Pros and cons of engine braking?

[vr2turbo]

How does this apply to non-DSG auto transmission with tiptronic?? Is it ok to engine brake?

My wife's SUV is steptronic, so I use to drop gear to overtake, going down steep slope etc., less for engine braking.....

 

[Tom]

Thanks for the guide and help, Tom. I appreciate that.

I have actually tried something like this before when I am downshifting. Sometimes when the rev matches, the downshift transition is smooth. But there are also many times when the rpm is not high enough to rev match after I blip the throttle. So there is still some slight jerking as the RPM climbs slightly higher after I release the clutch.

I will try it again on tomorrow as I will be going for a long drive.

Good reply, then your situation is extremely easy to fix.

You are either:

1. Not jabbing the throttle hard enough. (note jab action, not press)
2. Not releasing the clutch quick enough (therefore revs drop)

Not jabbing the throttle hard enough:
The rate at which the throttle is pressed is extremely important and determines how fast the engine revs climb. What we want is a sharp rev climb. Throttle response also differs vastly from car to car. So it's ever more important to know the throttle pedal.

Why we need a sharp rev climb:

• To achieve the desired rpm range in the shortest time possible
• To take advantage of the very short window / time we have between clutch on and clutch off.

The way an engine revs differ:

• Linear Climb: When throttle is normally pushed / pressed
• Sharp Climb: When throttle is jabbed / poked / prod / jerked

Not releasing the clutch quick enough:
This is a common problem, many drivers don't release the clutch quick enough. This delay results in drop of engine revs, therefore a mismatch in engine speed and wheel speed. - failure to capitalize on engine revs

A point to remember is when the throttle is blipped and when the rpm is at its highest desired range is when the clutch needs to be fully released. Never after or before.

try it Renesis

 

[RENESIS VIII]

Good reply, then your situation is extremely easy to fix.

You are either:

1. Not jabbing the throttle hard enough. (note jab action, not press)
2. Not releasing the clutch quick enough (therefore revs drop)

Not jabbing the throttle hard enough:
The rate at which the throttle is pressed is extremely important and determines how fast the engine revs climb. What we want is a sharp rev climb. Throttle response also differs vastly from car to car. So it's ever more important to know the throttle pedal.

Why we need a sharp rev climb:

• To achieve the desired rpm range in the shortest time possible
• To take advantage of the very short window / time we have between clutch on and clutch off.

The way an engine revs differ:

• Linear Climb: When throttle is normally pushed / pressed
• Sharp Climb: When throttle is jabbed / poked / prod / jerked

Not releasing the clutch quick enough:
This is a common problem, many drivers don't release the clutch quick enough. This delay results in drop of engine revs, therefore a mismatch in engine speed and wheel speed. - failure to capitalize on engine revs

A point to remember is when the throttle is blipped and when the rpm is at its highest desired range is when the clutch needs to be fully released. Never after or before.

try it Renesis

Yeah, I understand what you mean by jabbing the throttle. Is like giving the throttle pedal a quick step or kick. Saw how those drivers did it before in Best Motoring videos. From what you have written, I felt that my error would be not jabbing the throttle hard enough. Probably because I am still not so familiar with how hard should I jab the throttle to achieve the desired RPM range.

 

[vr2turbo]

Wah! learning a lot, Very soon bro. Renesis becomes terror of Ipoh......hhahhahahahhahahhaha

 

[VoodooEx]

My CLA is using 7 speed DCT. In sports modes, It will downshift a few gears progressively as I applied brake to enter a corner. All these happen at the same time, you can feel the downshift from the inertial force. The sound of the exchaust is louder as it keep downshifting, giving further hint on when exactly the gear downshifted.

I believe using manual transmission, you can applied all type of brakes together as long as the gear shift is progressive as what many has pointed out.

My other manual car, I usually applied brakes and hardly using engine braking. It's a slow car anyway.

 

[Izso]

This is Tom the racer talking not Tom the owner. Haha!

 

[RENESIS VIII]

Wah! learning a lot, Very soon bro. Renesis becomes terror of Ipoh......hhahhahahahhahahhaha

Car is still mostly stock, can't become anything terror.

My CLA is using 7 speed DCT. In sports modes, It will downshift a few gears progressively as I applied brake to enter a corner. All these happen at the same time, you can feel the downshift from the inertial force. The sound of the exchaust is louder as it keep downshifting, giving further hint on when exactly the gear downshifted.

I believe using manual transmission, you can applied all type of brakes together as long as the gear shift is progressive as what many has pointed out.

My other manual car, I usually applied brakes and hardly using engine braking. It's a slow car anyway.

So, basically your CLA applies engine braking automatically without your input?

This is Tom the racer talking not Tom the owner. Haha!

He is always the race car driver isn't it?

I feel honored that he replies my question despite being a newbie here. Really appreciate his help a lot.

 

[marv3]

So, basically your CLA applies engine braking automatically without your input?



.

Actually i think the more modern cars with DSG or auto tiptronic, will downshift itself when you step on the brake. My car also like that, but of course, it is not as fast as when you do it yourself. There is a lag between the time you brake and the time it downshift itself. Ok for when daily driving. But if spirited driving, change to manual mode and shift yourself is better....

 

[vr2turbo]

My CLA is using 7 speed DCT. In sports modes, It will downshift a few gears progressively as I applied brake to enter a corner. All these happen at the same time, you can feel the downshift from the inertial force. The sound of the exchaust is louder as it keep downshifting, giving further hint on when exactly the gear downshifted.

I believe using manual transmission, you can applied all type of brakes together as long as the gear shift is progressive as what many has pointed out.

My other manual car, I usually applied brakes and hardly using engine braking. It's a slow car anyway.

With 7 speed it has closer ratio, that is why dropping a few gears is not a problem...

 

[vr2turbo]

Actually i think the more modern cars with DSG or auto tiptronic, will downshift itself when you step on the brake. My car also like that, but of course, it is not as fast as when you do it yourself. There is a lag between the time you brake and the time it downshift itself. Ok for when daily driving. But if spirited driving, change to manual mode and shift yourself is better....

My wife drive the SUV in D, but when I drive it, normally goes to the + and - side......hhahhahhaha

 

[6UE5t]

Actually i think the more modern cars with DSG or auto tiptronic, will downshift itself when you step on the brake. My car also like that, but of course, it is not as fast as when you do it yourself. There is a lag between the time you brake and the time it downshift itself. Ok for when daily driving. But if spirited driving, change to manual mode and shift yourself is better....

Hmm mine during braking, it will not downshift on it's own to follow the speed. It'll only downshift once you go back on throttle and the engine sense that it's on too high gear and not enough torque. But my car is old car with old technology, the shift response is also lagging and no throttle blip. The CLA45 should be the state of the art technology already.

My wife drive the SUV in D, but when I drive it, normally goes to the + and - side......hhahhahhaha

I actually very seldom use the sport/tiptronic mode. I only use it if I want to go fast or go up/down Genting or that sort of interesting routes for driving.

 

[RENESIS VIII]

Tried rev matching today for many times throughout my drive. Initially I am still not used to it but as I try it on, I seemed to get the hang of it.

When the rev matches, the downshift transition is very smooth without any jerking or lurching at all unlike normal downshifting. Just the engine noise is slightly louder (more like sound from intake) because I jabbed the throttle.

But there are also several times when I am going at lower speeds and I tried rev matching but I end up jabbing the throttle too hard which resulted the RPM to jump higher than the matching point. That makes my car jerk slightly forward.

For now, I think rev matching is a bit difficult to pull out at lower RPM like under 2500RPM.

 

[marv3]

My wife drive the SUV in D, but when I drive it, normally goes to the + and - side......hhahhahhaha

Hehehehe...Proves that the racer/touge devil is in you....

 

[vr2turbo]

Hehehehe...Proves that the racer/touge devil is in you....

Around town with jam will be in D......hhahhahahha

 

[Tom]

Tried rev matching today for many times throughout my drive. Initially I am still not used to it but as I try it on, I seemed to get the hang of it.

When the rev matches, the downshift transition is very smooth without any jerking or lurching at all unlike normal downshifting. Just the engine noise is slightly louder (more like sound from intake) because I jabbed the throttle.

But there are also several times when I am going at lower speeds and I tried rev matching but I end up jabbing the throttle too hard which resulted the RPM to jump higher than the matching point. That makes my car jerk slightly forward.

For now, I think rev matching is a bit difficult to pull out at lower RPM like under 2500RPM.

Good to know you're trying hard Renesis

Okay, as mentioned,

The higher the gear the less the blip
For example,

• 6th to 5th : blip level 1
• 5th to 4th : blip level 2
• 4th to 3rd : blip level 3
• 3rd to 2nd : blip level 4

What you can experiment now to determine the rev range at which you should be blipping:

1. Drive at 100km/h on 5th gear and note RPM range (e.g.: 2500)
2. Drive at 100km/h on 4th gear and note RPM range (e.g.: 3500)
3. Now you know what rev range you're at at a certain gear number
4. Then proceed to drive and maintain at 100km/h in 5th gear
5. Try dropping to 4th and blip throttle between 3500-3700
6. Adjust footwork to find sweet spot
7. You should be able to repeat this smoothly from now on

Good luck

 

[^pomen_GTR^]

and my method of blipping only have little different between high rpm spirited driving and relaxed shopping driving....

key is how fast to release the clutch and how agressive the clutch-bitting transition point....

example-

race mode: release the clutch like a reverse of kicking the clutch

sport mode: release the clutch like normal drive...

relaxed mode: super slow-motion clutch release....

 

[RENESIS VIII]

Good to know you're trying hard Renesis

Okay, as mentioned,

The higher the gear the less the blip
For example,

• 6th to 5th : blip level 1
• 5th to 4th : blip level 2
• 4th to 3rd : blip level 3
• 3rd to 2nd : blip level 4

What you can experiment now to determine the rev range at which you should be blipping:

1. Drive at 100km/h on 5th gear and note RPM range (e.g.: 2500)
2. Drive at 100km/h on 4th gear and note RPM range (e.g.: 3500)
3. Now you know what rev range you're at at a certain gear number
4. Then proceed to drive and maintain at 100km/h in 5th gear
5. Try dropping to 4th and blip throttle between 3500-3700
6. Adjust footwork to find sweet spot
7. You should be able to repeat this smoothly from now on

Good luck

I felt that I still need more time to adjust and familiarize myself with my footwork because all these while, I'm not used to blip the throttle during downshift. So, there are occasions that I got slightly messed up in my footwork. I need more time and practice.

Another thing is, rev matching is easier to do on open roads or mainroads where I can drive at higher speeds or higher RPM. In town/city driving, it is quite difficult to do it because I'm mostly driving under 2500rpm or under 40kmh. I think rev matching is not needed in such situation right?

 

[6UE5t]

Btw what car actually do you drive? If the pedal position is not nice where the distance between brake & gas is too far apart, and/or the height or level of the the 2 pedals is also too different, then it's a lot more difficult to do it smoothly, for example Toyota Avanza. You may want to try some pedal kit accessories which widen up the pedals and hence can make them closer to each other. Some pedal kits have adjustable extension on the bottom right of the brake and the bottom left of the gas pedal (if not mistaken like Razo brand) hence makes the distance so much closer and easier to heel & toe.

 

[vr2turbo]

Bro. Renesis have our famous Wila loh......

 

[6UE5t]

Bro. Renesis have our famous Wila loh......

You mean Proton Wira? If it's the same pedal positioning as the Lancer CB then a bit apart also and a good pedal kit should help.