Clutching in and speed bumps

[VTECaddict]

i have to go over any and all speed bumps at like 3 mph.

[tehfade]

Sorry to digress but that dog is just great!

Thanks. Dogs can be so expressive....that pic reminds me of my old black lab, Duke. He used to have a great "confused" face too. Puts a grin on my face just thinking of that, lol.

[AHTOXA]

Yeah, being lower I have to be cautious over speedbumbs but I can normally take most of them in second without clutching in.

[StickIt]

I go over this one speedbump that is on a hill so I think I could normally clutch in and pick up 2nd if it were on a flat road, but since it is on an incline I feel like I am going too slow to pick up 2nd. If I want to downshift to 1st at such a slow speed, do I need to blip the throttle to rev-match?

Another question. The other day I was turning right into a gas station off a main road and the entrance ramp is inclined and also has a small bump at the start so I slowed down quite a bit. I clutched in and then tried to pick up 2nd once I had turned onto the ramp but when I engaged the clutch I heard the engine make like a sputtering sound, it was probably lugging based on my understanding of what lugging is. How do I handle a situation like this. If I need to downshift to 1st, when do I actually downshift? Then similar to my 1st question, do I need to blip the throttle to rev-match?

[bde]

if there is a steep incline and u have to climb it to get to the plaza and do it very slowly because of pedestrians and stuff, I usually approach it in whatever speed i was in; say I'm going 60km/h in 3-4th gear. I slow down, clutch in just before turning to the incline and then while i'm still climbing the incline slowly, due to momentum i still carried with me - i engage 1st gear. (2nd might be sufficient as well, especially with a 6 speed ) You also don't want to roll back during the shift so plan well)

You should plan so that you have enough speed and not be forced to switch to 1st slowly or botch it up while u still have ur back on the road and someone might hit you from behind because of your slow approach/shift to/at the incline.

[Prodigal Son]

Always always always get into the correct gear before you turn or go over a bump, or do anything else. Don't float round, through, or over anything. You will be both smoother and safer that way. Remember, one of the biggest advantages that a manual has over and auto is that the driver can anticipate what gear will be needed in an upcoming situation and get into that gear before encountering that situation. This is one of the most important principles of manual driving, and if you remember it and follow it you will find your driving becomes much easier and more reliable.

And no, sputtering is not lugging. Sputtering is sputtering. Chances are that if you drive a modern car you will never hear lugging in your life.

[StickIt]

Always always always get into the correct gear before you turn or go over a bump, or do anything else. Don't float round, through, or over anything. You will be both smoother and safer that way. Remember, one of the biggest advantages that a manual has over and auto is that the driver can anticipate what gear will be needed in an upcoming situation and get into that gear before encountering that situation. This is one of the most important principles of manual driving, and if you remember it and follow it you will find your driving becomes much easier and more reliable.

I hear you on getting into gear before going over a bump, but I've read in a lot of threads around here that people clutch in, coast their front wheels over, then might have to downshift to 1st if they slowed too much. So in this case I am wondering how you execute the downshift to 1st. If I know I need 1st to get over the bump then based on what you are saying I need to basically come to a stop before I get on the bump so that I can get into 1st gear and then approach the bump. Is this true?

And no, sputtering is not lugging. Sputtering is sputtering. Chances are that if you drive a modern car you will never hear lugging in your life.

Yeah, I have heard you say this before but I have seen some conflicting things on this subject.

[jomotopia]

if you're going so slow that you really do need first then you probably don't need to do anything special, just stick it in 1st and ease off the clutch, maybe with a little throttle input like a rolling launch.

whether or not your modern car will allow you to lug the engine depends on the car. modern cars are definitely smart and with the ECU and especially drive by wire, they can prevent the throttle from opening so much that the engine will really lug. Prodigal says his Jetta will not let him lug. i have lugged my STi once when i was a noob when i quickly braked while in 5th, did not realize how slow i was going and forgot to downshift, and mashed the throttle while still in 5th. violent shaking and loud loud noises. once you actually experience true lugging, you will know it.

and lugging is not just being at X low rpm in Y high gear. it's dependent on what you are asking from your engine. you can accelerate from a low rpm in a higher gear (depending on the speed, rpm, gear, cart, etc etc) if you are very gentle on the throttle and do not ask the car to accelerate quickly. in this case you may get a slight rumble for a second as the revs begin to climb. it's when you ask the engine to try and really do a lot of work and it's in to high a gear/too low rpm to do it that lugging can occur.

[Prodigal Son]

Yeah, I have heard you say this before but I have seen some conflicting things on this subject.

At some point, just about everyone is told that they must be careful not to lug their engine. Problem is, they are not told what lugging actually is. At some point, they let the revs fall and the engine growls or sputters and they say to themselves, "Ah, that must be the lugging that I was warned against."

Well it's not. Lugging is premature detonation cause by excessive heat in the engine. It occurs when the engine is asked to do a lot of work at low revs. The premature detonation throws the engine out of sequence which causes a highly irregular and extremely loud noise from under the hood. It can damage the engine by causing the pistons to scar the cylinder walls. If you only think you were lugging, you weren't lugging. When you hear lugging, you'll know.

Perhaps, as Jomo says, you can lug some modern cars, but it is certainly a heck of a lot more difficult than it used to be, thanks to modern engine controls. In my Jetta, if I mash the gas at low RPM, the ECU simply ignores the request for full throttle and the car gently accelerates until the revs are high enough to open the throttle more. If I ever manage to accidentally lug the Miata, I'll let you know. (Should be easier to do, I suppose, since it is peaky engine rather than the torquey engine in the Jetta.)

[SonyAD]

Speed bumps don't slow you down. They make you slow down. Friction slows you down. What momentum you lose climbing the bump you regain descending it.

The smoothest is to clutch in to go over the bump. I fail to see how clutching in to coast over a speed bump before you re-engage first or second is unsafe.

[pmacutay]

In my Jetta, if I mash the gas at low RPM, the ECU simply ignores the request for full throttle and the car gently accelerates until the revs are high enough to open the throttle more.

Drive-By-Wire!

I haven't personally lugged my Golf but my friend managed to, she put it into 4th gear instead of 2nd trying to climb maybe a 25% slope. It pretty much sounded like a jackhammer going off under my hood as the car started shaking itself to pieces...

There are some pretty ridiculous speed bumps in apartment complexes...all of the ones in mine I have to go over in first or risk breaking the teeth out of my mouth.

There's a reason the lowered Audi that lives in my complex parks on the street all the time, haha.

[permabanned]

In my Jetta, if I mash the gas at low RPM, the ECU simply ignores the request for full throttle and the car gently accelerates until the revs are high enough to open the throttle more.

i couldnt stand it if my car would do that. i dont want the car to do what it thinks it right, i want it to do what i tell it to do. last thing i need is a 3000lb piece of metal doing what it feels like

[pmacutay]

i want it to do what i tell it to do

...including crash into a wall?

j/k j/k

[permabanned]

didnt see that one coming






if i hit a concrete wall at 80 i probably wouldnt have the parts for he 5spd swap lol. i got lucky tho, theres a concrete wall, and about 100 feet of guardrail between the 2 underpasses. im sure hitting a solid wall that wouldnt move back 2 feet would hurt more than the airbag busting my lip and giving me rudolph nose