I'd use neutral, and let the clutch out. If I'm just waiting in traffic, or at a red light, I'll always keep it in gear, with the clutch in.

I've had manual transmission vehicles go 15+ years on a clutch / release bearing. And what eventually got me to get rid of it is because someone else hit the vehicle and wrote it off. Release bearing still worked fine. As did the clutch.

[sierra]

Originally Posted by JSUB

Was just generally speaking that cruising around town if in the right gear you should be + - in that RPM range...and when cruising you don't really feel the torque dip. All am saying is that 2K RPM is too low to cruise as it'll take forever to get back in the real power band without downshifting.

To be in the rpm range to get quick power you need 4500rpm and above.
Surely you don't advocate driving at those revs in case you need to suddenly accelerate in the shortest possible time?

I use 6th gear down to 60kph which is about 1600rpm and it's happy to accelerate gently and smoothly from there. If I need more I change down, it's a pleasure, not a chore.
Cruising at 110kph[116kph usually] in 6th gear is about 3000rpm and sweet for torque and economy but if I come up behind another vehicle doing say 95kph I usually slip it into 4th which is 4000rpm and then enjoy some healthy urge as it moves into the power band.
I don't cruise at 116kph in 5th at 4000rpm or 4th at 4900rpm in case I meet that vehicle to save changing gear. I look for excuses to change gear because it's a great box and equally great engine.

[sierra]

Originally Posted by titan_rw

I have to disagree with you on this.

A friend of mine is a mechanic who has done lots of clutch jobs. He's said you almost never have a release bearing fail before the pressure plate. Even though you normally replace the release bearing while doing a clutch job, it's not because it's worn out. It's just because it's not new, and it's a fairly cheap part, and you're there anyway.

Even if you reduce the wear on the release bearing by using neutral, with the clutch out, you actually increase the wear on the syncros when going back into gear on the green light. They have to slow down the idler shaft to 0 rpm for you to get into gear when you're stopped. Since syncros are much harder to replace than the clutch, and are replaced far less frequently, if at all, I'd rather just do the release bearing whenever the clutch needs doing, and not worry about it.

It's not that common for a release bearing to fail but when it does the gearbox has to be removed from the engine. I've certainly known of cars where thay have failed but i've never known of a car where the syncro in 1st has failed.
With the engine idling at 750rpm the 1st gear triple? syncros only have to pick up the gearbox from zero to 750rpm. That is a miniscule load on them compared to slipping it into 1st at 30kph without rev matching, although it happens a lot more.

It also saves the clutch master cylinder and slave cylinder from being held under pressure for extended periods.

I'll concede it's not critical but when you have an engineering background these things gain more relevance in your mind, just in case.

[jmaryt]

Originally Posted by titan_rw

I have to disagree with you on this.

Yes, there's 'slight' wear on the release bearing while the clutch is in. However this wear is simply the bearing spinning. You normally don't have to remove the gearbox to replace the release bearing. The release bearing is part of the clutch assembly. A friend of mine is a mechanic who has done lots of clutch jobs. He's said you almost never have a release bearing fail before the pressure plate. Even though you normally replace the release bearing while doing a clutch job, it's not because it's worn out. It's just because it's not new, and it's a fairly cheap part, and you're there anyway.

Even if you reduce the wear on the release bearing by using neutral, with the clutch out, you actually increase the wear on the syncros when going back into gear on the green light. They have to slow down the idler shaft to 0 rpm for you to get into gear when you're stopped. Since syncros are much harder to replace than the clutch, and are replaced far less frequently, if at all, I'd rather just do the release bearing whenever the clutch needs doing, and not worry about it. (usually any kind of transmission work involves removing and reinstalling the clutch anyway, so if you wanted to rebuild the trans in order to replace syncros, you might as well do a clutch job too.)

All that being said, if you're 'parking', and waiting, I'd use neutral, and let the clutch out. If I'm just waiting in traffic, or at a red light, I'll always keep it in gear, with the clutch in.

I've had manual transmission vehicles go 15+ years on a clutch / release bearing. And what eventually got me to get rid of it is because someone else hit the vehicle and wrote it off. Release bearing still worked fine. As did the clutch.

if you know how to drive a manual properly,the "throw-out" bearing should last a very long time! basically IF you do NOT 'ride" the clutch,the tranny will literally last forever,unless components are defective,of course,but these components will fail in a relatively short space of time anyway! yes it's not unusual at all for a tranny to last that long, along with the "throw-out" bearing. a "slush" box,on the other hand? well!
good luck with that,and when they fail,you'll take a beating in your pocket book!..just sayin'

[titan_rw]

Originally Posted by sierra

syncros only have to pick up the gearbox from zero to 750rpm.

Actually I think this is the opposite.

Motor running with the clutch out means the transmission is turning at idle speed, lets say 750 rpm.

Push the clutch in, and engage any gear, and the transmission is now directly linked to the wheels. If you're stopped, this means the transmission gets slowed down to 0.

(Tractor trailers that don't have syncros have a 'clutch brake' to 'brake' the transmission to 0 rpm so that you can actually engage a gear. Without the clutch brake, the transmission in a big truck can take many minutes to slow down on it's own.)

The clutch master cylinder is also something that is sometimes replaced during a clutch job, depending on the mileage on the vehicle.

I'm still sticking to my recommendation of clutch in while waiting in traffic, and neutral while parked. Obviously if there's an accident or something, and they've closed the road, I'd use neutral. But in that situation, I'd be likely to shutdown the car too.

[titan_rw]

Originally Posted by sierra

To be in the rpm range to get quick power you need 4500rpm and above.
Surely you don't advocate driving at those revs in case you need to suddenly accelerate in the shortest possible time?

Exactly.

1600 rpm sounds fine for doing 60kmh. The (lower) power required to maintain lower speeds like that the motor can easily provide at lower rpms. Just like if you're cruising around in a parking lot, there's no problem with 900 rpm.

Same thing on the highway. 6th gear in an accord at freeway speeds only turns about 2,500 rpm. If I need to pass someone, I grab a gear. If I really need to pass quickly, I'll grab two gears. Heck, I could even grab three if I wanted the most power.

I see this as one of the joys of driving a manual transmission. Accelerating / passing isn't just mashing the gas. I like being able to throw the clutch in, pop it out of 6th, let the clutch out, and rev it up to 6,000. Clutch back in, and pop it into 3rd. Let the clutch out, and get on it. No, the double clutch probably isn't necessary, but on really big downshifts like that it sure pops into gear nice when you do.

[sierra]

Originally Posted by titan_rw

Actually I think this is the opposite.

Yes, you're right. I got that wrong!

The gearbox idler shaft would be doing 750rpm and then be stopped by the stationary gear trains as the syncros engaged them. Very little momentum to be absorbed by the cones from that shaft.

[sierra]

Originally Posted by titan_rw

Exactly.

1600 rpm sounds fine for doing 60kmh. The (lower) power required to maintain lower speeds like that the motor can easily provide at lower rpms. Just like if you're cruising around in a parking lot, there's no problem with 900 rpm.

Same thing on the highway. 6th gear in an accord at freeway speeds only turns about 2,500 rpm. If I need to pass someone, I grab a gear. If I really need to pass quickly, I'll grab two gears. Heck, I could even grab three if I wanted the most power.

I see this as one of the joys of driving a manual transmission. Accelerating / passing isn't just mashing the gas. I like being able to throw the clutch in, pop it out of 6th, let the clutch out, and rev it up to 6,000. Clutch back in, and pop it into 3rd. Let the clutch out, and get on it. No, the double clutch probably isn't necessary, but on really big downshifts like that it sure pops into gear nice when you do.

I noticed the little arrow up suggesting when to change flashing at 57kph in 5th the other day, so the ECU agrees 6th is good to go then too.

I find people travel below the limit and when you pass put their poxy foot down to try to prove a point, might have read it's underpowered? So grabbing 4th or even 3rd is needed sometimes to save face but I haven't been left in the middle of the road yet.

Off topic but interesting I think. I've averaged 6.9L/100km for the first 2000km, calculated at the pump and also exact on the average readout.
Because i'm an economy nut i've tried resetting that L/100km readout for each run since then to see what works. What I have found is that taking the engine up into the 4 - 6000rpm range while accelerating but on 1/3 to 1/2 throttle sounds great, pulls much better than you would think and sips the fuel. I did a 1/2hour trip yesterday on winding country roads with hills and one full throttle 7000rpm run to average 5.8L/100km.

[JSUB]

Originally Posted by sierra

To be in the rpm range to get quick power you need 4500rpm and above.
Surely you don't advocate driving at those revs in case you need to suddenly accelerate in the shortest possible time?

I use 6th gear down to 60kph which is about 1600rpm and it's happy to accelerate gently and smoothly from there. If I need more I change down, it's a pleasure, not a chore.
Cruising at 110kph[116kph usually] in 6th gear is about 3000rpm and sweet for torque and economy but if I come up behind another vehicle doing say 95kph I usually slip it into 4th which is 4000rpm and then enjoy some healthy urge as it moves into the power band.
I don't cruise at 116kph in 5th at 4000rpm or 4th at 4900rpm in case I meet that vehicle to save changing gear. I look for excuses to change gear because it's a great box and equally great engine.

This resumes it pretty well for me either:
"I don't cruise at 116kph in 5th at 4000rpm or 4th at 4900rpm in case I meet that vehicle to save changing gear. I look for excuses to change gear because it's a great box and equally great engine"

I agree with pretty much all you saying Sierra except that for myself I never cruise on at givin gear at less than 2K RPM because of lower oil pressure and lack of torque to "relatively" react fast enough without changing gear.

All good. Cheers :happy0180:
P.S. Just read your prior post and now I understand your type of driving...your an economy freak if I can say it like that so that's why the super low RPM. I avg 10L/100 km (28 mi/g)...enjoying this very pleasant car as much as I can. Sure you are too.

[dori.]

here's what I learned from anime:

get a cup, fill it 60% with water, stick it in the cup holder

try to drive without spilling the water
when you find yourself getting smoother, fill it with more water

[kchkwan]

Lol Initial D alll the way?

[kchkwan]

ok its been a couple days, I've gotten some more lessons from couple ppl that have been driving manual for yrs n yrs. I can get all my up shift and down shift pretty smooth like auto, except shifting from 1st gear to 2nd, why da hell is it so hard to shift smoothing on the BRZ from 1st to 2nd, I usually have to go as slow as hell to get it completely jerkless... maybe its my 10 days worth of manual driving, but wth... its like every 5-6 shifts I get 1 smooth from 1st gear to 2nd. Anyone got any recommendations?!?! =[
its starting to piss me off to the point that I shouldn't even care anymore...

[sierra]

Originally Posted by kchkwan

ok its been a couple days, I've gotten some more lessons from couple ppl that have been driving manual for yrs n yrs. I can get all my up shift and down shift pretty smooth like auto, except shifting from 1st gear to 2nd, why da hell is it so hard to shift smoothing on the BRZ from 1st to 2nd, I usually have to go as slow as hell to get it completely jerkless... maybe its my 10 days worth of manual driving, but wth... its like every 5-6 shifts I get 1 smooth from 1st gear to 2nd. Anyone got any recommendations?!?! =[
its starting to piss me off to the point that I shouldn't even care anymore...

It's going to be a bit slow going into 2nd until it's warmed right up but try taking it up to about 3-4000rpm in 1st and see how you find the shift then?
If you still find it crunching change the oil for a full synthetic.