Just wanted to clear up some facts about engine braking in the tc...

1)is it okay to use engine braking in 1st, 2nd, and 3rd gear as well as 4 and 5...because when i take my foot off the gas pedal in 2nd (especially) and 3rd a bit too, the car jerks forward quite a bit. Then it jerks again when i re-apply throttle.

2)if i'm engine braking in 4th eg. going 40 mph, can i shift to 5th without re-applying pressure to the gas pedal? ie. just let clutch out (assuming the rpms are over 2000)

i have some more minor questions, but thats all i can think of right now....

 

1) it sounds like you're reving the engine up and leaving it hanging up there if the car jerks a lot when taking your foot on/off the throttle. That surely isn't good for the tranny.

2) You can in fact shift to 5th when going 40mph without touching the gas. Heck, you can shift to 5th when going 25mph without touching the gas, but you will have no power whatsoever. You are putting yourself well out of the powerband. Rev-matching is usually a good idea and keeping the car in the powerband is also a good idea. Not that its harmful to the car IMO to be in 5th gear going 30 or 40, but it is dangerous in that you have little control of the car other than braking - ICE, you are really in trouble.

engine braking isn't usually the best idea. There is a big controversy over it, but here is the way I look at it. By engine braking, you reduce wear on the brake pads yet it adds strain to the engine/tranny. If you do your own brakes like myself, new pads cost like $50. Quite frankly, it takes me 45 minutes to change em. Its not a big deal to change brake pads. It IS however a big deal to have tranny work done, aside from being very expensive.

 

Yes, you can do all the things in the tC. When done correctly, none of them will harm the tC. The caveat is, I have no idea if you're doing everything the right way, as I don't get the "double-jerk" you described.

 

First, there is no harm being done to your engine or tranny under engine braking. Just be smooth when you let off the gas in lower gears and you'll be rid of any jerky movements.

Second, the whole point of going into a lower gear is not to slow down your car, it's to be in the proper powerband when it's time to accelerate again. For instance, when coming up to a corner, heel-toe downshift and you'll be in a lower gear to accelerate out of the turn, versus just braking and trying to accelerate with the car in a higher gear bogging along the way.

With a blip of the throttle at stoplights, you can shift from 5th to 4th, then blip 4th to 3rd, etc. You'll probably wear your clutch a little if you don't match revs properly, but you do extend the life of your pads slightly. It's a trade-off at that point, do you trust your driving skills to keep it smooth every single time you downshift at a light? or are you willing to change your clutch rather than your brake pads?

 

i never said i downshift to slow down. i downshift when approaching a turn/corner when i know i'm going to have to slow down and then accelerate again. but is it better to keep it in 2nd, engine brake (rpms drown down to 2000) and brake at a stop sign then let off the brake and back on the throttle (still in 2nd, don't need to clutch) to accelerate away from the stop sign? or should you disengage the clutch (keep pedal depressed) and brake to the stop sign. then clutch out and match rev to depart?

"By engine braking, you reduce wear on the brake pads yet it adds strain to the engine/tranny. "

the way i'm looking at it, it [engine braking] is saving my clutch and throwout bearing too. say i'm driving in 4th or 5th on the hiway; i come up to some slower traffic. i can just let off the gas pedal and engine brake a little bit to bring my speed down, then contine coasting behind the traffic...instead of disengaging the clutch (wear on throwout bearing and little on clutch), braking to appropriate speed, then re-engaging the clutch (slip clutch and wear on TO bearing). I guess a little stress on engine (rotational mass of internals slows engine/car) is better than constantly wearing on the clutch/TO bearing?? also, yeah, saves a bit of brake pad wear.

the pedal placement is such in the tc that i cannot heel/toe, but i do blip the throttle when i downshift.

 

The way you describe it, it's better to keep the clutch engaged until you're ready to stop, at which point you should press the clutch in, pop it into neutral, then release the clutch pedal. If you're going to accelerate out of the turn without stopping, then you want to just stay in the low gear without pressing on the clutch. Trying to accelerate out of a turn while engaging the clutch not only is bad for the clutch, but you're upsetting the balance of the car mid-corner.

You don't want to keep the clutch pedal depressed while moving because you might not have it pressed in all the way and you'll be "riding your clutch." The clutch disc and flywheel will be rubbing slightly if that happens and it's bad for your clutch.

How can you not heel-toe in your car? Have the ball of the foot on the brake pedal, and heel of the foot blip the throttle. How far you have to move your heel over depends on the car, but no car has it so far that you can't reach it. Practice and you'll get it.

 

yeah, like i said, i know how to approach/exit a corner. but thanks for the input.

riding the clutch is the same as slipping it. except riding implies that your slipping for an extended period of time. Every time you shift, you slip the clutch to a certain degree. Thats how the clutch engages against the flywheel. As your letting it out, it begins to make contact with the fly (slipping at first), the more you let it out, the more it BITES, and by the time you've fully released the pedal, its engaged. The key is to Minimize the amount of time you slip the clutch.

Keeping the clutch pedal fully dedressed or fully released is NOT slipping/riding the clutch. Only when the pedal is between fully depressed/released can the clutch be slipped. Keeping the pedal down to the floor only stresses the throwout bearing (and clutch rod/fork, but insignificantly), so yeah, its not a good idea to keep the pedal down for extended periods unneccessarily.

Heel toe is a race technique. i don't race on the streets, especially going around corners. plus, being in 3rd, depressing clutch, shiftin to 2nd, braking to enter corner and quickly blipping throttle to get revs up, then releasing clutch is basically the same thing, except you have a more stable feel for the brake pedal and you blip the throttle .3 of a second later. maybe .5

i have a difficult enough time feeling the input response (feedback) on the throttle pedal on my foot in my normal driving style, i don't need to be reducing my pedal feel by trying to use my heel or side of my foot. believe me, i've tried. the angles of the pedals are different and their travel is different to. ie. to slow the car you need to really depress the brake pedal a bit, but once your foot is that low, if you touch the throttle, you'll redline almost. anyway, i can't feel the pedal at all with my heel or side of foot. its too soft. like stepping on a pillow. there should be slight resistence (not to be offensive, but i think they made it that way so girls could drive it...

 

everything you do is fine.

The jerkieness is normal... its simply what happens as a consequence of lower gears + a direct connection between wheels and engine (via tranny). It happens on any manual transmission car. The "jerk" is just engine braking suddenly kicking in, and when you press the throttle, it overcomes and cuts out engine braking, so its a little jerky.

Since the lower gears are high ratios (sorry if I'm using the worng language here) they are very sensitive to that. Just make sure to keep an extremely smooth right foot movement and you're fine.

Just don't rock the car. I don't know, though, I got used to it... it just requires some fine control. You shouldn't be jerking the lower gears if you can help it.

heel-toe is plenty useful on the street... helps you to stay in gear for the longest amount of time possible

any more questions, feel free to visit us over at www.standardshift.com

 

Although I agree, its a bad habit to be coasting in neutral around corners, why do you say its bad for the clutch? I don't see any additional wear being added over a regular shift, unless you're feeding power through a slipping clutch, which there's no reason why it would happen in particular during a corner downshift.

I think I probably misunderstood your post

 

I think you misunderstood because I agree with you completely, lol. The way he was explaining in his post, it sounded like he was downshifting mid-corner and trying to get the clutch engaged while the car is coasting through the turn. It's mostly bad for car balance (especially at higher speeds), so you're forced to feed power through a slipping clutch, which is what I was getting at.

Engaging the clutch normally in the middle of a turn would be okay if you're no where near the limits of traction, but let's say it was wet and you engaged it kind of rough, you'd get wheelspin and mad understeer, probably into the center divider if you were going fast enough. (I've seen it happen @_@). And mad oversteer on a rwd car. Of course, this wouldn't happen under a normal downshift because you would already be in the right gear when you enter the turn.

 

^^ ahh yes, I guess I did just misunderstand then :D

I agree, downshifting mid-corner in general isn't a good idea, but especially while driving at the limit. The slightest mistake during the downshift can completely screw you over! don't want that

 

A friend of mine floated a few valves by engine braking... I don't engine brake.. The way I see it is that during engine braking, your RPMs are way up and the fuel needed isn't typically there. Depending on how smart the ECU is in the vehicle, some expect a throttle load to be there when you're rpms are so high. If you're not tossing enough fuel during repetitious engine braking, you WILL fry some stuff. Brake pads are meant to be replaced as are rotors.. Stop trying to save your pads/rotors and save your ENGINE/Tranny instead.

Jay

 

Under engine braking, no fuel is entering the cylinders. The ECU doesn't have to compensate for anything. The rpms are going to drop anyway, the rate at which it gets to the bottom doesn't effect anything. If it did, I would have blown my engine already.

 

well, I'll have to disagree, since the purpose of fuel isn't to lubricate the moving parts in the engine - that job is the oil's, and the oil is always there.

Engines are designed to operate anywhere within the range from idle to below redline. Your friend may have money shifted/misshifted, and that will certainly cause strong engine braking, as would any downshift to significantly high RPMs. Yes, that can cause damage and valve float.

Engine braking won't hurt your car. There's no additional wear over just running the engine at those same RPMs, except there's no combustion going on. You won't have to "replace an engine" before the pads or anything silly like that


Also, I notice that whenever someone talks about engine braking, everyone assumes people are using it as an exclusive replacement for braking. That's not true. Brakes are meant to stop the car, so use them, but that doesn't mean engine braking can't be used as an assist.

For example, what I usually do is if approaching a red light, I'll just get off the throttle, and ride the engine braking in 5th down as much as I can, then use the brakes and go to neutral once I hit idle. I don't downshift for braking since its unnecessary and isn't the most fuel efficient way to drive. Also, since I have the engine assisting me at least a little, I don't even have to use as much braking force.

I also use engine braking (backing off the throttle a bit) to maintain my distance with all the auto drivers in front who feel the need to tail the person in front of them and brake every 3-4 seconds. You'll see others braking right along with them, because they don't know how to maintain a proper distance. Only how to mash two pedals.

 

^^good post^^^ and x2 about the auto drivers not knowing how to drive on the hiway.

yeah, i don't (and its basically impossible to) use engine braking as a substitute for your brake pads. the idea is, if you're approaching slower moving traffic, instead of disengagin the clutch (rpms fall to idle), braking to appropriate speed, then having to reengage the clutch again at the proper engine speed (unneccessary clutch wear)....just let off the gas pedal and let the engine slow the car down.

No fuel or air (because the you're not on the throttle) is entering the cylinders. No combustion is occuring. The crank is still rotating because its connected to the wheels (which are rotating) through the driveshafts/tranny/clutch-flywheel. The force (friction/mass) of the con rods and pistons cycling gradually slows down the crank, which in turn slows the wheels. Just like when you add fuel/air, the combustion force accelerates the crank, which accelerates the wheels.

thats why its also called compression braking (because you are using the energy lost during the compression stroke) to slow the car.

I just would like to know why you can hear the engine braking sound louder out the exhaust, like when semi trucks do it. the tc does it to a lesser extent.

and, in 2nd, what is the lowest rpm you can allow the engine braking to drop to (say approaching a stop sign) before you'll stall out or damage engine or tranny? i'm not man enough to stay off the throttle and see what happens..

 

semis have a special feature, commonly referred to as a "jake brake." It's an exhaust brake that works differently from just regular engine braking... I'm not sure exactly how it works but they pull some lever and it increases engine braking greatly

It's also responsible for that really loud noise you hear on the highway when trucks are stopping... that's the jake brake. On older trucks it sounds like a really loud fart.

Yea and I'm not sure about your question. I've noticed the engine note is louder during engine braking as well, but I have no idea why

 

If you don't brake, it would eventually just idle and coast in 2nd. My idle is between 700-800, and my car just keeps going at about there. In higher gears, though, it'll start sputtering because it's having a harder time pushing the car along with just the idle.

 

^^ oh yea, you can't stall in 1st or 2nd, ever, unless the wheels somehow stop (hitting a high bump, you hitting the brakes, hitting a wall :D) stuff like that.

I *think* you can probably idle along in 3rd as well, but I've never tried it. I'm sure you could, though. Might sputter a bit. 4th and 5th, yea, those struggle once you hit idle.

 

right, and you have to adhere to the speed rating for each gear. aka. you shouldn't be in 5th gear going 15mph...right? not only are you out of the power band, but your below the recommended speed for 5th gear...right?

 

I think it's impossible to go 15mph in 5th unless you go below idle, at which point you'll be sputtering and stall out.