Questions on rev matching and engagement points

[pirripal4]

Hey guys, after lurking the forum for some time, I finally got to register, and just wanted to begin by saying that this forum has been an extremely big help in understanding and driving a car with a manual transmission, so kudos to all of you.

I've been driving a manual for a few months now, and just the other day attempted to perform a downshift rev match, which I finally succeeded at a little later! I've read A LOT of information here on the forum on rev matching etc., but not much on the following:
Say I'm driving normally, upshifting at relatively low RPM. When driving like this, say in 2nd and wanting to upshift to 3rd, I notice that when I start bring up the clutch to friction point/catch point, the RPM needle shoots to approx. 1500 RPM, but if instead I am almost going WOT in 2nd, I notice that when I upshift to 3rd and the transmission catches, the RPMs shoot to approx. 3000 RPM. Therefore, won't that mean that if my throttle application changes considerably (low RPM upshifting vs. WOT upshifting), my downshift rev matches to any particular gear at a particular corresponding speed will differ based on the different driving conditions?

To further complicate matters for me, I don't know the gear ratios of my car since it was handed down to me as a car to learn on, without the owner's manual..it also kinda sucks because I have to guess the engine oil viscosity for the car, as well as the coolant type.

Anyway, thanks in advance, and thanks again for such a cool forum!

Al

[ClutchDisc]

Welcome to the forums! What kind of car do you drive? I'm glad you've found the site so useful. I love being part of the community here!

About the rev matching questions, you don't have to rev match....I don't. I'll let someone else answer them.

[pirripal4]

Welcome to the forums! What kind of car do you drive? I'm glad you've found the site so useful. I love being part of the community here!

About the rev matching questions, you don't have to rev match....I don't. I'll let someone else answer them.

Thanks! I drive a really old car, an '88 Toyota Corolla 5-speed.

[IMBoring25]

Welcome.

Unless the clutch is slipping, when the clutch is out, the same speed in the same gear will always give you the same RPM. This is regardless of throttle position, the gear you were previously in, the phase of the moon, or the price of tea in China.

Someone can probably look up ratios with a make, model, and year, but you really don't need to know specific ratios or even have a tach to drive a manual successfully. Listening and feeling with trial and error to fine tune things will suffice.

[ClutchFork]

Thanks! I drive a really old car, an '88 Toyota Corolla 5-speed.

You should be able to find the gear ratios with a Google search, maybe someone has posted on a website, or you might get an old Toyota manual that has it.

As for motor oil grade, on the oil guy site they are always saying that Australians like their oil thick, like 20w50. I would go at least 10w30 but if it is really hot you could/should go thicker.

[potownrob]

Thanks! I drive a really old car, an '88 Toyota Corolla 5-speed.

You should be able to find the gear ratios with a Google search, maybe someone has posted on a website, or you might get an old Toyota manual that has it.

As for motor oil grade, on the oil guy site they are always saying that Australians like their oil thick, like 20w50. I would go at least 10w30 but if it is really hot you could/should go thicker.

if you have one of the 1.6 litre engines, it most likely calls for 10w30. in the warmer months at least, you may want to try 10w40, if your engine is consuming oil (as many of those engines did and do).

[monkeyhunk]

Learning how to rev match or even drive it at all is really vehicle specific. Just about every one you drive will feel differently. That's part of the fun of driving manuals. As said above it's about sound and feeling. The more time ypi spend behind that wheel doing it the more it will become second nature. There is no amount of reading you can do that will compensate for wheel time.

[tankinbeans]

Welcome to the forums! What kind of car do you drive? I'm glad you've found the site so useful. I love being part of the community here!

About the rev matching questions, you don't have to rev match....I don't. I'll let someone else answer them.

You'd better get under that chair, we ain't havin' none of those there controlled release guys pollutin' the forum. If you loved your car you'd double clutch on all the upshifts, rev-match on all your downshifts, and go drifting around every Saturday at noon. I expect you to do this and have a full write-up by Monday.

EDIT: Welcome to the boards, OP. Don't be afraid to ask plenty of questions.

[pirripal4]

Thanks for the welcomes and the advice

I think I may have described my 'dilemma' poorly. I just remember reading somewhere on the forums really briefly about how differences in RPMs can predictably vary between gears if your driving is suburban (somewhat slow) vs. driving on the freeway.

[Squint]

Thanks for the welcomes and the advice

I think I may have described my 'dilemma' poorly. I just remember reading somewhere on the forums really briefly about how differences in RPMs can predictably vary between gears if your driving is suburban (somewhat slow) vs. driving on the freeway.

Welcome!

The difference between the gears in RPM should be about the same whether you are driving casually or with some more vigor. My Fiesta tends to drop 600-800 RPM when I shift from 2nd to 3rd - though it can be hard to tell depending on how quickly you shift and what kind of throttle you are giving the car. (Someone feel free to correct me if this is wrong, but logically, it makes sense as the gears are the same no matter how you drive the vehicle)

Ignore that ^^ - had a brain fart and daleadbull is correct.

The gear ratios, like IMBoring said, aren't required in the slightest to be a perfect manual driver. I don't have mine memorized, though I know I have looked them up before out of curiosity to find how many overdrive gears I have. Rev-matching isn't required either, though it should help your clutch last vaguely longer (BUT don't worry about clutch wear - it is designed to wear). If you are curious about the gear ratios just start researching your vehicle. It might be slightly more difficult as it is older, but someone has probably posted ratios already. If you can't find it, you can always figure them out yourself with some math if you want to take apart your car

[daleadbull]

Thanks for the welcomes and the advice

I think I may have described my 'dilemma' poorly. I just remember reading somewhere on the forums really briefly about how differences in RPMs can predictably vary between gears if your driving is suburban (somewhat slow) vs. driving on the freeway.

Yea your wording makes its difficult to know what you mean exactly but if you shift at the same RPM, the following gear will fall at the same RPM no matter whether your throttle input was light or you were WOT.

But lets say you are shifting from 1st to 2nd at 2000 RPM and when you engage the clutch in 2nd the RPM drops to 1200. Then, lets say you shift from 1st to 2nd at 4000 RPM then your RPM for 2nd will now be 2400. This is because the ratio remains the same: 2000/1200 = 4000/2400. So your RPM will need to drop twice as much if you shifted at 4000 as opposed to 2000. I'm sure you know all this but maybe this clears it up.

I also agree that you don't need to know your exact ratios in order to be good at rev matching, most people do it by feel. No one is driving around doing math in their heads every time they shift. lol But it is good to have a general idea of what your ratios are. In general, just know that the difference gets smaller and smaller as you go through your gears. I.e the rpm drop between gears will get smaller and smaller as you go from gears 1-2-3-4-5.

[tankinbeans]

Could he possibly be referring to the RPM falling more quickly for some shifts than others? I know that shifting closer to redline is easier and goes more quickly.

With his car, though, I don't think it would be an issue...too old. He likely has good old fashioned cable throttle and no electrical bastards to trip things up.

[theholycow]

Could he possibly be referring to the RPM falling more quickly for some shifts than others? I know that shifting closer to redline is easier and goes more quickly.

With his car, though, I don't think it would be an issue...too old. He likely has good old fashioned cable throttle and no electrical bastards to trip things up.

It's a 1988 Corolla, there's no "likely" about it, it's a sure thing. It's most likely that he has a carburetor, not even fuel injection. A carburetor may have a dashpot to slow the throttle closing but it would behave consistently regardless of RPM and what not. (Cold weather might make it slow or stick, but that would be obvious.)

I have nothing to add to directly answer the question, it's all been said quite well.

[pirripal4]

Wow, thanks for all the help you guys, things are definitely more clear now.

Yes, my car is very old, and therefore has no computer, has a carburettor, and a throttle cable; so I'd assume rev hang wouldn't be an issue. Is this a correct assumption?

I have a slightly related question to my original:
When I upshift, say from 1st to 2nd, I add a little bit of gas to make the shift smooth, maybe to around 1500 RPM (btw, are our RPMs here in Australia equivalent to yours in America?). As my clutch comes up to the friction point/catch point, my tachometer needle shoots to something over 2000 RPM, after which it immediately comes down to something near idle, waiting for me to add throttle. Does that mean that 2nd engages at that RPM at that particular speed (dumb question, I know), but then, won't that mean I'm doing something wrong?

Sorry for the dumb questions, you guys are literally all I have in learning to drive it properly.

Thanks,
Al

[IMBoring25]

Yes, RPM stands for Revolutions Per Minute. It means how many times the crankshaft goes around every 60 seconds, and it's the same unit everywhere.

Also yes, the RPM where the tach goes when you let the clutch out is the right RPM for that gear at that speed. You're probably still getting a little bit of forward head-bob as you let the clutch out on that shift. Using a little more throttle as you let the clutch out at that speed in that gear will lessen the head-bob and be (slightly) easier on the car's mechanicals.