Caveman74

I laugh at all these comments. I always downshift, revmatching is for the track, If you do it on the street you are a loser. I have downshifted since I was 16, i'm 35 now. All the cars I have driven have been 5-6 speeds. My previous car was a 94 Civic EX, It currently has 275k on it. It has had 3 clutches in it's time. So dont tell me downshifting will wear out your clutch.

Kidnkorner

FijiBlueFG2

What do farm subsidies have to do with other nations?

Farm subsidies keep the produce market stable. While I disagree with government intervention in most forms, this system seems to be working fine. Unless a cob of corn starts selling for $12, I think we're all set in that department.

Education is paid for by the public. It may appear "free", but it is really just backhand tuition paid by the general public. IMO, those individuals who choose to attend private institutions should be able to opt out or receive some sort of tax rebate, since they are not receiving any benefits from the public institutions.

Ultimately, you gotta pay to play. By allowing the government to handle your money, and its allocation, you do nothing but set yourself up for mismanagement and poor quality of service.

Why not just cut through all of that and handle your finances yourself?


That is barely 92,000 miles per clutch. Had you been rev-matching, you'd probably see that clutch last much longer.

K'arsrkool

^^That statement on healthcare is ridiculous and ignorant. I can't believe you actually feel that way. I am not schooled on the works of the whole thing, but I do believe that if you needed a transplant and couldn't afford it you would have a different view.

As for the topic of this thread....O M G....Shut up and drive...that's directed at everybody.

FijiBlueFG2

You say, "ignorant", I say, "fair".

It's perfectly all right to believe in large government, and social welfare, but lets have some level of civility.

2008fijibluesi

Wait....wait...wait. You're claiming that getting less than 100k miles on a clutch isn't premature wear?! Are you nuts? My '94 Accord just had the original clutch changed at 198k miles.

*And...sorry Fiji just saw that you said something similar above.*

08SiFreak

Agreed.

rhennin

As some of the other guys have said, double clutch downshifting is completely unnecessary in todays cars as they have synchros that allow for variation between the trans input shaft and engine speed. Honestly though, as many different racing videos showing footwork as I've seen, I can't remember seeing many that show double clutching.

As for engine braking. imo, it shouldn't put significant additional wear on engine or clutch unless it's in a very tall gear like 1st or 2nd. I say this, because you can get lurching as I'm sure some of you have experienced when in stop and go traffic and not being so smooth with the gas. This could cause some stress on the clutch disk and the pressure plate but I can't really quantify how bad this might be.

Heal and toe downshift is a great way to smoothly downshift the car to the desired gear and honestly should be recommended to everyone imo. It's tricky in some cars to learn at first, but it could greatly reduce the clutch wear assuming you rev match properly as you downshift. When dropping gears without heal and toeing like say from 5th to 3rd, it's not as easy to exactly match the engine speed imo.

Kidnkorner

heel toe is technique that allows you to double clutch without having to take your foot off the brake.

rhennin

^^^ Reread what I said. I know what it is, no need to explain to me something I think I already showed I understood.

Heal toe "I guess" can be used with "double clutching", as I've never done it as it's useless in my car since it has synchros, however that was NOT what I was refering to. Double clutching is NOT NECESSARY if you have a normal car and even still is not necessary even if your racing assuming your using a trans with syhcros. I really would like to see a reasonable answer to why this is a usable and effective practice in a trans with synchros and a normal type of racing application where this would be used as I have rarely seen race car drivers using this technique.

Mattgrimes

When you're saying heel toe down shift, are you inferring when going straight and then shifting to a lower gear, and leaving it IN gear WHILE you break?




And (to whoever it concerns) just so we are clear, I am aware that double clutching at all is unnecessary with synchros, and was before creating this topic. Although I don't see how double clutch down shifting makes you a "loser" or worth a "speed racer" remark for doing it on the street. It makes down shift's much more smooth and I personally just find it more fun to drive when doing more clutch work. I've been practicing Double clutching/synchro matching in normal gear progressions just for the fun to learn a new task, IMO it provides smoother gear changes, I do it when skipping gears (i.e. going 1st to 4th on a residential street; I don't know if skipping gears is bad, but I would think double clutching would help if it is) and, it's just something worth learning in case for some reason I might need to know it some day.
But, whoever said it, you are right, We all have different driving styles and there's no reason to discount the way another person drives. My only concern (and the reason I made this topic) was if engine braking could/would damage your engine. the /clutch part was only because a friend said to me recently "engine braking is dumb, it just wears out your clutch" and I was confused as to how it might do that.


And, correct me if I'm wrong, but to my knowledge heel toe technically does not do what double clutching does because the key component of double clutching is engaging the clutch while in neutral to neutralize the engine to shift it into the next gear. Heel toe will synchro matcg, but it doesn't perform the task of double clutch. Although, As it's been stated countless times this shift to neutral is unecessary in synchro-ed cars. I'm just saying. Again, I am not 100% sure about this information.

George Knighton

I'm afraid this is going to start another fight, but in all honesty, there is no such thing as engine "braking" in our cars.

As long as the motor is engaged, the rotating mass of the engine and gearbox package is going to serve to be moving the vehicle forward.

That's all there is to it.

If you are interested in braking then we have to face the fact that maximum braking efficiency will be obtained with the motor disengaged. Watch the trained drivers on the race track. If it's only stopping they are after, then the clutch is going to be pressed in.

However, if these same drivers are slowing for a turn at the end of a long straight, then they will threshold brake with the clutch pressed in and then rev match (it's not engine braking) to eliminate any jerking when the lower gear is engaged for the turn.

When changing gears for parts of the track where there is little or not straight line threshold braking, then this rev matching and downshifting will happen with a fast ball-and-ball or heel-and-toe technique that might disguise from casual eyes the fact that there is still no engine "braking" going on.

Proper rev matching is not something that will put a great amount of wear on your clutch, motor or transmission.

But proper rev matching is smooth, and is not being used for any kind of erstwhile braking.

Let the brakes do the braking. It's more efficient and it's cheaper to replace brake pads than to replace a clutch, transmission or engine parts.

If you are rev matching correctly, which simply means to avoid upsetting the car as you shift downwards, then you will introduce very, very little extra wear on any components.

If you are trying to brake your car using the motor and clutch, then you will introduce an extra wear component that was not meant to exist.

I'm not going to argue about this. I know that everybody wants to talk about engine braking, but engine "braking" is complete, utter falsehood.

Caveman74

I bought the car used with 150k on it. Replaced the clutch when I got it. It now has 275k and I replaced that one because I gave the car to my stepson when he turned 16. Yea the clutch was probably still good, But I would rather have a NEW clutch in the car for a FIRST time manual driver. I could of been like you and had well over 100k on a clutch.

rhennin

To your first point. Yes, there actually can be such a thing as engine braking and you almost just proved my point but just didnt provide any insight into it. When the car is moving and the motor is disengaged from the wheels, the car has momentum obviously and the only resistance it sees at that point is from the road and the drivetrain from the wheels all the way up to the transmission. When you compare this to when the motor is engaged with the wheels, then you clearly have more resistance as you have to turn the motor and all of its connected components. EVERYONE can figure this out easily. Drive your car just once at a certain speed and try to let the car coast with the clutch in and then try it with the clutch out at the same speed, there is and will be a difference. This is basic physics really.

Second point. As a general rule, driving on track with the car out of gear is a no no. I say this because I know many different amateur weekend racers in the southeast and I've heard them all say this at some point when talking about footwork and when to put the clutch in etc... Also, assuming that a racer would put the clutch is as he does not have to downshift, when would this happen? Not really sure there is a case for this unless they're coming into the pits.

George Knighton

I said I wasn't going to argue about it, and I am not.

You need to talk to people like the NASA Chief Instructor. I'm not going to debate it at Honda-Tech, because I know you won't listen.

rhennin

I'm not trying to argue for the sake of arguing if that's what you think I'm after. I'm just clearly stating my reasoning and the proof behind it. If you have a reasonable answer to back you statement, there's no reason why you shouldn't post it up.

I know SEVERAL of the instructors and other cheifs in NASA Southeast. The current timing and scoring chief is a good friend of mine. Not trying to prod at you; just want to make it clear that I have been fortunate enough to know alot of great guys that can help instruct me when I make the move to driving on track.

Your last statement is a little unfounded don't you think? I'm not a huge regular on Honda-tech bc people don't listen and generally don't try to keep conversations at a calm level with actual sound reasoning and facts to back statements. Please don't lump me with these guys. It's not appreciated as I'm sure you wouldn't if I were to do the same with you.

invsta

I bought a civic...WELL, guess i have to double clutch now...

FijiBlueFG2

To not rev-match is just lazy/improper driving. If you want to be lazy, buy an AT.

What happens when you have to drive a vehicle with an unsynchronized transmission?

clemsonhatch

Maybe they have the term wrong. Our cars DO slow down when you let off the gas without touching the brake pedal...that is a fact not and utter falsehood. This is what they are calling engine braking, what is the proper term?

An interesting fact is when you let off the gas while in gear coming to a stop or going downhill the injectors actually turn off and you save gas.

Just curious do you have video of drivers holding in the clutch while braking on track?

George Knighton

Yes, of course. Your car will appear to have slowed its rate of forward progress because you are no longer providing as much fuel.

You'll no doubt recognise, nonetheless, that since even at idle you are feeding fuel, the entire reciprocating mass of the pistons, valves and gear is serving to propel the car forward.

You'll not have maximum braking while the clutch is engaged, and if you are down shifting because you think you are slowing the car, you're simply not doing what you think you are doing.

Rev matching is something else.

You should rev match in order to avoid upsetting the car.

No, but it shouldn't be that hard to find.

When braking someplace like Turn 5 at Summit Point, it's going to happen too fast for you to have a clear idea. You're on gas through T 4, you stay on the gas to keep from upsetting the car, then you theshold brake to get the car down from about 110 to 45, and you're still slightly on the brakes as you turn left, get off the brake, rev match, and accelerate to Turn 6.

It's different at the end of a long straight, like braking for Turn 1 @ Summit Point. Just about anybody will be caught for about a partial second having his foot hard on the brakes, but the clutch in while he's preparing to rev match for third gear and the right turn. I can't think of anybody who's fast enough in a Honda not to be seen having the clutch in for about 3/4 of a second.

But if, at either Turn 1 or Turn 5 you are in gear and clutch out before you make the turn, then you are not going as fast as you could...period.

George Knighton

It might do you some good to ask this question in RR/Autox Forum, where perhaps you will have a better idea whom to believe.

I fully understand that you probably have no idea who I am, and wouldn't have an especially good idea that I wouldn't talk about things like this without understanding what I was talking about.

rileyrat

Pointless argument is pointless.

Rev match, don't rev match, it doesn't really matter all that much. I do it out of sheer habit. I don't heel-toe and I don't double clutch, I simply hold the RPMs where they are and shift. The syncros simply make it more forgiving. Hell I've always rode the crap out of clutches when I had the kids in the car. Sure it's bad for the clutch but to hell with it, clutch isn't really all that pricey, the PITA is installing it.

clemsonhatch

Interesting info about maximum braking...I just have the following comments:

You're correct that at idle the computer feeds fuel to maintain idle.

The part that is misleading about your above post is that you say "as much fuel" but what really happens at driving rpm's when you let off the gas the computer completely shuts the injectors off, so no fuel is being used when you let off the gas and are above a certain rpm. For example you're driving at 3000+rpm and let off the gas while in gear the computer completely shuts the injectors off until the rpm's drop to the point in which the car wants to idle at (it's at an rpm slightly above idle when the injectors start feeding fuel again I don't know the exact rpm). Therefore the entire reciprocating mass is not being propelled at all because there is no fuel being fed to the combustion chamber. That is why your car slows when you let off the gas. If you turn the ingition off the car will slow at the same rate but will come to a stop (on flat land).

I don't want to argue, I'm just stating facts about how the ECU is programmed.

A couple weeks ago I had to take 800KG of samples over a 4800m pass in the Andes of Peru from the job site in the jungle (680m above see level) to Cusco so I could send them to Lima a drive of 240km. The problem was that the truck had no brakes. I made it by going down hills in 1st and 2nd gear using "engine braking" for lack of a better term. I was a little nervous at first but I made it and it really wasn't that bad, the trick was to not build speed going downhill.

George Knighton

I understand. But as long as you have this huge reciprocating, rotating mass connected to the driving wheels, you are serving to move the vehicle forward in almost all cases that you would experience on the race track or on public roads.

Okay. This makes sense. :-)

Ben850

that steep incline scenario is more of a life and death situation though! my buddy accidentally lit his breaks on fire, so we had to pull over and blow the little flames out LOL